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Anat. Rec.: 1 - 1906-08 | 2 - 1908 | 3 - 1909 | 4 - 1910 | 5 - 1911 | 6 - 1912 | 7 - 1913 | 8 - 1914 | 9 - 1915 | 10 - 1915-16 | 11 - 1917 | 12 - 1917 | 13 - 1917 | 14 - 1918 | 15 - 1918-19 | 16 - 1919 | 17 - 1919 | 18 - 1920 | 19 - 1920 | 21-22 - 1921 | 23-24 - 1922

Links: Historic Embryology Papers

THE ANATOMICAL RECORD

EDITORIAL BOARD Irving Hardestt Warren H. Lewis

Tulane University Johns Hopkins University

Clarence M. Jackson Charies F. W. McClure

University of Minnesota Princeton University

Thomas G. Lee William S. Miller

University of Minnesota University of Wisconsin

Frederic T. Lewis Florence R. Sarin

Harvard University Johns Hopkins University

George L. Streeter

University of Michigan

G. Carl Huber, Managing Editor

1330 Hill Street, Ann Arbor. MlehlEan

VOLUME 19 JUNE — NOVEMBER, 1920

PHILADELPHIA

THE WISTAR INSTITUTE OF ANATOMY AND BIOLOGY

El preseiito trabajo es una descripci6n detallada dc la anatomfa externa e interna de una jM^rra j6ven que poseia im par adicional de pata.s posteriore.s bastante nomiales y colocadas sim^tricaniente. Este ni<')nstruo jjresentaba un par de pelvis casi norniales fusionadaf; entre si, una cloaca en el lado derecho, ano y vagina .separados en el lado izquierdo, dos vejigas urinarias, un .'«ol<> rin6n. un ur(t('r iinpar en conexi6n con la vejiga izquierda, un solo intestino deigado. dos colon, dos ciego.s con sus corres{)ondientcs apendices, giandulas suprarrenales pares y dos literos provistos cada uno de un tubo uterino y un ovario. La.s tibias de Ia.s patas supernumerarias estaban fusionadas.

Tr»n*Ution l>y Jc*^ K Nunidrs Conirll l'nivrr»ily Mrth'-aK'ollrgr. N. V.

AUTHOR B ABSTRACT OP TH!9 PAPER ISSUED BY THE BIBLIOGRAPHIC SERVICE, MAT 10

A Description Of A Six-Legged Dog

JOHN SHELTON HORSLEY, JR. Department of Anatomy, University of Virginia

Sixteen Figures

On January 11, 1919, Mr. John R. Raines, a farmer living near the University, brought to Prof. H. E. Jordan's laboratory a dead female dog with an extra pair of hind legs. The thoracic and abdomnial cavities were opened and the dog at once placed in a 10 per cent solution of formalin. This specimen was subsequently turned over to me for study and description. The work was done in the Laboratorj^ of Histologj' and Embrj'ology under the supervision of Professor Jordan, to whom I am greatly indebted for the privilege.

From Mr. Raines were secured the following data: The dog was born October 7, 1918; died from exposure to cold the night of January 9, 1919. Her father was a shepherd, her mother a bull-terrier; both parents were apparently normal. The litter included in addition to this abnormal individual one normal brother and three normal sisters. The six-legged puppy appeared in life otherwise normal and healthy, and was apparently but little inconvenienced in walking and running by the extra pair of legs, which she carried slightly raised above the ground. The unpaired tail was apparently under perfect control.

EXTERNAL APPEARANCE

As regards the shape and general appearance of the head this dog more nearly resembled a fox-terrier, and she was about the size of this type of dog (fig. 1). With the exception of the nipples, she appeared normal cephalad of the umbilicus. "\Mth the exception of the tail and anus, she was double caudad of this point.

Closer oxaiuiimtion rovoalo<l the following details: The log, vagina, aims, and tail of iho loft sido woro displacod about 1 cm. lalorad of ihoir norinal rolativo ])()sition with rospoct to the vertobrtl column. The sagittal plane of the proximal portion of the tail made an angle of 'Jo degrees with that of the verteliral colunui. The right leg was tlispiaced slightly forward and dextrad of its nonnal position. It was .^lightly smaller than the left leg and presenteil a rather undeveloped appearance, especially in the size of the thigh nuisoles. Between these two legs hung the extra pair of legs. The pair was inclined a little to the right of the medial line and it was enveloped in a common integument Wi far (list ally as the ankles. The members of the pair were of apj)roximately efiual size and represented genuine hind legs. Barring a ver>' slight ventral bend at the level of the knees, the pair was extendetl in a straight line and it was placed in such a way that the pads of the feet faced toward the groimd when the dog was standing. The pair measured IS.o cm. from the heads of the femurs to the tips of the toes. These extra legs were only slightly more slender and shorter than the other two hind legs. Palpation nidicate<l a fu.sion of the tibiae, a conclusion confirme<l by roentgenograms (figs. 2 and 3) and subsequent dissection. The extra legs articulated with the medial surfaces of the opposite halves of the paired jielves slightly forward, and to the right, of the root of the tail. There was no second tail or anus, but there was a second set of external genitalia 2 cm. below and to the right of the articulations of the extra pair of legs. The vertebral column in the region of the sacrum seemed abnormally wide on the right side and presented abnoniial landmarks, description of which will be reverted to subsequently. Just below the right side of the double knee there was a roughened scarlike area, whose significance will also be indicated below.

INTERNAL ANATOMY Osteology

The vertebral column contained the usual number of vertebrae, namely seven cervical, thirteen thoracic, seven linnbar, three sacral, and nineteen caudal (fig. 2). It remained single throughout and was normal as far as the seventh lumbar vertebra, which latter was normal on the left side, but presented a large wellrounded mammillary process that was twisted dorsally and slightly caudally extending on the same level with that of the corresponding ^•ertebral spine. The sacrum was very slightly bent to the left. On the right the articular surface of the first sacral vertebra was turned dorsally, and accordingly produced a slight elevation. There was also on the right side an oblong, irregular plate of bone that measured 10 mm. in length, 7 mm. in thickness, and 6 mm. in the vertical plane (fig. 4, M). It was fused with the first and second sacral vertebrae, and represented a second deformed sacrum. On the left side the sacropelvic articulation was normal with the exception of a small piece of bone, 8 mm. in length, which jutted out caudally from the left ilium at the level of the sacrum and was fused with the second and third sacral vertebrae. There was a gentle curve to the left, formed b}' the first three caudal vertebrae, the first of which articulated on its right side with the base of the fused ilia. The remaining caudal vertebrae were normal.

Two pelves were present (fig. 3). At first observation there seemed to be a smaller medial pelvis fused dorsally to a larger and practically normal ventral pelvis; but after closer examination of all of the related structures the conclusion was reached that the condition was one of lateral fusion between a right and left pelvis. The course of the unpaired sciatic nerve is the only obstacle to the latter interpretation. The right and left lateral ilia were of normal size (figs. 4 and 5). The left iUum articulated with the sacrum of the left side in the usual manner, with the exception of the intervention of a small spur of bone extending caudally from it. This has alreadj- been described. The crest of the right ilium was displaced cephahcly 1 cm. and dorsally 3 mm. .\ sninll triftiiRular piece of bone, 1.5 cm. in length, articulutcMl with the riplit deformed saenmi bj' a number of strong hgamciits forming an amphiarthrosis (fig. 4 A). The crcst.s of these hiteral iUa were about G nun. further apart than they shouhl have been if the right had its normal position and the two considered part of one pelvis.

The right anil left nie<lial ilia were fused to form one bone which presented a dorsally protruding crest (fig. 4). This fused medial ilium was approximately a third the size of the nonnal lateral ilia. The vestigial right sacrum was fused with the base of the metlial fused ilium. These two structures were continuous on the ventral surface, but dorsally there was a de]5ression partially separating them. On the left the base of the fused ilium was joined to liie third sacral vertebra by a sjnichondrosis, and with the first (proximal) caudal vertebra by a syndesmosis. This fusion of the ilia had brought the two medial acetabula so close together on the dorsal surface that they nearly touched each other (fig. 5). The long axis of this medially fused ilial portion of the compound pelvis made a 15 degree angle with the midline on the right side. If considerefl as a dorsally interpolated {)elvis, it would be al)out half the size of the larger pelvis.

The two metlial ischia formed a basin, which was open dorsocaudally and close<l ventrocephalicly, presenting on each side the relatively high crests of the two medial tubera ischii. The basin measured 3.7 cm. from crest to crest (fig. 5). In this basin lay the necks and proximal fourths of the femurs of the extra two legs, along with that portion of the heads that did not enter directly into the hii)-joints (fig. 4). The two obturator foramma opened ventrocephalicly through each side. They were completely closed by thin ligamentous bands and were of about half the normal size. Caudal to the fusion of the medial ilia, and aI.so to the acetabula, there was a ver>' firm union between the right and left pelves along the whole length of the pubo-ischial 8^^nphysis of each (fig. 't). This lino of fusion would call for the .'iame description whether the fuseil i)elves were interpreted as right and left or dorsal and ventral components.

The heads of the femurs of the extra two legs were about 1 mm. apart and articulated with the two medial acetabula, each forming an enarthrosis. The articulations were alike on both sides, and normal to the extent that they formed ball-and-socket jomts, with synovial bursae, ligamentous capsules, etc. There was a slight twisting, however, produced by their abnormal positions. All of the structures that entered into these articulations were of approxunately half the size of the corresponding structures of the normal right and left lateral hip-joint. The movements of these articulations were Umited practically to a dorso\-entral action due to the fusion of the tibiae of the two extra legs (fig. 3).

The right and left lateral ischia were of normal size, but were slightly twisted laterally, the right more so than the left. The crest of the right lateral tuber ischii was 1 cm. laterad of that of the right medial tuber ischii at the widest point (fig. 4). The right colon, vagina, and urethra united within the basm formed by these ischia into a cloaca (fig. 12). The opening of this basin was the pelvic mouth of the right pelvis. The corresponding crests of the left side were 2 cm. apart at their widest points and formed a somewhat less constricted basin for the left vagina. The aperture of this basin was the peh-ic mouth of the left pelvis (fig. 5).

The bones of the right and left lateral legs were normal. Those of the extra two medial legs were verj^ slightly shorter and slightly more slender than the lateral ones, as may be seen in figure 3. The tibiae of the supernumerary legs were fused medially along their whole extent. The fibulae appeared slightly larger than normal, the left fibula being more intimately fused with its tibia (fig. 3). No other marked abnormalities occurred in the bony structures. The double knee-joint was practically immobile except for a very sUght action in the caudocephaUc direction.

Myology

The muscles of the left lateral leg, thigh, and hip regions were nonnal; those of the right thigh also appeared normal except for a somewhat smaller size.

In the hip repion of the two extra legs there occurred only a vt'Pk- few small imKscles that i)asso<l down to the thiph. These muscles were inserted aloiin tlie i)r(>xinial portions of the two femurs and seemed to re|>resent only remnants. There was a layer of superficial fascia over the whole of this nuiscle mass. Some atri>i)hic vestigial muscles covered the popliteal fossae extending up over the distal two-thirds of the two femurs and down well over the ventral portion of the knee-joint. They were better devclojied on the loft member than on the right. The .space between the two femurs was oc('Ui)icd by an arterj', a vein, a large nerve, and an abundance of loose connective tissue. The two legs of the extra pair were bound together by a sujierficial layer of fascia and the integument. There were two verj- distinct teiulons of .\chilles: the one of the left leg was more pronounced, and it was stretched so tight as to permit only very little movement of the left foot. The right foot was more free to move. The Hexor digitorum brevis tendons were very distinct on the feet, but none of the muscles could be found. No muscles occurred beyond the extreme proximal ends of the fus(Hl tibiae: there was an enveloping layer of superficial fascia along their entire length.

The ligamentum nuchae was the only abnormal structure observe<l cephalad of the diaphragm. This was a very thick, round ligament rather than, as usual, a tliin ligamentous raph^.

Splanchnology

The stomach, small intestines, liver, gall-bladder, spleen, and pancreas were unpaired and apparently normal.

The large intestines were double; one colon was very nmch distende<l and lay ventrad and to the right of a smaller colon (figs. G, 7, and S). The former had verj- short ascending and transverse portions, but a long descending jiortion which was constricted in the middle. This constriction j)r(xluced two large .nacculations, the caudal being the more distended. The wall of this portion was rigid and brittle, ai)parently lacking muscle con.stituents. This larger colon pa.s.sed through the right pelvic mouth and opened into the vagina of the right side, thus contributing to the formation of a cloaca. The smaller colon of the left side had neither teniae nor sacculations; and there were practically no corresponding ascending or transverse portions. It joined a normal rectum which ended in a normal anus; it was on the whole more nearly normal than the right colon. Feces were found in both colons, and there were no adhesions or constrictions that could hinder either from functioning.

The iliocolic portion of the small intestine was slightly enlarged, and at this point of enlargement the two colons anastomosed with each other and with the small intestine (fig. 6). Each colon had a caecum with an appendix. The right caecum was the larger and, excepting its increased size and its associated appendix, it seemed normal. This appendix was a constricted apical portion of about 1.5 cm. in length (fig. 6). The left caecum was very short, being about 1 cm. long. Its appendix had a smaller diameter than that of the right and was about three times as long (fig. 7). It was sharply folded at four distinct points into a compact structure.

The single ileocolic vah-e was relatively large and covered both colic orifices, but was thickened in that portion overling the right orifice (fig. 8). Its opening was directed somewhat laterall}^ and gave vent nearly directly into the left colon. At a point immediately distal to the valve the lumens of the two colons united. On account of the thickening of one side of the valve, the connection between the lumens of the right colon and the small intestine was thrown to the left, somewhat toward the smaller colon. The caecocolic orifices of both colons were apparently normal (fig. 8). It may be of interest to note that there were ten persimmon seeds and a few whole grains of corn in the right colon. The great enlargement of the right colon may find its explanation in a gradual distention by fecal contents which could be only slowlj- voided due to lack of peristalsis following the paucity or lack of smooth muscle.

On the right side the larger colon, the urethra, and the vagina had a common exit chamber, forming a cloaca (fig. 12). The right rectum formed the largest part of this chamber, and on this arroimt the orifires of the vagina and the urethra seemed to empty into it at a point about 3 cm. cephahul of the common external opening, the vagina on the medial and the urethra on the lateral sides, re.><pectively.

The external genitalia of that side were slightly smaller than those of the l»ft. Itut had a generally normal appearance.

The urogcnilal system

The single kidney was situated on the left side. No trace of even a vestigial kidney could he found on the oi)posite side. 'I'his lone kidney, locatetl at the usual level, was considerably larger and more spheroidal than nonual (fig. 9). It received a large renal vein from the left side of the inferior vena cava; and slightly dorsad and caudad of this point it received a renal artery from the alidominal aorta. Midway between the latter and the pelvis of the kidney the renal arterj' divided into two, one entering dorsally and the other, after curving around the renal vein, entering ventrally and cephalidy to it. Before entering the pelvis the renal vein gave off a branch that coursed laterally over the ventrocaudal portion of the kidney to the left ovary and oviduct. .\. single large ureter passed caudally to empty into tlie left urinary ijladder in a normal way (fig. 10). The minute anatomy of this kidney was perfectly nonnal. Cephalad of the kidney, and in their proper positions, occurred two adrenals (fig. l»).

Of the two urinary bladders the left was apparently normal, except that it wa.s slightly displaced to the left. The displacement was due chiefly to the presence of the greatlj' distended right colon. This bladder was comjjletely collapsed. Its urethra was normal, emptj'ing by means of the left vagina (fig. 10). The right urinary bladder was rigid and distended. It was comiKKSctl of brittle tissue a|)parently like that of the larger colon. It was obviou.sly smaller than the left bladder when the latter harl l)ecome distended. At its cephalic end there was a narrow circular area (.'i mm. in <liameter) of ver>' delicate tissue simulating a membrane, which yielded on the slightest pressure (fig.

11). There was no vestige of a ureter in connection with this bladder. Its urethra had about twice the normal diameter, and was composed of the same kind of brittle tissue as the bladder. A medial longitudinal section of the bladder revealed a lining of elastic tissue that was hard to peel off and that had the macroscopic appearance and general consistency of a thin plate of cartilage. Irregular partitions extended from the walls fonning two large pockets at the eephahc and caudal ends of the bladder, respectively (fig. 11). Between these and in the central portion there were about ten smaller pockets. Along the entire ventral wall there was a space between this cartilage-like lining and the wall of the bladder which was continuous with the hunen of the urethra (fig. 11). The urethra had a very thick wall and emptied into the cloaca (fig. 12).

The genital organs

Two ovaries, each with its respective uterine tube (unpaired cornu uteri) leading to a respective uterus (corpus uteri), were situated in their normal positions. The ovary of the left side was flattened and oval in outline; that of the right side was flattened, elongated, and ahnost crescent-shaped, with a deep longitudinal groove extending over its lateroventral surface. The two uterine tubes extended caudomedially to their corresponding uteri (figs. 12 and 13). The right tube was the shorter and slightly the thicker of the two. The right uterus was about twice as long and thick as the left. The latter presented no peculiarities in its continuation into the vagina of the left side. The right vaguia was relatively short; it was continued mto the common chamber which formed the cloaca. Both uteri were abnormal to the extent that the}^ were unicornuate.

Four rows of asymmetrically distributed nipples, twelve in number, were present (fig. 14).

Angiology

The hIcMMl su|)i)ly of the kidiioy has horn tlescriho<l ahovo. No triu'os of any hloocl-vessols that niiKht have corresponded to the right renal arterj- and vein coultl lie found.

The alxlotninal aorta and the inferior vena cava remained single throughout their entire course, but they gave off extra branches which supjilied the suijcrnunierar}- structures. The distribution of these two chief vessels and their principal branches is shown in figme 15. The abdominal aorta gave off a right eommon iliac arterj- a short distance cophalad of its usual place of branching. The left conmion iliac was larger than the right and seemed to represent a direct continuation of the abdominal aorta. Its course was in direct line with that of the aorta to a point about 1 cm. caudad of the i)oint of branching of the right conmion iliac. Here there was a gentle curve to the left, the main portion being continued as the left external iliac which |)rocee<le<l down the left lateral leg as the femoral artery. Slightly caudal to the beginning of this curve on the left common iliac just nientioned, and on the outside of it, a large branch came off which supplied the two extra legs, ^'ery close to the origin of this larger i)rancli there was a small branch which went to the left urinar>' bladtler; while just caudal to this a larger one came off and divided into two, the medial representing the caudal (middle sacral) and going to the tail, the lateral going to the structures in the left jielvic cavity and probably representing the left internal iliac artery.

One principal artery and one principal \oin supplied thetwo extra legs. The i)lan of the arterial supjily is represented in figure 1(>; that of the venous sujiply is practically indentical. The vessels continued their course caudally between the two femurs, giving off two small branches, one on each side, just distal to the heads of the femurs, to supply the scanty muscles and fascia of that region. No other branches were discernible cephalad of a level about 2 cm. proximal to the knee-joint. At this point, however, both the artery and the vein divided into one meilial and two lateral branches, the two lateral branches of each vessel passing distally to the lateral sides of the fused tibiae and finally coming around on the dorsal side to f onn an anastomosing arch over the distal portion of the tibiae in the region of the ankle. From this arch sprang two main arteries and veins which passed on to supply the feet, the right set to the right foot and the left set to the left foot. Two medial smaller branches arose from the arch and supplied the structures in the immediate vicinity. The medial branch (fig. 16 M) of the principal vessels mentioned above represented a terminal branch. The medial artery and vein passed distally along the ventral line of fusion of the two tibiae where they became resolved into branches that supplied the structures of the ventral portion of the fused legs. The lateral branches supplied the structures of the lateral and dorsal surfaces. The \'enous system of the supernumerary legs paralleled the arterial system throughout its entire course.

Numerous lymph nodes were found scattered throughout the abdomen. Just cephalad of the kidney occurred the two largest nodes. The smaller nodes were relatively more abundant along the inferior vena cava and the abdominal aorta. Those of the paired pelvic cavities were rather large and numerous. A large bean-shaped hanph node, about 1 cm. in length, was situated at the level of the stifle-joint on the ventral side. This probably represented a composite popliteal node and was apparently the only lymph node of the two extra legs.

Neurology

A large nerve accompanied the principal artery and vein of the two extra legs. This nerve presented an oval cystic enlargement, macroscopically suggestive of a ganglion, at the point where it entered the double leg, just distal to the heads of the two femurs. The nerve passed dorsal to the blood-vessels, accompanying them as far as they went, and then accompanying the terminal or medial branch down over the midline of the double stifle-joint. As the nerve passed the latter point it presented a gradual cone-shaped enlargement and, tiu'ning laterally and dorsall}^ around the medial condyle of the head of the

12 JOIIX SHELTON HORSLEY, JR.

rijclit til)ia, rii(lo<I abruptly in the skin (fig. Ki). On the external .surface of the skin this terniination presented a roughened scarlike appearance, the size of which was approximately that of the diameter of the nerve. Three smaller scar-like patches oceurred below, and slightly Tuedial to the principal one. No nerve fibers could be traced within the skin. The whole appearance of this nerve tennination seems exactly what might have been expected if the nerve had penetrated the skin and its external part had subsequently sloughed ofT, thus leaving a scar with the nerve firmly attached. The proximal part of this nerve was attached to the right wall of the cavity through which it coursed to the extra legs in company with the two main bloodvessels. This attachment was made by strands of tissue chiefly to the middle portion of the small opening. The portion of the nerve from the cyst forward consisted of a hollow, circular strand of tissue that tapered down almost to nothing. There remained no connection with the spinal cord. This nerve probably represented fused right and left medial sciatic nerv^es.

CONCLUSIONS

Viewing the double portion of this dog, it is seen that the left comjjonent is more fully tievel<)])ed and that it is nearly in nonnal jiosition. while the right component is entirely at the right of the median plane. The blood- vascular, the tligestive, and the urogenital s\stems, excepting the kidney, and the fusions and articulations of the pelvic limbs, all consistently support an interpretation of this monster in terms of a side-to-side pelvic fusion of twin primordia, with complete resorption of the prediaphragmatic portions. .V variant of this interj)retation might l)e based upon the supposition that an original unpaired embryonic disc suffered a caudal splitting to the point including the primordia of the pelves. It is not po.ssible with the available data to decide finally between the suggested alternatives of iusi(»n and splitting. However, the mixed character of the alxlominal vi.^cera (e.g., single kidney, double colon) .seems to favor the interpretation of fusion rather than of splitting. The

SIX-LEGGED DOG 13

one chief objection to the interpretation of lateral, as opposed to dorsoventral, fusion is the presence of the unpaired sciatic nerve of the extra two legs. It the interpretation of lateral fusion is accepted, then the compound sciatic nerve seems to be greatly displaced. The sciatic nerve normally passes through the pelvic mouth and then courses laterally over the acetabulum on down the leg. The sciatic nerve of the right and left lateral legs followed this normal course. The fused sciatic nerves of the supernumerary limbs, however, entered the pair by a single root, having passed thither between the two medial acetabula, and not, as normally, through their respective pelvic mouths. The apparently ectopic position of the fused sciatic nerv^es can be explained on the very probable supposition that the primordia of the originally paired medial sciatic nerves fused before the medial components of the pelves had developed beyond their blastemal stage. This explanation becomes the more plausible when it is recalled that the fused sciatic nerves had suffered degeneration at their proxhnal ends, due in all probability to pressure here following the further development and subsequent fusion of the two medial components of the right and left pelves.

This dog belongs in the categorj' of duplicate monsters designated dipygus dibrachius tetrapus, and corresponds in general to the six-legged rat recently described by Conrow' and more closely to certain human monsters described under this designation by Broman.^

LITERATURE CITED

1 CoNuow, Sara B. 1917 A six-legged rat. Anat. Rec, vol. 12, p. 365.

2 Broman, Ivar 1911 Normale und abnonne Entwicklung des Menschen.

Bergmann, Wiesbaden, S. 190.

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THE ANATOMICAL RECOllD, VOL. 10, NO. 1

PLATE 2

DESrRIPTIOX OF FICtJRES

2 anil :{ U(irntgt'nogr;imby Dr. II. V. Ili|ip.

ir>

SIX-LEGGKD DOG

JOHN SHELTON H0R6LEY, JR.

PLATE 2

17

I'l.ATK :i

DESCniPTlON OF FIGUKES

4 Drnwinn of the (limbic bony struct iirps in the pelvic region viewed from the rinht side. A, left medial femur; li. ri(thl mediul femur; C, leftmedial tuberischii; D. riRht medial tuber isehii; E, right lateral tuber i?chii; F. right lateral femur; G, left lateral femur: //, right lateral ilium; /. left lateral ilium; J, fused medial ilin; A', fifth lumbar vertebra; L. caudal vertebrae; ^f , right deformed sacrum; .V, .•mall piec-e of bone articulating with right deformetl sacrum and right lateral ilium (possibly remnant of a second vertebral column*. Four-fifths life size. Drawn by Helen Lorraine.

5 Drawing of thedouble bony structures in the pelvic region from a caudoventral aspect. .1. left medial femur; li. right medial femur; C, mouth of right pelvis; D, central point of the fusion between the right and left pelves, which extends along the pubo-i.schial .synij>hysis of each; E, left lateral obturator foramen; F, right lateral femur;fi, left lateral fenmr;//. sixth lumbar vertebra. Four-fifths life size. Drawn by Helen Lorraine.

18

SIX-I.EGGKD DOG

JOHN 8HELTON HonsLEY, JR.

PLATE 3

lu

I'LATK I

DESCRIPTION OF FIliCHES

6 Dniwinis of the iiiiastomosis of the siiiiill intcsfiiie witli the ri(];lit and left colons from a riRlit ventral aspect. The right eaeeiini with its associated appendix is also shown. The portion of the right eolon here shown rei)resents only one of the two sacculations that were i)re.sent. The second was approximately the same size. Four-fifths life size. Drawn by Helen Lorraine.

7 Drawing of the anastomosis of the small intestine with the right and left colons from a left ventral aspect. The left caecum with its associated appendix is also shown. Four-fifths life size. Drawn hv lli'leii Lir.aine.

20

SIX-LKGGED DOG

JOHN 8HELT0N HORSLET, JR.

PLATE 4

."Rt.cisecuTn

5TnnaU\TilestvTi(?

21

I'LATK .)

DESCRll'TION OK KKJURES

8 Drawiiifc of tlio ileocolic valve from the riulit side. The ileum and right colon are .slit o|)en lonRitiulinally. Fcnir-fiftlis life size. Drawn by Melon Lorraine.

9 DruuinK of ventral view of kidney with its hlood-siipply. sliowinR also the two adrenals. A', .single kidney of left side; /. anil L' . left and right adrenals; V, Hingle ureter leading to left urinary bladder; .1. abdominal aorta; V, inferior vena cava; R and IV, renal vein and artery; P. phrcnico-abdominal vein. Branch of renal vein to left ovarj' and uterine tube not shown in this drawing. Fourfifths life size.

10 Drawing of left urinary bladder partially distended. The bladder is in a position to show^ the ureter emptying on the dorsal surface. Four-fifths life size.

•a

SIX-LEGGED DOG

JOHN SHKLTON HOHSLKY, J».

PLATE 5

iLeo cestui

caecLL-m

caetairn.

•Ur.te

liritkrk

23

PLATE 6

DKSCHIITION OF FIGURES

11 Drawing of the interior of the ri({ht urinary Madder from a dorsal aspect. It is slit open dorsally in the longitudinal plane. Four-fifths life size. Drawn by Helen Lorraine.

\2 Drawing of the cloaca and genital organs of the right side. Cloaca is slit open. O, right ovary; Ut, right uterine tube (uni)aired horn of right uterus) ; f, biHly of right uterus; i'r, urethra from right bladder; E and E', orifices of uterus and urethra into common exit chamber forming the cloaca; C, right colon. Four-fifths life size.

13 Drawing of the genital organs of the left side. Vulva, vagina, and uterus (in parti arc slit open. 0, left ovary; Ul, left uterine tube; U, left uterus; E, external uterine orifice; //, hymen; E', external urethral orifice; V, vulva; .V, central projection of fold of mucous membrane which conceals the clitoris; F, fossa clitoridis; L, labia vulvae. Four-fifths life size.

24

SIX-LEGGED DOG

JOHN SHELTON HOHSLEY. itt.

I'LATIO 6

,cvst wall

'j-Te*

nOTniai TTvuCOv

u

E'

12

25

I'l.ATi; 7

DESCRIITION- OK KKiUBES

!• l)i:iKr:iiii of the :>rr:ingoiiicnt of the nipples. Each small blaek dm represfiiM a nipple. One-Kfteenth life size. ^l^iaSW

l*> Diagrammatir drawing of the distal portion of the abdominal aorta and its branches .scon from a ventral view. .1, abdominal aorta; li.C.I., right common iliac; R.E.I. . right external iliac; li.F., right femoral to right lateral leg; L.E.I., left external iliac; L.F., left femoral to left lateral leg; D.L., artery to extra pair of legs; (', caudal artery to the tail; n and a', arteries to neighboring lymph nodes and other structures; b, artery to dorsal abdominal wall; c, arterj' to right colon; e and <•', arteries to structures in the right and middle portions of the pelvic cavity;/, artery to structures in the right i)orti(ui of the pelvic cavity (probably right internal iliac); (/, artery to left urinary bladder; h, arten,' to left ventral abdominal wall (probably left deep epigastric); i, artery to structures of left pelvic cavity. By pelvic cavity above is meant that portion enclosed between the lateral components of both the right and left i)elves. Veins accompanied the arteries.

16 Diagram of the arteries and nerve of the extra pair uf legs as seen from a ventral view. The ner\-e ran immediately behind the main artery, but in the diagram it is shoved to the right. A, point of emergence of arterj- between the hea<ls of the two femurs; (', cystic enlargement on the unpaired sciatic nerve; W.the curve of the sciatic nerve around the medial condyle of the right medial tibia; E. tennination of the .sciatic nerve in the skin; I), point about 2 cm. above proximal end of fusion of two medial tibiae;/^, lateral branch which passed arounil the left medial leg (also level at which the sciatic nerve i)assed behind the stifle-joint I ; li, lati-ral branch which curved around the right medial leg; .1/, medial branch which ran along dorsal line of fusion of the two medial tibiae; .\r, anastomosing arch on the dorsal s\irface of the fused medial tibiae in the region of the ankles, formed by the two lateral branches; F and F', branches to right and left feet; m. small branches to the skin, fa.scia and scanty muscles; /. terminal branches of the medial branch supplying neighboring skin, fa.scia, and "-nnty muscles. Veins accompanied the arteries.

26

SIX-LEGGED DOG

JOHN SHELTON HORSLET, JR

PI-ATE 7

27

Rosuiiifii por el Mutor. Hiiwanl ]i. Adoliuann, I'liivorsidad Coiiicll. Itliafa.

I'll caso cxtremo do espiiia l)ifida con lioinia dorsal en la ternera.

El presentc trabajo es una dosoripci6n do un caso en el cual una porci6n de la nieinbrana mucosa intestinal emei"ge del cuerpo a travi's do lui orificio situado en la region lumbar de la cohunna vertclnal. ICste dofecto es una consecueucia de un defecto en la linca primitiva.

Tnmnlation hy Jun^ P. Nonidci Cornell l'nivon»ity Mo<lirat Oilhiei'. N. Y.

ACTHOR'S ABSTRACT OF THIS PAPER 18»UEl> BY THE BIBLIOGRAPHIC SERVICE, MAY 10

AN EXTREME CASE OF SPINA lUFIDA WITH DORSAL HERNIA IN A CALF

HOWARD B. ADELMANN

Deparlmcnt of Histology and Kiiibrijolo(j>/, Cornell University, Ithaca, Xcw York

TWO FIGURES

The foetus forming the subject of this note is a part of the collection in obstetrics of the New York State Veterinary College and was siibniitted to me by Dr. B. F. Kingsbiny for an explanation of the striking and unusual anomaly which it presents. I was unable to find an exactly similar case in the literature of teratolog}'.

The cases found in the literature which are to some extent analogous to the one about to be described are by (!urlt ('77), who gives an account of a calf embryo with a lateral prolapse of the abdominal viscera through the spinal column; "\'eraguth COl) described a human embryo with ectopia of the spleen and intestines. Finally, in 1917, Williams described a calf with the omasum and spleen extruded from an opening in the occiput. In all these cases the spinal defect is in or near the cervical region, while in the calf here described the defect occurs in the lumbar region.

Unfortunately, the head and extremities of the specimen which I describe were removed before it was brought to the museum, "^riie musculature was removed and only that part of the vertebral column and viscera shown in figure 1 remained. No clinical history of the case is available. ■

The sj^ecimen under consideration is a nearly mature calf foetus which exhibits two well-marked defects: 1) an extreme degree of spina bifida and, 2) a well-marked dorsal hernia.

The cleft in the spinal colunm is com])lete and involves the entire lumbar region. X-ray ])hotographs show that the six

29

30

HOWARD H. ADKLMANN

luiiihnr vortelmic arc atTcctod and tliat halves of those arch arnuiui both sides of the defect, producing a somewhat triangular vertel)ral fissure. 7 cm. long and I? cm. wide at the cejihalic end. However, the area of comi)lete sphia bifida extends for only 2 cm. fron; the cephalic end of the defect; caudal to this point merely the verteliral arches are sei)arate<i.

The vertebrae are more or less fused, especially in the cephalic end of the defect, where a bony prominence on the ventral side of the specimen gives evidence of this fusion. The tip ofthe transverse process of the sixth lumbar vertebra on the left side

Kin. 1 Iilcnlizo<l snijittnl section of foetus to slmw the relations of the intestines. (', caerum; 1), dorsnl oprninK of the intestinal pad; /, intestinal I'ad; O, OS coxae; /?, rectum; S, blind .sac; -SV, spinal cord; \', ventral opening of intestinal pad.

lies under the innominate bone. The spinal cord is divided, the resulting halves passing around the defect. Nerves are given ofT on each side.

.\ pad of intestinal mucous membrane protrudes through the opening in the spinal colunm. "\Mien sectioned, this pad proved to be mucous membrane of the large intestine. Two openings in the mucous membrane, one dorsal and one .somewhat ventral, communicate with the large intestine (fig. 1). The dorsal opening is the larger and conmiunicates with a .small portion of the large intestine posterior to the caecum and with a blind pouch which also jjroved to be a portion of the large intestine when

SPINA BIFIDA WITH DORSAL HERNIA IN A CALF

31

examined under the mierosrope. Ihe remainder of the large intestine, that is, the portion extending fiom the anus to the pad, ends in a small oiiening on the ventral side of the caudal end of the pad.

Kig. 2 Dorsal view of the defect, showing the relations of the intestinal pad. D, dorsal opening of the intestinal pad; /, intestinal pad; 0, os coxae; R, rib; T, transverse process of lumbar vertebra ; V, vertebral column.

The literature dealing with the causes of spina bifida is most extensive and the theories advanced are numerous. The theories of maternal impressions and amniotic adhesions need only be mentioned heie. The first has long been discarded and the latter theory has also Imhmi looked iijion as invalid, durlt (77),

THE ANATOMICAL RECOKD, VOL 10, SO. I

V2 HiiW \l;i( II. AUKI.MAN.N in jissinninn a causr for tlic coiKlition wliicli lie doscrihos, iiiontimis llic nillu'siniis of tho iiioiiil)raii('s cau.scil l)y tearing due to luniinti of tlio foetus. This is a rather vapjue exjilanation at l)ost. Modern invest ipators would more likely agree with ]\Iall, who says: "Sinc(> monsters are i)rodueed in animals without an anuiioii, it would l)e well, it seems to me, to relegate the anmiotic theor>- of the pnxluetion of monsters into the class into which that of maternal impressions has fallen."

Of more imjiortanee, it seems to me, are the theories which regard a disturl)ance of growth metabolism as the causative factor in jiroducing abnormalities. The experiments of Hertwig, Morgan, ."^tockard, and others may be briefly mentioned.

In IS'.fJ Ilertwig published his classical essaj' on "Uruiund und Spina Bifida," in which he showed that spina bifida could be producetl by the action of morj)hine. ^lorgan, in 1894, prfMluced spina bifida by adding O.ti per cent sodium chloride to the water in which eggs were developing. Hertwig, in 1890, found that salt solutions stronger than ().() ])er cent retarded develojiment and the eggs dietl witliout going beyond the gastrula stage. Similar results were obtained by Hertwig and Morgan by raising the temjierature of the water.

(Jodlewski ('97, '00, '01) and Samassa ('96, '98) found that spina l)ifi(la could be produced through lack of oxygen. This might easily be the case in faulty implantation.

lialdwin ('15) was able to produce spina bifida in ahnost every instance by treating the yolk portion of the egg with violet raj's. The action of the ultra rays, by destroying a portion of the yolk hemisphere, results in an upset of the balance between the (lifTerentiation of the neural canal and the approximation of the blastoporic lips. The differentiation is not retarded, and the half tuix's (lilTcrentiate into two tubes before the lips of the blastopore close.

In the present instance, the defect un(|uesti()nably arose very early in the develojiment of the individual and is essentially the same as tho.se produced by Hertwig, in who.se experiments spina bifida or 'ring' embiyos resulted from incomplete approximation of the bl.'istfiporic lips.

SPINA BIFIDA WITH DORSAL HERNIA IN A CALF 33

There is no evidence that gastrulation in the calf is accomphshed by means of blastoporic Hps, but we may regard the primiti\-e streak as homologous with the blastoporic lips, since both give rise to spinal cord, notochord, and mesoderm. The opening, in this instance, may be a secondary condition which has arisen in the region of the potential neurenteric canal, the persistence of which has been recorded in numerous instances.

The failure of the blastoporic lips (primitive streak) to approximate closely, differentiation, however, not being retarded, results in an opening bounded by material which becomes spinal cord, notochord, mesoderm, and perhaps a small amount of entoderm. In any case, liowever, the latter would adhere to the edges of the opening forming a passageway- into the primitive digestive cavity which may or may not coincide with the position of the potential neurenteric canal. Yeraguth ('01) regards the open neurenteric canal as the cause of the anomaly which he describes.

The dorsal hernia which occurs in this specimen may be interpreted thus: There is a gap in the dorsal wall of the intestine at the primitive streak, and the ventral wall pushing up through the gap has produced a pad of mucous membrane such as here found. I regard the blind sac as an outpocketing caused by a fold in the intestinal wall. The steps in the formation of this dorsal hernia may be easily understood by consulting a series of figures given by Cullen in "The Umbilicus and its Diseases," page 224.

It is interesting to note that spina bifida always occurs high up or low down in the spinal axis and to speculate why the defect should be so restricted. LebedefT's ('81) theory that the curvatures of the spinal axis disturb the normal de^-elopment of the medullaiy tube seems to be invalidated by two facts: 1) the neural folds have already closed before the body ac(]uires its normal curvatures and, 2) the cervical flexure is most pronounced, whereas spina bifida is most frequent in the lumbar region.

In conclusion, I wish to thank Professor B. F. Kingsbury for many helpful suggestions; Professor W. L. WilHams, who loaned the specimen for descrijjtion, and Mr. R. R. Huinphrej', who made the drawings.

V} ll<l\V\HI> H. ADEI.MANN HlHI.KiCliAl'lIV

F^AI.^^VI^•, F. M. lOl.'i The action of ultia-violpl rays upon tlic fioc's ogg.

Anat. Hoc, vol. 0, p. :J(15. Bai.i.antynk, J. W. ISO" TorntoRpiipsis: An enquiry into tlie ca\ises of monstrosities. Oliver \- Hoyil, I'Minlmrnh. Brom.vn, I. 1911 Norniale unil ahnoriiie KnlwickcUing des Menfclicn. ^'crlaR

von .1. I'". HerKtiinnn, Wieslintlen. CrLLKN, T. S. 191(1 Tlie unil>ilieiis and its discase-s. W. H. Saunders Co.,

I'hiladelpliia. (iobLEWBKi, K. mt)I Die Kinwirkung des SauerstofTes auf die Entwickclung

von Rana teniporaria. .\rch. Ent. Mech., Bd. 11. Good, J. P. 1912 Spina bifida in the neck region of a ferret embryo 8 mm.

long. Journ. .Vnat. and I'hys., vol. 46, p. 391. Cii-RLT, E. F. 1877 IVber thierische Missgeburten. VerlaR von A. Ilirschwald,

Berlin. HERnvKi, O. I.S92 I'rmund und Spina bifida. .Arch, niikr. .\nat., Bd. .30,

s. ,sef..

Kkrmm-nkii, F. 19(19 Mis-^liildungen des Runipfes. In Vj. Schwalbe, Morph.

der Missbildungcii, 111 teil, I. Liefcrung, 1. .\bt., 3 Kap., S. SO. Kkuikl, F., and Mall, F. P. 1910 Iluiiiau embryology. J. B. Lipi)incott

Co., Philadelphia. Lebkdkfp, a. 1881 I'eber ilie ICnt.stehung der Aneneephalie und Spina bifida

bei Vogeln und .Menschen. Arch. path. .Vnat., Bd. 80. LiLLiK, F., AM) KxowLToN, F. P. 1897 On the effect of temperature on the

development of animals. Zool. Bull., vol. 1, !>. 179. .Mall, F. P. VM\S \ study of the causes underlying the origin of human monsters. .Jour. Morpli., vol. 19, p. 3. MoR(iAN, T. n. 1S97 The development of the frop's ckk Mncinillati iV: Co.,

New York.

19O2-10(tt .Several papers in Arch. Ent. Mech., Bd. 15, 10, IS, 19. Stockard, C. R. loot) The development of Fundulus heteroclitu.s in solutions

of lithium chlorid, with ap|>pnilix on its development in fresh water.

Jour. Exp. Zo(>l., vol. 3.

1907 The artificial production of a single median eye in the fish embryo

by mean.-* of sea-water solutions of magnesium chlorid. Arch. ICnt.

Mech., Bd.23. Veracuth. O. 1901 Teller nieder diffcrenzirte Missbildungen des Ccntral nervensystems. Arch. Ent. Mech., Bd. 12. Wmkklkr, T. 1918 Study of a human Spina bifida monster with encephaloceles

anil other abnonnalitics. Contributions to Embryology, no. 22, vol.

7. Carnegie Institute of Washington. Williams, \V. L. 1917 Veterinary obstetrics. Published bv the author, Ithaca,

N. Y.

"t

Rosiimcii ])()r el autnr. H. M. Stroiifi. Escuola do -Mcdiciiia dc la I'niversidad Loyola, Chicago.

Sobio un iiiodcio pcoii6inico de los priiK-ipales tractos de la niodula cspinal y tallo cerebral.

Este niodelo incluyo dibujos de secciones transversales (auniontadas ocho diaiiiotro.-^) practicadas on cuatro iiivolos de la iiu'dula y on sieto iiivolc.>< del eje cerebral, inontadas ^iobre un tabloro de diez pi6s de longitud y un pi6 de anchura. Para ropres(>ntar lo.s tracto.s mas inii)ortantes se eniplean cintas coloroadas. El problema de indicar el trayecto de los tractos entre ol tallo cerebral y el corebelo se resolvio colocando un arco .><obre la regi6n del puente. En este arco se insertan los tractos con conexiones corobelo.^as, represent ados por cordon(>s coloroados. Los niateriales enipleados en este niodelo sujjonen un gasto mfnimo. Este modelo ha sido usado con gran provecho por varias cla.se.s, siendo especialniente util para la i)t)tenci6n de conceptos sobre la proyecci6n de los tractos.

TnnwUtioti by JfWi F, Nonidoz Comcll I'nivfmity .Mfdiriil Coll<'«i-, .V Y.

ATTTHOR 9 ABSTRACT OF THIS PAPER ISSUED BY THE BIBLIOGRAPHIC SERVICE, MAY 10

AN INEXPENSIVE MODEL OF THE PRINCIPAL SPINAL CORD AND BRAIN STEM TRACTS

11. M. STRONG Deparlmcnt oj Anatomij, Loyola University School of Medicine

TWO FIGURES

The apparatus described here has been useful in heli)ing my students in the difficult work of learning the tracts of the cord and the brain stem. It is especially helpful in getting projection conceptions, and it involves Uttle expense.

Drawings with a magnification of eight diameters were made for four levels of the cord and seven levels of the brain stem, the last being through the diencephalon. These drawings were made on light bond typewriter paper, and thej^ were pasted on light binding board to produce what will be termed sections in this paper. In order to have the structure outlined A-isible on both faces of each section, a reverse copy of each drawing was made. This was accomplished by tracing the second drawing for each section on a piece of paper which was held against the back of the sheet of paper bearing the drawing. The two sheets were placed against a window pane with the first drawing against the glass. With sunlight transmitted through the two sheets, it was easy to make the tracing.

The pictures can of course be made by photography or with the aid of a projection outfit. A pantograph can also be used to advantage in getting a desirable size for the drawings.

A board 10 feet long and 12 inches wide was used as a base; it was stained and varnished. The sections were mounted on the board by means of strips of galvanized sheet iron (figs. 1 and 2) These strips were cut 1§ inches wide by 4^ inches long. Each strip was bent so that two limbs making a right angle with each other resulted. One of these limbs, 3| inches long, was fastened

'M\ H. M. STRONG

to tlif Ixiarti hy scrows. Tho otlicr liiiil), 1} inches liif>;h, has a vertical jiosition. Two ])airs were used for each section, and thoy were inountcHl so that tlie vertical limbs had just enough space l>ctwoon them to insert the l)ase of a section with a tight fit.

Before mounting, holes were ma<le in the horizontal limbs for the screws used in fastening them to the board. It was not found necessary to fasten the vertical limbs to the sections as tlie tiglit (it antl the strings employed in the model hold the sections in place.

There is a tendency for tlie sections to be pulled away fioni a vertical i)osition by the taut strings. This difliculty was met by using a piece of white string as a stay line. It was attached to the top of each section at its middle and was tied at the ends of the board, after being made taut.

("()h)red strings were used to indicate tracts, and they were fastened at their ends to nails. A tract not extending the whole length of the cord, for instance, is represented by a string which was deflectetl beyond its last level in the model to a nail at one side.

Descending tracts are represented by red strings, exteroceptive liy blue, projirioceptive by yellow, and association tracts by purple. The colors fade eventually and become dull from .soiling, in which ca.se it is a very simple process to substitute new strings for the old. The regions occupied by the tracts are indicatetl diagranunatically with corresponding colors in the drawings.

'I'he ccrel)ellum presented a jieiplcxing problem in constructing the model. This was finally solved by placing an arch as se<'n in figure I over the pons regi(m. Tracts passing through the restiform body, brachium pontis, and brachimn conjunctiviim are represented by strings which have the cerebellar ends attached at the top of the arch.

Decussations are re|)resente(l in the drawings by the usual methods ((ig. 2). In the ca.se of the strings, the problem was solved by passing the string across the face of a section in the region of the deeu-s.sat ion in question. The section is perforated three times by each string in such eases instead of once. The

MODEL OF SI'i:^AL CORD AND BRAIN STKM TRACTS 37

Vrf'h I'cr r-tTt^lM'llniil

Fig. 1 View of entire model Fig. 2 View showing region of fillet and pyramid decussations

.■* moilel is large enough to permit a number of students to study it simultaneously and it is in almost constant use during laborator)' periods. I have not labeled any part of it, as I prefer to have the students identify the structures represented. A limited amount of a.'^.-^istance ui interpreting the model is given.

>'i

Hcsimion por c\ alitor, .lacoli l^cif^lianl. Pfpartaniriilo dr Zoolo^fa, riiivcrsidad dc -Michigan.

K! alniacenaniioiito y inanojo de cuadros murales.

Va\ v<>z dc los listoncs do niadora (\nc so usaii ordinariainonte, ol autor oiiiploa listoiios do inadoia "hasswood" tefiidos con crcosota. Las diiiionsioiios do ostos listonos son ', dc pulgada dc cspesor por ] do pulgada dc anchura. So olavan ostos list ones a los cuadros onii)loando clavos de alanibie de ] pulgada de diaiuctro, y dol)ajo dc las cabezas de dichos clavos se perforan oiiaiirados do liiorro jiahaiiizado ilel nuni; 28. Los list ones ocupan la supoiHoio anterior do cada cuadro y los olavos se clavan on los lados libres. Cada list6n superior ilcv a iin fiaiiclio Hndjio atornillado en el centro del list6n. Cuando se hace ^irar al ^inx'bo dc niodo quo venga a coincidir con el piano de la lamina, sine para oolfjar osta ultima de una barra dc hierro colocada on ol cuarto on donde se guarden las laniinas. De osto niodo ostas so cons(>rvan sin arnifjas, y puosto i|Uo los listoncs ooujjan nuiy poco espacio, puodon oolfjarso todas ollas dc un mode seniejante al de las hojas de un libro suspendido por el lomo. I-as laniinas se arreglan en ordcn de materias j)or medio do minicros. como si se tratase dc un catalogo de materias, y cuaKiuiora <le ollas puede faoilmcntc sacarse y volvcrla a su .sitio. Cuando se necesita usar una dc las laniinas se hace girar ol ii.anclio i)n graflos, y entoncos puodo oolgarso do un l)astidor, alanibro o cualiiuicr otro sojjorto on la claso. Algunos de los mccanismos descritos han venido usandose hace largo tiempo; otros son nuevos. Sirven para coleccionar himinas de todos los tamanos en un espacio mfnimo y para podcrlas guardar en onion y oniploarlas invirliondo ol monor tiempo i)osil)lo. Kl prcsente trabajo indica dondo puodon obtenerse los materiales omploados y su coste.

TraiwUtinn hy J(m^ K N'oDJftra Cornfll ('ntvfniily Mrfliral Oftllrgr, N Y.

author's ABeTRACr OV THIS PAPEH ISHL'KD BY THE BIBLIOCKAPHIC PEKVICK, MAT 10

THE STORAGE AND HANDLING OF WALL CHARTS

JACOB REIGHARD

Dc pnrlmcnl of Zoology, University of Michigan

FOUR PIGUKES

The maker usually supplies charts with wood rods tacked and glued to the ends. In use they are hung from hooks on the \\all of the lecture room by means of two metal rings tacked to the upper rod. When stored they are rolled and tied about with tapes. In the Zoology Laboratory of the University of Michigan we have tried probably every known device for the storage of rolled charts. They may be jiiled on racks such as once were used at Harvard rni\'ersity. To make these, pieces of round iron, some 30 inches long or more, are bent for a couple of inches at the ends, flattened and drilled at the middle, and screwed horizontally to wooden uprights to as to project on both sides like large coat hooks and form two ladder-like sets of supports. On two such uprights, properly spaced, one may store man}' charts and classify them roughly. The uprights may be built on a base with casters beneath it and the whole contrivance wheeled from place to place. Labels may be written on discs of cardboard tacked to the ends of the chart rollers. As the charts accumulate and are piled sevei'al deep on each support, it is impossible to keep them in o'rder and much time is wasted in locating and reading the small labels. In spite of the most ingenious labeling it is often necessary to unroll the charts to find those that are suitable, and this entails not only loss of time, but damage to the charts.

To find the charts more readily, we have tried supporting them on pairs of large iron hooks screwed into vertical wood strips nailed to the walls of the lecture room. The charts then lie in one plane like the rungs of niuiierous ladders set agamst the wall. They may be classified and labels put beneath the groups. But

39

40 JACOB REIGHARD

as the colloftion grows it takes imicli wall space. It may beroiup necessary to cliiiil) to reach the uppermost charts and thej'^ have still to he uin-oilcd.

In place of sup|)ortin{t the roiled charts on metal rods, one may use deep wood frames divided into comi^artments like the hoxes in a post office. These may l)e arranged to hold tlie charts in vertical or horizontal position, l)ut we have found this plan as cumbersome and wasteful of time as the other.

Home-made charts accunmlate in every laboratorj'- and are apt to be of various sizes and of material that deteriorates if kej)t rolled and frecjuently unrolled. To avoid the labor of attaching them to rollers, one is tempted to let them lie flat, and we have piled them thus in large cases with numerous close-set shelves on which they maj' be roughly classified. It is not easy to label such charts so as to find readily what is wanted, and in pulling one from a pile for examination it is likely to be torn or damaged by rubbing. To return it to its proper place the whole l)ile must l)e taken out. Naturally one puts the chart back on top of its pile or on top of some otlicr jjilc and tlic wliolc collection is thrown into confusion. In addition to this, if .some charts are kept flat and others rolled, there are two places to look and time is wasted in the search.

In hanging the charts for use the two rings at the top must be put over hooks on the wall of the lecture room. To accommodate the unequal spacing of the suspension rings of dilTerent charts, the hooks mu.st be movable. One may suspend picture hooks from a molding or wire and slip them along until the su.speiision rings of the chart will go over them and one must climb a ladder to do it. One maj' dispense with the ladder by using a wooden frame filled with wire netting and arranged to be raised and lowered by ro|)es and i)ulleys. The picture hooks may be stuck into the lowered netting at suitable intervals, the chart rings slipped over them, and the whole thing hoisted, or one may cover the hfiistable frames with cotton cloth and pin or clip his charts to that.

.\fter trA'ing most of the plans outlined, we sought a means of keeping all charts in a minimum space in one collection with

STORAGE AND HANDLING OF WALL CHARTS 41

out rolling them and so that they could be classified and examined and each removed and I'etiu'ned without disturbing the rest. We sought also the easiest way of hanging them for use. The result combines the unj^ublished devices of friends with some of my own. The universities in which 1 have seen some of these devices in use are indicated in parenthesis. I do not know that any other consistent scheme has been described in print.

We now store all our charts together by hanging them from a piece of f-inch iron pipe supported from the ceiling by a wire and stayed by wire to the side ^^all (^Visconsin) . They are in a small room reserved for the purpose. The charts hang flat, one against another, like the leaves of a book. Because the wooden rods take too much room, we ha^-e remo^'ed them and have substituted thin strips of basswood (fig. 4, chart at right.) A thousand of these j x f inches by 40 inches, cut at a planing mill, now costs $18.00. Probably any good soft wood would answer, but hardwood warj^s so that the strips do not stay flat. The strips are stained bro\\n by dipping in creosote. They are tacked to the face of the chart along its ends bj^ means of ^inch wire tacks or clout-nails set from 4 to 6 inches apart and clinched on the free face of the strips. To keep the heads of the nails from tearing through the charts we have put under each a piece of 28-gauge galvanized iron. This is | inch square, perforated at the center, and has the corners turned with pliers to as to form small points that penetrate the chart and go a little way into the wood. We find it better not to use glue, and none of our charts attached to the strips by tacks in the manner described has yet come loose from its supports. A piece of sheet iron 2x2 feet now costs fifty cents, and from it about 1000 squares can be made in the laboratory.

For suspending the charts we use the hook de\-ised by Prof. C. F. Hodge. It is screwed into the upper strip at such a point as to make the chart hang level. When the hook is turned into the plane of the chart it serves to suspend it from its support in the chart room as a suit of clothes is hung from a rail (fig. 1). ^^^len the chart is to bo used, the hook is turned through 90 degrees and may then be slipjied over a picture molding, wire, or other

42

JACOU RKICillAKK

e a

'a.

c

^ ^^'^^\

c

STORAGE AND HANDLING OF WALL CHARTS

43

support in the lecture room. To hoist it into place and get it down again, we use a light wood pole Oi feet long, also Professor Hodge's device. At one end the pole is provided with a ferrule through which is driven the sharpened end of a piece of f-inch round-iron. This is bent as shown in figure 8 and has its free end slotted to form a pair of claws like those on a tackhammer. The hump on the suspension hook fits between the

d

b

Fig. 2 The Hodge hook. See text Fig. 3 Pole for putting up and taking clown charts. For description, see text

claws on the pole and permits the chart to be handled without waste of time. In each lecture room a short suspension rod is provided. To this the charts are transferred after use and from it an assistant collects them from time to time and returns them to the chart room. The Hodge hooks were obtained from the Wire Goods Co., Worcester, Massachusetts, and cost, before the war, $1.35 per gross. The iron claw may be made by any blacksmith.

THE ANATQMICAI. RECORD, VOL. 19, NO. \

I I JACOU UKIfillAIlD

KordisplayiiiK cliarls in tlic IcH'tmv room we have uschI a niodifipil form of a dovicc made for displaying buRSy rnlus, and nso<l for charts at tin- I'nivcrsity of Wisconsin. As used l)V us, tliis tlovicp consists of eighteen wood arms, each supported by an iron riMl. and arranged to swing Hke tlie arm of a derriclc (fig. 4). 'Ihe arms are pivoted to steel sectors which turn on the central u|)right axis, hy turning the sectors all the arms maj' be thrown either to right or left. Kach arm supports two charts back to back. .\ny one of these may be brought into view by turning the arms as one turns the leaves of a book held vertically. The device may be attached to the wall, as ours is, or caiiied on a movable base resting on the Hoor. It nuiy be obtained from .h.lm Best. Calva, Illinois, and cost (in lOlo) .SID.OO.

The whole arrangement has proved very satisfactory. The charts are designated liy tlic numbers of the Concilium Bibliograjihicum gunuucnl to the u|)per wood strip (fig. 4). They are arrange<l on the rail in .systematic order, and any one may be locate<l, removed, inspected, and returned to its place without difliculty. To subdivide them, index labels are hung at intervals (fig. 1). The.se are wood strips suspended from the rail l)y Hcxlge hooks. '1 hey project beyond the charts at one end and each liears at that end a square of chart cloth with an aj)])ropriate label and at the opposite end a thin bag of sand to balance it. Charts of any ordinary size may be accommodated. \'er>- large maps may have to be kept rolled in a separate place, but they may be represented in the chart collection by appropriate dummies on which are written references to their location and to which may be attached |)hotograi)hs of them. Our collection consists now of 'Mi) charts vaning in size from 2x2 feet to 5J X 'A feet and made of various materials. These occupy in storage a s|)ace 1 1 feet long, but the same space will probably aoconinHMlate nearly twice as nuiny and .still pemiit anyone to be exaniini-fl in situ. If longer hof)ks were used the charts could be hung alternately high and low from parallel sujiports so that the wood .strips would not be opposite. The .same .space would then accomnKKJate manv more.

STORAGE ANO HANOLIMG OF WALL CHARTS

45

-I() JACOn REIOHARD

As our polloction grows wo shall make a cartl cataloniio of the charts ill which oacli chart will !>(> rciiroscntcd hy small jjhoto^laphs I I'ciiiisyUania). Hy attaciiiiij!; (■(incilium mimluTs to the (lu|)licate photographs aixi anaii^iiig them according to the concilium system, cross references will he made to many of the charts, thus the chart shown at the right in figure 4 would he represent(Hl in the catalogue hy several photographic cards, each of which would hear an identical nuniher to show the location of the charts in the collection. These cards would l)ear also distincli\-e concilium numhers hy which they would he placed in the catalogue under Crustacea, emhryology. and under one or more anatomical designations.

Hosuinon por el autor. Roy Lee Moodie, Departainento cle Anatoniia, I'niversiclad de Illinois.

I,a naturaleza del sistema Haversiano priniitivo.

Los huesos mas antiguos, encontrados en el Silurico y el Dev6nico. careoen de A-erdaderos sistemas Haversianos, que se desarrnlhui prinieraniente con cierta extensi6n en Diiiichthys, del Dev6nieo. En este pez aoorazado alcanzan el niiixinio de desarroUq en Ponexi6n con el proceso dentario de la maxila y preinaxila. Las lagunas ])aiticipan de la. naturaleza de los od(niti)l)last(»: los canalfculos nunca comunican entre sf; la laniinilla filnilar existe: las filjias ]ierfoiantes no se han desarrollado: el canal central es ancho. El polarfscopio es litil para distinpuir la naturaleza de los sistemas Haverisanos priinitivos. No existen pruel)as sobre la evolucion de la estructura liol luieso; se percibe un canibio Ijastante brusco con la introducci6n de la-s fonnas de mamfferos.

Trannlation by Joe*^ F. Nonidcz r.,rii.ll Itiivrr.itv M.ili.-nl CIL-Bt . \. Y.

author's abstract of this taper issued by the bibliographic service, may 10

The nature of the primitive Haversian system

ROY L. MOODIE

Department of Anatomy, Uniocrsily of Illinois, Chicago

ONE PLATE (three FIGURES)

The term Haversian system is necessarily of very general significance and is used in a broad wax to distinguish any concentric arrangement of osseous lamellae around a central canal. It is often difficult to distinguish between a dentinal system, that is, a concentric arrangement of dentine, around a dentinal tubule and a true Haversian system as seen in long bones, since the two often grade into one another. The presence of lacunae does not seem to be essential to an Haversian sj-stem, though they usually are present. In the fishes, both modern and ancient, osteoid tissue, largely lacking lacunae, may arrange itself around a vascular opening and thus have all the appearances of an Haversian system, and give the same orthorhombic light reactions under polarized Ught.

The type of such a system may be taken as those most highly specialized Haversian arrangements seen in the long bones of man, especially in the femur. From this complete system down to a slight lamellar arrangement of substances one may find all gradations in a series of fossil bones representing the history of the vertebrates from the Devonian to the Pleistocene. Such a review has been made, and it will doubtless be of interest to describe and illustrate the most ancient Haversian sj-stem of which we have any knowledge.

There is no apparent indication of a gradual evolution in form of the Ha\'ersian system from the most ancient vertebrates to modern mammals, although there is a gradual de^•elopment in the form of the lacunae and canaliculi. The reptiles do not show a higher typo of Haversian system than do the ani|)liiljians or fishes, as they do in their skeletal organization. Haversian systems in dinosaurs are as primitive as they are in Devonian fishes. They seem to have sprung into existence full formed without undergoing the proce.ss of evolution such as has obtained in the bodily organization of the vertebrates.

The most ancient organization of osseous elements which simulate an Haversian system are to be found in the dental i)rocess of the premaxilla of a Devonian arthrodire, Dinichthj's (figs. A and Hi. allied by some paleontologists with the lung fishes. This arraiigom(Mit is well known to paleontologists and has been descril)cil by Claypole (94). These curious structures arc not present in other portions of the armor of Dinichthys and are to be regarded as specialized dentinal sj'stems, though not found in the true teeth whicli are not connected with the cranial skeleton. 'Ihe Haversian canal resembles a dentinal tubule, the the lacunae are those seen in the cementum of modern fishes, the lamellae are fibrillar and partake of the characteristics of dentine as seen in the teeth ifig. C) of Carboniferous sharks, the interlamellar sjjace is filled with cement and there are true interstitial lamellae, though never any of the type due to the partial ab.sorption of other Haversian systems. I have not seen this tyjje. known as false iliterstitial lamellae in any fossil vertebrate. The orthorhombic light reaction under polarized light is exactly like that of the highly specialized Haversian systems in the fenun- of man. The canaliculi from the lacunae conununicate neither with each other nor with the central canal, nor do they do so in any fossil vertebrate below the mammals. The lacunae are not confined largely to the interlamellar spaces, as they are in mammals, nor is there any apparent i)lan in their arrangement. Often, as in a Permian reptile, one finds three lacunae grouped together, surrounded on all sides by wide areas of osteoid tissue lacking lacunae.

The use of polarized light is essential to an adequate understanding of the structure of fossil bone, since usually under polarizatirm, lamellae, fibrillae, canaliculi, and other minute histological units, invisible under ordinaiy light, stand out with startling distinctness. The importance of this has been commented upon by various authors in their studies on the histology of fossil structures.

Arey ('19) has recently called attention to the presence of Haversian systems in the membrane bones of man. The systems he described and figured, however, cannot be called true Ha\'ersian systems, but resemble those seen in fossil reptiles. It is interesting to note in the temporal bone of an Oligocene mammal an arrangement of substances exactlj^ similar to those described by Arey for man. These intermediate or pseudoHaversian systems often fail to give an orthorhombic light reaction, as thej^ do in the case of the Ohgocene mammal. The difference between the true and the intermediate types of .systems is to be found in the absence of intercommunications of the canaliculi with either the central canal or other lacunae and in the occasional failure to secure the same light reactions. In all other respects they are similar.

The review was undertaken with the idea of gaining a conception of tissue organization in ancient vertebrates so that I might judge as to the disturbing effects of pathological processes upon the structure of the part. The presence of osteoid tissue in ancient vertebrates is a normal condition. Kolliker f'.57) noted that many fish bones are composed entirely of osteoid tissue. One interesting effect in pathological conditions of fossil bone is to stimulate the growth of pseudo-Haversian systems, and to increase the vascularity of the bone. The same fact has been noted by Foote ('16) in the fractm-ed femm- of a frog, where Haversian systems are ordinarily absent.

SUMMARY

Prhnitive Haversian systems of the very ancient vertebrates differ hut slightly from highly de\'eIoped sj'stems of motlern mammals and have been but slightly modified by the passage of time. Each group of vertebrates has its own tj'pe of lacunae, but the organization of the Haversian systems remains the same. The concentric arrangement of lamellae is not an incident of evolution, but a ri'spousc to the iiicchaiiical laws of organization of the |)aii. True Haversian systems are confined to the niannnals.

A more complete account and more adequate illustrations will be found in the A\'illiston Memorial \ olume now in preparation.

BlBLIOC;RAiniV t Arf.y, L. B. 1910 On the presence of Haversian systems in membrane tjones.

Anal. Her., vol. 17, i)p. .59-62. Claypolk, E. \V. 1894 .Structure of the bone of Dinichthys. Proc. .Vnicr.

Micros. Hoc, vol. 1,5, pt. .i, pp. 1,S9-191, figs. FooTE, J. S. 1916 Comparative histologj- of the femur. Smithson. Contrib.

to Knowledge, vol. 3.5, no. 3. K(iLLiKEK, A. 1S.57 On the difTerent types in the microscopic structure of

the skeleton of osseous fishes. Proc. Uoy. Soc. London, 18,57, vol. 9,

pp. 6.5G 068.

PLATE

PLATK 1

KXl'LANATIO.N OK UliUHKS

A A (icld in u «ccti()n uf the prcmaxilla of Dinichthys,a Devonian A it li rod ire, showing the distribution of the oldest known representatives of the Haversian systems. Between adjacent systems are to be seen interstitial lamellae. Two systems, at the lower left-hand corner show the concentric lamellae. X 70

B A single system showing large size of central canal, concentric lamellae, distribution of lacunae and nature of ground substance, which under polarized light is seen to be fibrillar. The bhiMc band at the left lower corner is a postfossilization crack and has no significance in the histology. X 300

C Dentinal tubules of Mazotlus, a carboniferous shark, for comparison with the spei-ializcd syslein- in Diiiiclillix s :iliove. X 70.

Uc'siiHiCii ])()r el autoi-, HulHTt Shcppanl, DopartanuMilo do Aiiatoinia, I'liivorsidad dc Kansas.

Heniuifroditisiiio on ol Honihre.

I'ji el hoinl)ro, el herniafroditisnio con existencia de teslfculos y ovarios nonnahnentc desairollados en el misnio inilividuo aparece raias veces. En el iiidividuo tlescrito en el prosente tial)a.j() los testiVulos aparecian on ol oscroto y los ovarios on la eavidad pelvica. Kl tejido que fonnaba anibos 6rganos era normal en ostruotura en todos sus d(>tallos. So podia distinfiuir pcrt'octanionte una pared niuseular utoiina (juo liniital)a una ravidad ([ue deseniboeaba en la vagina. Las tunicas del conducto deforente y el oviducto, asi como sus cavidades podian taiiil)i<'n distingnirso. Kl ciiello del ntero ocupaba casi exactanionto la jjosicion del utri'culo proslatico do! varon. Kn todos los cases do liennafroditisnu) se ha podido comprobar una distinci6n niarcada entre los tojidos genitales niasculino y femenino, .sin encontrarse nunca una niezitia indotinida de anibos elonientos (es decir, un verdadero ovotesticulo). Kn el raro caso doscrito encontrannos el mismo fonuinono cini una soparacinii .-lun mayor do las (los dasos do tojido, ])uosto (|Uo los tosti'cuios y ovarios ocuj)ai)an su jjosicion normal correspondicnte.

Trnnjilatinn by Joe* F. Nnnides Cnrnrll Onivi-raity Mrcliriil CViIli-KC. N. V.

Hermaphroditism in man

HUBERT SHEPPARD Deparlmcnl of Anatomy, The University of Kansas

SEVEN FIGURES

An opportunity to make a study of the anatomical structures of the genital organs of hermaphroditism in man is seldom found for two reasons: first, such irregularities seldom occur and, second, when they do occur the material is exceedingly difficult to obtain for laboratory purposes. As recently as 1911 it was asserted that "hermaphroditism in the sense that separate testicles and ovaries are found has not Ix'cn demonstrated in man, nor even in other mammals beyond a <luubt."" We thought it worth while, in the light of this and other in^•estigations, to report a study of the anatomical structures of an extreme case of hermaphroditism Avhich came to the dissecting room. The gross study is supplemented bj' microscopical examinations in so far as the condition of the material would permit.

The cadaver featured, objectively, both as a male and as a female subject. Hair was lacking on the face and scant around the genitals, the body was large and obese, with the mammae well developed, large and flabby, which in every way resembled a female rather than a male organ. One would have judged, in so far as the external genitals were concerned, that they were male rather than female genitalia. However, upon a closer examination, one could see that there were certain irregularities. The penis was small with a dilated urethral orifice three-fourths as large as the organ itself (fig. 1). The scrotum appeared to be abnormally large, although the testicles, upon palpation, were found to be normal and synunetrically formed. When the region posterior and beneath the scrotum was palpated, its apparent unusual size was found to be due to a large fold or ridge which extendeil from near the anus to the pubis on either side of the penis.

THE FKMALE EXTERNAL GENITALIA

After (lie skin and scrotum wore completely reflected from the urogenital triangle, the large ridge beneath the scrotum was found to l)e a structure which res(Mnl)Icd female external genitalia. Hiiili till- lai)ia niajoTa and minora were nearly nornial in size, the former extending to the posteiior connnissure, while the latter formed the fremdum. The skin and dartos of the scrotum di\ided into two lamina on reaching the postero-inferior part of the labia majora. The superficial layer continued as the skin and fascia of the f(>moral region, the imier lannna thickened into the labia majora. The nunora was two mendjranous folds within th(> majora and surrounding the penis or enlarged glans clitoris. M this stage of the dissection, if one would disregard the latter enlargetl organ, the cadaver was nearer a female than a male subject.

The PENIS AND VAGINA

The penis in all i('s|)ecls resembled a glans clitoris which had develoi)ed into an organ that closely figured externally as male genitalia with a cone-shaped dilated urethra (fig. 1). At the large or vaginal end of the urethra was an ojiening that extended back into the uterus through the prostatic-cervix of the uterus (fig. 2), which will be descril)ed later. The penis was small, mea.suring a little more (li;in 1' inch in length and \ inch in diameter. The glans had a pr('|)uce fuseil with the erectile tissue of the corpus cavernosum. and was only a rudhnentaiy fold at the end of the organ. The dorsal vein, arteries, and nerves were regular and similarly related as those found in a normal subject. Kxternally, the urethral orifice of the corpus cavernosum urethra (fig. 1), measured ^ inch in diameter. This opening gradually increased in diameter until it was a little more than an inch in diameter at the urogenital dia|)hragm. In so tar as we could note, there was no spongiosum tissue present in the mrtlnal i)art of the organ. Both the urethra and the vagina opened into this enlarged urethra. The true urethra itself was only about f inch in length. This duct passed through the upper part of the prostatic-cervix portion of the uterus, while the vagina was located in the lower two-thirds and extended up\\ard and backward into the uterus proper. Posteriorly, the corpus cavernosum penis divided into two short crura (fig. l) f inch in length.

THE UTERUS

The body of the uterus was separated from the bladder by the vesico-uterine fold of peritoneum in the usual manner. However, the uterus as a whole was somewhat lower down in the pelvic cavity than is ordinarily found in normal cases. This was due possibly to the development of the organs — the fusing of one genital system with the other. The greatest width of the uterus was 1.5 cm., with a total length of 5.5 cm.; the body was 4 cm., and the prostatico-cervix 1.5 cm. A uterine body cavity was perfectly developed, and measured nearly 5 cm. This cavity extended into the uterus with little demarcation between the two organs. The entire cervix was fused with the prostate; in fact, the prostate was a mere enlargement of the cervix of the inferior extremity of the uterus. The uterus held the same relation to the prostate that utriculus prostaticus holds in a normal male subject. Not only the lumen, but the uterine glands and muscular walls could be easily defined (fig. 3). The ductus deferens entered the prostatico-uterine canal of the cervLx by piercing its posterior wall (fig 2). A broad hgament was well developed, resembling in every detail a normal female subject except the course of the ductus deferens, which will be described later, and it was a little thicker and wider, due to the fact the uterus was a little lower in the pelvis as has been previously described.

THE DUCTUS DEFERENS

The ductus (vas) deferens differed in no respect from a normal male subject until it passed through the annulus inguinalis abdominis in connection with a very rudimentary ligamentum teres uteri (fig. 2). It then coursed alongside, and posterolateral to the oviduct, at tii>;l encircliiif; iIk- ovaries. When it readied the level of the uterus, it made a quick S-.shaped turn, and entered the .superior part of the cervix of the prostatico-uterus. The hi.stolopical structures of the duct are veiy well developed. The epithelium surrounding the lumen is slightly disintegrated, a.s is shown by the photograph The circular and longitudinal muscle layers are clearly defined, and in a number of sections the tunica projiria and the inner longitudinal layer are also easily recognized (fig. 4).

THE OV.\RIES .\ND OVIDUCT

The ovaries mea.siu-ed about 1 inch in length and ' (> inch in breadth. They were attached to the mesovarium in the usual way. However, the ovaries were found to be in a poor state of jjreservation for hi'^tological purposes; nevertheless, some of the materials stained sufficently well to demonstrate the ovarian tissue. One of the larger follicles as well as a number of smaller are shown in figure 5. .\ little below the folicles is a light area where the corpus lutoum has disintegrated from the rest of the tissue.

Each oviduct took a nornuil course to the proximal opening into the uterus (fig. 2). The course of each duct was at first almost horizontal, lateral, and posterior from its attachment to the uterus until it reached an inferior lateral portion of the pelvic wall where it came into relation with the uterine extremity of the ovaries. Then it coursed at right angles, and passed almost vertically upward along the mesovarial border of the ovary to the mouth of the infundibulum and the fimbriated extremity of the duct. Microscopically, the sections of the oviduct very clearly difTerentiated the various tunics; the serosa, the longitudinal, and the circular miiscle layers show with marked clearness (fig. ()). The ei)itliclium as well as the inner i)art of the mucosa has somewhat disintegrated from the lumen. It was jKissible in many of the sections to define the epithelial cell structures. .V lumen extended throughout the full extent of the duct.

THE TESTES

The testes did not differ from a normal testicle, except in size. The right testis measured IJ inch in length, f inch in breadth and 1 inch in diameter anteriorposteriorly. The left testis was nearly the same size as the right except for length. It measured a little more than l-^- inch. Each testis lay upon and slightly laterally to the large ridge or fold beneath the scrotum. This arrangement gave the scrotum its extremely large appearance when viewed in its normal state. The funiculus spermaticus had all of its usual structures, even the pampiniform plexus was easily worked out. A small round ligament, before mentioned, was fused with the fimiculus as far as the point where the labia majora began. At this point it was lost and could not be traced any farther along the cord.

This tissue, like the ovaries, was in a poor state of preservation for histological study. However, in many of the sections the convoluted tubules could be easily differentiated (fig. 7). Only the shape of the tubule with its contents could be clearly defined. It was impossible to differentiate between sexual and sustentacular cells except in a few sections. In these better sections, a few interstitial cells could be observed under oil immersion.

DISCUSSION

According to Virchow, this individual subject would be an individuum uterusque generis, since both male and female organs are found almost equally developed. Klebs regards a hermaphroditismus verus as a subject who possesses both male and female genital organs united in it. In the spechnen under consideration, we find two set;; of reproductive glands. They were not united in the sense of ovitestes, but since both the ductus (vas) deferens and the oviduct (Fallopian tube) enter the uterus and, further, the round ligament and the spermatic funiculus have a union as well as a natural position and course, we can say that there was an indirect union. Even according to Kleb's definition this would be an hennaphroditisnms verus.

nuilornatsch says that "herinaphnMlitisni in the sense that separate* testicles and ovaries are formed has not been demon8trate<l Ix-yond doubt." Except for minor variations which we have previously describe<l, we find not only separate testicles and ovaries which are in their noniial position in the body, but also a complete male and female urogenital system with the exception of the urethro-vagina and the prostatico-cervix of the uterus. Here we have noted the fusion of the two systems into a single system where male and female are combined.

Such a finding as this substantiates the old theory of Waldeyer that there is a bi.sexual anlage of the genital ridge. We cannot quit« .SCO how Benda's theory, "that the primary anlage of the entire sexual system of the vertebrates must be regarded as female," would hannonize with facts now recorded. A separate devclo|)ment would seem to be further substantiated by the fact that in every case of hermaphroditism on record there is always a .sharp tlistinction between the two kinds of tissue, and never an undifTerentiated mixture of botli elements, as would be the ca.se if the germinal epithelium could produce either male or female reproductive tissue.

In ever}' male subject the prostatic utriculus, a homologue of the vagina of the female, can be demonstrated. It would appear from what we know of the embry^ological development of the urogenital system that there would be a fusion of the prostate, vagina, and uterus in an hennaphroditismus verus. This would no doubt explain the variation or fusions of the two systems found in the cadaver we are considering.

LITERATURE CITED

Benda, C. 1895 Hermaphroditismus unci Missbildungcn mit Verwischung

(los Gesphlechtscharakters. Ergebn. d. allg. Path., Bd. 2, S. 627. C'oHUY, H. 1905 Removal of a tumor from a hcrmaplirodite. Brit. Med. J.,

vol. 2. GvDERN.^T.scH, J. T. 1911 Hermaphroditismus verus in man. .\ni. Jour.

Anat., vol. 11, pp. 267-78. H.\LB.\N, J. 1903 Die Entstehungder Geschlechtscharaktere. Arch. f. Gvnaek.,

Bd. 70, S. 205. IIiRSCHFELD, M. 1905 Ein seltener Fall von Hermaphroditismus. Monats.schr.

f. Harnkr. und sex. Hyg., Bd. 2, S. 202. Janosik, J. 18S7 Bemerkungen liber die Entwicklung des Genitalsj'stems.

Sitzungsber. Akad. Wiss. Wien, Bd. 99, 3. Abt., S. 260. Ldksh, F. 1900 i'ber einen neuen Fall vom weit entwickeltem Hermaphroditismus spurius masculinus internus. Ztschr. f. Hellk., .\bt. f. Path.,

Bd. 21,8.215. Meixner, K. 1905 Zur Frage des Hermaphroditismus verus. Ztschr. f.

Heilk., Abt. f. prakt. Anat., Bd. 26, S. 318. NBUGEBAtJER, E. 1908 Hermaphroditismus beim Menschcn. Leipzig. PiiiLiPPS, J. 1887 Four cases of spurious hermaphroditism in one family.

Trans. Obst. Soc. London, vol. 28, p. 158. Reizenstein, A. 1905 Uber pseudohermaphroditismus masculinus. Mlinchn.

med. Woch., Bd. 52, S. 1517. Salix, E. 1899 Ein Fall von Hermaphroditismus verus miilatcralis beim

Menschen. Verb. Deutsch. Path. Ges., Bd. 2, S. 241. ScHECKELE, G. 1906 Adenoma tubulare ovarie (testiculare). Hegar's Beitr.

z. Geburtsh. u. Gynack., Bd. 11, S. 263. Si.MON', W. Hermaphroditismus verus. Virchow's Arch. f. path. .\n., Bd. 172,

S. 1. TouRNEiTX, F. 1904 Hermaphroditisme de la glande genitale chex la taupe

femelle adulte et localisation des cellules interstitielles dans le segment

spermatique. (,'omp. rend, de I'assoc. des. anat., Toulouse, p. 49. Unger, E. 1905 Beitriige zur Lehre vom Hermaphroditismus. BerL klin.

Woch.,Bd. 42, S. 499. Waldeyer, W. 1870 Eierstock und Ei. Leipzig.

KXl'LAXATION (»!■ I'LATKS

All the figures !»ro untoiiohiMl pliotoffaplis cif the organs (lesoribcd in this paper. Figures 1 and 2 are niacroseopie photographs of the external and internal genital systems. The remainder of the figures are microscopic iihotographs.

l'I,.\Tl'; 1

EXI'LAX.^TION OF KHiUnKS

1 .\ photogra|>h to show the external genital organs. The short penis has Ix'eii dissected out with its crura and laid upon the jiuhis. The dilated urethra has l)ecn split and pinned open to show the small opening into the vagina as it turns liackward to enlor the uterus.

2 .\ i)hotograpli of the same section from a pelvic view. The vagina and uterus have heen laid open and |iiniied backward to the l>road ligament. The ductus deferens can lie seen on the right side near the upper extremity as it enters the cervix of the uterus. Near the lower extremitj' of the uterus can lie seen both oviducts coming off from the angle of the uterus. The bladder could not be shown in the photograph.

',i A microscopic sectitm to show the lumen and nmscular wall of a portion of the uterus. This was taken from the right side 2 cm. from the cornu.

62

I1I;k\1 MMIIiODITISM IN MAN

111 IIKUT SlIKI'l'ARD

ri.ATK 1

I'LATE 2

F.XI'LANATION OF FIGURES

4 A section of I lie ductus deferens to show the tunics. Considerable disintegnition 1ms taken place in the lumen. However, all the layers of the duet show clearly in the |)hoto);ra|)h.

■) A section of the ovary. .\ large follicle is seen near the top of the photograph. T«o smaller follicles to the right can also be seen. Helow and near the bottom of the photograph is a light area. This was an area of disintegrated corpus luteuni.

6 .\ .section of the oviduct taken about half-way between the ovary and the uterus.

7 A low-]iowcr section of the testicle, to show the convoluted tul)ules and the connective tissue among the tubules.

BOOK REVIEW

Le Emopatie. By Prof. Dott. Adolfo Forrata dclla H. Univorsita di Napoli. Vol. 1. Parte Generale, XVI and 1-482 pp., 21 colored lithographed plates and 8 text-figure.s. Milano: Societa Editrice Libraria, 1918. Price, unbound, L.30.00.

This is one of the most interesting, complete, and usable books on morphological hematology ever published. It is the kind of book which unfortunately cannot be produced in this country, for no American publisher covikl furnish the splendid colored lithographed plates and probably no pulilisher in this country would publish such an extensive text on a subject which necessarily a]ipeals to a small audience. The plates are of exceptionally high quality, and the figures are so arranged that the plates will prove verj^ useful even for those who have difficulty with the Italian text.

The text matter is arranged very systematically, and each chapter is followed by a very extensive bibliography. Citations to literature and discussions of theories are so numerous that the l)ook will be of great value as a reference work to anyon(> working in this field. It should be accessible to every laboratory in which there is an interest in hematology.

The book is far more than a compilation of the work of others, for there is a hardly a phase of the subject to which the author has not contributed by his own researches, the results of which have appeared in numerous previous publications. The work is really an extended resume of Ferrata's own work and that of his students aTid collaborators, Di Ciugliehno anil Negreiros-Rinaldi. Of special value is the fact that it has been possilile to include the results of most recent research in this field. It is thus the only ])lace where oiu^ will find a suiiunarv of nuich of this work.

The chapter on technique, to which the first eighty-four pages are devoted, gives a very complete account of the modern methods of counting, haemoglobin estimation, fixation and staining of blood smears and of the blood-forming organs, with consideral)lc space devoted to the methods of supravital staining of fresli blood and the making of permaninit preparations of blood smears stained in this maimer.

Part II, sixty-three jiages and eleven jilates, deals witli the red blood-cells. The results of supravital staining, the maturation of the red corpuscle, and the pathological m()r])ho]ogy of erythrocytes, including polychromatophilia, basophilic punctation, Howell-JoUy liodies, etc., are promincnl f(>atures of this section. Sixteen pages arc devoted to till- discussion of hiisopliilic piinctation. In ri'nanl to tlio orinin of the l)a.sopliilif uriiiiulcs it is to hv nott'(l that Forrata has fcivcn up his foruKT view that tlioy arc derived from tlie paracliioiiiatin of the miclcus. Willi Pappeiiiieim and Askauazy lie now ajirees that they are of cytoplasmic origin. Mis ^I'lx'i'id conclusion in re^rard to basophilic granulation is that it represents a i)hase of maturatioti of normal erythrocytes in ceitain |)eriods of emhryonic life: it is alvpical for the adult, and morpholonically it corres])on(ls to the l)aso|)hilic suhstancc of the primitive lymphoid erythrohlast. In the normal adult the erytiirocyte passes through a polychromato|)hilic i)hase in order to reach its final acidophilic state, hut in pathologic conditions of the adult 'conclohation'of the basophilic substance during the polychromatophilic stane ^ivcs origin to the basophilic granules. Clinically, basophilic crannies appeariiii; in more or less severe types of anemia indicate a return of the mechanism of maturation of the erythrocyte to an embryonic type. In this connection it must be remembered that Ferrata's previous researches havr- shown that a condition analogous to ba.sophilic punctation is a normal jihase dining the maturation of the erythrocytes of early mammalian embryos.

Several plates arc devoted to illustration of the maturation of the erythrocyte and megalocyte. The numerous exceptionally clear figures include all import. ant stages in the dilTerentiation of red cells from the 'hemocytoblast' (jirimitive progenitor of all the granular leucocytes and erythrocytes) to the fully matured non-nucleated orthochromatic erythrocyte. Ferrata and Negreiros-Kinaldi have been successful in recognizing the very earliest stages in the dilTerentiation of the red-cell series in a cell-type which they have named 'proerythroblast.' This cell retains the nucleoli of the 'hemocytobla.st' ('lymphoidocyte' of Pappenheim), but shows some slight differences in other res[M'cts. The chromatin network is .somewhat coarser and the light spaces l)etween the chromatin strands are more sharply defined. The cytoplasm is more homogeneous and more basophilic and does not show the spongy ditTcreiitialion of the primitive stem-cell. This cell is inserted between the lyin|>hoid hemoblast of Pappcnhcim and th(^ stem-cell. I'or the nicgaloblast a similar stages is iccognized — the promegaloblast.

Part III, j)ages lti7 to 212, plates XI to X\'I, deals with the leucocytes. In the evolution of the neutrophil leucocyte Ferrata distinguishes between the 'proneutrophilic myelobla.st' and the 'neutrophilic jiromyelocyte.' Isxcepting for tin- jiresence of fine azin-o|)hiiic granules in a basophilic cytoplasm, the former resembles the hemocytoblast in structme. In the neutrophilic promyelocyte the fine azm-ophilic granules are gi'aduall>' replaced by neutrophil gramiles lying in an oxyphilic cytoplasm and the nucleus giadually assiunes the coarser structure which is characteristic of the myelocyte. The ])roeosinophilic myelobla.st contains very coarse azurophil granules and tlie eosinophilic promyelocyte eosinophil granules in addition. It should be jjointed out here that most authors do not agree with FerrataV assumption of relationship between the character of the azurophil granulation and the further differentiation of the myeloblast, although it is generally conceded that the azurophil granulation of 'myeloid' cells differs from that of lymphocytes.

Part IV, forty-four pages and one plate, deals with the blood-platelets. Naturally a large portion of this chapter is devoted to the various theories on the origin of blood-platelets and to discussion of the extensive literature on the subject. The discussion is unusually complete for a book of this kind.

Ferrata derives blood-platelets from megakaryoc}i:es, as originallj^ discovered by Wright, and also from 'monocytoid' cells having azurophil granules arranged in small groups as in blood-platelets. These latter cells are found especiall.y in the bone-marrow of the embryo.

Part V, pages 31.3 to 399, dealing with the hematopoietic tissues, is the most interesting and original section of the book. Due consideration of the connective tissue as a diffuse hematopoietic tissue is a decided and much-needed innovation. The 'hemohistioblast' (resting wandering cell of Maximow, clasmatocyte of Ranvier) of the connective tissue and the 'hemocytoblast' comprise a uniform anatomical system, identical in embryological origin and differential potentialities; they form the hematopoietic parenchyme in the widest sense of the word.

The specific hematopoietic tissues of the bone-marrow, lymph nodes, and spleen are discussed first, this portion of the chapter being altogether too brief in proportion to the space devoted to the diffuse hematopoietic tissue. The hemocytoblast, similar in structure to Pappenheim's lymphoidocyte, is the progenitor of all the bone-marrow cells, and a similar cell in 'lymphoblastic function' gives rise to the lymphocytes of lymph nodes and spleen. The monophyletic theory is, therefore, accepted by Ferrata, but not the extreme unitarianism of Weidenreich and Maximow, for Ferrata believes in functional dualism to the extent that fully differentiated lymphocytes are incapable of differentiating into granulocytes or erythrocytes. In the spleen pulp the myeloid function of the hemocytoblast is retained to a certain extent, which explains the limited production of myeloid cells in the pulp of the normal adult.

The section devoted to the 'hemohistioblastic,' or 'diffuse hematopoietic' (connective) tissue is of special interest. The colloidal dyes (Trypanblau, Pyrrholblau, Lithiumcarmine) are made use of for the purpose of determining the relationships of the cells of this tissue. The jirimitive cell of this tissue is the resting wandering cell (^Maximow) derived from an amoeboitl emliryonic mesenchyme cell and giving rise to all the other tyj^es of cells of the connective tissue. These are divided into chromophobe (without dye granules) and chromophile (with dye granules) types. The latter include the resting wandering cells, fat cells, endothelial cells, and filiroblasts. The fibroblasts, on account of the character of their dye granules, are regarded as highly differentiated cells, while fat cells and endothelial cells are considered to be functional adaptations of the hemohistioblast (resting wandering cell). The chromophobe cells include jilasma cells, mast cells, eosinophils, and lyiiipliocytos, and tlipy arc also clitTcirntiated from the henioliistiohlast wliicli lost's its capacity for storing colloidal dyes during tluMr diffcri-ntiation.

In tlic opinion of the reviewer, much remains to be proved before this classification of Ferrata's can l>e adopted. The whole structure is built up on the assumption that the reaction of the cells to the colloidal dyes is specific. Recent work of the reviewer' seems to indicate that the reaction is not specific, but that the behavior of cells toward colloidal dyes depends entirely on functional and environmental conditions, in other words, the presence or absence of dye granules is not sufficient to enable us to distinguish between hemohistioblasts and lymphocytes, or between monocytes of the tissues and large mononuclears of the blood.

Serious objection may also be offered to the view that the 'hemohistioblasf is always a more i)runitivc cell than the lymphocyte, and that the lymphocyte i of normal circulating blood) is a difTercntiated mature cell incapable of being transformed to a granulocyte and incapable of reverting to a hemohistioblastic resting wandering cell. In this connection it is sufficient to refer to the recent work of Weill, '^ who has shown conclusively that lymphoc>'tes, even those having the structure of small lymphocytes, are capable of differentiation into granuloc>-tes. It is true that these obser\-ations were made on human and manmialian thymus, spleen, and nmcosa of digestive tract, but until real or even functional differences between lymphocytes of the blood and those of the tissues have been demonstrated, they must be regarded as valid objections to Ferrata's theory.

Numerous objections to FVrrata's view of the relationship between resting wandering cells and lymphocytes could be offered, but this is not the place for the lengthy discussion which would be necessary. Many of these topics are considered again in the following section, where the literature is given due considcTation.

Fart \l, pages 400 to Kit), deals with the morphogenesis of the cells of the blood. The first part of the section is concerned with the genesis of the blood-cells of th(> embryo. \'arious theories are considered, but emphasis is i)laced on the results of the author's own researches. Although space will not permit discussion of this chapter, the reviewer wishes to call special attention to Ferrata's own conclusions in regard to the relationship of the blood-cells. The first basophilic lymphoid blood-cells derived from the mesenchyme of the early embryo are not lymphocytes, but a special type of 'primitive transitory hemocj'to ' Dow.vKY, Hal 1917 Reactions of blood- and tissue-cells to acid colloidal dyes undfT experimental condition.s. Anat. liec, vol. 12.

191K Further studies on the reactions of blood- and tissue-cells to acid colloidal dyes. .Vnat. lire, vol. 15.

' Weill. P. 1919 I'oIkt die Mildung von granulierten Leukozytcn im KarzinomKcwcbe. Virchows .Arcliiv. H<l. TM. Heft '2.

1919 I'rbcr die lourorvtiiren Elemcnte der Darmschleimhnut der Siiugctiere. Arch. f. nukr. .\nat.. M.'m. U-'t 1.

1919 I'etwr dii-s reKclinJuwigc Vorkominen von Myelocytcii in der Milz dcs envachsrnen Mcn.-tchen. Arch. f. niikr. Annt., Bd. 'Xi. Heft 1.

))lasts' wliifh are all under ei ythro])la.stie function. P^or a time they all differentiate into promegaloblasts, megaloblasts, and megalocytes, the primitive red-cell generation of the early embryo. In the second phase, that of the hematopoietic activity of the liver, the mesenchyme cell (hemohistioblast) differentiates into a new type of primitive cell, the definitive hemocytoblast in myeloid function which in turn differentiates into erythrocytes, granulocytes, and megakaryocytes. This second hemocytoblast corresponds morphologically to the 'myeloblast' or stem-cell of the adult. In the third (fetal) phase, during which the lymphoid tissue appears, the mcsenchymatous hemohistioblast gives rise to a hemocytoblast of lymphoid function which produces lymphocytes, although it is morphologically identical with the myeloid hemocytoblast. The different end-jiroducts are due to temporary functional differences only.

According to this scheme all the lilood-cells are traced back to the fixed tissue cell, the hemohistioblast, the cell which stores colloidal dyes in the connective tissue of the adult. In the early embryo this cell differentiates into the primitive transitory hemocyi:oblast, and this in turn to the primitive red cells of the embrj'o (megalocj-tes), while in the adult, lymphoid and myeloid hemocytoblasts (functional differences only!) and monocytes are the products of its differentiation. The monocytes may also be derived from both the lymphoid and myeloid hemocytoblasts.

This scheme seems to harmonize the actual observed facts with both the unitarian and dualistic theories better than any other scheme which has been presented. A good part of this section of the book is devoted to discussion of the unitarian and dualistic theories and the last fifteen pages to the doctrine of Fcrrata.

In part ^TI, pages 469 to 482, the author discusses the morphological significance of the cells of the blood and the hematological formula. The discussion of the .significance of azurophil granulation is of special interest. Ferrata takes the stand that the presence of azurophil granulation in a myeloblastic lymphoid cell indicates beginning differentiation toward a granulocyte, which may be either an eosinophil or neutrophil granulocyte, according to the character of the azui'e granules. The azure granules are not transformed into the specific granules of the leucocytes, but are replaced by the latter. The presence of azurophil granulation in myeloid cells, therefore, indicates maturity and beginning differentiation and is of greater significance than the mere temporar\' secretory activity assumed by Pappenheim.

The reviewer has picked out only a few of the interesting and significant parts of the liook for special mention. In closing he wishes to state that the book constitutes one of the most important recent additions to hematological literature. The statement on the title page that it is a "Trattato per mcdici e studenti" is somewhat misleading, for it is more than an ordinarj- text-book.

Hal Downey, University of Minnesota.

THE ANATOMICAL RECORD, VOL. 19, NO. 2

Resumen por el autor, J. A. Pirer? De Lima, Instituto de Anatomla

de la Facultad de Mcdirina,

Oporto, Portugal.

Estudio de un feto clclope de cabra, macho, procedente de Nova Goa (India Portuguesa).

El feto estudiado tenia un solo globo ocular con dos c6rneas y tre.s pdrjiados, uno superior y dos inferiores. Ausencia complota de aparato nasal; labio superior terminado en punta roma y niandfbula prognata y recurvada hacia arriba. Cerebro chato y cninco en gran parte lleno de un liquido seroso que se veia por transparencia a trav(!s del frontal. .Vusencia de nervios olfativos y oculo-motores externos: un solo nervio 6ptico. Un solo frontal, dos parietales, dos inter-parietales, un solo maxilar y, por encima de 6\ un hueso al cual llama el autor interzigomdtico. Una sola 6rbita. Agenesia del etmoides, de los cornetes, intermaxilares, palatinos, lacrimales, nasales y v6mer. Tres de los incisivos ya en franca erupci6n. Se trata de un ciclocefaliano cicloc6falo, segun la clasificaci6n de G. Saint Hilaire, y de un Cyclops arrhynchus segun la nomendatura de Gurlt. 8e compara este caso con otros descritos por el mismo autor y por diversos teratologistas.

TransUtion by Joa^ F. Nonida Cornell Vni^-enity Medical Collc«c, N. Y.

Anatomy Of A Fetus Of A Cyclopean Goat

J. A. PIRES DE LIMA Institute of Anatomy of the Faculty of Medicine of Oporto (Portugal)

SIX FIGURES

Prof. Froilano de Melo, of the School of Aledicine and Surgery of Nova Goa (Portuguese India), sent me for study a monstrous fetus of a goat. It was received by the Museum on the 4th of January, 1919, immersed in alcohol.

The skin was covered with white hair, except at the upper part of the head, where there was an extensive areaof black hair, stretching forward and encircling the eyelids, as well as the lips; besides, some small disseminated black spots. At the top of the head there were noticed three vortices of hair arranged in the form of a triangle.

The fetus was of the male sex, and kept the umbilical stump of the cord. Only the head was abnormal. On external inspection (fig. 1), the presence of a single median eye was noted, under which there was found a deep depression corresponding to the nasal apparatus, which was completely missing. The tongue protruded from the mouth and inclined to the left. Above it, in the median line, one noted the upper lip ending in a blunt point, and underneath, a voluminous mandible, prognatic and turned up.

The ocular globe of this monster was possessed of two corneae separated by a narrow light median zone. It was surrounded with three eyelids, an upper one with a free and convex border and two lower eyelids convex free at the borders and united in the median line. Only one conjunctiva connected the ocular globe to the deep faces of the three eyelids, in its reflexion forming conjunctival culs-de-sac, superior, inferior, and lateral, right and left. The palpebral cleft was 2 cm. wide and 1 cm. high.

Close to the corners of the eye there were found long lashes, and on the right one there were observed long hairs inserted above and below the eyelids. In the depression existing between the eye and the mouth, on the wrinkled skin, two vortices of hair on the median line were to be seen and two tufts of hair (tentacles) crowned the anterior part of the lips.

The head was flattened transversely. The following measurements were obtained:

im.

Maximum anteroposterior diameter 5

Maximum t ransverse diameter 4

Distance from the nape to the symphysis of the mentum 7.3

Length of e.ich car 5

The cephalic index 80.'

The remainder of the fetus presented the following measurements:

cm.

Circumference of the neck 9

Length from the nape to the basis of the tail 25

Length of the tail 4

Perimeter behind the implantation of the thoracic members 22

This specimen did not possess behind the mandible the pyrifonn appendices called in Portuguese brincos (ear-rings), commonly seen in goats, representing an auditory appendage of the second branchial cleft.' After having studied the external morphology, the osseous skeleton was exposed. The upper surface of the skull (fig. 2) presents the form of a lozenge, to the angles of which the frontal, parietal, and occipital bones, respectively, correspond. '1 he cranial vault i)rese;itcd a .smooth surface, comprising the following bones: frontal {F} single; parietal (P, P) separated by the sutura interparietalis; squama occipitalis (iu> notices ii) it from hofore to behiiul: the single optic nerve, on tlie median line, penctratinfj an optic foramen (//) as wide as tlic occipital one; a nerve (///, I\'}, which must represent the coimnon ocnlomotorius antl the pathetic nerve, distinct before the dura mater hail been withdrawn; the n. trigeminus {V): the facial and auditoiy nerves {VII, VII I), and last all the following ones (/.V- . . .) '" 1^ single fascicle. The hypoglossal nerve, which ai)peared well detached before the removal of the dura mater was not to be seen afterward.

'I'he ocular globe was large, oval with a single optic nerve and a single cavity. Only the cornea .showed signs of duplicity in the forcjiart. On o|)ening the ocular globe, this was found so macerated as to make it unsuitable for stud}'.

Contrary lo what is generally the case, in this specimen,^ wiiich I sui)pose to be a deail-liorn fetus, three of the incisor teeth had already appeared ; t lie piiicer, the first right mitoyenne, single, as well as the fir.st left mitoyenne, this being considerably developed. The left pincer and the secontl mitoyennes were beginning to appear.

The dissection of the neck tind the autopsy of the thorax and of the abdomen did not reveal any abnormal disposition worth registering.

According to the clas.sification of I. (ieoffroy Saint-Hilaire,' this monster belongs to the class of the Cyclocei)haleans; that is to say, to the class of monsters having the nasal ai)])aratus more or less completely atrophied, the ajiparatus of vision imperfectly formed, sometimes quite rudimentary, directed to the median line and almost always united.

It still bch)ngs to the 'C'yclocephalus' genus, to the cycloccphaleans having a single orbital cavity, two contiguous eyes or a double eye occupj'ing the median line, the nasal apparatus atrophied ;uid no j)roboscis.

• ('himvcuii iind .XrloiiiK (Inc. cit.) .iny that the pincers apiu-iir from tlic third til the fifth ilay, iis well a.s llic fir.Kt initoycniie. Tlic second niitoj-enncs would make (heir appearance about llie tenth day after birth.

' I. (leoffrey Saint-liihiiru Ilistoire GC-nfraic et partieiiliero des anomalies d'orKanisalion eliez I'llonimc et les animaux, I'uri.s, ls:jG.

According to Gurlt's classification, my specimen should be classified as a 'Cyclops anynchus.'

Besides this cyclops. I have already had an opportunity to study three in the human species.' A fetus 9 Cyclocephalean rhynocephalus, having an ocular globe adherent to the eyelids (1 sujjerior and 2 inferior) without conjunctival culs-de-sac, either superior or inferior. The ocular globe, shapeless, seemed to be formed by two eyes which had fused into one. There were two frontal bones with sutura metopica.

The second case was a Cyclocephalean cyclocephalus cf. A superior eyelid and an inferior one, formed, by two soldered palpebrae. Ocular globe atropliied and deformed. Frontal single. Genu varum.

The third case was a skull of a fetus with a median orbit, a single optic foramen, frontal single, very salient frontal and parietal protuberances.

' 'rurudi-Slciri:! ilclhi Toratolofjia. T. (1. Bologna, 1891.

' J. A. Pires de Lima. Sobrc Ires inoiistros ciclocefalianos (Anais Scientfficos da Faculdade de Medicina do Porto, vol. 4, no. 2).

III an Otocophak'un pi^ v which 1 stiulietl,* the frontal and parietal hones were rcclucctl to a sin{?lc piece, forming the cranial vault.

An Oimilymus cat cf. wliicii 1 doscril)e(l,' had a concentric ()rl)it with a double eye, apparently rather similar to the single ocular globe of the present observation. However, it has two optic nerves, besides two corneae.

According to Cieoffroy Saint-llilaire,'" the C'yclocephalean rhinocephali, as in the present observation, mostly have too small an encephalon to fill the cranial cavity; there exists then almost always a larger or smaller (juantity of fluid,

In ISOO, (lintrac" studied a human fetus 9 born at term, Cyclocephalean rhinocephalus. Its skull was much reduced. The median eye had two corneae and the hind jiart of the skull a sac full with a lemon-yellow fluid. The brain was atrophied. The olfactory nerve was missing; perhaps also the patheticus, the oj)tic nerves were in close proximity.

Tarufli'- also mentions the presence of a remarkable quantity of li(iuid within the skull of the cyclojjs. The same author records that in these monsters the olfactory nerves are always missing and that there is a single optic nerve with the chiasma absent.

Tarufli, moreover, states that the cyclopia is much more common in the female sex.

I'hisalix" has studied four monsters cyclocephalean or otocephalean, one in dog, two in sheej), and a human fetus; in the last, attention wa.s nnmediately drawn by the absence of cerebral hemispheres normally constituted; the skull once openetl, there came out a serous, light, opaline liquid, lodged in a sac, at the

' J. A. PircH (Ic Lima, fitiido diiii iii(>[istrc otoct-phalicn (Bulletin de la Soci(St6 l*iirtiiKui«<> <k'9 Sciences Natiirelles, T. .S).

• J. A. Pircs dc Lima, Study of an opodymua kitten (Journal of Anatomy, vol. .V.').

'• I. G. Saint-llilaire, loc. cit.

" (linlrac, ('onsiderations sur la cycl<)c<phalie (Actos de I'.Vcaddmie Imp6riale de Sciences, Belles lettres et Arts, Bordeaux, 1800).

"Taniffi, loc. cit., T. 8, Bologna, 1804.

" Phisalix, Monstres Cyclopes (Journal de rAnatomic ct de la Physiologie, Paris, 18.89).

bottom of which was the ciicephalon. Instead of brain, one noted a whitish and flattened mass. In this specimen nerves of the I and IV pair were wanting.

Rabaud," in an extensive memoir, has discussed fifty abnormal chicken embryos, concluding, in accordance with Dareste's opinion, that the cyclocephalia is due to a developmental disturbance of the encephalon.

Watkyn-Thomas'^ has described a human fetus 9 with incipient cyclopia; it had two eyes drawn nearer and a single nasal orifice, without olfactory ner\-es. In the Museum of the Anatomical Institute I have stored a similar monster, which I will presently study.

Lately in America several works dealing with cyclopia have been published. I shall mention the following:

Stockard"' has made some interesting experiments on teratogeny of fishes, artificially obtaining cyclopean monsters by means of solutions of JMgCb or Mg(N03)2 and he believes it may be concluded that such monstrosities in man and other mannnals are due to an excess of magnesivun salts in the maternal blood or in the amniotic fluid.

Warren Lewis has likewise published experimental observations on teratogen}^ of fish embryos.

Whitehead' 8 has studied a human fetus cj^clocephalus.

Chidester has described a cyclopean rat, an atocephalean pig, as well as the brain of a human fetus cyclocephalean. The same author^" has studied some double monstrosities in fishes, one of them complicated with cyclopia.

Finally, Werber^' has also occupied himself with experimental teratology and specially with teratophthalmia.

"Riibaud — Recherches embryologiques sur les cyclocephaliens (idem, 1901-02).

'* \Vatk}-n, Thomas, A cyclopean foetus with hernia encephali (Journal of Anatomy and Physiology, vol. M).

'* Charles Stockard, The artificial production of one-eyed monsters and other defects, which occur in nature, by use of chemicals (Anat. Rec, vol. 3).

" Warren Lewis, The experimental production of cyclopia in the fish embryo (Fundulus heteroclitus) (idem). "Whitehead. A case of cyclopia (idem).

" Cliidcstor. Cyclopia in mammals (Tlie Anatomical Record, vol. S).

"' Idem. Twins in fish, one with cyclopean deformity (idem).

-' Werber, Experimental studies aiming at the control of defective and monstrous development (idem, vol. 9).

ResunicM p<>r el autnr, O. 1'. Kainpnioior, EsdU'hi (if Mc'diciiKi Marquette.

Los canihios en el plan sistemico vciutso durante el ilesarrollo y

la relaci6n do los oorazones linfatioos de los

anuros con estos canibios.

I)es|)uesde iiulicar l>rovoiii('iit(' los trabajos de Ooette y Hochstetter sohre el desarroUo del sistenia venoso on los anfihios, el autor dcs(Til)e la forniaci6n do las venas sistrniicas ei\ Bufo. Mc'diantees(iueniasdciuuestra(|ue exist e una correspoiidencia mas estreeha en la disposicl6n priuiaiia y <ainbios de estas venas en los vertebrados inferiores y superiores, (jue lo que se ha supuesto. Por ejeniplo, el componente subcardinal del sistema venoso existe ya en los estados j6\ones de einbriones de anuros. El autor denuiestra tan)l)ien conio se i)roducen las diferencias, aparentem(Mit(> irrecoiu'ilial)l(>s, entre la situaciAn do las oonuuiioaciones linfatico-venosas del cnibn6n y las de los individuos coniplctaniente desarroUados. En el anfibio anuro adulto, por ejemplo, los corazones linfatioos antoriores desembocan en la corresponilionte vena vertebral anterior, que a su vez es trigutaria mas antoriormonte do la vena yugular interna. En en embriAn, por otra parte, el coraz6n linfatico anterior, que se origina a expensas de la vena de la linoa lateral que pasa a este nivel, oomunioa con el seno venoso i)r(jnefr6tico, cjuc reprcsenta la confluencia de las venas pre- y postcardinales alredodor del i>ronefros. De un niodo semejante, los corazones linfatieos posteriores se originan a lo largo do las vonas do la linoa lateral, poro on el adulto vionon a punorso en rolaoiAn eon las vonas is(|uiaticas ])or iutoriModio lie las vonas vertebrales posteriores. Los esquemas demuestran adonuis con (pio faoilidad las variaoionos tan connmes .se producen i)or la ex|)an.si6n. roducci^n o persistoncia dc diferentcs .■^oginentos de las venas intersegniontarias originariamente sinietricas. cuyas variaciones dan lugar a diferentes relacioncs con los troncos veno.sos principales.

Tranalntion by J<m^ V. Nonicirs Comrll I'nivpraity Medical Collrsr, N. V.

aitthor's ad&tbact of this paper issued by the bibliographic service, may 24

The Changes Of The Systemic Venous Plan During Development And The Relation Of The Lymph Hearts To Them In Anura

OTTO F. KAMPMEIER

Department of Anatomy, Marquette School of Medicine, Milwaukee, Wisconsin

NINE FIGURES

Our knowledge of the primary venous plan of anuran embryos and its subsequent transformation is based almost wholly on the observations of Goette and Hochstetter.^ In his classic work, " Entwicklungsgeschichte der Unke" (1875), Goette gives a clear account of the development of the systemic veins of Bombinator. In some respects, however, the venous system of Bombinator differs from that of the more typical Anura, the most marked difference being the persistence normally of the anterior portions of the postcardinal veins, for which the term 'venae azygae' has generally been employed in the literature. In the retention of the postcardinals alongside of a postcava, Bombinator closely resembles the urodeles, the salamander, for example. Hochstetter ("Beitrage zur vergleichenden Anatomic und Entwicklungs ' This paper represents a section of a larger paper on the origin and development of the lymphatic system in Anura which was originally intended for publication in a monograph, as indicated in The Anatomical Record, vol. 16, August, 1919. Adequate funds were not available to publish that work as such, and it was decided to split it into several parts and have them appear as separate papers in two or three of the anatomical and morphological journals. Though, in a sense, the unity of the work is thereby destroyed, the disadvantage is offset by the advantage of its wider circulation.

' For a comprehensive list of the literature on various aspects of the venous system of the .Vnura, I refer to the following works: "Beitrage zur vergleichenden Anatomie und Entwicklungsgeschichte des Vcnensystems der Amphibien und Fische," by Hochstetter in Morphol. Jahrbuch, 1S8S; ".\natomic des Frosches," by Ecker and Wiederscheim, 1896 (Oaupp's revision); 'Vergleiehende Anatomie der Wirbeltiere," (7th ed., 1909), by Wiederscheim.

posrhichto dos Venensysteins der Ain])hil)icn und Fische," Morphol. Jahrburh, 1888) has indicated wherein the differentiation of the cardinal system of veins in the frog varies from that in Bonihinator.

Since the time of Goette's and Hochstetter's work, no systematic study, so far as the writer is aware, has dealt with the above problem in the light of the more recent work on other vertebrates, nor have the changing relations of the larger venous branches to the main trunks during development been considered. The following diagrams and brief description show that a closer correspondence exists between the lower and the higher vertebrates in the genetic history of their venous systems than has been supposed.

A matter of greater importance in the writer's opinion, is the fact that no account has demonstrated how the seemingly irreconcilable differences between the situations of the lymphaticovenous communications of the embryo and those of fully formed individuals are brought about. This process has interested the writer greatly not only in his investigation of the lymphatic system of Anura, but also in his effort to furnish a systematic presentation of the comparative morphology of the systemic lymphatics in vertebrates.^ It is a well-established fact that in the adult anuran unii)hibian the anterior lymi)h hearts discharge into the corresponding anterior vertebral vein, which further cephalad is a tributary' of the internal jugular vein. In the embn,'o, on the other hand, the anterior lymph heart, arising on the transient vein of the lateral line, comnumicates with the pronephric venous sinus, which represents the confluence of the preand postcardinal veins around the pronephros and is continued to the sinus \enosus as the duct of Cuvier. Similarly, the posterior Ijanph hearts arise along the lateral-line veins, but in the mature form come in relation to the ischiadic veins through the posterior vertebral veins. In comparing the anterior hnnphatic taps of an adult anuran with those of a manunal, for example, one would hardly conclude that they are identical, and yet, when their embryonic history is revealed, both can be definitely re ferred to the cardino-Cuvierian district, where such communications occur with remarkable constancy either temporarily or permanently throughout the entire series of vertebrates, from the lowest to the highest. In the same way, the posterior lymph hearts can be compared with certain members of the lateral series of mtersegmental lymph hearts in the tailed amphibians on the one hand and with the iliac and coccygeal lymph hearts of reptiles and birds on the other. Studies like these have impressed the writer, as other investigators have doubtlessly been impressed before, that biological homology becomes an exact science only when it rests squarely on the comparative anatomy of the embryo.

This work is in process of preparation.

The following account is based almost wholly on a study of the toad, Bufo. The younger embryonic stages belong to the European species, Bufo vulgaris, the later stages, including young individuals shortly after metamorphosis, to the American form, Bufo lentiginosus. Besides these, a few mature frogs, Rana pipiens, were examined. The inserted diagrams have been constructed from a series of graphic reconstructions of the venous system of progressively consecutive stages.

Toad embryos (Bufo ^allgaris), 4 to 5 mm. long, possess the primary venous ground plan of vertebrate animals, namely, the simple symmetrical cardinal system, as illustrated in figure 1. There are a number of peculiarities, however, which should be emphasized, since they are directly or indirectly involved in the development of the lymph hearts and associated veins. At the junction of the precardinal (internal jugular) and postcardinal veins, a proportionately large venous sinus (si. proneph.) has been formed, a broad plexus of channels which encompass the tubules of the pronephros. Of greater interest are the mtersegmental veins {1-8 v. seg.),* a metameric series of vessels which pass vent rally between the myotomes and epidermis to empty into the cardinal vein tnink, the first three into the pronephric sinus and the remainder into the postcardinal. But not all of them are present at the same time, for in their appearance, as with other events of cmbrj-ogenesis, the processes of developmeni proceed in an anterioposterior direction. WTien the foremost intersegmental veins have been established, the more caudal ones may still be lacking, and when these have been laid down and have attained importance, the anterior ones have already begim to disappear or become modified (figs. 1 to 4) ; only in the lower Amphiljia do the intersegmental veins persist as such during the entire life of the animal. Occasionally, too, there are slight irregularities in their arrangement, such as the convergence of two consecutive vessels to join the postcardinal at the same point. But these are insignificant fluctuations, and in the diagrams they have been disregarded.

It should be stated that since there is a possibility of the reduction of intersegmental veins at the extreme anterior end of the series during phylogenesis, just as the spinal ganglion I is an evanescent structure, the designation of the intersegmental veins by specific numerals must be taken with reserve when homologizing Bufo with other Amphibia.

The original condition of the postcardinal, lying against the medial side of the primary excretory tube of Wolffian duct, is soon altered by the formation of a second channel on its lateral side as the result of longitudinal anastomoses between the intersegmental veins near their points of confluence with the postcardinal (figs. 2 and 3). At the same time, these two parallel channels, which for the time being maj'^ be considered as the medial and lateral divisions of the postcardinal {med. and lal. v. card, post.), become united by numerous transverse anastomoses which pass around, over, and under the Wolffian duct so that this structure becomes enclosed by a cylindrical venous plexus. Hochstetter states that the latter condition only obtains in the salamander, but the writer's material shows without doubt that such takes place normally in the larval Anura as well. At the posterior end of the trimk, the postcardinal vein fuses with its fellow of the opposite side and is prolonged into the tail as the caudal vein (v. cnitd.). Here, too, a paired vessel, the common rudiment of the proximal part of the abdominal and external iliac (v. iliac.) veins, branches off and passes laterally around the hind-gut to its under side where it extends forward a short distance.

Figure 1

Figs. 1 to 4, diagrams of the systemic veins in 4-, 6-, 7-, and 10-mm. embryos of Bufo vulgaris, respectively; figs. 5 to 7, in 15- and 18-mm. tadpoles of Bufo lentiginosus, and a stage immediately before metamorphosis; fig. 8, in the young toad (B. lentiginosus) immediately after metamorphosis; fig. 9, in a mature frog, Rana pipiens. All figures (except 9), XSSj. As all the structures are shown in the diagrams as lying in the same plane, there is, of course, a certain degree of distortion; thus, the intersegmental veins appear to be lateral tributaries of the cardinal- veins when in reality they are dorsal ones.- The spinal ganglia, I, II, III, etc., were introduced to indicate levels.

COT tym. ant., cor lymphaticum anterior cor lym. post., cor lymphaticum posterior d. Cuv.. ductus Cuvieri SI. proneph., sinus pronephros sin. ven., sinus venosus V. abdom., vena abdominalis V. brack., vena brachialis V. card, ant., vena cardinalis anterior V. card, post., vena cardinalis posterior {med. and lal.), medial and lateral divisions V. caud., vena caudalis V. cot), ant., vena cava anterior V. cav. post., vena cava posterior V. cut. fem. post., vena cutanea femoris

posterior V. cut. mag., vena cutanea magna V. dors, lumb., vena dorso-lumbalis

fern., vena femoraUs hep. rev., vena hepatica revehens iliac, vena iliaca

iliac, trans., vena iliaca transversa ischiad., vena ischiadica Jacobs., vena Jacobsonfi ■ jug. exl., vena jugularis externa jug. int., vena jugularis interna Ja/., vena lateralis ,^,

om. mes., vena omphalo-mesenterica (vitelline veins)

ren. adv., vena renalis advehens seg. 1, S, 3, etc., venae intersegmentalis

subcard., vena subcardinalis stibclav., vena subclavia vert, ant., vena vertebralis anterior vert, post., vena vertebralis posterior interanastomosis between the subcardinals

Soon after, in 7-iiiin. embryos, the two divisions of the postcardinal begin to diverge from one another in the middle of their course (fig. 3) due to the crystallization, as it were, of the anlagen of the mesonephric tubules, which crowd between them. Consequently, the medial postcardinal components, which may now be termed the subcardinal Kins, since Ihey are unquestionably the homologucs of Kssels bearing the same name in higher vertebrates, approach each other in the center, and the first hint of their eventual fusion to create the posterior half of the future postcava is offered by a simple interanastomosis (fig. .3,*) at the level of the eighth spinal ganglia. Coincident with the merging of the subcardinals (figs. 4 and 5) occurs the fomiation of the proximal half of the postcava; this is already potentially present in the right vitelline vein, which, at first equal in size to the left (fig. 1, V. cm. mes), grows larger (figs. 2 to 5, v. hep. rev.), and, traversing the liver, establishes continuity with an apparently independent segment which is developed between the liver and the right postcardinal (fig. 2). This segment soon becomes confluent with the latter vein at the level of the fourth spinal ganglia (fig. 3), and the postcaval trunk is complete. Obviously, much of the blood in its return from the caudal regions of the body to the heart is now deflected through the postcava, and in time, as an increasingly greater volume of blood follows this more direct route, the portion of the original postcardinal veins between the postcava and the pronephric sinus of both sides gradually falls into disuse and atrophies, the right disappearing earlier than the left (figs. 5 to 7) .

Changes as far-reaching as the al)ove take place caudally. The most distal segment of the subcardinal (medial postcardinal division) does not fuse with its fellow, but undergoes reduction

Figure 6

and finally breaks away (figs. 4 to 6), thus severing the connection between caudal vein and iiostcava. Hence, all of the blood from the hinder regions is compelled to flow through the expand

ing lateral postcardinal divisions which may now be called the venae renales advehentes (Jacobsen's veins, figs. 7 and 8), thence through the sinusoids of the mesonephroi to enter the postcava

Figure 7

through the revehent branches. In the meantime, the paired abdominal vein has morped anteriorly into a single vessel which joins the hepatic portal vein (not shown in the diagrams) and so produces a second pathway of return for the blood-stream from the posterior region. CJradually, the two unfused and divergent rami of the abdominal vein remain united with the external iliac veins which extend out into the developing limb buds as the rudiments of the femoral veins. Extensions of the postcardinals backward along the caudal vein (fig. 6) represent the anlagen of the ischiadic veins (v. ischiad.) which enlarge as the hind extremities develop and the caudal vein degenerates. The transverse iliac veins (v. iliac trans.), obliquely connecting the external iliac and ischiadic veins, are a later acquisition (fig. 8).

As the mesonephroi are progressively differentiated and as they assume the function of urea excretion, the pronephroi suffer regression in a corresponding degree (figs. 7 and 8). During the growth of the tadpole a marked shifting of relations occurs, for, as the diagrams indicate, the pronephroi in earlier stages lie slightly back of the niveau of the sinus venosus and are directly placed in the path of the postcardinals, but later, owing to the atrophy of the proximal segment of these channels, they come to lie anteriorly, at the junction of the external and internal jugulars.' In fact, the pronephric sinus at the time of metamorphosis forms the terminus of the internal jugular where it appears as a swelling (fig. 8), but the difference in diameter is gradually equalized by further reduction of the sinus. Changes like these are instrumental in bringing about the striking dissimilarities between the venous relations of the lymph hearts in embrj'onic and in adult stages. Further changes in this region that produce the definitive relations of the anterior Ijinph hearts to the veins are indicated in the following paragraph.

.Associated with the alterations of the large venous trunks, radical modifications take place in the series of intersegmental veins. Another paper will show how the first three of these are intimately concerned in the development of certain lymph • In using the term 'external jugular vein,' I am following Gruby and Ecker; Goette and many other authors refer to this vein as the 'inferior jugular.'

atic channels, the third contributing largely to the formation of the a,nterior lymph heart (fig. 2, cor lym. ant.). Only the mouth of the anterior vertebral vein {v. vert, ant.) of later stages, in other words, the efferent channel of the anterior lymph heart, can be considered as a direct transformation or derivative of the proximal portion of the third intersegmental vein, the remainder being an outgrowth from the latter just medial to the l3ini)ii-h(>art anlage. During the period of the degeneration of the anterior segments of the postcardinals and the consequent dwindling of the pronephric sinuses, each anterior vertebral vein, besides extending at first in a posterior direction, soon develops a second fork which extends forward and eventually establishes a connection with the internal jugular some distance anterior to the pronephric sinus. Sometime later, the original connection of the anterior vertebral vein with the vestige of the pronephric sinus, now the terminal portion of the internal jugular, breaks away, and the secondary junction farther cephalad becomes the permanent outlet of the lymph stream from the anterior lymph hearts. These changes are clearly expresedin the diagrams 5 to 8, inclusive.

During development all of the intersegmental veins back of the anterior lymph hearts become interjoined by a longitudinal anastomosis (figs. 2 and 3) which may be termed the lateral vein (v. lat.) because it courses in the lateral-line region and is without doubt homologous with a similar vein in the tailed amphil)ians. Subsequently, the tennini of all intersegmentals except the 9th and 11th (fig. 7) in toad embryos become very nnich reduced or vanish, although variations happen, such as the persistence of the vessels in intervals otlier than those. The anterior one of the retained intersegmentals becomes the transverse piece or mouth of the dorsolumbar vein (figs. 7 and 8, r. dors, lumb.), while the greater extent of the lateral vein becomes its longitudinal portion (rami iliolumbalis and iliacus). While these changes are taking place, the posterior lymph heart {cor. lym. post.) on each side* develops from a lymphatic plexus along

• Bufo po.sspssi's only one posterior lymph heart on each side. .Vmong the frogs there are multiple posterior lymph hearts, from two to four in number on eaeh Hide in the adults; thus in the American common species, Rnnn pipiens, there are normally two pairs of these 'diagram 9) with the occasional vestige of a third, present in the tadpole. The development of these hearts and their relation to the veins will be considered iti one of the subsequent papers.

Figure 9

the lateral vein at the level of its 11th intersegmental branch (fig. 5). The proximal portion or junction of the latter branch with the postcardinal (vena renalis advehens) becomes the mouth or terminal segment of the posterior vertebral vein (v. vert, post.) and the caudal part of the lateral vein becomes its distal extension (figs. 7 and 8). A break occurring in the lateral vein between the two parts of it, referred to the longitudinal portion of the dorsolumbar and the posterior vertebral veins, respectively, estabhshes the independence of these two veins.

In the meantime the posterior lymph hearts have formed a connection with the corresponding posterior vertebral veins, so that these channels now become the outlet of the lymphatic drainage of the posterior region of the body. The shifting of the mouth of the posterior vertebral vein back along the ischiadic vein uj) to the point where the transverse iliac vein is forming is clearly indicated in figures 7 and 8. These diagrams show how easily the variations that are so common arise by the expansion, reduction, or persistence of different segments of the originally symmetrical intersegmental veins, resulting in different relations with the main venous trunks.

The degree of displacement, during development, of the various components of the venous conduit system, brought about by the more rapid elongation of some and the suppression of others, may be readily determined by comparing the successive stages with reference to the relatively fixed positions of the spinal ganglia, as indicated in the diagrams.

Resunicn por el autor, II. E. Jordan, Universidad de \'iiginia.

Estudios sobre la estructura del musculo estriado.

\' 1 1 . El desarroUo del sarcostflo del musculo alar de la avispa,

con consideraciones sobre la base fisicoqufmica

de la contracci6n.

La estructura del sarc6mero del relativamente grosero sarcostilo del musculo alar de la avfspa susministra la base de un intento de exi)licaci6n fisicoquiniica consistente sobre la contracci6n muscular. Las metafibrillas extremadamente pequenas que constituyen este sarcostilo, hom61ogo de la miofibrilla del musculo estriado de los vertebrados, exhiben durante la contracci6n exactamente los mismos cambios estructurales que la fibra muscular estriada voluntaria en conjunto. El cambio esencial durante la contracci6n se refiere a la divisi6n igual de la substancia fuertemente tingible del disco Q al nivel del mesofragma y el movimiento de las mitades resultantes en direcciones opuestas, aplicdndose contra los telofragmas terminales del sarc6mero, donde se forman las bandas de contracci6n. La causa de la contracci6n muscular esta localizada en este moviniiento de cristaloides entre las partfculas coloidales (submicras) de los segmenos claros terminales. El acortamiento y aumento de espesor de los sarc6meros durante la contracci6n se interpreta como el resultado de un cambio en la forma de las partfculas coloidales intrafibrilares que pasan de la forma elipsoidal a la esf^rica, a causa de un aumento en su tensi6n superficial resultante de la disminuci6n de sus cargas el<>ctricas suj)erficiales, la cual sigue al paso de electrolitos entre ellas durante el movimiento de la substancia fuertemente tingible desde el mesofragma a los telofragmas.

Trannlntion by J(M^ F Nontdrt Cornell rnivrnillv Mnliral C*<illi>Kr. \ Y

Studies On Striped Muscle Structure

VII. THE DEVELOPMENT OF THE SARCOSTYLE OF THE WING MUSCLE OF THE WASP, WITH A CONSIDERATION OF THE PHYSICOCHEMICAL BASIS OF CONTRACTION

H. E. JORDAN Department of Histology and Embryology, University of Virginia

THIRTEEN FIGURES (tWO PLATEs)

INTRODUCTION

In the last number of this series of studies' it was shown that the constituent sarcostyles of the wing muscle of the wasp exhibit the same changes during contraction, with respect to the cross-striations, as do the complete fibers of striped muscle generally, namely, a reversal of striations as regards a deeply staining substance of the dim disc. It was assumed that the relatively coarse, cylindric sarcostyle of the wasp's wing muscle is the homologue of the more delicate myofibrils of vertebrate striped muscle. If this assumption accords with the facts, then Schaefer's** explanation of the appearance of a reversal of striations during contraction, as an optical illusion due to the accumulation of intersarcostylic fluid at the telophragma levels of relative constriction, must be erroneous. Moreover, the idea that this sarcostyle during functional contraction swells at the levels of the dim discs, thus producing a relative constriction at the level of the telophragma, is itself erroneous. As was shown in the previous number, ' the beaded condition of the sarcostj'le is the result of an artificial contraction following the osmotic action of a hypotonic medium. The functionally contracted sarcostyle, while it shortens and thickens, maintains meanwhile, nevertheless, a straight, unbeaded contour. None the less it seems desirable to establish definitely the actual morphologic status of the wasp's wing-muscle sarcostyle by a study of its development.

This is the primary purpose of this investigation, namely, to trace the developmental history- of the wasp's wing-nmscle sarcostyle with a \'iew to determining its value in terms of the elementary myofibril of vertebrate striped muscle. The evidence which will be given below seems conclusive that the sarcostyle of the wasp's wing nmscle and the myofibril of vertebrate striped muscle are actually strictly homologous elements. This being so, it follows that in our efforts to discover the ultimate physicochemical basis of contraction we may more profitably, and quite legitimately and confidently, confine ourselves to the relatively much coarser sarcostyles of certain insects' wing muscle (e.g., Diptera, Hymenoptera, and Coleoptera). The second purpose of this investigation is finally to attempt a physicochemical interpretation of the structural changes suffered by the sarcostyle during contraction, and to formulate a consistent hypothesis in explanation of the cause of muscle contraction. The entire series of these studies on muscle structure had for one of its chief objects the accumulation of sufficiently numerous and precise data for the establishment of a correct physicochemical interpretation of muscular contraction.

M.\TERI.\L anD METHODS

The material available for this study consists of two fairly complete series of specimens ranging from the newly hatched larva to the older pupae, one series fixed in 95 per cent alcohol, the other in a 10 per cent solution of neutral formol. For this material I am indebted to Mr. Massie Page. For the purposes of the present problem we may confine ourselves to four salient developmental stages: 1) the oldest larval stage (or youngest pupal stage), namely, one in which the thorax is outlined and wing pads are discernible, but no external leg rudiments; 2) an intermediate white pupa; 3) a later gray, or slightly pigmented, pupa, and, 4) the black, almost mature, pupa. The thorax was embedded in jiaraffin. Sections were cut at An, and stained with iron-hematoxylin, followed in some cases by eosin counterstain.

DESCRIPTION

In the youngest, legless pupal stages very delicate wings are already present. Serial sections through the thorax show the imaginal discs still in continuity with the ectoderm ventrocaudally. Here, then, occur the initial myoblasts (fig. 1, a and 6). Older stages in the muscle histogenesis occur anterodorsally (fig. 3 and 4). Between these terminal levels occur intermediate developmental stages (fig. 2, c).

The initial myoblasts are long, fusiform elements with a vesicular, centrally located nucleus. The nucleus originally contains a single, dense, chromatic nucleolus. The latter subsequently divides, the nucleus now containing a pair of nucleoli. This condition foreshadows the ensuing direct nuclear division. The myoblasts fuse terminally, their tapering ends overlapping (fig. 1, b), to form the definitive muscle fibers. Meanwhile the nuclei multiply greatly by amitotic division. No mitotic figures were seen in the myoblasts or later muscle fibers at any stage. The muscle fiber accordingly arises by fusion of originally discrete cells, not solely and primarily by growth of the myoblasts. The nuclei multiply by direct division chiefly in planes perpendicular to the long axis of the myoblasts, thus forming axial columns of nuclei (fig. I, b); but to some extent also by division in the longitudinal plane, thus originating more peripheral nuclei. Appearances like those illustrated in figure 2, c, represent in part the latter sort of division, but in part also no doubt levels of sections where the tapering ends of fusing myoblasts overlapped.

Already in the earliest myoblasts, like those of figure 1, a, an occasional peripheral myofibril is faintly discernible. The nature of this material does not permit of any definite statement regarding the origin of the myofibrils. I am unable to determine whether the original fibrils arise as such or by the alinement and subsequent coalescence of precursory myochondria. Nor can I be quite certain whether later fibrils arise by longitudinal division of preexisting myofibrils, or independently. I incline to think that the later myofibrils arise chiefly independently; at any rate, there is no clear evidence of a longitudinal splitting. The fibrils soon extend uninterruptedly through several original cell limits, and they remain for a relatively long time homogeneous. In figure 2 (a and b) are illustrated transverse sections of myoblasts corresponding with a and b of figure 1. Illustration c of figure 2 represents an older myoblast. Connective-tissue cells occur among the mj^oblasts. At least some of these divide by mitosis. Many of these cells become fatcells. The cell c.t. of figure 2 is at an early stage of differentiation into a fat-cell.

The earUer muscle fibers, formed by the fusion of myoblasts, grow rapidly in diameter (fig. 3). Both nuclei and myofibrils meanwhile undergo enormous numerical increase. In a transverse section (fig. 3) the nuclei, now granular and more chromatic, appear to be scattered at random. Longitudinal sections of fillers at this stage (fig. 4), however, show that the nuclei are arranged in long colunms, in single or double file. The connective tissue cells have also meanwhile increased greatly in number. The interfiber spaces have a diameter approximateh' equal to that of the nmscle fibers. These spaces are closely packed with stout, fusiform, and irregular connective-tissue cells. The latter subsequently differentiate largely into huge fat-cells. The myofibrils are still homogeneous and quite delicate. In transverse section they have the appearance of fine granules (fig. 3).

Passing now from the stage of the oldest larva to that of the white pupa, with well-developed wings and legs, the wing-muscle fibers are seen to have enlarged enormously (fig. 5). The nuclei are numerous, but of smaller size in transverse section than in the preceding stage. Longitudinal sections of such fibers (fig. 6) reveal the fact that many of the nuclei are now greatly elongated elements. These continue to divide amitotically. The fiber is enveloped by a delicate sarcolemma. In certain cross-sections the peripheral myofibrils appear to be arranged in radial lines (fig. 5). This is the sole evidence that myofibrils may in part arise by longitudinal splitting of preexisting fil)rils. The myofibrils are now relatively coarse (figs. 5 and 6), but still clearly unstriped, and between the fibrils appears a very finely granular sarcoplasm (fig. 6).

Thus far there is no indication of even a telophragma. In a slightly older pupal stage (gray pupa), however, this membrane has made its appearance (fig. 10). The myofibrils, or sarcostyles, are now relatively very coarse, as may be seen by comparing figure 7 with figure 5 of the previous stage, and with figure 8 from the adult muscle. The stages of muscle development in the gray pupa are of the utmost significance in this connection. We meet here with the initial steps in the origin of the crossstriations due to the presence of dim discs. Certain large masses of fibers are composed of sarcostyles in which only the telophragmata have appeared (fig. 9^ a). In other masses the sarcostyles contain also delicate, but deeply staining, Q-discs (fig. 9, b) . In such sarcostyles the telophragma has changed to an only relatively faintly staining membrane. Still other large masses of fibers consist of sarcostyles with relatively wide Q-discs (fig. 9, c). In certain other groups of fibers the Q-discs appear double (fig. 9, d), and occasional sarcostyles of such groups reveal very clearly constituent finer elements, the metafibrils (fig. 9, e). The clear indication of metafibrils, as in e of figure 9, may probably represent an artificial condition ; but that the sarcostyles actuaU}^ are composed of still finer fibrils seems demonstrated by the conditions which obtain where the muscle is attached to the hypoderm (fig. 10). Here the sarcostyles appear to break up into very fine 'tendinous' fibrils. The transition from muscle to tendon appears to be through direct continuity of muscular metafibrils and tendon fibrils The latter stain deeply in very dilute solutions of eosin, in contrast with the muscle which remains unstained. The metafibrillar composition of the sarcostyles is a point of cardinal significance with respect to the phj^sicochemical explanation of contraction, and will be fully discussed below.

The order of development of the cross-striations here disclosed is also a fact of much importance. The Q-disc appears only after the telophragma becomes discernible. The Q-discs are at first only very delicate, and only gradually attain their typical width between successive telophragmata. Coincident with the appearance of deeply staining Q-discs, the telophragmata suffer

THE ANATOMICAL BECOHD, VOL. 19, NO. 2

102 H. E. JORDAN

a diminution of staining intensity. The meaning of the double condition of the Q-dises, as in figure 9, d, is uncertain. It may have the same significance as in the mature sarcostyles, namely, indicative of an earh* phase of contraction.

The foregoing observations are specially significant bj- reason of the light they throw on the question of the function of the telophragmata. The data strongly suggest that the telophragmata furnisli the pathways along which are transported the materials which contribute to the formation of the dim discs, as well as the materials which supplj' the nutritive demands of the sarcost\-les. The genetic order of events here revealed ex])lains the horizontal alinement of striations in cross-strijK-d muscle. This matter also will be reverted to and more fully discussed below.

Thus far no evidence appears, either in the formalin or alcoholfixed j)rej)arations of sarcosomes. The latter appear first in formalin-fixed muscle of the almost mature black pupa (figs. 11 and 12). A largely lipoid nature of these sarcosomes is suggested by the fact that they entirely disappear in muscle of this stage fixed in 95 per cent alcohol. The sarcostyles have attained almost their definitive diameter (compare figs. 12 and 8 and figs. 11 and 13). In longitudinal sections (fig. 11) the sarcosomes appear spheroidal, but transverse section at this stage reveal the fact that they are alreadj^ laterally somewhat compres.sed, and so possess short, blunt, lateral wings (fig. 12). Generally only two sarcosomes occur to an intertelophragma .space, indicating that the teloj)lniigniata ofTer an efTective liarrier against their pas.sage through these levels, and suggesting that the materials for their elaI)oration were also transported through the telophragmata, a sarcosome each being contributed by one telophragma. Comparison of figure 12 with figure 8, the latter from an adult muscle, shows that the sarcosomes undergo considerable subsequent growth, a circumstance involving still greater compression between adjacent sarcostyles, with the formation of longer, thinner wing processes. The relatively late origin of the sarcosomes, that is, just prior to functional activity of the wings, suggests a close relation between

STRIPED MUSCLE STRUCTURE 103

sarcosomes and the metabolic requirements of the relatively very rapidly contracting wing muscle.

In figure 13 are illustrated three successive stages in the contraction of the sarcostyle of the wing muscle fiber of an adult wasp. The sarcostyle a is in a condition of repose. The sarcostyle b is at an early phase of contraction. The Q-disc has become bisected by the appearance of an H-disc. The deeply staining substance of Q is accumulating at the levels nearest the telophragmata. The sarcostyle c is at a still later phase, when the deeply staining substance of the sarcoplasm has aggregated about the telophragma, so that now this membrane bisects a dark disc, instead of bisecting a light disc as previously. A true reversal of striations, as regards this deeply staining constituent of the sarcoplasm, has been effected. Sarcostyle d is in almost complete contraction. The sarcostyle has become thicker, and the sarcomeres relatively shortened. The deeply staining substance about Z in sarcostyle c has here condensed so as to form a contraction band of the contracted fiber. The double nature of this band is clearly shown in sarcostyle d. The telophragmata are, however, no longer discernible. The optical disappearance of the membrane Z in sarcostyle d is interpreted as resulting from the thickening of the sarcostyle, effecting thus a drawing out radially and a consequent thinning of this membrane to a point where it is no longer within the range of microscopic vision.

The above seriation of stages in contraction of the adult sarcostyle gives the key for the interpretation of figures 11 and 9, d, of immature sarcostyles. Sarcostyle d of figure 9 would thus appear to be in an early stage of contraction, the sarcostyle of figure 11 at a later stage corresponding with that of c of figure 13. Apparently the immature sarcostyles are capable of some degree of functional contraction even before the wrings are moved in flight.

104 H. E. JORDAN

DISCUSSION

The foregoing description shows that the wing-muscle fiber of the wasp is essentially homologous with voluiitarj^ stripednuiscle fibers generally. The liber is a multinucleated structure resulting from the fusion of originallj" discrete myoblasts, and subsequent growth, accompanied by an increase in the number of myofibrils and by the amitotic multiplication of the nuclei. The fibrils first appear as homogeneous elements, which only later become cross-striped. The wing muscle of the wasp, as that of Hymenoptera, Diptera, and Coleoptera generally, differs, however, from the usual type of voluntary striped muscle, in the definitive stages of its differentiation, in that its fibrils grow to relatively enormous radial dimensions. But the developmental history of this relati\oly very coarse sarcostyle demonstrates its strict homology with the more delicate myofibrils of vertebrate skeletal muscle.

The question then arises concerning the functional significance of the relatively coarse sarcostj'lc of certain insects' wing muscle. Clearly the coarse, cylindric condition of the sarcostyle bears no direct causal relation to flight as such even among insects, since in the Orthoptera and certain Odanafa the wing muscle fibers of the thorax are characterized by lamellar 'sarcostyles' with constituent very delicate myofibrils. When we seek for a possible explanation of the difference in girth of sarcostyles in the several groups of insects, we note the fact that what distinguishes the flight of Di])tera, Hymenoptera, and Coleoptera from that of the Orthoptera, for example, is not so much the rapidity of flight as the ability on the part of the former groups to sustain rapid flight for relativel}' long periods of time. The suggestion then presents it.self that a relatively coarse type of sarcostyle, characteristic of wing muscle of which is demanded long-continued function, may somehow better subserve the conditions of this demand than a structure characterized by relatively delicate cylindric or by lamellar sarcostyles. Such hypothesis is suppf»rtcd also by the fact that the sarcostyles of the analogous pectoral muscles of thf> humming bird and the bat are

STIUPED MUSCLE STRUCTURE 105

relatively coarse cylindric structures. However, all speculations along these lines lose plausibility in view of the definite fact that also the coarse, apparently unitary, sarcostyles of wasp wing muscle resolve themselves finally into extremely minute constituent fibrils (metafibrils). This is true also of the lamellar type of wing nmscle sarcostyle (e.g., mantis'). It might then perhaps be argued that the coarse, so-called sarcostyle of the wasp's wing muscle is not actually the homologue of the myofibrils of, for example, human leg muscle, but in fact represents a fascicle of such fibril homologues. The apparent force of such argument, however, is neutralized by the fact that also the myofibrils of mammalian skeletal muscle may be seen to consist of collections of still finer fibrils. The sarcostyle of the wasp's wing muscle differs, moreover, from the lamellar, so-called sarcostyle of Orthoptera, in that the latter includes relatively fewer constituent fibrils and relatively much larger quantities of intrasarcostylic non-fibrillar sarcoplasm. Successively more detailed analysis of muscular fibrils reveals successively finer constituent meta-fibrils up to the limits of visiblitj^. As above described, however, and already explained, the early stages in the development of the wasp's wing-muscle sarcostyle show that it is strictly homologous with the myofibril of vertebrate striped muscle. Clearly, also, rapidity of function, or long-sustained function, is not directly related to complexity of cross-striation; for the wasp's wing muscle, and vertebrate cardiac muscle, is characterized by a relative simplicity of striation. Complexity of striation, resulting from the presence of an additional N-disc, as in insect leg muscle generally, would thus appear to be related to force of function rather than to rapidity or long continuance of function.

Insect wing muscle generally, however, differs from voluntary striped muscle of vertebrates in the occurrence of numerous, relatively' large sarcoplasmic granules or sarcosomes in the former. But comparable elements occur also in the analogous pectoral muscles of bats and birds (Thulin"'), and in mammalian heart muscle (Bullard'). The common factor in the conditions underlying the peculiar function of these three types of muscle is the

infi 11. K. JORDAN

ability of loiiR-sustainod function. The evidence suggests that largo and al>undant sarcosoines subserve the peculiar metabolic nee<ls of muscles -which act continuously for long periods of time. The absence generally of at least large and abundant sarcosomes in insect leg muscle, and in vertebrate skeletal muscle generally, suggests that forceful function only at intervals does not necessitate exactly the same type, or at least the same degree, of support of its metabolic requirements.

The sarcosomes develop relatively late. They appear first in the almost mature (black) pupa (fig. 11). They are at first spherical in shape; subsequentlj-^ they become modified into winged elements, the result of mutual pressure between the adjacent growing sarcostyles and the enlargmg sarcosomes. As was suggested in a previous article,' the winged type of sarcosome probably largely persists throughout the life of the individual, ^licrochemical evidence was also given indicating that, besides a predominant lipoid constituent, the sarcosomes, at least in the later phases of elaboration, include an additional substance, possibly a carbohydrate. The verj' definite arrangement of the first formed, spherical sarcosomes, two to each sarcomeric interval, suggests that the material for their elaboration enters the intersarcostjdic spaces via the telophragmata.

A detail in muscle histogenesis about which there has been much confusion and unprofitable speculation concerns the fact of the regular horizontal alinement of identically differentiated levels of the cross-strii^ed myofibrils of a striped muscle fiber. The question arises as to how these alternating discs of adjacent fibrils are first brought into horizontal alinement. If the crossstriped myofiijrils arise originally independently of telophragmata, as the illustrations of Ciodlewski^' and of Luna" for example, purjwrt to indicate, then it is almost inconceivable how they may subsequently be brought into horizontal alinement. ^^^latever idea different investigators may hold regarding the origin of the initial myofibrils in various instances, whether as fibrils, mitochondria, or as prefibrillar myochondria which subsequently coalesce to form fibrils, all agree that the first genuine myofibrils are originally apparently homogeneous and only sub

STRIPED MUSCLE STRUCTURE 107

sequently become cross-striped.' The illustrations of Godlewski, while showing cross-striped myofibrils unconnected by telophragmata in young myoblasts of mammals, give no indication of how the secondary myofibrils originate. Possibly Godlewski failed, or was unable by reason of their extreme tenuity, to see the telophragmata actually spanning the interfibrillar spaces among the original myofibrils. Be this as it may, we possess two definite observations which explain how this transverse alinement of identically differentiated levels of the myofibrils of a muscle fiber is produced.

The clearest evidence concerning this point accrues from the present investigation. It seems perfectly plain in this material that telophragmata precede the appearance of Q-discs (figs. 9 and 10). It was shown in previous papers^ "^ that the telophragmata are intimately connected with the sarcostyles and with the peripheral sarcolemma. In this way each sarcostyle is brought into relation with the interfiber tissue spaces and thus with the nutritive tissue fluid. Assuming that the telophragmata are pathways for the entrance and exit of materials between the

' M. R. Lewis, however, claims that in the myocardium of the chick embryo it can be demonstrated by a certain fixing and staining technic that the 'fibrils' are completely cross-striated from their first appearance (Johns Hopkins Hospital Bulletin, vol. 30, p. 1). Moreover, she interprets the 'fibrils' as fixation prodwcts, a view long since urged for striped muscle geneally by Van Gehuchten (La Cellule, T. 4, p. 247, 1888), but never widely accepted. The cross-striations she regards as genuine fundamental structural features of the myoblast as a whole. If the conclusion here reached with regard to the artificial nature of the fibrils of the primitive myocardium of the chick were applied to the wing muscles of the wasp, we would be obliged to interpret the sarcostyle (homologue of the vertebrate myofibril, as above demonstrated) of the latter muscle as a developed and differentiated fixation product; since, no one I suppose, would seriously attempt to explain this definitive sarcostyle of adult wing muscle of wasp as also an artifact. It maj' be suggested that the reason why the primitive myofibrils described by certain investigators in cardiac muscle are not discernible microscopically in living myoblasts is not because they are not actually present, but because they are relatively fluid and because in consequence the refractive index of their sarcoplasm is so close to that of the interfibrillar sarcoplasm that the contrast between the two is insufficient to permit of clear differentiation under the microscope. The coagulative effect of fixation may bring about a greater relative difference between the refractive indices of the two sarcoplasmic colloids, and so render visible the denser fundamental sarcoplasmic fibrils.

108 H. E. JORDAN

sarcostyles and the intcrfiber tissue spaces (and this would appear to be their chief fuiu-tion), it becomes clear why the secondary modification of the originally homogeneous sarcostyles, namely, the formation of the Q-discs, follows the development of the telophragmata. Such genetic course explains at once the reason for the maintenance of a strict transverse alinemcnt. The investigations of ^lacallum'- and of ]\Ienten have shown that the dim discs contain potassium salts, chlorides, and phosphates. The presence of these substances in these regions may be the reason for their deeper staining capacity. These substances, considered physicochemically, are soluble crystalloids, at least in part electrol}i;es, and their segregation in the middle of the colloidal sarcomeres against the mesophragma, after entrance is thus explained.

The difference in staining reaction of the telophragmata at the several successive earh' stages in the development, from the viewpoint of the relative amount of Q-substance, supi)orts the idea here advocated, namely, that the materials for the production and growth of the Q-discs enter via the telophragmata. In figure 9, a, the telophragmata are relatively coarse and stain deeply. In h, where a thin Q-disc has ai)])eared, the telophragmata are now delicate and relatively pale. The sarcostyle a may be interpreted as at the stage where the telophragmata are saturated with the deeply staining material, which in h has become segregated in the delicate Q-disc. To the latter is later added more of similar material to produce the relatively thick Q-<lisc of sarcostyle c. In view of tlie fact that the sarcostyles are closely connected with the telophragmata, the subsequently stratified sarcostyles (differentiating in the manner indicated through segregation of ciystalloids entering the colloidal sarcomeres through the telophragmata) nnist of necessity hold their alternating .strata in horizontal alinemcnt.

The other pertinent observation in this connection concerns the mode of the development of the my()fil)rils in the body muscle of the newly hatched rainbow trout." The same histogenetic sieries of events in trout has been described also by Heidenhain.* Here the myoblasts originally contain a single, coarse, homo

STRIPED MUSCLE STRUCTURE 109 geneous, deeply staining, cylindric myofibril lying close to the nuclear wall within the cytoplasm. The origin of this initial sarcostyle could not be determined. This prmiordial sarcostyle produces four secondary sarcostyles by two practically simultaneous longitudinal divisions. These secondary sarcostyles assume a stout lamellar form, and subsequent sarcostyles arise only by successive radial and central longitudinal fissions. Thus while the sarcostyles, both peripheral lamellar and central cylindric, become cross-striped during the early stages of histogenesis, all subsequent myofibrils must maintain a similar ahnement of their different alternating strata by reason of their origin by longitudinal division of already striped fibrils and their continued interconnection through the original telophragmata. Telophragmata are discernible following the first division of the initial sarcostyle. The available definite evidence therefore indicates that the cross-striations, as regards the Q-discs, only follows the appearance of telophragmata connecting with the peripheral sarcolemma, and so with the interfiber tissue spaces; and that the stratification results from the intake via the telophragmata of soluble crystalloids which become segregated in the Q-disc.

The foregoing descriptions and discussions, together with the data comprised in the previous papers of this series, lead naturally to an attempt to formulate a correct interpretation of the structural changes which the sarcostyle undergoes during contraction, in terms of physicochemical factors, and to an effort to explain muscle contraction in terms of these changes. The specific central problem narrows itself down to a question of the intimate structure and physical chemistry of the contracting single sarcomere of the relatively coarse sarcostyle of the wasp's wing muscle.

The sarcomere is bounded at both ends by a true membrane, the telophragma. Its middle is occupied by a disc of variable width, the so-called Q- or dim disc. This disc is composed of a substance which appears darker in unstained preparations, and which takes a deeper stain in fixed preparations treated with basic dyes. It contrasts in these respects with the lighter por

1 10 H. K. JORDAN

tions, halves of so-called J- or clear discs, intervening between it nnd the terminal telophrapniata. The sarcomere is Innuuled l)erii)herally l)y a layer which lias theproperties of a semipermeable membrane, as demonstrated bj' its response to hypo- and hyper tonic salt solutions. This layer, the sarcostylic membrane, is intimately connected with the telophragmata. Bisecting the Qdisc there occurs a delicate dividing structure, presumably a membrane, as demonstrated by the equal division of this disc in contraction along the midline, the niesophragma. This membrane, however, is not discernible as such in this sarcomere under the highest powers of the microscope. Minute analysis reveals the fact that the apparent Ij- homogeneous sarcomere consists in fact of ultimate metatibrils. The latter are intimatelj^ attached to the telophragmata. Macallum'- and Menten" have shown that the Q-disc contains segregated chlorides, phosphates, and potassium salts. The presence of these substances in this area prcsumablj' accounts for the 'dim' appearance and the deeper staining capacity, possibly also for the relatively greater anisotropy, of this disc in contrast with the terminal J-segments. These salts represent soluble crystalloids, therefore, at least in part, electrolytes, and give to the Q-disc a composition physicochemicalh' different from the predominantly colloidal terminal clear portions. The sarcomere, tlierefore, consists of a cylinder of minute fibrils enveloped bj' a peripheral membrane, each colloidal fibril containing medially a mass of segregated crystalloids. Through the terminal telophragmata of the sarcomere, each fibril (metaHl)ril) is placed in capillar}' relation with the intersarcostjlic fluid spaces. Presumably there exist between the metafibrils capillary interfibrillar canaliculi. When the muscle contracts, the jiredominanth- crystalloidal medial disc (Q-disc) of each metafiliril of the sarcostyle divides along the midline (mesophragma level) and the resulting halves move in opposite directions to fuse with similar halves, from successive sarcomeres, along the terminal telophragmata, thus forming contraction l)ands. The contraction bands accordingly' represent discs of predominantly crystalloidal composition, and a reversal of strata (striations) as regards the deeply staining crystalloidal substance of ♦he relaxed sarcostyle has occurred during contraction.

STRIPED MUSCLE STRUCTURE 111

The problem of muscle contraction, therefore, resolves itself, in the final anatysis, into a physicochemical explanation of the shortening and tliickening of the sarcomere in relation to the movement of a medial mass of crystalloids (electrolytes) through the terminal colloidal segments against the telophragma boundaries. It is here assumed that the movement of crystalloids among colloids is the cause, not simply the accompaniment, or the result, of contraction.

The solution of the above-stated problem involves also an explanation of why, during the original determination of the stratified condition of the sarcostyle, the crystalloids, presumably^ entering terminallj^ via the telophragmata, take a definite median position. The attempt at such explanation must first be disposed of. In regard to this aspect of the complete problem, we are actually deaUng with a colloidal compartment, a hydrogel of myosin, bounded on the side where the crystalloidal substance presumably enters bj' a relatively coarse telophragma, at the opposite end where it is deposited, bj^ a relatively delicate mesophragma. WTien crystalloids mingle with a colloid, the molecules of the latter suffer a change of surface electrical charges, and it may be assumed that the crj^staUoidal particles or ions are repelled (or perhaps simply passively carried by fluids, due to the fusion of collodial particles behind thus propelling fluids forward) to the lunit where thej^ are held by the mesophragma and the adjacent mass of electrol}i:es.- The electrical condition of the now polarized sarcomere maj' now be considered to be in stable equilibrium in the resting fiber. "\Miatever the original form or state of aggregation of the colloidal particles, the passage of the crystalloidal particles, and their

-The manner of origin of the initial stratification may perhaps be comparable to that of the so-called Liesegang phenomenon of colloidal chemistry, which phenomenon occurs when a gel containing a substance in solution is treated with a second solution capable of reacting with the solution in the gel; e.g., when to a test-tube partly filled with 1 per cent agar gel containing calcium chloride is added a solution of sodium carbonate. The calcium carbonate formed by the interaction is deposited in strata throughout the agar cylinder (vide Hatschek, ".4n introduction to the physics and chemistry of colloids," p. 73, P. Blakiston's Son & Co., 1919).

112 H. E. JORDAN

segregation in the future Q-disc, must be considered to cause the assumption of an elUpsoidal form of the colloidal particles witli the long axis j)arallel to the length of the sarcostyle. Such original elongation of the colloidal particles may cause a certain amount of elongation or longitudinal growth of the prefunctional sarcostyle. A possible original change of form, under the influence of the entering crj'stalloids, from an ellipsoidal form (with long axis of colloidal particle parallel to length of fiber) to a spherical shape, would offer the same basis for a future contracticjn of the sarcomere, if we assume that the formation of the contraction band involves a change of form of the colloidal particles (due to alteration of surface tension) from a spheriodal form to an ellipsoidal form in which the long axis of the colloidal particle is placed at right angles to the long axis of the sarcostyle. .Vll things considered, however, the former alternative seems the more probable.

\\'e may now proceed to consider contraction in the histologically mature sarcostyle. Contraction is initiated by a nervous stimulus. The latter may be regarded as a wave of negative electricity. We may suppose that the negative charge enters the sarcomere at the level of the more delicate mesophragma. This disturbs the electrical potential and causes repulsion of the electrolytes; that is, the charged ions are made to travel from the level of the mesophragma through the adjacent colloidal area against the telophragmata, where contraction bands are formed. The movement of the electrolytes among the colloidal particles causes a change of surface energy, hence of surface tension, by reason of the discharge of surface electrical charges and in conse(iuence a change of shape of the colloidal particles. If we assume that this change of shape is one of change from an ellipsoidal fomi (oriented in the longitudinal plane) to a spheroidal shape, the shortening and thickening of the constituent sarcomeres of the sarcostyles, and thus nmscle contraction, is accounted for. The formation of the contraction band again results in a condition of stable electrical eciuilibrium, which latter is again upset when the particular nervous stimulus is internipted, and a movement of the electrolytes is started in the opposite direction, resulting thus in the characteristic strati

STRIPED MUSCLE STRUCTURE 113

fication and the electrically stable condition of the sarcostyle in repose. If this is in fact the central significance of the deeply staining Q-substance, its variable relative width in different fibers of the same muscle becomes intelligible: its relative quantity within certain limits may not be a fundamentally essential requirement for adequate function of the contractile mechanism; all that may be required is a certain minimal amount and hmitation within certain maximal amounts. Furthermore, the apparent relative amount of the Q-substance may be largely incidental to the degree of its concentration.

Since I have previously deduced and supported the hypothesis that intercalated discs, characteristic of heart muscle, and occasionally found also under certain conditions in voluntary striped muscle/ represent in essence modified irreversible contraction bands, it seems demanded in this connection that the formation of these intercalated discs be also explained consistently with the above outline of muscle contraction. During muscle contraction lactic acid is formed, ^\^len a muscle is made to function to exhaustion, the amount of lactic acid is excessively increased. Acid has a precipitation or coagulative effect upon colloids and upon mixtures of colloids and crystalloids. Intercalated discs would thus find their explanation, in accordance with the above scheme of contraction, in the supposition of the production of a relatively excessive amount of lactic acid under certain conditions, sufficient to effect a precipitation, that is, an irreversible coagulation, of a part of, or an entire contraction band.

The above-outlined physicochemical explanation of muscle contraction is in essence veiy similar to that presented bj^ Prenant, Bouin, and Maillard.'^ These histologists describe contraction as an electrocapillarj^ phenomenon. The cause of the shortening and thickening of the sarcomeres they also locate in a change of shape of the ultimate colloidal particles of the intrafibril sarcoplasm, following an alteration of electrical potential of opposite surfaces of contact of adjacent particles. But these authors do not carry their analysis and interpretation to the point above indicated with regard to the first appearance and the segregation of the crystalloids within the primitive colloidal

114 II. E. JORDAN

sarronicre, nor do they rccoKiiizc a niovenient of crystalloids during contraction from the nicsophragina to the telophragma, nor do they locate the cause of change of shape of colloidal particles specifically in the surface of contact between electrolytes and colloidal i>articles.

Similarly l<illie's"' explanation of muscle contraction has a close resemblance to our hypothesis. However, Lillie conceives of the intimate structure of the sarcomeres in our opinion erroneously, in that he regards the dim Q-disc as the result solely of a greater concentration, or of a different state of aggregation, of colloidal particles at tliis level. This alleged constitution jiresupposes relatively large interstitial fluid-containing spaces in the clear J-disc. Nor does Lillie recognize a movement of dim substance during contraction. He does, however, assume a movement of interstitial fluid from M to Z, but only as an incidental result of the closer aggregation of the colloidal 'submicrons' of the dim disc. Lillie conceives of the energ>' of contraction as transformed surface energy of the ultimate structural element or colloidal particle (submicron) composing the fibril gel. The shortening and thickening of the sarcomere is thought to result from the massing of the colloidal particles in the 'anisotropic' segments, the massing itself resulting from the heightened surface tension resulting from diminished electrical surface polarization. He regards contraction as similar to reversible coagulation of colloids. This hypothesis, considered in detail, gives no clue for the consistent interpretation of intercalated discs. It is readily conceivable that the conditions here jiostulated might lead to an irreversible coagulation of sarcoplasmic colloids; but such areas of irreversibly coagulated sarcoplasm would be at the level of the mesophragma, according to Lillie's explanation, and not, as is actually the case, at the levels of the telophragmata.

.\ccording to our hypothesis, on the contrarj', the shortening and thickening of the sarcomere, that is, contraction, results from the change of shape of the ultimate colloidal sarcoplasmic particlas following an increased surface tension, the latter resulting from decrease or disappearance of the surface charges of the

STRIPED MUSCLE STRUCTURE 115

(•olloidal particles accompanying the movement of electrolytes among them from the mesophragma to the telophragma, the movement being initiated by the disturbance of electrical potential of the membranes, primarily of the mesophragma, surrounding the sarcomere following the passage of nerve stimulus. It must be admitted, however, that a precipitation of colloidal particles by electrolytes would have essentially the same effect of shortening and thickening of the sarcomere as would a change of shape of the particles. But LilUe's hypothesis permits of no plausible explanation of the dim character of the contraction band. If, as Lillie assmnes, the Q-disc of the fibril in repose is 'dun' because of a closer aggregation of colloidal particles at this level, and if, as he further assumes, contraction is essentially a matter of a still closer massing of colloidal particles at this level, with a forcing of interstitial fluid into the telophragma borders of the clearer J-segments of the sarcomeres, then the latter areas should become Hghter instead of becoming darker, as they actually do become as parts of contraction bands. If the Q-discs are 'dim' because of a closer aggregation of colloidal particles here, then the 'dimness' of the contraction bands should consistently be explained in the same way; but that the latter are areas of closer aggregation of colloidal particles is in contradiction to the central idea in Lillie's hypothesis. Reconciliation of this damaging contradiction can be effected, and the integrity of Lillie's hj^jothesis maintained, onlj^ on the assumption that the Q-disc is dim because of the presence here of an additional darker, more fluid substance, which latter becomes forced against the telophragmata during contraction and here gives the darker color or 'dim' appearance also to the resulting contraction band. But when this further assumption has been added to the basic assumptions of Lillie's hypothesis, we are very close to the hypothesis here urged and supported, namely, that the cause of contraction is located in the final analysis in the fact of a movement of 'dim' substance among the colloidal particles of the sarcomere from M to Z. And in view of the demonstration of the segregation of crj^stalloids in the dim discs (Q-disc and the contraction band) the latter hj-jiothesis would seem to be the most satisfactory alternative.

116 H. E. JORDAN

No hypothesis of imiscle contraction can of course be satisfactory that cannot be harnioiiizod with the principle of the conservation of energy. We must be able to find within the muscle, sources of energy apjiroxiinately equal in sum to the amount of energy expended l)y the functioning muscle; which energies must both be approximately equal to the underlying chemical energy of the metabolic processes of active muscle. The details of the exact relation between the chemical energy of nmscle metabolism and the postulated surface-tension energy of the sarcoplasmic particles need not be here considered. The energ}' of the nerve stinmlus need of course be only sufficient to start the initial link in the chain of chemical reactions of the metabolic processes underhing the assumed surface-tension energy of contraction. Lillie supports the hypothesis that the contractile energy of muscle is due to changes in surface tension of certain muscle elements by these statements:

In contraction the surface tension of these elements is supposedly increased. If this increase of tension is sufficiently great, and the area of the active surface sufficiently large, the transfomiabie surfaceencrgj', which is measuretl bj- the product of these two factors, may be sufficient to account for the work done by the muscle in contraction There is ... . good reason to regard the ultimate coiloi(hil particles of the fibrils as corresponding to such elements. By their union to fonn larger particles, as in the general process of colloid-coagulation, sufficient mechanical energy to account for contraction might conceivably be freed, since the reduction of surface-area in such a process may be very great, implying a correspondingly large transformation of surface-energj" (p. 252).'

In r^^'sumc?, the gist of our hypothesis involves the following assumptions, which are consistent with the fact of a movement of 'dim' substance from the Q-disc to the contraction band during contraction: The nerve .stimulus causes a movement of ions from M to Z effecting a change in shape of the colloidal particles from ellipsoidal to .spherical; cessation of stimulus, an instant return of ions from Z to M with a return to the original ellipsoidal form of the colloidal particle; the change in form of the

• For a review of the earlier literature touching similar interpretations of muscle contraction, the reader is referred to Lillie's paper and to Schaefcr's textbook (p. 189).

STRIPED MUSCLE STRUCTURE 117

latter being the result of an alteration of surface tension following alternating increase and decrease of surface electrical charges under the influence of the reversal of the direction of the current of action and the moving electrolytes.

The histologic data relative to the intimate structural changes in contracting muscle above given seem in strict accord with the conclusion that the source of the contracting energy of muscle resides in alterations of surface tension in the colloidal particles of the ultimate muscle fibrils. My conception of the physicochemical process in ultimate detaU differs from that of Lillie in essence only in that Lillie interprets contraction as the result of an aggregation or union (resembling reversible coagulation or precipitation) of the colloidal particles mainly in the Q-disc, with expression of interstitial fluid into the J-disc, following increase of surface tension due to decrease of surface electrical charges; while I view the histologic data (supplemented by the microchemical data of Macallum and of JMenten) as indicating an actual movement of soluble crystalloids (electrolytes) from the mesophragma to the telophragmata, which movement of electrolytes may be interpreted as the chief factor in effecting an increase of surface tension of the colloidal particles and so altering the shape of the particles, which alteration of shape, rather than a massing of the particles, effects a shortening and thickening of the sarcomeres.

SUMMARY

1. The relatively very coarse sarcostyle of the wing muscle of the wasp is strictly homologous with the mj'ofibril of vertebrate striped muscle. Both varieties of fibrils consist of bundles of extremely minute constituent metafibrils. The wasp's sarcostyle has an enveloping layer with the properties of an osmotic membrane, the sarcostylic membrane.

2. The structural changes exhibited by a striped muscle fiber during contraction are the result of similar changes in the constituent metafibrils. The fundamental and essential change con THE ANATOMICAL nECORD. VOL. 10, NO. 2

11^ H. E. JORDAN

cerns the equal division at the level of the inesophraKiiia, and the subsequent movement, of the more deeply staining substance of the Q-disc, against the terminal telophragmata of the sarcomere, where are formed the contraction })ands.

3. The salient histogenetic steps pccur in the following order: The myoblasts of the iniaginal disc difTerontiato from ectoderm; the lirst-formed myofibrils are homogeneous; the teloj)hragmata precede the appearance of the Q-discs; the latter are at first very delicate and only gradually acquire their tj-pical definitive width. The sarcosomes appear only relativel}^ late, shortly before functional activity of the wings.

4. The order of development of the two chief cross-stripes, the connecting Z-membranes and the Q-discs, explains the exact horizontal alinement of similarly modified levels of the constituent fibrils of a striped muscle fiber. The telophragmata probabl}' function chiefly as the pathways along which the deeply staining substance of the Q-discs first enter the sarcostyle, and along which metabolic products pass to and fro between the sarcostyles and the interfiber tissue spaces.

5. In the effort to disclose the ultimate physicochemical bases of muscle contraction, we may legitimately and confidently confine ourselves to the structure of the sarcomere of the relatively coarse myofibril (sarcostyle) of the wasp's wing muscle. The fundamental factor in muscle contraction is located in the movement of the deeply staining sul)stance of the Q-disc against the telophragmata in the formation of contraction bands. The concomitant shortening and thickening of the sarcomeres is interpreted as the result of a change in shape, from ellipsoidal to .spherical form of the ultimate colloidal particles of the intrafibril sarcoplasm, following an increase of surface tension of these particles (submicrons) resulting from a decrease of surface electrical charges due to the passage of electrolytes (crystalloids of the deeply staining substance of Q) among the colloidal particles.

STRIPED MUSCLE STRUCTURE 119

LITERATURE CITED

1 Hdllard, II. II. 1916 On the occurrence and physiological significance of

fat in the normiil myocardium and ntrioventricuhir syHtom (bundle of His), intcr.stitliil K>°aniiK'» (mitnrhiiii<lriiil and |>h>>.Mpholipinc8 in cardiac muscle. .\m. Jour. .Vnat., vol. 19. p. 1.

2 GouLEWsKi, IC. 1901 Ueber die Entwirklung dcr qucrgestreiftcn musku losen Gewebcs. Krakauer .\nzciger fcitcd from Ileidcnhain).

3 Heide.nh.mn-, M. 1911 Plasma und Zcllc, S. G41-648.

4 IIeidenhain, M. 1913 Ueber die Kntstehung der quergestreiften Muskel substanz bei der Forelle. Bcitriige zur Teilkorperthcorie, II. Arch. f. mikr. Anat.. Bd. 83, S. 427. 3 Jordan, H. E. 1917 The microscopic structure of striped muscle of Limulus. Pub. no. 251, Carnegie Inst, of Wash., p. 273.

6 1917 Studies on striped muscle structure. III. The comparative histologj' of cardiac and skeletal muscle of scorpion. .\nat. Rec, vol. 13, p. 1.

7 1919 Studies on striped muscle stnicture. IV. Intercalated discs in voluntary striped muscle. Anat. Rec, vol. 16, p. 203.

8 1919 Studies on striped muscle structure. V. The comparative histology of the leg and wing muscles of the mantis, with special reference to the N-discs and the sarcosomes. .\nat. Rec, vol. 16, p. 217.

9 1920 Studies on striped muscle structure. VI. The comparative histology of the leg and wing muscles of the wa-^p, with special reference to the phenomenon of stripe reversal during contraction and to the genetic relationship between contraction bands and intercalated discs. .\m. Jour. Anat., vol. 27, p. 1.

10 LiLLlE, R. S. 1912 The physiological significance of the segmented struc ture of the striated nmscle fiber. Science, vol. 36. p. 247.

11 Luna, E. 1913 Sulla importanza dei condriosomi nella genesi dclle myo fibrillc. Arch. f. Zcllf., Bd. 9. S. 4.>S.

12 Maoai,i,um. \. B. 1905 On the distribution of potassium in animal and

vegetable colls. Jour. Physiol., vol. 32, p. 95.

13 Mbnten, .Maud L. 1!X)S The distribution of fat. chlorides, phosphates,

potassium and iron in striated muscle. Tran. Canadian Institute, vol. 8. p. 403.

14 Phena.nt, A., BotJiN, P., ET Maillakd. L. 1904 Traitd d'Histologie, T. 1,

p. 440.

15 ScuAEFER, E. \. 1912 Textbook of microscopic anatomy. Longmans,

Green & Co. 10 TintLiN, I. 1915 1st der Grundmembran eine konstant vorkommende Bildung in den quergestreiften Muskelfasern? .Vrch. f. mikr. .Vnat., Bd. SO. S. 31S.

EXPLANATION OF FIGURES

T!if drawings were made from sections of tissue fixed in 10 per cent formalin. The sections were cut at 1^. and stained with iron-hematoxylin. With the exception of figure 13. the magnification of the drawings is 1300 diameters. The section from which figure 10 was made was lightly counterstained with eosin.

PLATE 1

EXPLANATION OF FIGURES

1 <j. Longitudinal section of myoblast immediately after separation from the imaginal disc. The originally single nucleolus has become divided in anticipation of the ensuing direct division of the nucleus. 6, Three slightly older, now multinucleated myoblasts, in process of fusion to form a muscle fiber. Delicute peripheral myofibrils are faintly discernible. The specimen from which these drawings were made was at the latest larval or earliest pupal stage; wing pads were present, but the legs had not yet appeared.

2 a, b and c. Transverse sections of three successively older myoblasts from the same specimen as figure 1. Sections a and 6 correspond to <i and 6 of figure 1 ; c represents a slightly older stage, cut at the level of lateral fusion as indicated by the two radially adjacent nuclei, c.t., an intcrfiber connective-tissue cell in early stage of metamorphosis into a fat-cell.

3 Transverse section of later wing-muscle fiber from same specimen. The nuclei are now very numerous and scattered apparently at random. The myofibrils are uniformlj- distributed throughout the sarcoplasm and appear as darker dots in transverse sections. <•.(., a connective-tissue cell. The latter are very numerous and completely fill the wide interfiber spaces.

4 Longitudinal section of fiber like the one of figure 3. The homogeneous myofibrils are conspicuous between the columns of nuclei. The interfiber spaces are approximately of the width of the diameter of the fibers. These spaces are completely filled with short fusiform and polyhedral connective-tissue cells.

5 Transverse section of older fiber, from white pujia (with wings and legs). The fibrils have become much coarser and appear radially disposed along the left border.

120

8TRIPED MUSCLE STRUCTURE H. E. jonnoN

PLATE 1

PLATE 2

EXPLANATION OF F1GUKE8

r> Loiiiiitudiiiiil siH-tion of filior like thiit of fig. 5. The nuclei are loiiR narrow oleiiieiits (livldiriK dirortly into smaller nuclei. Among the homogeneous coarse myofibrils are scattered smaller irregular granules. There is as yet no indication of telophnigmata or other stratification in the fibrils.

7 IVri|iheral portion of older fiber in transverse section, showing the coarse myofibrils (sarcostyles), a iieripheral nvicleus. and the sarcolemma. Sarcosomes have not yet made their appearanre. The .section is of a later pupal stage (gray pupa).

8 Portion of adull w ing-muscle fiber in transverse section, showing the coarser myofibrils and six included irregular sarcosomes.

9 a. b, c, (I and e. Three successive stages in the later development of the myofibril, from a longittulinal section of the thoracic (wing) muscles of a gray pupa (same as fig. 7). a shows two adjacent fibrils in which only the Z stripe (telophragma) has appeared. This strijie stains very intensely at this stage. In fibril /> the Z-slripe is faint, and a deeply staining but thin Q-disc has appeared.' In c the Q-disc has become much thicker. </ and e are at the same stage of development, but in (I the (^-disc has become bisected and an H-dise has in eonsecpienee appeared, and in c the nietafibrillar constituent elements of the sarcostyle have become conspicuous.

10 Longitudinal section through region of attachment of nuiscle to epidermis. The nucleus lies in the 'tendinous' portion of this connection. This tendinous portion stains much more deeply in a very dilute eosin eounterstain than the muscle. At the levels where the sarcostyles break up into the 'tendon fibrils' the telphragmata disappear.

11 Small area of longitudinal section of wing-muscle sarcostyles of older (black! pupa. Between the sarcostyles are single rows of small oval sarcosomes, generally two to a sarcomeric interval.

r2 Portion of a transverse section of a fiber like that of figure 11, including one nucleus. Many of the apparently oval sarcosomes are now seen to have lateral wing-like processes. Compare with figures 7 and 8.

1.3 Sarcostyles of definitive wing muscle of adult wasp at four successive stages in contraction. Fibril o is in repose; b is in an early, r in a later stage of contraction; </ represents a contracted fibril with almost f\illy formed, double contraction band.

12--J

raiPED MUSCLE STRUCTURE

H. E. JORDAN

PLATE 2

-J_.

-1H

Z •^•r<) ■<■>*

e ~

10

Rosumen por la autora, Kaothe Weller Dewey, Universidail do Illinois.

r(mtnbuci6n al osliulio dpi sistema linfiltico del ojo.

La autora considcra a la (•ol()raci6n vital conio cl niojor medio para donioiistrar los capilaros linfaticos y espacios linfaticos del ojo, del inisiiio iiuulo <iue los de otras partes del euerpo. I.as eelulas endoteliales cjue tajjizan estos eanales tienen la propiedad de tenirse con e! colorante \ital. Los resultados de los experinientos eon la parafeiiileiidiaiiiiiia liaeen resaltar las difereneias eiitre los espacios de los tejidos y los espacios linfaticos, el plasma y la linfa jiropiament edieha. Las ohservaciones llevadas a cabo niediante el tenido vital eon referenda a su signifieaci6n presunta en el sistema linfiitico no estiin en eontradieei6n con los hechos anat6micos reconocidos. Aceptando cl hecho de que las c^lulas endoteliales vitalniente tenidas denotan la presencia de canales linfaticos, se eomprueba la ausencia de dichos canales en la c6rnea, niientras que la conjuntiva los posee abundantcs. La escler6tica posee muy pocos capilares linfaticos, que a veces faltan en absoluto; puedcn acompanar a los vasos sanguineos que la atraviesan. Tanijioeo existen en la retina. La coroides los presenta principalmente en los coriocapilares. La jilandula lagrimal. el tejido orbitario y los parpados presentan abundantes capilares linfaticos. No existen en el cartilago tarsal de los parpados. Las eelulas vitalniente tenidas son mas abundantes en el euerpo eiliar y, especialmente, en los procesos ciliares, que en cualquier otro parte del ojo. Esto coincide probableniente con niayores actividades funcionales, tales conio la intensa i)articii)aci6n en la secrecci6n del fluido intraocular. El iris estd provisto de esca.sos capilares linfaticos, a pesar de su rica irrigaci6n sanguinea. Esto indica (\w tal 6rgano no deseiniienii las mi.-inias actividades funcionales fine el euerpo eiliar.

TrnrMlatiiin l>y Jim^> K. Nonidn Cornrll L'nivcraity Medical College. N. Y.

AUTHOB e ABSTRACT OP THIS PAPER ISSUED BY THE BIBLIOQRAPHIC SERVICE, MAT 24

A CONTRIBUTION TO THE STUDY OF THE LYMPHATIC SYSTEM OF THE EYE

IvAETHE W. DEWEY Research Laboratory of the College of Dentistry, University of Illinois

THREE FIGURES

In view of the great interest which evidences of an etiological relationship between infectious processes about the teeth and pathological conditions in other regions are receiving in recent years, clinical and anatomical investigations vie with one another in furnishing the necessary scientific foundation for more or less empirical conclusions. Relations between certain affections of the eye and diseased teeth have been recognized since the remotest ages, but reliable reports of actually observed transmissions of pathological processes from the teeth to the eye are all of a relatively late date. The number of these published reports is not inconsiderable.' Little, however, is yet known concerning the routes of transmission that could in any way be considered as positive and final. The dental origin of cases of the so-called dental eye fistula, orbital phlegmon, and abscesses is revealed chiefly through the fact that the eye conditions either promptly disappeared with treatment of the involved teeth or that they developed upon the extraction of a tooth with or without involvement of the maxillary sinus. The traveling of the pus from diseased teeth to the orbit, as, for example, in phlegmon, has often been represented as being per continuitatem along the outer surface of the maxilla over the orbital border. Frequently a transmission by way of the \'eins is assumed, and also a few casual suggestions occur in the literature that the processes may progress by way of the lymphatics. The latter route, however, is probably more important and much more frequent than the

'A report of clinical observations along these lines will be published in .\rchives of Ophthalmologj', July, entitled ".\ffections of the Eye from Diseased Teeth."

125

126 KAKTHE W. OEWEY

scanty and incomplete statements concerning it would make us Relieve.

The demonstration of direct comnuinieations between the lymph sujiply of the dental region and that of the ej'e is obviously difiicult. In ])rovious experimental work for the demonstration of the lymphatics of the dental pulp and the peridental membrane' - indications of extensive anastomoses in the lymph-supply of these two regions were sometimes incidentall}^ obtained. In injections by the derota method of Prussian blue into the gum tissue the fluid was not only forced through the bony tissue of the jaw into Ijnnph-vessels of the peridental membrane, but sometimes deep and superficial lymph-vessels of the infraorbital region were also injected. The looseness of the orbital tissue makes injections in the region of the eye unsuitai)le for purposes along these lines: the injection mass will follow the direction of the least resistance and fill the loose tissue of the orl)it. This occurs also in injecting the liuid through the infraorbital foramen, which is the most accessible place for reaching hnnph-vessels in either direction to the eye as well as the dental region.

I'ntil recently our knowledge of the lymjih-supply of the eye region was very limited and it is still (|uite incomplete with regard to the lym!)hatic system of the ej'e proper. Bartels,' in I'.IOi), writes: "Nowhere besides in the lids and the conjunctivae have geiuiine lymi)h-vessels been surely demonstrated, while we may say that it has been shown with a proljability bordering on certainty, that in the cornea, the lens, aiid the vitreous body they are completely lacking. In fact, we need not look for a current of liuid in a stal)Ie oi)tic apparatus. It is <iuite dilTerent, however, in the other parts of (he eye which constantly have to perform most important work and where therefore correspondingly active metai)olic interchanges nuist be assunuul a priori. They have not yet been demonstrated, however."

.\ lymphatic apparatus of the orbit has been demonstrated by Birch-Ilirschfeld.' That the existence of such a system may be jjresupposed has been claimed l)efore him l)y some writers who are unwilling to consider the lymphangiomas of the orbit as heteroj)lastic formations; the occurrence of these speaks for the

LYMPHATIC SYSTEM OF THE EYE 127

presence of Ijanphoid tissue in the orbit even if in such minute amounts as to escape microscopical observation. By methods which, according to Birch-Hirschfeld, produce an increased lymph secretion or Ijinph stasis resulting in dilatation of the lymphcapillaries, this author believes he has seen distinct hmiph spaces in the orbital tissue — in the lipoid tissue, the lacrimal gland, between the muscles, and in the neighborhood of the optic nerve and the periosteum. With his methods he could not demonstrate the direction in which the lymph flows off nor a connection with any lymi^h-gland. He belie\'es, howe\'er, we may assume that communication exists between these spaces and the lymphvessels of the nose, and that there is a connection between the orbital lymph system and that of the surrounding regions through the perivascular spaces about the vessels passing through the superior and inferior orbital fissures.

Histologically, the demonstration of the minute lymph-vessels of most organs is very difficult. if notaltogetherimpossible. Postmortem, they are practically virtual spaces and the endothelial cells lining them are in general indistinguishable from the slender nuclei of the surrounding connective-tissue cells. In order to distend them and thereby render them more amenable to microscopic study Birch-Hirschfeld employed a drug which is known in pharmacology and toxicology' to produce chemosis and edema of the orbit, exophthalmus and increase of the iirtra-ocular pressure. This drug is paraphenylendiamine hydrochloride. He also made use of dionin, small pieces of which he introduced into the orbital tissue. The action of this drug is to cause dilatation of the capillaries and increase of the lymph excretion, and this is especially well demonstrated al^out the eye. Paraphenylendiamine, according to him, pi'oducos stasis of the Ijanph, and an increase of the secretion of the lacrimal gland, of the mucous secretion of the conjunctiva and the salivary glands. If a large dose is given, the edema of the orbit extends also to the face and the neck. Edema of the glottis is the final cause of death. Similar observations are reported by (Irunert,* ^latsinnoto,* Puppe.' The spaces in the orbital tissue and those in the lacrimal gland which Birch-Hirschfeld found dilated and filled

128 KAETIIE \V. UEWKY

with fluid after (iiainiiie poisoning arc believed by him to be lyMii)h-spaces, and he states that in some of the larger and medium-sized sjjaces he found a tlistinet endothelial membrane.

These statements bj' Bireh-IIirsehfeld seemed to me of extreme imiiortance. If the observations eould b(> verified and his eonelusions shown to be right, the use of paraphenyleiidiamine shouUl enable me to prove the correctness of a view obtained from previous experimental work on vital staining, which, in the absence of more positive proofs, I could express only suggestively.* N'ital staining, I stated, may be the means of demonstrating the lymi)h-chamiels of origin in most organs of the body by exhibiting their endothelial cells which havo an affuiity for vital stains, (iranting the correctness of Birch-llirschfeld's observations, paraphenylendiamine should be a valuable aid in such investigations by demonstrating a lumen in such endothelial-clad lymphchannels.

I tested this drug on two dogs, two cats, tea labbits, and ten frogs. The larger number of these animals were injected with lithium carmine ]>revious to their treatment with the diamine poison. The results of these experiments will be reported in detail in another paper as a question dealing largely with phannacology. They were disappointing to the extent that they contributed nothing to the main purpose of this study: the microscopical study of the tissues in diamine poisoning failed to reveal what I had expected to find. The dilated spaces in the edematous tissues are not lined with vitally stained endothelial cells. ^lost of them are simply surrounded by delicate fil)ers without any cellular elements; occasionally a slender nucleus maj' be seen in this wall, resembling as much the nucleus of a connectivetissue cell as that of a flat endothelial cell. Vitally' stained cells may be .seen near these spaces, but never so near as to justify the impression that they form any part of the wall. I am, however, not inclined to believe that these spaces are lymph-spaces, as Hirch-Ilirschfeld does, but consider them simply as tissue spaces and di.stended meshes in the connective tissue, nor do I regard the fluid as lJ^nph proper, but as a serous efTusion, plasma from the blood-vessels.

LYMPHATIC SYSTEM OF THE EYE 129

Sections from the edematous subcutaneous tissue of the face and over the lower jaw in rabbits show that all this tissue is split up into inniunerable spaces and sUts filled with fluid, to regard all of which as Ijinph-spaces, potential or actual, would not be reasonable. One of the chief effects of the drug seems to be on the blood-vessels, perhaps irritating the endothelial wall of the capillaries, and thereby rendering it more permeable. This is particularly noticeable in muscles of the eye. The bundles and fibers of the muscles are separated more than is normal; the fibers of the connective tissue in these intennuscular spaces are slit apart and all these widened meshes and spaces are filled with fluid, which stains well with hematoxylin. The muscles are richly supplied with blood-capillaries which wind in and out about the muscle fibers. But we fail to see any lymph-capiUaries with a perceptible lumen; if they are present, as is to be presumed, they are at any rate not dilated. The muscles about the eye, like some muscles of the face, show a brown discoloration after diamine poisoning. It is an interesting observation that, while the anatomical and clinical effects of paraphenylendiamine are so widely different in the different species of animals, and even in animals of the same species, they all have one feature in common, viz., this brown discoloration of certain muscles of the face. Some of the writers who have studied the effect of this drug claim that the cause of the edema is to be sought for in the lacrmial gland. On the other hand, Puppe believes that the stasis edema is perhaps due to the formation of thrombi in the veins, and KunkeP also assigns to the blood-vessels and the blood a greater significance for the development of the intoxication edema. My observations agree with the latter view.

On account of the extensive anastomoses of l>^nph-vessels obstruction to the outflow of lymph does not readily occur. We may conceive of the action of paraphenylendiamine as follows: in subcutaneous injections the drug enters the lymph channels, thence it is carried into the blood, where it irritates the walls of the blood-vessels, possibly having an injurious effect on the endothelial cells of the capillaries. Transudation of the plasma occurs very rapidly, the fluid filling all the tissue spaces and sep

130 K.VETHK W. DEWEY

arating the tissue elements. The function of the endothelial oell-^ of the lyniph-rapiilarios being not simply one of absorption of such free fluid, l)ut pr()bal)ly one of a selective action, of an interaction of metabolic processes, the fluid is not taken up and carried off rapidly enough with the result that stasis-edema develops.

The formation of l>nnph is not, as was formerly believed, a mechanical process, i.e., one of simple filtration and diffusion, but is work essentially done by the organs themselves. The mechanical theory' has been sujierseded by the cellular-physiological theory. The endothelial cells of the lj'mph-cai)illaries probably play a chief part in these processes. Although these capillaries end or begin as absolutely closed culs-de-sac, and the presence of a continuous endothelium represents a barrier between them and the surrounding connective tissue, "the relations between the vascular cavity and the connect ive-t issue spaces renuiin very close," as Delaniere'" states, "anil cellular inunigration and osmotic exchanges may always take place and the capillaries fulfill their function of drains, and, if the observations of Renaut are conHrmed, may even act as selective drains."

The value of i)araphenylendiamine in conjunction with vital staining is, in my opinion, this, that it illustrates and supports the theoiy of a difference between spaces filled with tissue fluids and real lymph-spaces and lymph-capillaries, which constitute the channels of origin of the lymph system. Bartels,' it is true, is rather skeptical as to any fruitful research along these lines. To him this nuich-debated (luestion is largely a philosophical one; he writes: The tiuestion concerning the origin of the lymph system and the development of the lymph stream from the flow of the tissue juices is a purely philosophical an<l not an anatomical one. This riuestion and that of the endings of the blood-vessels should be eliminated from anatomical discussions." Nevertheless, the contemporar>' conception of the origin of the lymph sy.stem is emphatic in uphohling the theorj' of an independence of the lymph-spaces and the tis.s\ie spaces, and of the absence of open communications between them, as also of a difference between plasma from the blood-capillaries and Ijmiph proper.

LYMPHATIC SYSTEM OF THE EYE 131

This fact is also illustrated by the observation that injections into the submucous cellular tissue of the skin may fill the tissue clefts and tissue spaces and produce edema, but not fill the lymphvessels. Similar observations may be made in injecting the blood-vessels with carmine gelatin; when the injection is continued under high pressure for some time, it may happen that the fluid portion of the injection mass is pressed through the stretched capillary wall and fills the tissue spaces producing edema without entering into lymph-vessels. In fact, I have never been able to fill lymph-vessels by way of the blood-vessels.

As a result of my observations from the experiments which I have made, I have come to the conclusion that the vitally stained cells within the connective tissue of organs represent the endothelial cells lining the capillaries of origin. By several writers the view has been expressed that the connective tissue evidently plays a much more important role than that of being simply a supporting stroma for other parenchymatous tissue, and this impression is imparted to them chiefly by the presence of these peculiar vitally staining cells which have been called rhagiocrines, resting wandering cells, macrophages, pyrrol cells, histiogenic wandering cells, etc. The ability of these cells to take up the vital stain apparently coincides with specific functional properties; they ha-\'e chiefly been alleged with secretory functions, and Renaut" writes of the connective tissue as "the largest of the glands with an internal secretion which exists in the body of vertebras." On the other hand, Ehrlich points out the extraordinary adaptability of the cellular elements of this tissue and that a specific modification adjusted to definite functions of the organ which it supports, cannot be considered as in any way astonishing. But nowhere in the literature have I found even a suggestion that these specific cells may belong to the lymphatic apparatus. Yet we know that everywhere in the body the structures which constitute the beginning of the lymph system are embedded within the connective tissue. It is only reasonable to assume that the endothelial cells which form the sole wall of these delicate priniaiy lymph-channels (l>nnph-spaces and lymphcapillaries) are more than a lining; that they are rather the chief

]^^2 KAETHE W. DEWEY

agents in taking up the ambient tissue fluid or plasma from the bUxxl-rapillarics after it has been altered in its contact with the cells. This jirocess is more than one of simple filtration, or even of a selective filtration; it is a process of vital elaboration, including probably secretion and excretion. Furthermore, as the plasma differs from the lymjih partiallj' as a result of the activities of the l)l()<id-caiiillary endothelium, so, too, the Ij'Uiph coming from these capillaries is again modified when passing through the Ijniiph-gland ; for there are distinct differences in the lymph entering the lymph-gland and that passing out of the gland. The latter shows an increase in the cellular elements; the tendency to fibrin formation and coagulation is more rapid, and the proportion of the water is diminished. This modification of the lymph is likewise the work of the enilothelium of lymph-capillaries, for the lymph-vessels entering the lymph-gland break up into capillaries, thus forming a true portal lymph system. Bearing this in mind, it is most significant that this whole process of the fonnation of a second capillary network and of a modification of the lymph bj- its endothelium is signalized, as in the endothehum of the lymph-capillaries of the connective tissue, by the property of the cells to take up the vital stain. We have here, therefore, the striking phenomenon that at the source of the lymph system there are specifically functionating endothelial cells of capillaries, and that these alone have the power to take up the vital stain. This property is absent in the endothelial cells of the Ijnnph-vessels arising from the capillaries, but is present again, and in a most marked degree, in the endothelial cells of the capillaiy network within the lymph-gland; these are most brilliantly stained, while the afferents and the efferents of lymph-glands have no vitally staining endothelial cells. Evans" also has pointed this out as a voiy striking phenomenon.

There are some other general observations on vital staining, agreeing well with anatomically established facts, to which I would call the attention. It is recognizeti that the lymphatics are unetiually distributed throughout the organism, seemingly in an arbitrarj' fashion. The same observation is made in regard to vitally stained cells. Lymph-vessels are considered to be

LYMPHATIC SYSTEM OF THE EYE 133

absent in a few organs and tissues; these are the same organs in which these cells are lacking. They are however, present in certain regions where lymph- vessels have not yet been demonstrated because of the almost unsurmountable difficulty in injecting them, but where they may reasonably be assumed to exist.

The character of these cells has been interpreted variously; but the name of resting wandering cells seems to be the least fitting, for the most striking feature about them is the stability which characterizes their occurrence, their distribution, their arrangement, and their number. They are invariably absent or present in the same locality and invariably scanty or abundant in the same region. The constant recurrence of these features gives a strong unpression that these cells are stationary and that they are part of some definite, functionating apparatus. As to the eye, the occurrence of the same unequal distribution in the various tissues is striking.

Schnaudigl'2 has studied the effect of vital staining on the eye and made observations concerning the occurrence of vitally stained cells which are on the whole in accordance with my own. They are as follows: the lens is devoid of vitally staining cells. No such cells are found in the cornea, but the conjunctival tissue overlying the corneal tissue shows such cells in large numbers. Occasionally a long, slender, vitally stained cell is seen to extend from the conjunctiva into the cornea. The sclera contains such cells in scant number; it is not quite clear whether they belong to the tissue proper or whether they accompany the vessels traversing the scleral tissue. The cells are quite numerous in the sclera and corneal conjunctiva and in great abundance in the limbus conjunctivae. The iris is very poorly provided with them; a cell is found here and there in the region toward the posterior chamber. This striking relative deficiency of the iris in vitally staining cells apparently was not noticed by Goldmann'^ who made the most extensive studies of vital staining with reference to internal and external secretions. But the statements of his findings in the eye are so brief that we hardly need discuss this difference in our observations. Assumhig that these cells denote the presence of lymph-capillaries, the extreme scarcity of such

THE ANATOMICAL RECORD, VOL- 19, NO. 2

l.M KAKTIIK \V. DKWr.Y

chaniiols in an mnaii wliicli is well siip])lio(l with I )loocl- vessels is siii'prisiiin. for we may admit witli some of tlic best authorities in anatomy that lympii-vossels maj' be supposed to exist uliercvcr there are blood-vessels. This iinaeeountable scarcity of vital staining cells in the iris is the more striking because the region which adjoins it is unusually rich in vitally staining cells, namely, the ciliary body and chieMy the ciliary processes. The cells are in i)roportion more plentiful here tlum in any other part of the eye. They are arranged along the i)lood-vessels, from which, however, they are alwajs some distance removed. They are present in all the processes; they arealways in abundance and they are always arranged in the same way. When the injections of the staining fluid have been continued for some time these cells are very large and the gramiles are very coarse; in the iris or sclera they remain small and slend(M'. an observation to which also Sclmaudigl calls the attention. This author believes that these fells have an almost dangerous afiinity for the staining substance; they are very vulnerable and show the injurious effect of the dye after prolonged contact with the staining fluid. He also believes that this affinity for the dye correlat(>s to sjiecific functions and that these consist perhaps in more than the secretion of the aqueous humor. From the root of the ciliaiy jMocesses the cells are observed to occur in small number along the subjacent inner layer of the ciliary body; the deejier region, facing the sclera, is scantily supjilied with these cells and resembles the iris in this respect. In the choroid, cells are found chiefly in the choroio-capillaris. There are none in the retina. The endo- and perineural tissue contains vitally staineil cells. The loose orbital tissue is relatively poor in the.se cells. The muscles of the ej'c show the cells in the interfascicular and interfibrillar tissue, generally in the neighborhood of the blood-vessels. They seem to be in closer relationship to tlie i)lo()d-capillaries than, for example, in the ciliarj' processes; they often seem to spin around the capillaries while these agidn wind aiiout the muscle fil)ers. In the lacrimal gland they occur in the interacinous tissue and the connective ti.ssue surrounding the glandular structures. The lids and the nictitating membrane are well supplied with them ; they always

LYMPHATIC SYSTEM OF THE EVE 135

occur in the same arrang;einent and the same distribution. The cartilage is absolutely free from such cells.

If we are to admit the view that these cells represent the endothelium of lymph-capillaries, we recognize that these findings corresi)ond quite well with what we actually know or may reasonably presume concerning the lymph supi)ly of the different parts of the eye.

Until recently our knowledge of the hmiphatic sj'^stem of the eye as of that of the dental region was very limited. I will sum up the most essential anatomical data which enter into the frame of this study.

The most important of recent work on the lymphatics of the eye is that of ^lost.'^ His results showed, in brief, the following: The conjunctiva of the lids and the eyeball contain very delicate l)ut dense networks of lymph-vessels. At the free border of the lids they pass over into those of the skin of the eyelid. The lymph-vessels from these two networks are divided into superficial and deep ones, chiefly according to whether they arise from the outer skin of the lid or from the conjunctiva; a sharp separation is not possible since both regions communicate with each other. The superficial vessels are apparently finer and less numerous; they course in front of the orbicularis muscle and in the superficial portions of the subcutaneous fatty tissue and only in the neighborhood of their regional glands do they pass into deeper regions. The deeper vessels form many anastomoses in the deep cellular tissue of the lids and then pass on peripherally behind the orbicularis muscle. The superficial as well as the deep vessels are divided into a lateral and a median set; they empty into the submaxillary lymph-glands.

The superficial lateral ^•essels originate chiefly in tlie skin of nearly the entire upper lid and about the outer half of the lower lid. Their first and chief regional gland is a typical gland situated superficially in the parotitl gland at the level of the external auditory canal. From this gland vessels go to other deeper parotid lymph-glands. Only exceptionally do the superficial lymph-vessels empty directly into the deep nodes. One or two lymph-nodes situated at the lower parotid pole and belonging to

13G KAKTIIK \V. DKWKY

the group of the sviperficial cervical ^lantls are also to be considere<l as rcfiional glaiuls, because they may receive direct afferents from those regions of the eye.

The deep lateral vessels arise in the conjunctiva of the upper lid and the outer third of the lower lid. The regional glands, besitles the superficial typical parotid lymph-nodes, include one or two nodes deeply emhedtlcd within the i)at()tid gland itself.

The superficial median vessels arise chiefly in the skin of the inner half of the lower lid and that of the inner corner of the eye. Their regional gland is one of the submaxillary lymph-glands, especially that situated mesially of the anterior facial vein. The deep median vessels arise chiefly from the conjunctiva of the inner two-thirds and from the region of the caruncula. They form frequent anastomoses in the lid and pass along the anterior facial vein to the submaxillaiy glands and chiefly to a gland lateral to the one mentioned before. Sometimes this one is also injectetl. All these lym])h-vessels go secondarily to the deep cervical glands situated along the internal jugular vein, at the junction with the facial \ein. A direct connection of hniiphvessels of the lids and conjunctiva with these secondary glands could not be demonstrated, liefore the vessels of the lids aiui conjunctiva, and especially the median vessels, enter the parotid and submaxillaiy Ijnnjih-glands they may pass through intcrmediarj- Ij-mph-nodes of the face (lymphoglandulae i)uccales sive faciales) situated along the course of the anterior facial vein.

The submaxillaiy lymjih-glands receive also the lymph from the outer vessels of the gingiva of the up])er and lower jaw, from the inner vessels of the lower jaw, and from the vessels of the peridental membrane of all teeth. No absolutely definite lines, however, can be drawn with regard to their relation to the different groups of teeth. For there are, on the one hand, variations in the number and location of the lymph-nodes themselves; on the other hand, it not infre(iuently happens that single lymph-vessels from a definite region |)ass by the regional node into which all the others enter and empty directly into a remoter lym])h-node. Another rea.son for this irregularity is the fact that the vessels from the gingiva form plexuses in the upper and lower mucosal

LYMPHATIC SYSTEM OF THE EYE 137

fold of the vestibulum oris, from which lymph-vessels pass out into the lymph-glands.

An unportant path of communication between regions of the eye and the teeth is through the infra-orbital canal with its nerves, arteries, veins, and lymph-vessels. These send branches in either direction. Two small canals, the anterior and median alveolar canals, divide off directly from the infra-orbital canal and are continued as grooves within the wall of the antrum of Highmore. They transmit the corresponding nerves and bloodand lymph-vessels to the premolar, canine, and incisor teeth. The posterior alveolar canals, of which there are two or more, are continued from foramina on the infratemporal surface of the maxillary bone. They transmit the alveolar nerves and vessels to the molar teeth and also to the walls of the antrum. Within the wall of the maxillary bone all these canals form grooves rather than canals. Very little is known yet of the lymph-vessels of the accessory sinuses. Schweitzer'" states he obsei'ved that lymph-vessels from the maxillary sinus passed out of the infraorbital foramen and entered the submaxillary lymph-glands.

In the endless contro^•ersies concerning the identity or difference of tissue spaces and true l>nnph spaces it has been customary to use the investigations of the cornea of the eye as the chief basis for discussions. The corneal spaces are not recognized now as lymph spaces. These and other spaces, like Tenon's space, the suprachoroidal space, spaces in joints and tendons, the endoand perilpnphatic spaces of the ear h&xe only a remote relationship to the lymph system; their functions differ in every case; frequently they serve only to fae-ilitate gliding motions and displacements necessary in the movements of the eye.

The iris contains spaces filled with fluid, which communicate with the anterior chamber and with the spaces in the ligamentum pectinatum through the furrows or crypts on the anterior surface. These spaces in the iris are regarded as belonging to the lymph system.

Cienuine hnnph- vessels have not been demonstrated either in the choroid or the sclera. According to Sattler, the veins of the vascular layer of the choroid are surroimded by perivascular

13S KAETHE W. DEWEY

sheaths, liiiod with eiulothi'lial cells. Toward the capillary layer, there exists, he believes, a eoiitimuius eiulothelial iiieinbrane which represents the liinitiiifi; iiieiiii)raiie of the vascular layer.

There are no lymph-vessels in the retina.

It has become customary to consider the ciliary body as the main source of the intra-ocular fluid (Leber," Wessely'*' '"). Hamburger-' ascribes also to the iris an important role in the function: in fact, he believes that every part of the eye participates in the secretion and resorption of the fluid, ^^'essely is of the opinion that it comes nearest to a transudate. It does not contain any substance which is foreign to blood-serum. There is, hence, no reason why we should not consider the process of its secretion as a filtration process. Some difficulties arise from the relatively high salt content and the involved greater o.smotic pressure, a property which it shares with the lymiih. The most striking difTerence is no doubt the low albvunen content which places it, on the one hand, in a class with the cerebrospinal fluid, the amniotic fluid, and the urine excreted in the glomeruli of the kidney, and, on the other hand, makes it stand in marked contrast to the lymph, ("ounterpressure to transudation may be the explanation: l)iit we are quite as well justified in supposing that the presence of a sjiecial epithelial layer which co\'ers the vessels may be the cau.se of the retention of the albumen. In the eye, the epithelium of the ciliaiy processes and the endothelium of the iris may act as such barriers.

Schnaudigl'^ expresses the view that the vitally staining granular cells in the connective tissue of the ciliary body may be the chief agents in the secretion of the intra-ocular Huid. The epithelial cells covering the ciliary jirocesses remain colorless in injections of trypan blue, an observation which I also made with lithium cannine. It does not seem permissible to me to assume this specific function from the mere fact that these cells have a pronounced affinity for stains. For we nmst bear in mind that not only <lo vitally staining cells practically occur throughout the body in the connective tissue, but also tiiat in\ariably they are larger and more coarsely granular in definite regions of the body, for example, in the pia of the brain, where they occur in patches,

LYMPHATIC SYSTEM OF THE EYE 130

in the choi'oid ])loxus. in certain regions of the nasal ajiparatus. On the other hand, there are cells admittedl}^ endowed with secretory functions, cells other than those within the connective tissue, which also have a pronounced affinity for vital stains (the epithelial cells of the choroid plexus, in the hypophysis, the thyroid glantl, the sj^ncytial cells of the placenta, the epithelial cells of the convoluted tubules of the kidney), while other cells of a similar type are not stained by trj'pan blue or carmine. I am more inclined to believe that, inasmuch as these particular vitally staining cells occur practically every^vhere in the connective tissue, they have everywhere the same function to perform and, inasmuch as in some localities they are invariably more intenselj' stained, they are involved either more intensely in the same process or in another associated function. Along this line of reasoning we may also assume that the function of lymph secretion or lymph resorption is associated with the secretion of a fluid related to IjTiiph, such as the cerebrospinal fluid, the intra-ocular fluid, or even the chyle. From this standpoint the great scarcity and smaller size of A'italh' staining cells in the iris would speak against the view of some writers that the iris is notably involved in the secretion of the aqueous humor, while the presence of a large number of intensely staining granular cells in the ciliary body support the more generally accepted theory that these are the main source of the intra-ocular fluid. On the other hand, there is nothing in my ^•iew of the part which the vitally staining cells play in the lymi^hatic apparatus that would contradict the view expressed by Hamburger that there is a more active resorption of the fluid by the iris through Ijnnphchannels than the generally assumed venous drainage into the canal of Schlemm. The fluid has a direct entrance into the iris through the crypts and thence into the lymph-vessels. According to mj^ observation, lymph-channels which simply convey lymph have no vitally staining endothelial cells. This might explain the curious fact that there are so few of such cells in the iris, especially in the anterior portion. As to the drainage mto the canal of Schlemm, Hamburger states, that the resorption through the spaces of Fontana may also be along perivascular lymph-spaces and not by the l)lood-\essels.

140 KAETHE W, DEWEY

lUnLIOGRAPIIY

1 Dewey, Kaethe, and Noyes, F. B. 1917 A study of the lymphatic vessels

of the dental p\ilp. Dental Cosmos, vol. oS, p. 436.

2 XovES, F. B., AND Dewey, Kaetiie lOlS The lymphatics of the dental

region. .lourn. .\m. Mod. .Xs.-*., vol. 71, p. 1171).

3 Bautei.s, r. I'.KH) Das Lymi>hKi'fasssy.stom. S. 50. Jena.

4 BiKCii-HiKsriiFELD, A. I'JO'J Die Krankheitcn der Orbita. Graefe-Sac misch Hnndbuch der gesamten Augenheilkunde, 107-170 Licferung.

S. 201. a GRrxERT. K. liX).3 Die Augensyniptome bei Vergiftung niit Paraphenylen diamin ncbst Bemerkungen iibcr die Ili.stologie derTriinendriise. Ber.

iiber d. 31, Vers. d. Ophth. Gescll.s., S. 20S. M.\TsrMOTo, H. 1901 Ucber die Giftwirkiing dps Paraphenylendiamins.

Wiirzbiirg, I. D.

7 PcPPE, G. 1S90 I'eber Paraphcnylendiaiiiin Vergiftung. Vicrteljahrs schr. f. geriehtl.Med., 3. Folge, Bd. 12, Siipplenirritsheft,.'^. 110 (quoted by Matsumoto).

8 Dewey, Kaethe 1918 A contribution to the study of the iiathways of the

cerebro.s|)inal fluid and the choroid plextis. Anat. Rec, vol. 15, p. 1. KuNKEL, .\. J. I'.Wl Handbueh der Toxikologie. S. 610. Jena.

10 Delamere, (!. 1904 The Lymphatics: Chicago. 71 (translated from Poirier

and Char|)ey by Leaf).

11 Resaut 1907 Les cellules connectices rhagiocrines. .\rch. d'anat. micro scop., vol. 9, p. 495.

12 Evans, H. M. 1915 The macrophages of manmials. .\iii. Jnurn. of Phys.,

vol. 37, p. -242.

13 ScilNAUDluL, O. 1913 Die vitale Fiirbung uiit Tryi)anblau am .\uge. .Vrch.

f. Ophthalm., vol. 80, p. 93. 11 GoLDMANN, K 1909, 1912 Die iiusserc und innere Sekretion des gesunden

und kranken Organismus im Lichte vitaler Fiirbung. Beitr. z. klin.

Chir., Bd. .54, S. 192, and Bd. 78, S. 1. 15 Most, \. 1905 Ueber die Lyin|)hgefasse und die regioniiren Lymphdriisen

der Bindehaut und der Lidor des Aiiges. Arch. f. .\nat. u. Physiol.,

.'Vnatomical part, ]). 90. 10 Schweitzer, li. liX)7, 1909 Ucber die Lymphgefiisse des Zahnflei.sches und

der Ziihne beim Menschen und bei Siiugeticren. Arch. f. mikrosk.

Anat. u. Entwickl., Bd. 09, S. 807; ibid., Bd. 74, S. 927. 17 Quoted by KoELi.iKER, .\. 1902 Handbuch der Gewebelehre des Men.schen,

Gefiisssystem. Bd. 3, S. GC5. Leipzig. IS Leher. T. 1913 Die Cirkidations- >ind Krnahningsverli:'iltnis.sp des Auges.

Graefe-.Saemi8ch Ilandbucli <ler ges. .Vugeidieilk., Bd. 2, 2. Aufl.

19 Wk.smely, K. 1905 Der Fliissigkcils- und ,'^lolTwecli.sel iles .\ugcs niit be sonderer Beriicksichtigung seiner Bc/iehungen zu allgemein i)hysiologischen und biologischeii Fragen. Krg. d. I'hys., Wiesb., Bd. 4, S. 505.

20 1908 Experimentelle I'ntersuchungen iiber den Augendruck, sowie iiber qualitative und quantitative Beeinflussung des intraokularen FlO.ssigkeitswechsels. Arch. f. Augenheilk., Bd. 00, i*^. 97.

21 Hamiiu RGER, C. 1914 Ueber die Erniihrung des Auges. Leipzig.

PLATE

141

PLATE 1

EXPLANATION OF FIGURES

1 Ui-trobulbar muscle tissue, stained with hematoxylin, a, blood-capillary windiiiK about a musdo fiber; h, vitally stained pranular endothelial cell, presumably of the linin)! of a lymph-vessel with collapsed walls; c, blood-capillarj' with two nuclei and separated blood-corpuscles, illustrating how the walls collapse as those of the lyni|)h-capillaries, when no corpuscular elements hold them apart .

2 Cross-section I hroURh the ciliary body, sclera, and conjunctiva. Unstained. a, large granular endothelial cells in the ciliary processes ;fc, smaller cells at the base of the processes; r, fewer slender cells in the outer third of the sclera. There are none in the inner two-thirds of the scleral tissue; (/, numerous larger cells in the conjunctiva.

3 Longitudinal section of a ciliary process. Stained lightly with hematoxylin, o, e))itlielial cells; h, blood-vessels; r, large granula cells.

142

LYMPHATIC SYSTEM OF THE EYE

KAETHE W. DEWEY

PLATE 1

ft

i* . ^

I.

143

Resunien por el autor, Ralph A. Kordenat, T'nivcrsidad de Illinois.

Contaniinaci6n de los cadaveres por cl Saccharomyces eerevisiae.

El crcoiinicnto do honRos sobre los cadaveres es causa de considerable i)erdida lie material en los laljoratorios anat6niicos. El presente trabajo da a conocer la existencia de tal contamiiiari6n. Vn estudio de los caracteres de los ciiltivos de dichos bongos, sus propiedadcs de coloraci6n, niorfologia y experinientos sobre aniinales, denuiestran que esta "levadura" es una variedad no pat6gena y saprofitica del Saccharoniyces eerevisiae. Vn estudio de varios gei'iiiieidas y antisepticos doiiiostr6 que el creciiiiiento de estos bongos se inii)ide enibalsainaudo los cadaveres con la siguiente f6rmula: Olicerina, 300 cc; forniol, 400 cc; alcohol, 1000 CO.; fenol, 90 granios; agua, 400 cc. Primero se us6 el bicloruro de niercurio (1)0 granios), pero despu^s se on)iti6 su enijjleo jiorcjuc forma un codgulo resistente y granular en los vasos sanguineos, cjue impide la penetraei6n completa del liquido embalsamador. y. adenuis, por el coste de dicha substancia quiniica. Su presencia en el cadaver no es necesaria para imi)edir el crecimiento del bongo. Como medida profilactica panos mojados en la siguiente soluci6n, con los {{ue se envuelven loscuerpos, imj)iden el crecimiento de la levadura asi como la desecaci6n y endurecimiento rajjiilos de los nn'isculos expuestos. La soluciAn se compone de: (llicerina, 50 cc.; fenol, 2 grainos; alcohol. ')() cc; agua (que se anadini) 1000 cc.

Tmnalatiun hy J(W- K. Xunidd Cornell Univcraity Mwlifal Collrar, N. Y.

author's abstract op this papkh issued by the didliographic aicuvice, may 24

CONTAMINATION OF CADAVERS BY SACCHAROMYCES CEREVISIAE

RALPH A. KORDENAT

Departments of Bacteriology and Anatomy, University of Illinois College of Medicine, Chicago, Illinois

TWO FICnBES

Recently the cadavers in the anatomical laboratories of the University of Illinois, College of JNIedicine, became covered by a moist, slimy, slightlj^ elevated growth that has caused no small amount of trouble and annoyance. The growth is dirty gray in color, loosely adherent, and does not penetrate the deeper tissues. It has never been noticed upon the unbroken skin of the cadaver; when the skin is remo\Td, however, the growth begins and spreads with great rapidity, making dissection of the specimen out of the ciuestion and causing great waste of material.

A quantity of this grayish substance was taken to the bacteriological laboratory for examination. Smears showed a large number of highly refractive, o\-oid cells, measuring about 7fx in diameter. In addition to these, there were large numbers of bacteria, especially staphjiococci.

It seemed plain that the slimy growth was largely made up of the above-mentioned ovoid cells, and cidtiu'es were therefore made in order to isolate and study them in detail.

After several attempts, pure cultures of the organism in question were obtained.

CULTURAL CHARACTERISTICS

Neutral plain agar. After twenty-foiu' hours' incubation at 37°C. small, round, bluish-gray colonies, about the size of a pinhead were seen. Their margins were smooth and regular. After an additional twentj'-four hours' incubation at room temperature

145

14li RALPH A. KORDENAT

these colonies turned white in color, l)iit did not increase in size or nunihor.

Fiiv per cent dcxtrnsc, agar. Twentj'-four-hour culures showed a growth similar ti> that on plain agar. After another twentyfour hours at room tcmjioraturo they were much larger and creamy white in color, becoming confluent in most cases so as to cover the entire surface of the media. The characteristic odor of 'yeast' was noticed.

Plain broth. The growth in jilain broth was not profuse. There was a slight flocculent sediment at the end of twentj-four hours. The broth was slightly turbid.

Fii<c per cent dextrose broth. The growth was similar to that in plain broth, but more pronounced; a heavy sediment and the characteristic odor of yeast.

Litmus milk. A marked acid production at the end of fortyeight hours with coagulation; the curd in most cases being completely digesteil, leaving a whitish turbid whey.

Gelatin stabs, (ielatin-stab cultures showed only a slight growth upon the surface, resembling that on jilain agar. No liquefaction.

The organism ferments glucose with the formation of carbon dioxide and alcohol.

ST.\INING PROPERTIES

Tiic organism stains fairly well with the oriiinary dyes and exceptionally well bj^ the Gram method, being strongly Grampositive (figs. 1 and 2). When stained by \\'right's stain, a welldefined blue cell membrane is seen with ])al(' lijue mitochondria and numerous vacuoles within.

iMOlU'IIOLOGY

The organisms average about 7 ix in diameter and are round to ovoid in form. In a hanging-drop preparation of a forty-eighthour culture, a highly refractive, non-motile, double-contoured cell is seen in an active state of bud<ling. The budding generally takes place from the long end of the ovoid cells. The younger

CONTAMINATION OF CADAVERS 147

cells are small and more rounded in form, while the older cells, from which the budding takes place, are more elongated. There is no tendency to form mycelia.

A pure known culture of Saccharomyces cerevisiae was comjiarcd with the organism taken from the cadaver, and it was found that in every way the two resembled each other in morphology, staining properties, and in general cultural characteristics.

4

I 2.

Fig. 1 Strain 'A.' Saccharomyces cerevisiae from cadaver. Gram's stain (X1200).

Fig. 2 Strain 'B.' Known pure culture of Saccharomyces cerevisiae. Gram's stain (X1200).

ANIMAL EXPERIMENTS

White mice, after being inoculated with rather large doses of a normal salt suspension of the organism, showed no ill effects.

An effort was made to reproduce the growth upon animals. Two dead rabbits, with the skin and viscera removed, were immersed in the embalming fluiil used for the preparation of the bodies in the anatomical laboratories. This embalming fluid consists of —

MS UALl'll A. KOUUENAT

Ctlyccrin 300 cc.

Koniitilin 400 cc.

Alcohol 1000 cc.

Phenol 45 grnni.s

Water 400 cc.

.\ftor a iicriod of diic wock they wore removed and a pure culture (if the cadaver orfiaiiisni planted upon one an<l a ))ure known culture of Saccharoniyees cere\isiac i)lantcd upon the other. At the end of three days the entire bodies of the two rabbits were .similarly covered with a slimy, grayish film. Two days later this growth became a dirty, creamy white and resembled that found u])on the cailavers. Thus, it is further evident that the two organisms are alike.

TIIEUMAL DKATII POINT

A series of small test-tubes, each containing 2 cc. of a suspension of the cadaver culture (strain 'A') and a known strain of Saccharoniyees cerevisiae (strain 'B') were used. At the different degrees of temperature indicated in the table, tubes of each of the two organisms were placed in a water-bath for a i)eri()d of ten minutes, allowing one minute for the temperature of the tubes to reach that of the water-bath. The tubes were then removed and per cent dextrose-agar slants inoculated and incubated. The results are given in the table. Both organisms were killed at 58°C'. for ten minutes, Init not at 5(i°(". for ten minutes.

Because of the apparent identity of the cultural characteristics and staining properties, as well as the results of the animal ex])erinients with the organisms, it is further evident that the contamination of the cadavers is a strain of Saccharoniyees cerevisiae.

I have been able to find nothing in the literature concerning the contamination of cada\"ers by Saccharoniyees cere\isiae. In a personal communication fir)Mi Dr. Irving Hardestj% of Tulanc I'niversity, he states that he has had a similar experience with 'molds,' that the mold thrives on formalin-hanlened bodies, that alcohol favors its growth, and that carlxilic acid will not check it unless the bodies are completely immersed in the carbolic solution.

CONTAMINATION OF CADAVERS

149

In order to find some disinfectant for this organism that might be effective in embalming fluids, the following experiments were performed :

The carbolic coefficients for potassium chromate, formalin, and mercuric bichloride were determined according to the method advocated by the U. S. P. H. S. (Hygienic Laboratory Bulletin no. 82) and further described by M. J. Rosenau in his test on "Preventive Medicine and Hygiene." Instead, however, of finding the coefficient with the use of a twenty-four hour culture of tj^phoid bacillus, forty-eight hour cultures of the two strains of

TABLE 1 Thermal death point

temperatdhe (10-mindte exposure)

STRAIN 'a' growth

STRAIN 'b' growth

°C.

48

Positive

50

Positive

52

Positive

56

Positive

58

Negative

62

Negative

64

Negative

68

Negative

70

Negative

72

Negative

74

Negative

78

Negative

Saccharomyces cerevisiae were used, because the yeast is in its most active state of budding at that time. It was found, by determining the carbolic coefficient, that phenol is the most efficient disinfectant for these yeasts. The action of mercuric bichloride toward these organisms is too inconstant for one to reach any definite conclusion as to its use. Formalin and potassiimi chromate have too low a coefficient to be of any value.

The prevention of this growth was now attempted bj^ altering the composition of the embalming fluid previously used. A rabbit was embalmed with the following fluid:

THE ANATOMICAI^ RECORD, VOL. 19, NO. 2

150 RALPH A. KORDENAT

Glycerin 300 cc.

Formalin 400 cc.

Alcohol 1000 cc.

I'lipnnl 90 Rram?

Mercuric bichloride 90 grnms

Water 400 cc.

It will be seen that this solution differs from the one previously mentioned in that the phenol is doubled and mercuric bichloride is added. The rabbit was immersed in the same solution for three days, seeded with cultures of both yeasts, and then covered with moist towels. \i the end of four days there was no growth. It was considered inadvisable to include mercuric bichloride in the embalming fluid not only because of the extra expense, but because there is a granular coagulation of the blood in the small vessels. This firm, granular coaguliun completely obstructs the smaller vessels, thus preventing the thorough penetration of the solution. Other rabbits, embalmed with the same fluid minus the mercuric bichloride, were seeded with both strains of the yeast and incubated for four days. These also showed no growth.

.\n examination was made of the dust taken from the floor, walls, and tables of the anatomical laboratory. Some of this dust was taken up by means of a sterile cotton swab and 5 per cent dextrose broth and agar inoculated and then incubated for twenty-four hours at room temperature. Many of the samples revealed Saccharomyces cerevisiae.

.\s a prophylactic measure, cloth was soaked with the following solution:

Glycerin 50 cc.

Phenol 2 grams

Alcohol 50 cc.

Water (q. 8. ad) 1000 cc.

and was draped over one-half of the bodies in the laboratory (group A) at the end of each dissection for a period of four months. The other half of the cadavers (group 1^) served as a control. During these four months none of the l)odies of group A was affected, while six of the bodies of group B became covered with the growth.

CONTAMINATION OF CADAVERS 151

By applying the above solution upon the embalmed bodies, the specimens are not only protected from the yeast but the glycerin keeps the exposed muscles more soft and pliable.

CONCLUSIONS

Because of the apparent identity of the cultural characteristics, morphology, staining properties, and of the animal experiments mentioned, it is concluded that the organism in question is a saprophytic strain of Saccharomyces cerevisiae.

The growth of Saccharomyces cerevisiae upon anatomical specimens renders them useless, thereby causing great waste of material.

Phenol is the most efficient disinfectant for this particular strain of yeast.

The contamination can be prevented by using the embalming fluids and the prophylactic measures mentioned.

The use of mercuric bichloride in embalming fluids is not practical; first, because it forms a firm granular coagulum of blood in the vessels, thus preventing the complete penetration of the fluid, and, second, because of the expense of the chemical. The prophylactic measures indicated not only protect the cadavers from the Saccharomyces cerevisiae, but prevent rapid drying and hardening of the exposed muscles.

1*3

THE AXATOMIC.VL RECORD, VOL. 19, NO. 3

ACGCST, 1920

Abstracted by E. D. Congdon, author. Loland Stanford .luiiior T'liivorsity.

Simultaneous occurrence of very small sphenoid and frontal

sinuses.

Because of the uncertainty as to the reason for failure or incompleteness of sinus development, the present almost unique instance of very rudimentary condititm of four siiuises merits description. The sphenoid sinuses were symmetrical in form and position. They were about 4 nun. in sagittal and 14 mm. in craniocaudal diameter. A lateral extension of the cavity brought each into series with the corresponding posterior ethmoid cells. The ostium of the left sinus was so far forward antl so lateral as to almost justify the interjiretation that it was an ethmoid cell. The ostium region on the other side was destroyed. The cavity interpreted as the left frontal sinus was so small that it is not certain that it extended beyond the ethmoid bone. There was no especial condensation of compact bone to warrant the supposition that, the sinuses may have been hindered in their development l\v infantile disease. It is possible that tlie sphenoid sinuses are to be grouped with others previously described by the writer which were apparently unable to exjiand through material of the concha-presphenoid fusion plane. Xo compen.^ation for the loss of these cavities was noticeable in the size of the other sinuses.

ATTHOR 8 ABSTRACT OF THIS PAPER ISSUED BY THK BIBLIOGRAPHIC SERVICE, JUNE 21

SIMULTANEOUS OCCURRENCE OF VERY S^VIALL SPHENOID AND FRONTAL SINUSES

E. D. CONGDON

TWO FIGURES

A few very small sphenoid sinuses have been recorded, and complete absence has been claimed bj' several observers. Incomplete de\-elopment and absence of frontal sinuses are both rather frequent. Only one previous record was found of the slight development of sinuses of two types in the same individual. This also had to do with the frontal and sphenoid cavities. I'hey were described by Wertheim ('01) in an eight-year-old child. The observation was made for a sufficiently early stage of development to admit of the possibility that the deficiency would have been made good to a considerable degree before adult life.

The explanations which have been advanced for the absence and incomplete development of the sinuses are at present supjjorted by little e^•idence. Information regarding the paranasal region needs to be collected in these cases if any explanation is to become more than a hypothesis. Although it is especially desirable that this be obtained for foetal and infantile specimens, since observations on such material will of necessity be rather infrequent, the conditions surrounding absence or incomplete development of adult sinuses should be examined for whatever information it can afford.

The rudimentary sinuses were found in the course of dissection and were preserved with the mucoperiosteum nearly intact. The subject was an adult male apparently of European parentage. The small spherical cavities were symmetricallj' developed and extended to the orbit behind the last posterior ethmoid cell (fig. 1). The anteroposterior diameter of the portion Ij'ing within the area usually ascribed to the sphenoid was 4 mm. and its height 14 mm. upon the right and 12 nun. upon the left side.

153

154

E. D. CONGDON

The ostium of the left sinus opened l):ick\vard, although it was so far lateral as to l)e little posterior to the nearest ethmoid cell. Were it not for the position of the aperture, the sinus could as well be classified as a posterior ethmoid cell with a recess in the sphenoid bone, because the |)art of the cavity in series with the ethmoid cells has a position frec[ucntly occupied by one of them, and the most posterior ethmoid cell also not rarely invades the supero-anterior part of the sphenoid where the median portions of these sinuses were located.

Fig. I Parasagittal diagrammatic drawing through left sphenoid sinus (a). Three posterii)r ethmoid cells as (6) represented by dash lines. .A. fourth, the most posterior which had been oi)ened in dissection outlined in an unbroken line. Above it the aperture of the sphenoid sinus also shown by an unbroken line.

The portion of the wall of the right sphenoid sinus corresponding to the aperture of the left is not jierforated and no comnumication of the sinus on this side with the nasal cavity occurs elsewhere. .V saw cut has destroyed that part of the wall lying a little more medially. Either the aperture niust have been situated in this region then or the sinus lacked an outlet. There ha.s been considerable discussion as to whether this second alternative ever occurs. Some authors categorically deny that a sinus can originate without an opening, since they believe sinus fonnation is always by the out-pocketing of the nasal cavity. Zuckerkandl ('93) states that he has seen two sphenoid sinuses

VERY SMALL SPHENOID AND FROXTAL SINUSES

155

without apci'tures in their bony walls. No other record of the lack of opening to the osseous wall of a s}:)henoid sinus was found. Evidently its absence is very rare, although closure of the aperture by the swelling of the mucosa is frequent. P"or this reason and because the closely similar companion sinus had an opening, it is very probable that its aperture was destroyed by the saw.

Fig. 2 Right frontal sinus lo). X 1.

The more rudimentary of the two frontal sinuses is shown in figure 2. There is a marked difference in the frequencies of absence of the frontal sinus as given by various authors. Onodi ('11) places it as high as 20 per cent, while Boege (,"02) finds it. to be only 4.9 per cent. Much of this tliscrepancy is probably due to different conceptions of what constitutes the earliest developmental stage of a frontal sinus as contrasted with a beginning ethmoid cell. The recess (fig. 2, a) is here regarded as a frontal sinus because it is already separated by a ridge from another division of the frontal recess and is in the ])roper position

1")() K. n. roNGDON'

to ciilarfio directly iiitu the i'rontiil bono. It is the passage into till' frniital hoiii' u|u>ii wliiih the aijplicatioii of tlip toiiii frontal to a siiiii^ should depend, liut it is u-iiaiiy not practieal)le, even if it is not impossible, to determine wlietlier small out-pocketiuKs of the frontal recess have passed beyond tlie confines of th(> ethmoid bone or not.

No peculiarities were observed in the other paranasal sinuses which could aid in lindinii the reason for the ruilimentary condition of the fr<intal and sphenoid sinuses. '1 he sponj^y bone surrounding the four sinuses was .-itjuiewliat more dense than the average. It may be, therefore, that foetal or infantile disease may have broniiht about a condition which interfered with the enlarfienient of the sinuses. Onodi (11) and Wertheini COl) have broufiht tofjether some eviilence of such an occurrence. The condensation of the spoiio:y bone was not extreme, and, since there was no atiophy of the nuicosa. the arjiument for (>arly disease is not convincinji. Furthermore, it would be surprising that sinuses at opjiosite ends of the nasal cavity should be affected while the maxillary and ethmoid sinuses opeiiinu: at iiiterjnediate positions are normally developed.

'riie explanation hrst suggesteil by Toldt "SSi for the origin of the bony plates in the s])henoid sinus and further elaborated by Cope ("17) and the writer ('!!•) may possibly be apjilicable also to the retardation of the sphenoid sinuses. Toldt regarded the planes and ridges as the renniant of material at the plane of fusion of the adjacent ossification centers of the sphenoid sinus which was able to re>ist the absorptive action of the periosteum during the enlargement of the simis.

Seven sphenoid sinuses out of two Innidred and forty two were found by the writer ('1'.)) whose posterior walls corresponded in position and direction with the usual i)lane of fusion of conchal and ]>resphenoid centers. This let! to the sviggestion that resistant material had prevented the e.vtension of (he sinus backwaril The two rudimentary sinuses Ikmc imder discussion lia\e jiosterior walls lying more anteriorly and somewhat more transversely than the usual position of the plane. It may be that in this instance a plane situated especially far anteriorly i)ut .in early stop to the backwaril extension of the sinuses.

VERY SMALL SPHENOID AND FRONTAL SINUSES 157

The incomplete development of the two pairs of sinuses in the same individual is suggestive of a correlation between the development of the two tj'pes. The interrelation of form and size of adult sinuses seems to show that alternative correlation is a common feature of sinus development when one of two adjacent sinuses succeeds in preempting space originally open to both and thus brings about the underdevelopment of its neighbor. The suggestion has also been made that as an adaptation to keep the total sinus space up to the usual amount the underdevelopment of some sinuses might be correlated with an unusually extensive growth of others through some unknown mechanism. As far as could be found, there is no evidence for the occurrence of a growth response of this nature. If there is a correlation which explains the concurrent retardation of development of the four sinuses in the specimen which has been described, it differs in type from the relationship just referred to in that the sinuses all vary from the norm in the same dkection. The retardation or absence of two frontal sinuses is so often bilateral as to be probably correlated. Less data are at hand for sphenoid sinuses, though a certain degree of correlation is probable. The retardation of development of frontal and sphenoid sinuses in the same head is so rare that its coexistence in the two types is probably a matter of chance.

LITERATURE CITED

BoEGE, K. 1902 Zur Anatomie der Stirnhohlen. Inaug. Diss., Konigsberg. CoNGDON, E. D. 1919 The distribution and significance of septa in the sphenoid

sinus. Cope, V. Z. 1917 The internal structureof the sphenoid sinus. Jour, of Anat.,

vol.51. Crter, M. H. 1916 The internal anatomy of the face. Philadelphia and

New York. Onodi, a. 1911 Die Nebenhohlen der Nase beim Kinde. Wlirzburg. ToLDT, C. 18S3 Osteologische Mittheilungen. Ztsch. f. Heilkuiule, Bd. 4. Wertheim, E. 1901 Beitrage zur Patliologie und Klinik der Erkrankungen der

Nasen nebenhohlen. .\rch. f. Laryngol., Bd. 11. ZucKERKANDL. E. 1S93 Xomiale und pathulogischc .Vnatomie der Xasenhohle

und ihrer pneumatisohen .-Vnhange. Bd. 1, Zweitc .Vufl., Wicn und

Leipzig.

Abstracted by E. D. Congdon, author. Lelaiid Stanford Junior University.

Anomalous fibrous cords in the hand and the phylogeny of the flexor digit orum sublimis tendon.

The fibrous cords are evidently renuiants of the ancestral short flexor muscles of the hand which are normally represented by the distal part of the flexor digitorum sublimis tendons, according to Eisler's theory. Thej' were attached proxiinally on the radial sides of the bases of the proximal jihalangos of the fourth and fifth digits and extended distally to bifurcate like the flexor digitorum sublimis tendons and insert on either side of the volar surface of the middle phalanx. The coexistence of the cores with normal flexor digitorum sublimis tendons apparently either contradicts this interpretation or disproves the theor3\ Also Bardelebon and Kajava state that the flexor digitorum sublimis tendon may exist side by side with the short musculature in certain mammals, and Fromont describes an anomaly in the human hand showing this condition. Since there are compelling reasons both from comi)arative anatomy and embryology for Eisler's theor>% it is proi>able that in these apparently contradictory instances the rudiments of the short flexors split to go only in part to the sul)limis tendon, while the rest was retained to form more or less jierfect short superficial flexor niusdes.

ACTHOB 8 ABSTRACT OF THIS PAPER ISSUED BY THE BIBUOGR.U>HIC SERVICE, JUNE 21

ANOMALOUS FIBROUS CORDS IN THE HAND AND THE PHYLOGENY OF THE FLEXOR DIGITORUIM SUBLIMIS TENDON

E. D. CONGDON

TWO FIGURES

Tendon-like cords were found in one hand of an aged male subject during the course of dissection by Mr. A. F. Warren. They lie upon the volar sides of the fourth and fifth fingers of the right hand and are closely similar in form and position (fig. 1). Each extends distally from an attachment on the radial side of the base of the proximal phalanx to the volar surface of the vaginal ligaments and there bifurcates. The slips thus formed pass to the opposite sides of the middle phalanx to insert into the vagmal ligament the adjacent fascia and the border of the dorsal extensor aponeurosis. Although of a somewhat less compact structure than a tendon, they can by no means be described as mere condensations of fascia. They did not bring about any marked flexion of the digits in the cadaver, and probably did not hamper movement during life.

The muscles to which the cords seem related are the short superficial digital flexors of amphibia, reptiles, and mammals. These take origin usually upon or in the volar fascia and have insertion in part at least by a pair of slips upon the sides of the metacarpo-phalangeal joint or more distally. The cords differ from the muscles in the position of their proximal ends. Instead of passing to the palmar aponeurosis along the mid-line of the digit they are deflected to the side of the base of the proximal phalanx. The dissimilarity is not great, however, because the cords are in continuity on the phalangeal bases with slips of insertion of the palmar aponeurosis. The relationship of the cords are not like those of the lumbricales or interossei, nor are either of these muscles abnormal or lacking.

159

100 E. D. CONGDON

The presence of ten short digital flexors in urodele amphibians, in nionotremcs, and marsupials is gonerally accepted as sufficient reason for regartling the structures as an anccstraf muscle for mar. and other mammals possessing the flexor digitorum sublimis muscle. .\s will be seen Testut and Fromont have also described the primitive short superficial flexors in the adult human hand. It can be accepted with a large degree of confidence then that the anomalies in question are actual short superficial flexor remnants.

Fig. 1 Hand (after Fromont, with parts omitted) showing abnormal digital muscles, a.a, tendon of flexor digitorum sublimis upon which are inserted muscles (e.e), interpreted here as short superficial digital flexors; 6.6, muscles interpreted as short superficial digital flexors taking the place of tendons of flexor digitorum sublimis. X i.

The flexor digitorum sublimis muscles of man and many mammals said to arise in part from the short superficial flexor muscles lie in large part within the fore arm, but send their tendons through the palm to the digits. Here they bifurcate to insert on cither side of the second phalanx. The flexor digitorum profundus, a companion nmsdc, whose muscle belly is also in the arm, inserts on the distal phalanges by tendons which pass between the bifurcations of the subHmis insertion. Eisler ('95) suggested that the tenninal portion of the sublimis tendon with its bifurcated insertion might be notfiing else than a degnerated superficial flexor muscle which after having changed completely to tendon had come, by means of its attachment to the palmar

ANOMALOUS I IBROUS CORDS IX HAND IGl

aponeurosis, to be continuous with a part of the fore arm flexor mass which earlier inserted on the palmar aponeurosis.

McMurrich's careful study of the flexor muscles of amphibians, reptiles, and mammals ('03) gave confirmation and amplification to Eisler's suggestion. It received support of another kind when (iriifenberg COo) found that a short flexor musculature in the hand of the himian embryo connected with a fore arm mass to form a flexor sublimis.

With this view of the origin of the flexor digitorum sublimis muscle it is not to be expected that any manmudian finger will possess at the same time one of its tendons and a short superficial flexor muscle. Kajava ('11) who has examined the digital flexor musculature of monotremes and eleven species of marsupials foiuid, as did McMurrich for other animals, that the two never occurretl together in the same digit. Yet Kajava states that there are certain insectivora and carnivora which do possess both the flexor superficialis brevis and the sublimis; Bardeleben ('90) much earlier made a like claim for Hyrax and, according to Eisler (95), for Paradoxurus.

References bj' two authors to aberrant muscles of the human hantl related to the anomaly here described bring confirmation to the theory of end-to-end fusion for the sublimis, but at the same time in part offer difficulties similar to those found by Kajava and Bardeleben. Testut is quoted by Kajava from a work which was not accessible as giving instances of the occurrence of a short flexor in the hvunan hand for the little finger which had replaced the corresponding sublimis tendon.

Fromont found a similar displacement of the flexor sublimis in two digits of the hand. His figure is copied here (fig. 2b). A better confirmation of the theory of end-to-end fusion bj' a reappearance of the primitive structures could scarcely be desired. The condition of the musculature of two other digits were found however to be more invoKed, the flexor sublimis was jiresent in each of them, l)ut theie W(>re also other slender nuiscle bellies taking origin from the trans\ersc carpal ligament, and inserting on the sublimis tendons (fig. 2a). The conclusion seems necessary that in these two digits part of the embryonic

1(12

K. I). CUNUUUX

lutlimont derived from the ancestral short flexor ha\e given rise to tlie correspondiiifi niuscles in the aihiit. The rehitionships and origin of these slender nuiseles are also like those of the two larger short sviperlicial flexors. Froniont terms the two of the four short muscles which insert on the suhlimis tendons sujierHcial hnnhricals, but likelihood of identitj- with Umibricals is excluded by their relationships and by the presence of almost normal lumbricals in the usual position in the digits to which thev are related.

Fig. 2 Fourth ;in(l liftli digits of loft hsuul witli tendinous cords (a.a) apparently representing remnants of short superficiiil digital flexors. X J.

It has been seen that llic instances of abnormal human nuiscular development described by Testut, Fromont, and the writer confirm the comparative anatomical evidence taken from a wide field by Kisler, McMmrich, anil Kajava for the theory of end-toend fusion to the extent that they reveal a tendency toward the formation of short suiierficial digital flexors in man. But at the .same time the anomalies of Fromont and the writer present a difficulty for the theoiy in the simultaneous occurrence of the short superficial flexors and the tendons which are .supposed to arise fro:n them. Observations of a like condition in the

ANOMALOUS FIBROUS CORDS IN HAND 103

normal structure of a few other mammals have already been referred to. A possible explanation of this contradiction is that when muscle and tendon appear together, the short flexor rudiment divided at an early developmental period to give rise to both the muscle and the tendon. The supposition that there were paired short superficial flexors in the human ancestry as in some other mammals and that their rudiments give origin one to the muscle and one to the tendon is not probable because of the rarity of the anomaly.

BIBLIOGRAPHY

Bardeleben, Karl v. 1S90 Uber die Hand- und Fuss-Muskeln der Saugetiere, besonders die des PraepoUex (Praehallux) und Postrainimus. Anat. Anz., Bd. 5.

Fisher, P. 189.5 Die Flexores digitorum. Verhand. Anat. Gesell., .\nat. Anz., Bd. 10.

Fromont 189.5 Anomalies musculaires multiples de la main. Absence du fl^chisseur propre du pouce. .Absence des muscles de I'eminence thenar. Lombricaux suppl^mentaires. Bulletins de la Societe anatomique de Paris, 5"" S6rie, T. 9.

Gr.Kfexberg, E. 1905 Die Entwickelung der Knochen, Muskeln und Xerven der Hand und der flir die Bewegungen der Hand bestimmten Muskeln des Untcrarmes. Anat. Hefte, erste Abt., Bd. 30.

Kajava, Y. 1911 Die kurzen Muskeln und die langen Beugemuskelu der Saugetierhand. I. jSIonotremata und Marsupiala. Vergleichendanatomische Untersuchungen. Anat. Hefte, erste Abt., Bd. 42.

McMuKKiCH 1903 The phylogeny of the palmar musculature. Am. Jour. Anat., vol. 2.

Abstracted by E. D. roiipdoii, author. Leland Stanford .Iiininr I'niversity.

Acquired skeletal deformities in a young fowl.

A young cockerel reared in an incubator till about three months of age showcil marked skeletal deformities which were in part mechanical efifects of confinement under a roof with which the bird gradually came in contact as it increased in height. The dorsoventral thoracic diameter was reduced a half. The tnmk anterior and posterior to the interacetabular line was bent downward. Apparently the down thrust of the neck against the thorax, due to the striking of the hea<l against the roof, together with the downward pull of the leg muscles upon the posterior portion of the trunk in the effort to keep the body from falling forward were responsible for the bend. There was marked underdevelopment and further deformity of the trunk skeleton. The cervical vertebral column approached adult size, but was retarded in differentiation. The wattles, comb, and beak showed a difTerentiation tyi)ical of a larger cockerel. The gross apjiearance of the trunk skeleton suggested that the cockerel may have had rickets. No microscopic examination was made. The only indication of poor health which was noted was a ruffling of the plumage for a few days before the animal was killed.

ACQUIRED SKELETAL DEFORIMITIES IN A YOUXG

FOWL

E. D. COXGDON Leland Stanford Junior University

SIX FIGURES

Two young cockerels reared in an incubator showed skeletal deformities approaching in degree the effects of a severe case of human rachitis. Although the influence of mechanical conditions upon the form of the mammalian and especially the human osseous system has long been studied, no descriptions were found in the literature of marked deformities in the domestic fowl or any other bird.

At the time when it was noticed that the chicks had been kept too long in the incubator, their backs were already in contact with the ceiling. As thej'^ grew, their heads must have been gradually' forced to a lower level relative to the rest of the body.

The cockerels evidenced poor health bj' a ruffling of their plumage (fig. 1), and they were somewhat sluggish in their movements. There is little doubt that the direct mechanical effects due to unusual posture and contact of the head with the roof were complicated by the influence of the other unfavorable conditions, such as high temperature and lack of exercise. It may be that the slight thickening at costochondral junctions and at the posterior ends of the uncinates, the bending of certain bones and other disturbances of growth, which will be described, are due in part to rickets and osteomalacia. Insufficient attention was given to the question before the skeleton was cleaned to answer the question. Tripier' tried the effect of diet with lowprotein content and containing little earth salts upon two young pullets, and described a change in the physical properties of their

' Arch, de Physiol, norm, ct pathol. (2) 1, 1S74.

16.5

IGO K. D. CONGDON

bones. He diil not mention, however, any change in skeletal projiortions or in the shape of the individual bones. » The larger and more deformed of the two fowl was used for a detailed examination of the skeleton. Two cockerels were chosen for comparison, one of these showed less maturity than the abnormal bird in comb, wattles, and bill, but was of nearly the same length and height. The other was chosen because the comb, wattles, and bill indicated an equal maturity. It was nuich larger than the abnormal fowl, though it was of average size in comparison with other normal cockerels in the same stage of development. The controls and deformed bird were all White Leghorn stock of ajipro-ximately pure breed.

Figures 2 to (i show the abnormal and the smaller control birds under equal magnification. The trunk of the abnormal cockerel is the smaller, although, as will be later seen, it would probably have been as large or larger had it developed normally. Some features of its deformity come out strikingly in the profile view with the trunk musculature in position (figs. 2 and .3). The thoracic region has a dorsal and a ventral diameter about half that of the smaller control. The posterior portion of the trunk is also somewhat smaller. \ comparison of figures 2 and 4 shows that incomplete development of the breast muscle and sternal keel ])la}' a consiilerable part in the thoracic reduction, though the body cavity in this region is also disproportionately small in cross-section in comparison with the parts external to the trunk.

The chief skeletal malformation which can be readily traced to a mechanical cause consists of a bending downward of the anterior and posterior portions of the trunk, so that their longitudinal axes meet at a slight angle at a transverse i)lane passing through the hip-joint. The pelvic bones are correspondingl}bent at their acetabuli and the sternum at the junction of the cartilaginous and bony portions of the keel. This condition evidentlj' develoijcd as an effect of the frequent down thrust of head and neck upon the thorax, when the head came in contact with the roof as the chicken tried to assume an erect posture. To retain the balance of the body upon the legs at the acetabuli.

SKELETAL DEFORMITIES IN A YOUNG FOWL 107

Fig. 1 Abnormal cockerel

Fig. 2 Abnormal cockerel

Fig. 3 Younger control cockerel. Magnification the same as in figure 2

Fig. 4 Abnormal cockerel.

THE ANATOMICAL Ri:i.ORD, VOL. 19, N0.3

KiS K. n. CONGDON

when the (lowiiwanl iiiipulso was (■oiiuminiratod hv the nock to till" thorax, the musculature from tin- lcfj;s to the part of the i)elvis postpiior to the acetuluilar joints must have contracted with more tlian ordinary vi^or. The two unusually powerful downward forces acting at opjHtsite ends of the trunk resulted in the hendinjj at the interacetahular transverse i)lane.

The trunk skeleton shows abnormalities throughout that may not he so directly connected with mechanical influences as is the hentling of the tnmk. The ribs ami uncinat(>s are thicker relative to their length than in the conlml liirds. The ends of the costal and sternal ribs, which articulate witli one another, and the posterior ends of the uncinates are enlarged. The disproportion of the trunk relative to the neck is shown in the vertebral column 1)\- a tlecrease in size of the successive dorsal vertebrae posterior to tlic siHDud. in place of the u>ual increase in their dimension.s.

The ossa coxae are not only bent, but are narrower than usual in conformity with the diminished diameter of the entire trunk relative to its length. The bend in the body of the .sternum has alreatly been mentioned. Its bony keel is of only half the usual dorsoventral extent at its posterior end, and decreases to an inconsiderable ridge anteri(»rly. The reduction of the keel is probably ilue in large part to the direct elTect of striking the breast against the bottom of the incubator, when as frequently happened, the down thrust of the neck at the thorax caused the animal to topjjlc forward after pushing its head against the roof. It is not prol)able that undenlcxclopmenl of the bivast muscle had much, if anything, to do with lack of develoj)ment of the keel, becau.se other bones as.sociated with these muscles including the coracoid furcula and body of the sternum, if of less than the usual size, are certainly much nearer to the norm than is the keel. The furcula which extends downward from the superior extremity of the coracoid to the antero-inferir)r angle of the keel has undergone a reduction in length coiiesponding to the decrease in the dorsoventral extent of the keel.

SKELETAL DEFORMITIES IN A YOUNG FOWL 169

There are details in the form of the skull which may be due to the repeated striking and pressure of the head against the roof. It should be stated, howexer, that these do not greatly exceed in amount the normal variation as shown in the skulls of four other cockerels of about the same age. The frontal region of the skull seems to have been pushed slightly forward and down (fig. 0). The weilge-shaped projection of the cranial cavitj- Ij'ing between the upper and posterior portions of the orbits is enlarged at their expense, so that the orbital processes of the frontal bone are unusually conspicious in a lateral view of the skull. The anterosuperior orbital region which usually has a nearly straight edge is convex and flares upward, as though the ej^eball had been pushed forward against it. A protrusion of the e^^eball was not looked for while the animal was ali\e and it was not noticed. In the photographs of figure 2 and 4 it appears to be present. • The comb is bent over as if from frequent contact with the roof, yet its deformity cannot be assigned to this cause with certaintj', because lopped combs are not rare among \Miite Leghorns.

Other gross malformations of the osseous sj^stem not directly traceable to the effects of pressui'c of the head against the roof manifest themselves both in the form and in the size of the bones. The ribs, uncinates, coracoid, furcula, and cervical vertebrae are. thicker and more rounded than in the controls. The pelvic l)ones and sternum are so irregular in form that they mask any abnormalitj- of a like nature, which may have been present. The surface markings of scapula, coracoid, furcula, sternum, cervical vertebrae, ribs, and imcinates are less sharply defined than in the control skeletons. The characteristics of form both as regards general outline and detail consist in a retention of an earlier developmental condition modified perhaps bj^ other pathological characters.

^'arious parts of the skeleton show irregularities in relati\e \(ilunie, some of which have been already mentioned. Though the retardation of the trunk is so marked that it can scarcely be questioned, the less marked differences of relative size in

170

K. D. CONfJDON

Fig. 5 Viiungor CKiiIri)! cockert,-!. Magnirication the same as in figure 4 I'"ig. 6 A. Skull and a portion of cervical vertebral rolunin of younger control eockerel. H. Skull and upper part of cervical vertebral C'>lunwi of aluiorinal cockerel.

SKELETAL DEFORMITIES IN A YOUNG • FOWL

171

other regions make it difficult to decide which if any of these have normal measurements. The wattles, comb, and bill indicate maturity equal to the older control bird, whose body is twice as large as that of the abnormal cockerel, and was chosen from a number of equal maturity as representing their average size. Since the skull of the deformed bird appears to be normal except for the deformity due to pressure against the roof and is of almost the same length as the control, it may be the birds would have been of equal size as well as maturity, had conditions been normal. The measurements of the skeleton of the extremity are unfortunately limited to the femur and the coracoid. Both agree closely in length with the smaller control. The appearance of the extremities in figures 2 and 3 confirm this view. The only careful observations of the bone form in these regions were upon the tibiofemoral joint. Here no retardation of development could be noticed.

Comparative measurements of abnormal cockerel, large and small control and rooster

ife

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AVERAGE ME.ASCBE

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Abnormal cockerel

11.5 12.0

6.7 6.5

6 7 6.7

0.98 0.91

0.62 0.54

1.24

Younger control (10 months old) .

1.15

Older control (13 months old). . . .

14

6.8^

10.1

0.93

0.54

1.10

Rooster

20.0

8.0

13.6

1.27

0.61

1.49

The cervical column has plainly undergone an excessive development in volume, since, as seen in the accompanying table, it is not only larger than the older control in three measurements which were chosen, but it even slightly exceeds a rooster in the minimmn transverse diameter of its centrum. The upper vertebrae are especial!}' large and the atlas largest of all (fig. 6.) These facts together with the correspondence, of the limb skeleton in

17:

E. D. CONGDON

loiigtli with the smaller fowl and its lack of abnormal characters Iciui some support to the view that the youiiKPr control may represent the true size of the deformed l)ird, had it developed normally and that there has been an overgrowth of skull as well as cervical vertebral column. The less sharply sculptured surface and the more massive form is found in the cervical column, which has been freipiently describetl in other instances of overgrowth. The skull did not show a sunilar condition, but its comparative freedom from surface elevations would prevent easy recognition of a slight deficiency in this respect.

Abstracted by FrancLs Marsh Baldwin, author. Iowa State College.

Notes on the branches of the aorta farcus aortae) and the subclavian artery of the rabbit.

.Vlthough the usual number of blood-vessels arising from the aorta in the rabbit is two- a so-called innominate or brachiocephalic and the left subclavian arteries- the variation from this condition herein described indicates the possibility of a considerable (leiiarturc. Of* 10() sjiecimens, about 20 i)er cent differed from what is usually considered normal, either in respect to the aortic vessels or the subclavian arteries of either side. In one individual a single vessel leaves the arch of the aorta, and after passing forward subsecpiently successively subdivided to form the left subclavian, the left common carotid, and the innominate or brachiocephalic arteries. When three vessels originate on the arch, they are usually the innominate and the two carotids, although in one ca.se the vertebral of one side contributed to this arrangement in the place of a carotid. Several individuals .show conditions suggestive of four vessels, comprising the two carotids, the left vertebral and left subclavian. The order and secjuential differences of vessels from the subclavian arteries of each side are noted.

AtTTHOR'B ABSTRACT OF THIS PAPER ISSUED BY THE BIBLIOGRAPHIC SERVICE, JCNE 21

NOTES ON THE BRANCHES OF THE AORTA (.\RCUS

AORTAE) AND THE SUBCLA^TAN ARTERY

OF THE RABBIT

FRANCIS MARSH BALDWIN Iowa Stale College, Department of Zoology, Ames, Iowa

ELEVEN FIGURES (OXE PLATE)

Bensley,' in his Practical Anatomy of the Rabbit (p. 3C5), in discussing the blood-vessels of the thorax, describes the arch of the

aorta as "beginning at the bast of the heart, passes

forward, and then describing a curve, in the course of which it lies slightlj' to the left of the median plane, turns backward along the ventral surfaces of the bodies of the thoracic vertebrae. VCith the exception of the coronary arteries the first branches are the large paired vessels arising from the anterior wall. They comprise the common carotid and subclavian arteries. On the right side the carotid and subclavian arise from a. short common trunk, the innominate arter}^ The left common carotid arises inunediately to the left of this vessel or from its base. The subclavian artery (a. subclavia) is the first portion of the artery of the antei'ior limb. It passes from its point of origin laterad to the anterior margin of the first rib, where it is replaced bj' the axillary arter3\ Near its point of origin, it gives off several branches, the relations of which are subject to considerable variation."

The large pah-ed vessels referred to above is not exact and leads to confusion, since even in the usual condition it applies to neither the right and left common carotid arteries, nor the paired subclavian arteries, but to an innominate artery on the right side, and the left subclavian artery on the other. That the left common carotid artery usually arises immediately to the left

17:5

174 FRANCIS MARSH RALDWIX

of the base of tho innominate is perhaps correct, although in by far tho greater minihor of rabbits dissected the origin of this vessel is well up on the mesal side of the innominate. In cases where the left common carotid artery arises to the left of the innominate, there would be three vessels arising from the cephalic curve of the aorta and not two (a pair) as above described, a condition normally found in the human, ^^'ith reference to the subclavian arteries, the statement as to their branches being subject to, considerable variation, is correct, but it seems important that the point should also be made, that great differences occur in these vessels on the right and left sitles in the same animal.

.\gain, Parker and Haswell- describe correctly the relation of these vessels as they occur in the majority of cases, but the figure shown (p. 4()5) represents the condition in an abnormal individual, where the left common carotid artep' originates as a branch from the arch of the aorta, and thus constitutes the third vessel from the arch, the innominate and the left subclavian being the other two. Since these discrepancies exist in the descrii)tions of the blood-vessels of the region in the various texts, and in view of the variability of both the arteries given off by the arch of the aorta, anil their subseciuent subdivisions, especially those of the subclavian, it seems of sufficient interest to record their frequency and extent. Accordingly, the following description is based upon the study of over one hundred sj)ecimens. Such records, of course, have no immediate practical value from the surgical or pathological sides, but from the educational considerations, es|)ecially from the standjioint of comparative anatomy they are rather imjiortant. No doul)t the variations which are described below are to be explained in part by the persistence of foetal conditions, or in some cases bj' abnormalities of the vessels themselves, or to the development of extrinsic parts in their immeiliatc region. Many of the changes brought about are probably due to different modes of transformation of the primary vessels of the branchial arches, especially the fourth, since the aorta as well as the pulmonary artery are derivatives of this arch, .\gain, it is well known that the heart itself originally develops high up in the neck region of mammals, and is

AORTA AXD SUBCLAVIAN ARTERIES OF THE RABBIT 175

gradually shifted downward, so that this gradual shifting might account for some of the variations noted.

Of one hundred and six rabbits dissected* nineteen individuals showed marked variations from the usual condition, either in the branches from the aorta, or in respect to the subclavian and its branches in either side. There were others (fifteen) which showed minor variations, but which could easily be placed in some of those showing marked variations, so that their condition is represented, j^artially at least, in some one or in a composite of the subjoined figures.

In what may be termed the usual condition, the aorta (fig. 1, A), after giving off the coronary arteries close to its junction with the left ventricle, passes cephalad a short distance, and then describes a curve of a half circle and passes down the back, a little to the left of the ventral vertebrae. From the cephalic curve (arch) a comparatively large innominate or brachiocephalic arterj' extends upward and a little to the right and soon bifurcates, forming the left common carotid artery which passes immediately across the trachea to the left side of the neck, and a common trunk which gives rise to the right subclavian and the right common carotid arteries. A second branch from the curve of the aorta is the left subclavian artery which passes laterad and forward to branch in \'arious ways. Usually on this side the superior intercostal (costocervical) (fig. 1,/) is the first branch to be given ofi", and passes caudomediad. Just distal in close jimcture with the superior intercostal artery is the internal mammary artery, while just opposite arises the vertebral artery. Distally the subclavian artery soon divides into the transverse scapular (T) and the axillary (X) arteries. On the right side the superior intercostal and mannnary arteries arise from a common trunk, as also do the vertebral and transverse scapular arteries just opposite to them. The axillarj^ artery passes to the region of the forearm. In some cases the superficial cervical artery branches from the subclavian, but usually it is a branch of the transverse artery of either side.

.My thanks are duo Mi'. Ralph L. Parker, my assistant, for aid in dissection.

17() FRANCIS MARSH BALDWIN

VARIATIONS OF THE SUBCLAVIAN ARTERY OF THE LEFT SIDE

A mimlier of interesting variations are noted in the order and sequential relationships of the various vessels arising from the left subclavian. Fre(iuently the arteries originating from the subclavian arterj' in close proximity to each other so that a veritable corona of the vessels is formed. In some cases, as shown in figures and 11, this takes p\aco at ([uite a distance from the arch of the aorta, and can be called the long corona type, while in others, tj-pified in figures 9 and 10 and perhaps less conspicuously in figure 8, the corona formation is closely approximated to the aortic arch, ^^'here the corona is formed, the usual order of the vessels may be described as normal, i.e., beginning with the vertebral arteiy originating on the cephalomesal siu'face of the subclavian, the transverse scapular, axillaiy, mammarj-, and intercostal arteries followed in the cycle clockwise. Tn one specimen an interesting departure is noted, in that the intercostal artery (fig. 6, 7) takes its origin from the vertebral so that there is formed in this case a veiy short innominate with the vertebral artery. A number of cases are observed where the intercostal and mammary arteries formed a short innominate in common as is shown in figures 4 and 7. In one rabbit (fig. 3 V) the vertebral artery of this side branches from the cephalic surface of the arch of the aorta at about its junction with the subclavian artery, and in this case it is comparatively a much larger vessel than normal. In this specimen also the transverse scapular and manunary arteries have their origin some distance cephalad, and the interval between the intercostal and manunary arteries is verj- noticeable. In no case is there found an iimominatc formed by the left subclavian and the left common carotid arteries, which of course is the typical avian condition, and which has been described to occur in most apes, and somewhat more rarely has been noted in the human. In three cases, however, varying in degrees, as shown in figures G, 8, and 10, the left conmion carotid artery is a separate branch from the arch of the aorta, and in these the condition closely simulates the normal condition found in the human. In one in

AOUTA AND SUBCLAVIAN ARTERIES Ol- THE RABBIT 177

stance the points of origin of the vertebral and the transverse scapuhir arteries are interchanged, as shown in figure 2, and in another, figure 5, the vertebral artery arises from the laterocaudal surface of the subclavian in the same manner but distal to the intercostal and mannnary arteries, and then turns niesal to enter the transverse foramina of the cervical vertebrae. In the last specimen also a number of excessory blood-vessels are noted, some of which parallel the mammaiy, others the intercostal arteries.

THE SUBCLAVIAN ARTERY OF THE RIGHT SIDE

The blood-vessels of this side which take their origin from the subclavian arterj' seem less variable in their relationships than those just described. There is the formation of what may be termed a corona in several instances, but this is with but one exception formed relatively close to the innominate, or to that portion close to the bifurcation of the innominate which forms the subclavian and right carotid arteries. Such a condition is typically shown in figure 5, where the vessels spread out in fanshape formation about the subclavian. In one instance, the vertebral artery (fig. 2, V) originates well cephalad and on the lateral surface of the right common carotid artery, so that its displacement from its usual position is rather striking. As regards the interrelation of the intercostal and internal mannnary arteries, all sorts of gradations of intervals exist from the formation of a conspicuous elongated innominate, as is indicated in figure 3, or a much-reduced innominate, as shown in figure 11, to the more or less widely separated intervals, as rejiresented in figures 8 and 9. Ihe intercostal artery in the last case is really a branch of the innominate, and has no connection with the sul)clavian. I'sually the superficial cervical arterj' of this side as in the normal condition is a branch of the transverse scapular artery, but in two cases it is greatly displaced; one originating fiom the subclavian (fig. 3) and another curiously entering the conunon jimction of the intercostal-mannnary vessels, as shown in figure 10. In one case the transverse scapular artery originates as a branch of the vertebral well cephalad of the latter's

178 FRANCIS MARSH BALDWIN

junction witli the snl)clavian, as in fiRiiio S, altlioufih in Iwo other siK'cinions this condition is hardy suggested in the close proximity of the origins of the two vessels, as in figure 9.

The manner of hrancliing of tlie two carotid arteries from the innominate is of interest, although not more variable than might he expected. In the majority of specimens showing differences in other respects, the two carotid arteries hranch well up on the innominate. In several cases the point of origin of the left common carotid artery is close to the curve of the aorta, and in three cases (figs. 0, 8, and 10) the junction is really on the arch, thus giving rise to an adilitional vessel in these cases, as indicated ahove, which sinuilates very closely that found normally in the human. Three individuals (figs. 7, 1), and 10) show the formation of a thyreoitl ima, so-called, a small vessel arising on the innominate hetween the right and left common carotid arteries, which passes forward to the thyreoid glanil anil gives off small vessels to the neck nniscles of the region and to the trachea. Its ])oint of origin varies somewhat in the three animals, but morjjhologically it bears the same jiosition as has been described for a similar vessel in the human (]\Ic]Murrich.' p. 511.), i.e., it pa.sses f«)rward from the innominate between the common carotid arteries of either side. It should he said, however, that since the common carotiilsof either side in man ditTer slightly in their jxiints of origin from those in the rabbit, the formation of this vessel in the rabbit does not contributeto the format ion of a fourth vessel arising from the ;.rch of the aorta, as is the case in man, I ut does form a fourth vessel from the innominate. Inasingleca.><e, as .shown in figure 11, the arch of the aorta gives rise to but one vessel, an innominate, which passes ce|)hala(l for some distance before it breaks to form, first, the left subclavian, anil a little further forward the left common carotid artery, and the brachiocephalic artery. This jjeculiar variation is interesting, since it closely simulates the normal condition found in the horse. It may be exi)laincd by the fusion of the two aortic .stems and the .shortening of the fourth arch so that the left subclavian arterj* joins with the common stem during the transformation of the i)rimary vessels. In one instance the left vertebral i^fig. 3, V) takes its origin well

AORTA AND SUBCLAVIAN ARTERIES OF THE RABBIT 179

(low 11 on the left subclavian vessel so that it is almost in a position to be considered a sej^arate branch from the arch of the aorta and could be interpreted as an additional vessel from the latter as has been recorded as a variation in the human (Mc^Iurrich, p. 511). It is e&sy to see how by a slight displacement caudad of the left common carotid artery in this case would produce four distinct vessels originating from the arch of the aorta instead of the usual two.

SUMMARY

Although the usual number of blood-vessels arising from the arch of the aorta in tlie ral)bit is two — a so-called innominate or brachiocephalic artery and a left subclavian artery — the variations from this condition herein described indicate the possibility of a considerable departure. In one individual (fig. 11) a single vessel leaves the aortic arch, and after passing a short distance forward subdivides successively to form the left subclavian, the left common carotid, and the innominate or brachiocephalic arteries, the latter subdividing again to form the right common carotid and the right subclavian arteries.

In a number of cases, as shown in figures 6, 8 and 10, three vessels have their origin on the arch, and in these the order is the brachiocephalic, the left common carotid, and the left subclavian arteries. In one individual (fig. '.i) the left vertebral replaces the left conmion carotid artery in the series, the carotid in this case having its orgin on the innomhiate as normally. This case suggests the possibility of four vessels forming the series.

Conspicuous differences in the order and sequence of the vessels from the subclavian arteries of the two sides are noted. On the left side the vessels in a number of cases show a tendency to group themselves either proximally or distally in the form of a short corona, as indicated in figures 6, 9 and 10. The formation of various innominate stalks common to certain arteries are found in some cases, while in others the intervals between certain arteries are rather noticeable. Less marked variations are noted in the vessels of the right side. The vertcliral artery in

ISO FRANCIS MARSH BALDWIN

ono iiistanco (Tip. 2") is (lis])hifO(l from its usual plarp to the lateral side of the right coininon carotid artery. The transverse scapular artery in two eases is a branch of the vertel)ral, while the superhcial cervical, which is normally a branch of the transverse scapular, in one case (fifi. 10 ) leaves the subclavian as a commnn stalk with the intercostal and mammary arteries.

In three cases a small so-called thyreoid ima is present, and in these this passes forward from its origin between the two common carotids, thus having the same morjjhological jKisition in the rabbits as a similarly described vessel occupies hi the human.

LITERATURK CITED

1 IU:\si.KY, B. A. lOl.S Pmotical anatomy of the rabbit, 2nd edition, pp.

■_'.')(>-2.')". I'niv. Toronto Press. '2 I'ARKKn AND Haswell I9I0 Text-book of zoology, 2n(l edition, vol. 2, pp.

•lGl-tG.5. .MacMillan Co. 3 McMruiiicii, .1. P. 1906 Morris's human anatomy, tth edition, pp. 510-511 ;

5.56. P. Blakiston's Sons & Co., Phila.

AORTA AND SUBCLAVIAN ARTERIES OF THE RABBIT 181 PLATE 1

EXPLANATION OF FIGURES

1 Diagrammatic ventral view of the arteries of the thoracic region of the rabbit, showing the various branches as they occur in the majority of specimens. The innominate (brachiocephalic) (N) and the left subclavian (S) are the two usual branches of the arch of the aorta. The left subclavian gives origin to a number of arteries as here shown, while the innominate bifurcates to form the two common carotids and the right subclavian arteries.

2 Schematic ventral view of the arterfes of rabbit 32, which conspicuously indicates the vertebral artery of the right side as a branch of the right carotid artery. Notice on the left side the transverse scapular and the vertebral arteries are morphologically interposed and the intercostal and mammary arteries are separated by quite an interval. The left common carotid is well down at the base of the innominate, almost constituting a separate branch of the arch of the aorta.

3 Ventral view of the arteries in rabbit 40. The vertebral artery of the left side is here formed close to the junction of the subclavian with the aortic arch, and thus forms what may be considered a third branch of the arch. The intercostal and mammary arteries of the left side are separated bj' a wide interval.

4 Rabbit 53 shows the formation of common stalks (innominates) for the intercostal and mammary arteries of both sides as well as the transverse and superficial cervical of the right. The brachiocephalic gives rise immediately to the left common carotid.

5 The arteries of rabbit 22 show differences in branches of the right and left subclavian vessels especially. The intercostal and mammary arteries originate separately on the right, the vertebral on the left is well cephalad of the other vessels, and makes a bend caudomesad as here shown. Accessory vessels are found on the left sitle also.

6 In rabbit 28 the formation of what may be termed a long corona of the left subclavian with a migration of the intercostal from the lateral surface of the subclavian to form a common stalk with the vertebral artery. The left common carotid artery is here a branch of the aortic arch so that three distinct branches are formed. The innominate is conspicuously long.

7 Specimen 19 shows among other variations the formation of the thyreoid ima, a small vessel originating on the innominate just caudad to the point of origin of the left common carotid artery and passing forward to the thyreoid gland of the neck.

8 Rabbit 21 shows interesting relationships of the innominate, left common carotid, and left subclavian arteries, and shows the comparatively immediate subdivision of the subclavian of either side. Such a condition may be designated as the short corona type.

9 Specimen 106 shows the so-called thyreoid ima and other minor variations especially in the interval between the intercostal and mammary arteries of the right side, and the formation of the short corona type of the left subclavian artery.

THE ANATOMICAL RECORD, VOL. 19, NO. 3

IS-j

FUANCIS MARSH BALDWIN'

10 In riil)bit 85, beside the thyreoid itiiii heiii); present, the left subclavian takes its origin on the arch and the superficial cervical of the right side passes out friini tlie common stalk of the intercostomamraary artery. The subclavian of the left side forms a short corona.

11 In rabbit 52 the innominate (brachiocephalic) artery is the only vessel originating on the arch of the aorta, and subsequently subdivides as shown, giving rise to a long conma typed left subclavian, left and right carotid arteries, and right subclavian artery. This condition thus typifies that found normally in the horse.

ABBREVIATIONS

.1., aorta, with its ascending, transverse arch and descending (dorsal) portions

C, common carotid arteries, (R) right and (L) left

/., superior intercostal artery

//., heart

A'., innominate artery

M., internal mammary artery 5., subclavian artery, right and left T., transverse scapular artery, including the superficial cervical artery v., vertebral artery, right and left .Y., axillary artery, right and left

AORTA AND SUBCLAVIAN ARTERIES OF THE RABBIT

FRAXCIS MARSH BALDWIN

PLATE 1

is:}

Abstracted by Joseph ^1. Thuriiiger, author. Tulane University of Louisiana.

A suggestion for improvement in projection and drawing

apparatus.

By substituting a focusing stage in the drawing apparatus, provided with coarse and fine adjustments, in place of the fixed stage used at present, variations in the magnification of the projected image due to focusing are eliminated, hence more accurate results in reconstruction work may be expected, e\en when slides and cover-glasses in a given series are not of uniform tliickness. The customary arc lam]) is discarded for a new conunercial form of incandescent illuminant which greatlj^ facilitates the control of the light.

ACTHOR 8 ABSTRACT OF THIS PAPER ISSUED BT THE BIBLIOGRAPHIC SERVICE, JUNE 21

A SUGGESTION FOR IiAlPROVE.AIENT IN PROJECTION AND DRAWING APPARATUSES

JOSEPH M. THURINGER Deparlmcnt of Anatomy, Tulane University of Louisiana, New Orleans, Louisiana

ONE FIGURE

Among the various tj^pes of apparatus manufactured for the projection of microscopic objects for tracings and drawings, the Edinger drawing and projection apparatus no doubt holds first place, both from a point of usefuhiess and of mechanical stabihty. For the drawing of individual microscopic objects it leaves little to be desired, except perhaps an improved form of illuminant. However, when used for the drawing of serial sections for reconstruction work by any of the various methods in vogue, we are at once confronted with a little more difficult problem.

It is highly desirable to hold the percentage of error in reconstruction work to a minimum. A well-prepared series of sections, of course, is the essential factor. Secondly, this series should be mounted with slides and cover-glasses of uniform thickness. Even the mounting medium should be of uniform consistency and temperatin-e for a given series, and all the slides after mounting subjected to a drying for a gi\-en number of hours at uniform temperature to insure an absolutely equal distribution of the mounting medimn over the entire surface. With all these precautions carefully observed, there still remains an appreciable somxe of error due to the difference of magnification obtained when using the present focusing devices. The sUghtest change in position of the draw-tube alters the magnification. To increase the efficiency of the above-mentioned apparatus the following changes are suggested and illustrated in the accompanying drawing.

The stage as manufactm-ed at present is only equipped with a clamp (K) for altering its position. This, however, does not

185

186 JOSEPH M. THURINGER

peiinit siifficiontly ronvoniont and arcuratr adjustment to answer till- purpose of a focusint? sta^c. Tlu' most i)ainstakint; care in the determination of the magnification by means of stage micrometer and rule will lje upset by the slightest change in position of the draw-tube or by having to refocus. To obviate thfs source of error the focusing stage illustrated (S) is suggested It is equipped with a coarse and fine adjustment identical with the one supi)orting the draw-tube of the microscope (.U) and therefore not entailing great additional cost in the mamifacture. This stage could also be supplied to all Edinger apparatuses in present use, thereby bringing them to their highest efficiency. After the desired magnification is once determined, all future adjustments are made by means of the stage coarse and fine adjustments. All errors due to differences in thickness of slides, cover-glasses, and mounting media are thus comjiensated.

The condenser (.C") is hinged on a support and guide<l by an upright which, however, is not secured to the stage, as at present, thus permitting more room for the use of a mechanical stage.

The arc lamp, which always reriuired more or less attention and needed new carbons at the most inopportune moment, is here replaced with the new low-voltage, high-amperage, concentrated-filament, incandescent lamp. On direct current this is operated in series with a suitable resistance and on alternating current with a small transformer. Both of these devices can be attached under the drawing table and require no further attention when once adjusted.

The lamp is heUl by a universal support (f), which allows adjustment vertically as well as horizontally, thus permitting the use of various-sized lami)s.

\ light-tight, ventilated hood, provided with an adjustable reflector (li), completes the outfit.

IMPROVEMENT IN PROJECTION APPARATUSES 187

Fig. 1. Diagram of projection ami drawing apparatus. C", stage condenser; C, condenser; L, lamp in ventilated housing; li, adjustable reflector; U, universal support; S, focusing stage; A', clamp; .1/, microscope.

Abstracted by James C. Watt, author. University of Toronto.

Symmetrical liilateral dystopia of the kidneys in a human subject, with outward rotation of the hilus, muhiple arteries and veins, and a persistent posterior cardinal vein.

In a male human subject, aged twenty-eight, who died of pulmonary tuberculosis, an associated series of rare anomalies of the kidneys was found. There was a symmetrical bilateral displacement caudally, each kidney lying from the level of the second to the fifth lumbar vertebrae. Synnnetrical displacement without fusion is rare. The hilus forms a long, narrow groove, the upper part lying on the anterior surface of the kidney, the remainder describing a spiral cutting around the outer border on to the posterior surface as it proceeds caudad. This lateral position of the hilus is extremely rare, previous ones being found in pelvic kidneys, and very few instances being recorded. On the right side were five renal arteries, two off the aorta, three from the common iliac artery. There were four left renal arteriejs, two from the aorta, one from the connnon iliac, and one from the hyi)ogastric arteries. Two spermatic arteries were present on the right side and three on the left. Two renal veins, uniting into a short common stem tributarj- to the inferior vena cava, occur near the upper pole of each kidney. In addition, on the left is a posterior cardinal vein connected at the ends to the common iliac and upper renal veins and having as tributaries a third renal vein and four lumbar veins. A fourth left renal vein goes to the hypogastric vein. The pelvis of the ureter enters the kidneys anterior to the main vessels. The ureter courses lateral to the kidney.

Symmetrical Bilateral Dystopia Of The Kidneys, In A Human Subject, With Outward Rotation Of The Hilus, Multiple Arteries And Veins, And A Persistent Posterior Cardinal Vein

Template:Ref-Watt1920

James Crawford Watt Department Of Anatomy, University of Toronto

Two Figures

In the laboratory of the Department of Anatomy of the University of Toronto a very interesting series of associated anomalies relating to the kidneys and their vessels was discovered during the regular course of dissection. The specimen was at once put aside for investigation, and on further study has been considered worthy of a detailed description.

The body was that of a well-proportioned but somewhat emaciated male, aged twenty-seven, who died of pulmonary tuberculosis. Apart from the abnormalities associated with the kidneys, no other gross anomalies were noticed in this subject.

THE KIDNEYS

Shape and size (fig. 2)

The outline of the kidneys is that of a long, narrow oval. The ventral surface is quite convex, the dorsal surface flattened. Of the two poles, the lower is much thicker than the upper. A shallow groove winding spirally from the \entral surface laterally and caudally on to the dorsal surface forms the hilus, and notches the outer border where it crosses it. Except for the presence of the hilus, the surface is smooth, and shows no special lobulation.

1S9

190

JAMES CRAWFORD WATT

The measurements taken are as follows:

Righl kidney I-cft kidney

Greatest length 10 5 cm. 11cm.

Width 3. 5-4. 5cm. 3.5-1.5 cm.

Thickness 2.5-3 5 cm. 2.5-3.0 cm.

Position and relations (fig. 2)

The two kidneys exhibit a displacement which is quite symmetrical on both sides. Each lies close in against the psoas

Iwfenor Ven* C«w4 i^^t*

Fig. 1 Outline drawing of the kidneys and their vessels and ureters. Veins are solid black, arteries striped, and ureters stippled. Lower part of right kidnev removed.

major muscle and shows the same degree of obli(iuity as the muscle. The upper i)ole of each kidney is about 1 cm. nearer the midline than the lower pole. The upper pole is opposite the middle of the second hmibar vertel)ra, the lower oposite the lower part of the fifth lumliar. The kidney thus lies with its upper portion in the lumbar region, on the quadratus lumborum muscle, the other portion in the iliac fossa, on the iliacus muscle. The sui)rarenal glands were placed over the upper jiole and slightly to the medial side of each kidney. The left gland was

RARE ANOMALIES OF THE KIDNEY

191

situated in a small space with the kidney below, pancreas above, spleen laterally and vertebrae medially.

Fig. 2 Drawing of the kidneys to show their relations to the dorsal abdominal wall and the viscera. The duodenum, pancreas, and spleen have been retained in position, the lower part of the duodenum being hooked up to expose the underlying vessels. The suprarenal glands have been removed to expose the upper pole of the kidney. Lower part of right kidney removed.

The pancreas was situated entirely above the left kidney and crossed right over the spleen. Owing to the downward displacement of the kidney, the spleen was displaced inward and

192

JAMES CRAWFORD WATT

was in contact with the vertebrae medially for two-thirds of its length. The lower pole, however, had the upper pole of the kidney inserted between it and the vertebral column.

On the right side the kidney and suprarenal gland lay entirely below the level of the liver, which was thus allowed to come into contact with the diaphragm on its posterior surface.

The upper pole of each kidney and the common renal vein from each side were under cover of the duodenum at the flexure of the latter at the lower end of the descending limb.

The hilm {fig. 2)

The po-sition of the hilus is most interesting, and is quite similar on both sides. Starting above, about three centimeters below the upper pole, on the anterior surface, it runs obliquely caudad to cut the lateral border of the kidney, formhig a notch on it about two thirds of the w-ay down. It then curves from here on to the posterior surface, ending about two or three centimeters from the lower end of the kidney.

The hilus is thus placed on the opposite border to the normal and fonns a spiral with gradually increasing rotation about the polar axis as it proceeds caudad.

VESSELS Arteries {figs. 1 and 2)

The renal arteries and also the spennatic arteries of both right left sides are multiple.

Right side. The right renal arteries are five in number. The first comes off the abdominal aorta at the level of the second lumbar vertebra and goes behind the inferior vena cava to the upper end of the hilus on the anterior surface of the kidney. The second renal artcrj- also goes to this surface, coming from the , aorta at the level of the third lumbar vertebra and running in front of the vena cava.

Off the right conunoii iliac artery come the third renal artery, a very small one, the fourth, quite large and dividing early into

R.\EE ANOMALIES OF THE KIDNEY 193

two, and the fifth, a small artery again. These three arteries running in close company pass behind the lower pole of the kidney and enter the lowermost part of the hilus on the posterior surface.

The right spermatic arteries are two in number. The higher one arises from the aorta between the first and second renals, and runs posterior to the inferior vena cava and both renal veins, but anterior to the upper pole of the kidney. The lower artery arises from the second renal, goes posterior to the inner renal vein, anterior to the outer vein, and anterior to the kidney. At the lateral border of the kidney the two spermatic arteries and the vein form a common bundle running in contact with this border and the ureter in the iliac fossa, and then turning over the psoas muscle to the internal abdominal ring.

Left side. There are four left renal arteries. The first is off the aorta at the upper limit of the second lumbar vertebra and runs down anterior to the upper pole of the kidney. The second artery is from the aorta, over the second lumbar vertebra, level with the highest artery on the right. It is also to the hilus on the upper part of the anterior surface of the kidney.

The third left renal artery is off the left common iliac, and is peculiar in that it runs across the upper part of the iliac fossa behind the kidney, to pass into the hilus just where it cuts across the lateral border.

The fourth artery is off the internal iliac, or hypogastric artery, just at its conmiencement, and runs anterior to the external iliac artery and psoas major muscle and penetrates the kidney on its medial border just near the lower pole.

On this side there are three spermatic arteries, the highest coming off a suprarenal branch of the first renal, the other two directly off the first renal. All three arteries and the spermatic vein form a common bundle coursing anteriorh- along the lateral border of the kidnej^ then lateral to the ureter in the iliac fossa and down to the inguinal canal.

I'.t4

JAMES CRAWFORD WATT

Veins (figs. 1 and 2)

Rigid side. There are two renal veins, both coming from the upper part of the hiliis over the anterior surface of the kidney, and uniting at the level of the upper pole of the organ into a common vein which is about three-quarters of an inch in length and empties directly into the inferior vena cava.

The right spermatic vein, a single vessel, opened into the lateral (if the two renal veins.

Lefl side. On this side are three renal veins. Two are quite .similar to those on the right, arising from the anterior surface of the kidney on the upper part of the hilus and uniting into a common stem which crosses anterior to the aorta and empties into the inferior vena cava.

.Tust at the junction of the above two veins, there comes into the medial one, a longitudinal vein which lies over the front edge of the psoas muscle, on the vertebral colunui, in the interval between the aorta and the left kidney. This steni starts at the level of the fifth lumbar vertebra, and connnunicates with the left conunon iliac vein below. As it ascencis it receives as tributaries four lumbar veins, one of which is double, and also a renal vein. This renal vein comes from the hilus where the latter cuts the outer border of the kidncj', and runs medially posterior to the kidney, alongside of the third renal artery, and ends in this ascending vein. This longitudinal stem is interpreted as a persisting portion of the embryonic posterior cardinal vein of the left side, which lies exactly in the position occupied by this present vein.

The left spermatic vein, single in spite of the presence of three arteries, empties at the junction point of the two large upper renal veins into the common trunk.

Ureter {figs. 1 and 2)

The position and relations of the ureter are remarkably symmetrical on the two sides.

At its pelvis, each ureter is divided into two parts. One is a long, narrow, tubular jiortioii which lies in the ujiper part of

RABE ANOMALIES OF THE KIDNEY 195

the hilus, on the anterior surface of the kidney. The other is a broad, short, funnel-shaped portion communicating with the kidney in the hihis just before the latter cuts round the outer border, of the organ.

The two parts unite at the lateral border of the kidney, which the ureter now follows to the lower pole, where it then crosses the iliac fossa, turns medially over the psoas muscle and external iliac artery into the pelvis, where its course into the bladder is normal.

The highest artery and the lateral vein accompany the upper branch of the ureter as it enters the kidney, the vessels lying behind. The other vessels enter the kidney mostly behind the lower branch of the ureter.

SIMILAR CASES

Multiple renal arteries and veins in all the locations found in this case have been previously described and discussed by various authors, and so call for no special consideration. Tonkoff ('03), for instance, describes and gives a figure of a right kidney slightly displaced downward and with an arrangment of its four renal arteries almost identical with those of the left kidney in this case.

Macalister ('8.3) and Morris ('85) both state that abnormal vessels occur in three individuals out of every seven.

The occurrence of a vena cardinalis posterior along with renal anomalies has been noted before. ]\IeIissinos ('11) found a case of pelvic kidney with a persistent right cardinal vein, and gives reference to a few other instances.

The presence of the rotation seen in these kidneys, on the contrary, is evidently quite a rare condition. Among the anomalies of position of the hilus, the particular one exhibited here is not even mentioned in the text-books on pathology or surgery. It is self-evident that such a position would be of great interest, especially to the surgeon.

Gerard ('05), in a review of 527 cases, states that the renal hilus, instead of lying medially, may be superior, inferior, ventral, or dorsal, but does not mention any instance of a lateral position.

196 JAMES CRAWFORD WATT

Miillprheiin ('02) describes a case where the left kidney was found in the pelvis, with its hilus not medial, but anterior, and he states that one of the characteristics of dystopia of the kidney is that the hilus is usually anterior in position.

Morris ('04), in a summarj' of displacements, states that the kidney may be rotated so that the hilus looks upward, outward, directly forward or backward, and mentions one case of the hilus occurring; laterally. This case was described by Farquharson ('94) as a left kidnev placed in the pelvis with hilus looking to the left.

Brown ('94) also describes a right pelvic kidney which had rotated till its posterior surface had become anterior and the hilus looked posteriorly to the right. Johnson ('14) described a case in the cat exactly similar to that of Brown's and Anitschkow ('12) describes and gives a figure of a left kidney in man displaced slightly back in the Imnbar region and with a hilus which he describes as anterior, but which, in the illustration, appears to course around the lateral border, as there is a marked indentation shown there.

^IcMurrich ('98), considering a series of crossed dystopia of the kidneys with fusion, pointed out that in nearly all cases the position of the hilus was anterior.

This retention of an anterior position of tlie hilus in displacements and in fusions of the kidneys is the retention of the normal embrjological position. Pohlman ('05) noted that until the kidney had ascended in the embryo to where it was approximately in the adult j)osition, the hilus was ventral, and then a rotation medially of 90° occurred about the polar axis. FeUx ('12) also states that this rotation occurs, but that a reverse rotation toward the ventral surface also occurs later, so that the hilus is finallj' ventromedial.

The kidneys in the present case have not reached the usual final level and so might be expected to have retained the hilus anteriorly. This is true of the upper part, but the lower portion exhibits the rare outward rotation through 90° to bring it laterallj', and the lowest part goes even further than this to lie posteriorly. There is thus considerable torsion in the kidney, the hilus forming quite a spiral in its course.

RARE ANOMALIES OF THE KIDNEY 197

The fact that the ureter lies ventral to the main renal vessels at the hilus at first sight appears as an anomaly. It will be seen, however, that if the hilus were to be rotated into its usual position the ureter would then lie posterior to the vessels. Thus at their entrance into the kidney these structures stand in their normal relations to each other, but the rotation makes them appear reversed.

The position of the suprarenal glands is interesting. McJVIurrich, Morris, Miillerheim, and others have all stated that the relation of these glands to the kidneys is merely topographical and that they are found in their usual places in cases where the kidneys are displaced. In this instance, however, they lie closely capping the upper pole of each kidney, and so are displaced somewhat caudally horn their normal location.

"\Miat was the actual cause of all the anomalies shown above is open to conjecture. It must have been a force acting in early embryonic life. The displacement into the iliac fossa was probably due to lack of growth in the ureter and the torsion due to a twisting of the pelvis of the vu-eter. It is of interest to note that Felix ('12) states that in the lumbar region the ureter shows a dilatation accompanied by a spiral twisting. An exaggeration of this process might possibly account for the result shown here. Whatever the cause may have been, the result is most remarkable for instead of a symmetrical displacement of the whole organ, we have here the upper pole with the upper end of the hilus facing still in the old embryological position, while proceeding caudad there is an ever-increasing torsion evident, until finally at the lower end the hilus shows a displacement of 180° brought about by lateral rotation.

The position of the kidnej-s in the lower liunbar region and iliac fossa seems to be a much rarer condition than the position within the pehds, as by far the greatest majority of cases of dystopia without fusion are reported as being in the pelvis.

The symmetrical degree of dystopia shown by these two kidneys seems to be almost as rare a condition as the lateral hilus. In all the cases quoted above and in many others not mentioned here, if the two kidneys are not fused to form the discoidal or the

THE ANATOMICAL RECOKD, VOL. 19, NO. 3

1«»8 JAMKS I UAWlOUl) WATT

liorscshoo kidney, pithor thorois a nnich fiioatordotirco of dystopia on on(> side than on llio other or else only one kiihiey shows displacement, the other beiuf!; in its normal position. Thus the kidneys in this instance are vmicivie in several respects and have therefore seemed well worthy of description.

BIBLIOCiRAr'HV

Anitschkow, N. \. 1912 Stiidicn iihcr NicrcnRcfiisse l)(>i Aiigehorener Nicr (•iulysti>]>ic. Virch. Arch, fiir path. .\nat., Bil. 207, S. 21:?. BuowN, M. 1S94 Variations in the positinn and dcvplopmcnt of the kidneys.

Journ. of Anat. and Physiol., vol. 28. FAHQUinnsox, W. F. 1S94 Case of left kidney, displaced and immovable.

Journ. of ,\nat. and Physiol., viA. 28. Felix. \V. 1912 The development of the urinoRenital system. Keibel and

Mall's Human Fmhryology, vol.2, J. B. Lippincott Co., Philadelphia

and London. GfiR.\KD, n, 19()o I.es anomalies cong(^nitalcs du rein chez I'hommc. Journ.

(le I'Anaf . et dc la Physiol.. T. 16, p. 241 ct 411. JouN.sox, C. E. 1914 Pelvic and horseshoe kidneys in the domestic cat. .\nat.

Anzeigcr, Bd. 46, S. 69. M.\CALisTKR, A. 1883 Multiple renal arteries. Journ. of .\nat. and Pliysiol.,

vol. 17, p. 250. MrMuRHifH, J. P. A case of crossed dystopia of the kidneys with fusion.

Journ. of .\nat. and Physiol., vol. ,32. Melissinos, von K. 1911 Beckenniere niit persistierender Vena cardinalis

dextra. ,\nat. Anzeiper, Bd. 30, S. 1 19. Monnis, Hknuy 1S.S,") Surgical diseases of the kidney. Cassell & Co., London.

19(M Surgical diseases of the kidney and ureter, including injuries,

malformations and misplacements, vols. 1 and 2. Keener & Co.,

Chicago, U. S. A. MCXLEKHEiM, U. I'ebcr dei diagnostischc und klinische Bedeutung der con genitalen N'ierendysto))ie, speciell der Beckenniere. Berlin, klin.

Wochschr., 1902, S. UM. PoHLMAN, .\. (i. 190,1 A note on the developmental relations of the kidney

and ureter in human embryos. Johns Hopkins IIosp. Bull., vol. 16,

no. 107, February, 19!t.'). ToKKOfF, \V. 1903 Beitrag zu den Niercnanomalien. Intern. Monatschr. filr

Anat. und Physiol., Bd. 20, S. 449.

\

THE ANATOMICAL RECORD, VOL. 19, NO. 4 SEPTEMBER, 1920

l{osunion por el aufor, Eben James Caioy. C'ologio Mrdico ("loiphtoii, Omaha.

Estudios sobre la diiuimica de la histogdnesis. La fuerza que

motiva ol crc'cimioiito como f^stimulo diiKimico vu la gen(?sis

de ios tcjidos esqueletico y muscular.

La iegi6n activa dominante en el crecuniento del intestine es el tuhd opitelial; la zona que crece meno.s activamonte es el mesen(iuima ([ue le rodea. Imi el colon terminal del oerdo el tubo epitelial erece en direcci6n caudo-cefalioa. Las figuras mit6siras siguen en su mayor parte la direceiAn de una helice sinistror.sa. Kn embriones de cerdo de 10 a 25 nun. de longitud, el colon terminal crece relativamente con mas rapidez en diiimetro que en longitud. Dmante este periodo la tunica interna de musculo liso estii en periodo de foniiaci6n. Cuando el embriAn crece de.sde los 25 a los 45 mm. el colon terminal crece mas rapitlamente en longitud que en anchura. Durante este periodo de alargamiento intestinal nipido .se inicia la capa externa de nu'isculo liso. La correlacion del crecimiento tubular epitelial en hmgitud y anchura, con la genesis de las tunicas nnisculares lisas interna y externa, respectivamente. se considera bajo el aspecto de "fuerza que moti\'a el crecimiento." La iegi(^ii de crecimiento acelerado en el miemi)ro en \ ias de de.^arrollo es el m'lcleo estiueletico central; la de crecimiento retardado es el mesenquima que le rodea, el cual se transforma ulteriormente en la musculatura y tejidos conectivos relacionados con ella. Estas dos zonas de crecimiento diferencial se iiiHuyen nuituamente, y esto es evidente objetivamente a causa de un c-ambio ile movimiento y por una alteraci^ii de la forma externa y estrnctuia intei-na de las celulas afectadas. El j)rimer material 6seo tlel embri6n .-ie distribuye econ6micamente en la periferia al principio, sobre la superficie convexa mas di'bil del femur curvo. Despues el hueso envuelve al centro de la diafisis y aparece en el lado c6ncavo del femur cartilagiiioso cmvo. La correhici6n entre el crecimiento esciueletico acelerado y el de.sarroUo mesenquinuitico retardado se con.sidera con referenda a la "fuerza que motiva el crecimiento diferencial."

TraruilBtion by Jof*^ V. Nunidcf Cornell Mrdirnl College, New York

AUTHORS ABSTRACT OF THIS PAPER ISSUED BY THE BIBLIOGRAPHIC SERVICE, JUhl 26

Studies In The Dynamics Of Histogenesis Growth Motive Force As A Dynamic Stimullts To The Genesis Of Muscular And Skeletal Tissues

Eben J. Carey

Department of A nalomy, Marquette University Medical School, Milwaukee, Wisconsin

TWENTY FIGURES

CONTENTS

Introduction 199

Definition of growth motive force 200

Early stages in the histogenesis and morphogenesis of the descending colon

of the pig (Sus scrofa) 205

Spiral path of mitosis in epithelium of colon 206

Growth motive force in intestinal development 210

Definition and classification of strains 211

Growth motive force in limb development 215

Summar}' 219

Literature cited 224

INTRODUCTION

The principle of unequal growth constantly confronts the emhryologist in his investigations. The local thickenings and foldings of the central nervous system, the unequal growth of the cardiac septa, the elongated intestinal tract, are common instances exemplifying the principle that the body parts develop at different rates.

This idea was recognized by Ai-istotle, but was not definitely formulated until 1774 from Wolff's convincing studies. In the latter's work on intestinal development the principle of unequal growth was definitely established and elaborated considerablj-. In 1874, His compared the various layers of the chick embryo to plates and tubes of an elastic nature. From these he suggested that some of the principal organs are molded bj^ local zones of unequal growth. Davenport ('96) resolves the changes in question into iiiovonipnts of cells or coll aRRiogatos, the latter beiiiK linear, superficial, or massive. He still further classifies each of these three divisions.

These local zones of uneciual growth anil the movements of cells have l)cen looked upon by Horl)st ('94) and Dreisch ('94) as physiological responses to definite stiTuuli. His and Davenport as well as Roux ('95) aim at something more than a mere description of unequal growth and ontogenetic events. They made an attempt to give a mechanical causal explanation for these processes. The function and aetiology were considered side by side with structure.

It is from the dynamic view-point that the present investigation was pursued. It is desired to emphasize the fact that in zones of imequal or differential growth, in limb and intestinal development, that an interaction of forces takes place, resulting in a transference of energy, and that these forces are factors in histogenesis. This action and reaction and transference of energ>' is due to a definite entity, growth motive force, a temi introduced by the writer.

Growth molive force is any agency which tends to produce a transfer of kinetic energy, from an active to a less active group of cells, and of potential energy from a less active to an active group, in a cellular field of differential growth until equilibrium is established. The active and less active zones are in reference to the rate of cell di\-ision per millimeter of cross-section. This principle was deduced from a series of studies on osteogenesis and myogenesis begun in 1914. Previous reports of a part of this work have been presented to the Association of .\merican Anatomists (Carey, '17, '18, '19).

The understanding of the causes underlying tissue formation or differentiation of an unspecialized cell is the central difliculty for the student of development .

The increase of cellular components, the transfonnation of these, and the perfection oi fonn out of the relatively fonnless antecedents are phenomena which demand the closest analysis. Growth and division of the nucleus, however, are merely changes concomitant with the specialization which the cell undergoes.

GROWTH MOTIVE FORCE 201

There are three theories regardmg cellular differentiation: first, the 'mosaic theory' of Roux ('88), later modified by Wilson ('04), Conklin ('05), Zeleny ('04), and Boveri ('04); second, the 'organization theory' of ^ATiitman ('93) and more recently elaborated by Child ('15) in the latter's studies on metabolic gradients and individuaUty ; third, the 'homogeneity theory' of Dreisch ('91-'93). Dreisch considers the peculiar organizing quality of protoplasm as due to the expression of a mysterious force wholly different from anj- in the inorganic world.

At least in certain of the earliest stages, the primordial cell is modified during development by the environment. It is not independent in its development but is dependent upon an interaction of developing parts before its external form and internal structure are perfected. This is the theory expressed by the terms, mutual interaction, correlation, interdependent s, dependent differentiation or differentiation due to position. This theory is upheld by His ('74), Hertwig ('94), Fischel ('98), Von Baer (1828), Pfluger ('83), C. Schultze (1900), Hans Dreisch ('94), Zoja ('95), Whitman ('94), Child ('99) and Thoma ('07) and to a limited extent by Roux. The latter investigator distinguished two periods in the development of the body parts: first, a period of self-differentiation iir which the parts arise, grow, and differentiate of themselves; second, a period of functional form development in which the more complete formation of the parts is accomplished through the influence of stimuli.

As to the first view, it has been convincingly proved that there are organ-forming stuffs in the cytoplasm. Wilson ('04) concluded from his studies that the cytoplasm of the primordial germ cell contains certain specific organ-forming stuffs which have a definite arrangement. These observations of Wilson have been confirmed by Conklin ('05), Zeleny ('04), Boveri ('04).

The third theorj' regards differentiation as dependent upon either an extrinsic or an intrinsic factor. Differentiation so considered is in the nature of a physiological response to a stimulus. The structure of the reacting as well as of the stimulating body, however, contributes to the quality of the effect. Specialization by this method is simply an 'induction,' according to Dreisch.

202 EBEN J. CARET

It is an effect jiroduceil upon the parts that are developing bj' other (lovelopinK parts or by an extrinsic factor in the environment. Three elements are conseeiuentlj- involved: first, the stimulus; second, the reception of the stimulus; third, the response. The first is some other organ or external agent ; the second and third are functions of the organ in process of formation. Lack of evidence has been the chief obstacles to the acceptance of Dreish's theory of induction.

The term induction' implies an effect or change pioduced without contact. But, in respect to the primordium of the muscular and skeletal ti-ssues, there is a definite .sj'ncj'tial continuitj-. Consequently, any effect produced by either tissue upon the other would l)c through 'conduction' and not through 'induction.'

In this action, through conduction of the ileveloping skeletal and muscular tis.sues upon each other, the factor of force is inherently involved. The primordial blastemal skeleton is undergoing the most rapid growth, as a consequence of which a tensional elongating or .stretching action is bound to be exerted upon the surrounding and less actively growing, continuous, syncytial mesenchyme. It is desired, therefore, to emphasize the following facts:

First, that there is a force manifested by rajiid skeletal growth.

Second, that this force exerts a ten.sional or .stretching action upon the surrounding mesenchyme, influencing the first steps of myogenesis.

Third, that the first differentiated muscles react upon the primordial blastcnud skeleton resulting in a definite series of changes. These are seen in the formation of the conden.sed cartilaginous skeleton and later, as the muscles become more developed and vigorous in physiological function, in the formation of the osseous skeleton.

This action and reaction of forming parts results in the condition that at .Tny period of development the degree of differentiation of the musculature and skeleton represents an e(|uilibrium estabii.shed l)etween oppo.sing myogenic and skeletal forces. .Mechanically, therefore, skeletal and the related muscular tis

GROWTH MOTIVE FORCE 203

sues are interdependent, one relying upon the other for its initial and continued differentiation.

The foregoing appUes to the skeleton and skeletal cross-striated musculature. Concerning the smooth muscle of the intestine there is a similar interaction of differential forming parts. The epithelial lining of the alimentary tube is the most active region of growth. The growth in diameter in the early stages is due almost entirely to the rapid degree of mitosis of the epitheliimi and not to the surrounding mesenchyma forming the bulk of the wall. As a consequence the lumen rapidly increases in diameter, and it is this increase which causes primarily the diametrical growth of the intestine. It is readily apparent that the rapid distention of the lumen due to epithelial growth would cause a tension upon the relatively passive, contiguous, syncytial mesenchyme. This action would tend to draw out or stretch the mesenchymal cells in a concentric manner somewhat similar to the tension put upon the strained elastic fibers of a rubber balloon when distended with air, the pressure of epithelial growth being comparable to the air pressure.

Once the encircling mesenchymal cells have formed a definite ring, the expanding lumen would meet a resistance to growth in diameter. The growth force, pursuing the lines of least resistance, would be directed in a longitudinal manner due to the shifting of the planes of mitosis from a longitudinal to a transverse direction. This shift is directly due to the external resistance of the first-formed ring of inner circular smooth muscle.

At this point the term force is one that will stand close scrutiny and careful thought on the pai-t of the embryologist. A force is one of a pair of equal, opposite, and simultaneous actions between two bodies by which the state of their motions is altered or a change in form in the bodies themselves is effected. Pressure, attraction, repulsion, and traction are instances in point. Muscular sensation conveys an idea of force, while a spring balance gives an absolute measure of it, and a beam balance only a relative measure. In accordance with Newton's third law of motion that action and reaction are equal, opposite, and simultaneous, forces always occur in pairs.

21(4 EBEN J. CAREY

Foicp is exerted in eertuin reffion.s of the embryo I)}- the genesis of ;i rapidly dividing Kioup of eells upon a less active or relatively passive group of eells. In turn the relatively passive group react ujxm the former. This action and reaction is ohjectiveh' evident by a retardation or alteration of the rate of growth or by u change produced in the external form or internal structure of the cells involved.

The most rapidly divitling grou)) of cells in a difTerential growing cellular field in syncytial continuity is subjected to a force tending to direct it in the path in which the resistance diminishes most rapidly, that is in the direction of a line of force. The mo.st rapitlly growing cells raise the kinetic energy of the field at the point of rapid growth above that of surrounding points, and hence a transference of encrg>' takes place until e(iiiilibrium is established. There will be a transfer of kinetic encrgj- from the growing to the passive group of cells resulting in an elongation of the latter and a consequent storage of potential energy due to position. On the other hand, there will be a transference of potential energy from the elongated relatively passive group of cells to the mo\'ing or growing group which will tend to restrict or retard the motion or growth of the fonner. This motive force of genesis, growth, and tlifferentiation continues until the difference in energj- disappears.

These biological generalizations are analogous to electromotive force. If two metal spheres at different jwtontials be connected by a wire, a transfer of positive electrification will take place from the one of higher to the one of the lower potential, or a transfer of negative electrification from the one of lower to the one of higher potential, or of both, until the difference of potential disappears. The higher and lower electrical potentials are analogous to the continuous zones of rajiidly dividing and less active group of cells, resjiectively. The term electromotive force is applied to any agency which tends to produce a transfer of electrification as exemplifictl above. Growth motive force consequently may be defined as any agency which tends to produce a transfer of kinetic and potential energy in a cellular field of ditTercntial growth.

GROWTH MOTIVE FORCE 205

EARLY STAGES IN THE HISTOGENESIS AND MORPHOGENESIS OF THE DESCENDING COLON OF THE PIG (SUS SCROFA)

The increase or decrease in size of certain parts of the intestine and the celkilar transformations which occur are of fiuidamental importance. By analysis and careful description of the changes which occur in sequence and by subseciuent synthesis of the data obtained, an interesting correlation in dynamics is thereby detected. Heretofore investigators of histogenesis have had independent and isolated view-points in their work on intestinal development, no correlation of the developmental processes being attempted. The admirable descriptive observations on intestinal development by McGill ('07) and Johnson ('11) fulfill the purpose of their respective authors, but lacked interpretation and correlation of the facts observed. Their point of view was descriptive morphology, not dynamic.

In an embiyo 10 mm. in length the descending colon presents in cross-section an oblong ovaL or pear-shaped appearance, the convexitj^ of which is directed toward the interior of the abdominal coelomic cavity. The tapermg end is attached to the dorsal abdominal wall through the intermediation of the relatively long and thick dorsal mesentery. There are three main elements which demand close attention (fig. 1). The first of these is the inner epithelial tube; the second, the outer peritoneal epithelium, and the third, the intermediate mesenchymal zone.

The inner epithelial tube in cross-section is oval in shape contaming a narrow oblong lumen with rounded ends. The lining cells of this tube form from two to three rows of nuclei. jNIitosis is usually found in the superficial row of cells. At this stage mitotic activity is prominent in the epithelial cells. The basal row of cells rest upon a well-marked basement membrane.

This basement membrane is directly contiguous to the intermediate mesenchymal zone. In this zone no clear-cut cell is found. The entire region is composed of protoplasm in syncytial continuitj^ embedded in which are found the nuclei. The nuclei are oval or roimd and present averj' dense network of chromatin, especially well seen when stained with iron-hematoxylin. The membranes of the nuclei are decidedly distinct. The protoplasm

206 EBEN J. CAREY

is pramilar, prosontinp: an inomilar network structure. Scattered in tlie niesenchyinal rejijion are seen isolated discrete vesicles. These are especially con^iegated toward the dorsal mesenteric attachment. The vascular vesicles are variable in size and shape and inesent vari(jus ile^n^es of confluence.

The thickness of the mesenchymal wall is nearly twice that of the diameter of the epithelial tube. It is to the rapid increase in diameter of the latter, due to rapid epithelial mitosis, that the uicreasc in width of the intestine is to be ascribetl. The mesenchyme remains relatively passive, and as a consequence is put under great tension by the internal distention of the epithelial tube.

Attention is especially directed to this difference in the rate of growth between the inner epithelial lining and the intermediate zone of mesench>nnal cells. The continued differentiation of the intestine is pivoted upon this fact. Furthermore, the epithelial distention is not a uniform one., Mitosis takes place in a spiral manner from the anal toward the ileocecal \alve. Conseciuently, the rapid growth of the epithelial tube is a specific type from below ujiwards.

The attention of the writer was directed to the fact, after l)lotting hundreds of intestinal epithelial mitotic figures, that these figures were usually confined to some definite region of the circumference of a single section. This region was found to change at diflferent levels of the serial sections. By graphic reconstruction (sections 45 to 04) this plot was found to form the path of a definite spiral describing a dexiotropic rotation in one case; in nineteen others the path was a left-handed sjMral. The si)iral itself presented a head or apical n^gion in which mitotic figures were found to be numerous and a tail or ba.sal end in which there were fewer and fewer figures. The apical end of the spiral path is always directetl toward the iliocecal valve and the basal end toward the rectum. (Jrowth is therefore from below upward in a sjjiral course. One sjjiral growth is (juickly followed by a second which rifles a i)ath slightly lateral to its predecessor. This in turn is followed by a third, in a path still more lateral, and so on around the circumference. This intermittent rhythm

GROWTH MOTIVE FORCE 207

of explosive spiral growth may be compared to that of the successive fire balls emitted by a roman candle in fireworks. The paths formed by this explosi\-e spiral growth may be compared to those within the barrel of a Winchester rifle.

Lining the outer peripheral portion of the mesenchynae is the peritoneal epithelium. In the 10-mm. embryo this is a single layer of oval or cuboidal cells. These are continuous from the dorsal mesentery and envelop the primiti^'e colon proper. The cell walls of this layer are contiguous and give a beaded appearance to the peritoneal epithelium. Later in development this cellular layer becomes flattened and markedly elongated, the individual cells becoming more and more attenuated and spindle-shaped.

The beginning of this flattening or elongation of the peritoneal epithelium is seen in a 14-mm. embryo (fig. 2). This cross-section represents the corresponding region of the descending colon in the 10-mm. embryo described above (fig. 1). In addition to the elongation of the nuclei, the cytoplasm is drawn out into a fine membrane between the separated nuclei. At the same time that the peritoneal epithelium is elongated, the epithelial tube is seen to have grown double in size, whereas the mesenchyme has only increased one-half that of the former stage observed.

The lumen of the epithelial tube is directed more transverse than vertical to the long axis of the gut . The lining cells appear to be overcrowding at the lower pole of the lumen due to rapid mitosis. This condition gives a stratified appearance to the epithelimn. This rapid mitosis constantly causes an increase of free surface, and consequently the lumen rapidly dilates in width.

Concomitant with the rapid increase in width of the epithelial tube, there is observed a change in shape and rearrangement of the surrounding mesench>^^^al cells. The nuclei and surroundmg granular protoplasm become elongated in a definite direction. Instead of the irregular arrangement characterizing the oval nuclei and stellate cytoplasm lieforc. there is now observed a definite tendency for the cells to form concentric layers. This tendency is more marked in the midzone of the mesenchjane between the epithelial basement memlirane and the outer shnple epithelial peritoneum. In this miilregion there is a condensation

20S EBEN J. C.VKEV

more dofinitp at the upjior (fig. 2) than at the lower pole of the epithelial tube and greater in cither polar region than on the lateral aspects of the tube.

With a further absolute increase in diameter of the epithelial tube (fig. 3) over that of the intestinal wall, the smooth muscle elements become more elongated, flattened, and spindle-shaped, and the definitive inner circular smooth muscle layer becomes more clearly defined out of its fonner nebulous state (fig. 2). By actual measurement with the filar micrometer, the intestinal wall is seen to become thiimer as the epithelial tube constantly increases in size. The embrj'o is now approxunately 20 mm. in length, and during this jieriod it is convincingly seen that the long axis of the elongated nuclei are arranged along the paths of concentric circles. The longitudinal gianular fibrils are likewise arrangetl in this concentric manner.

^^'ith the constant increase in width of the epithelial tube there is a progressively greater and greater elongation of the muscle elements — nuclei and granular fibrils. These fibrils branch and anastomose with neighboring fibrils, and constantly maintain the original continuity of the protoplasmic sjTicj-tium. With the ever-increasing tension of the fibrils there is a progressive loss of water and increase in viscosity.' Definite physicochemical changes take jilace in the granular fibrils resulting in condensation and fusion of the granules into a continuous coarse irregular strand. Near the nuclei the swellings upon the strand are marked, but toward the poles of the nuclei the fibrils are more attenuated.

As fonnerly reporte<l by McCill, there is the same tendency in the development of the colonic, nuiscles to form coarse and fine myofibrils as detected in the oesophagus. These fibrils are of variable length and run through several neighboring cells in many cases. The coarse and fine granular fibrils are seen side by side. The coarser ones being primarily located at the periphery' of the ill-defined spindle cell, whereas the finer graimlar myofibrils are located more internally and nearer to the nucleus. Between the fibrils more or less undifi"erentiated granular cytoplasm persists.

' The chemical elianges in myogenesis will be reported later with my colleague in biochemistn', Victor K. Levine.

GROWTH MOTIVE FORCE 209

In embryos, between 24 and 4() mm., the descending colon increases rapidly in length. Peripherad to the inner smoothmuscle coat there is found the beginning of elongation of cells similar to that described for the inner smooth-muscle coat. Similar changes in shape and arrangement of the components take place, however, in a longitudinal rather than in a transverse plane. At first this layer is more or less uniform throughout (figs. 3 and 4), but there is soon detected a greater proUferation of cells immediately underlying the dorsal mesentery. This aggregation of cells represents the inception of the longitudinal mesenteric taenia coli band of fibrils. This is definitely seen in figure 6.

The initial genesis of the mesenteric taenia coli before the other bands appear is significant. If we remember that this location represents the outer curvature of a coiled tube in the process of rapid formation, it is readily seen that more definite tension of differential growth is exerted at this location. These bands are more definitely developed nearer the ileocecal valve. The dynamics involved will be considered later.

The longitudinal muscle, however, is only slightly developed at 28 mm., and at 45 mm. is not as conspicuous as the myenteric Auerbach's plexus. This plexus is located between the welldeveloped circular smooth-muscle coat and the attenuated outer longitudinal-muscle coat. The nerve plexus at these stages 10 to 46 mm. is composed of a continuous layer of groups of cells with crowded nuclei and many non-medullated fibers.

The inner submucous plexus of Meissner is not as prominent as the outer one. It is similarly constructed, although it contains fewer and much smaller ganglia and the meshes of the plexus are much finer. The tenninal nerve fibers were traced to the epithelium and between the epithelial cells at 46-mm. stage. The plexus first appears along the inner border of the inner circular coat.

The muscularis mucosa is not differentiated at 45 nmi. The lymphatic channels, however, are abundant at 32 mm. along the line of the mesenteric attachment. L>^nphatic nodules are not formed, on the other hand, in the submucosa until the 150-mm. stage is reached.

210 EBEN J. CAREY

The lumen of the doscoiuliuK colon is patent thiougliout developnient; no sign of atresia is observed. Between the 10- and l4-niin. stages small vacuoles were found, but no diverticulae are seen. At 10 and 14 mm. the colon is round or slightly elliptical in shape, gradually enlarging toward the cloaca. The lumen possess in tlie earliest stages a shape comparable to that of the entire tube. Between 53- and 46-mm. stages, however, lateral, evaginations are do\eloj)ed which give the lumen a crucial instead of a round or elliptical appearance. These evaginations push out at the lateral aspects where the circular muscle is least developed, along Unes of least resistance. At the dorsal and ventral poles of the lumen the smooth muscle forms a thicker layer than on the lateral aspects. In addition, resistance is still further increased by the formation of the longitudinal mesenteric taenia along the dorsal, attached margin of the descending colon.

GROWTH MOTIVE FORCE TX INTESTINAL DEVELOPMENT

In the inorganic world that which jiroduces motion or pressure is considered as due to a force. This entity has already been defined. One result of its action on an elastic body, namely, a strain, should now be considered. This is imperative, for if mechanical forces are at work on organic matter the\' tend to ])roduoe similar results as those acting upon inert matter. Too frequently the term self-difTerentiation is applied to alteration of form and internal structure of developing cells without searching the inunediate environment of the specializing cells or syncytium to ascertain whether or not these changes are attributable to forces outside of the differentiating zone. This applies particularly to the differentiation of bone and muscle tissue. If a cell changes in form successively through the spherical, ellip.soid, and spindle stages it undergoes a strain. A strain is usually due to an external force wliich elicits internal reacting stres.ses in the body acted upon, ("ytological differentiation is frequently a manifestation of these internal reacting stresses.

It will prove to be an illuminating study to search for the celhilar forces outside of the inimediate differentiating zone under

GROWTH MOTIVE FORCE 211

observation. This search necessitates lower magnifications in order to enlarge our field of view. Heretofore cytological differentiation has been studied per se with magnifications of 1000 to 2000 diameters which considerably reduces our range of view. The higher magnifications are profitable in revealing cytological detail,, but the interpretation of the process is lost unless in conjunction with the higher, intermediate magnifications are used. By employing all possible magnifications of the microscope in connection with naked-eye studies we are less likelj^ to lose the forest for the trees. Such a method is likely to reveal the interaction of related developing jiarts. Before applying this method it will be of advantage to consider biiefly the different types of strain with wliich we are concerned.

DEFINITION AND CLAS.SIFICATIOX OF STRAINS

Elastic bodies are those in which a change takes place in the relative positions of their parts in contradistinction to rigid bodies in which no change occurs in the relative positions of their parts. Elastic bodies may suffer changes in their size or shape. Any definite alteration in the form or dimensions of an elastic body is called a strain.

This fact may be brought out in the following illustration: A rod which becomes longer or .shorter is strained. Water when compressed is strained. A stone, beam, or mass of metal in a building or in a piece of framework, if condensed or dilated in any direction or bent, twisted or distorted in any way is said to experience a strain. A ship is said to 'strain' if, in launching or when working in a heavy sea, its different parts experience relative motions.

The simplest strain is a Unear one. The stretching of an elastic cord is an example. This strain is called homogeneous when every portion of the cord has its length changed in the same ratio, so that the ratio of the initial to the final length of each part is the same as this ratio for the whole. The ratio of the final to the initial length is called the ratio of the strain; it represents evidently the quantity by which the initial length must be multiplied to obtain the final length. The elongation is the

212 EBEX J. CAREY

ratio of the change in the length to the initial length. A negative elongation, or shortening, is called a compression. A j)ositive elongation, or lengthening, is called a tension.

When all linos in a bodj* parallel to a certain direction are changed in the same ratio, and no lines peqjendicular to these arc changed either in length or direction, the bodj' suffers a strain of simple elongation. If. however, a second set of lines at right angles to these also suffer such a change, then there is elongation in two perpendicular directions: and if these lines are all in the same ])lane, the strain is a surface strain. A square elastic sheet, if the longation be e in a direction parallel to one edge, and e' parallel to another, will be converted by the strain into a rectangular sheet, the sides of which are proportional to the strainratios. Evidentlj- two equal and parallel lines drawn on the square will remain equal and parallel after the change in form; and the strain will be homogeneous. If the elastic sheet be circular, the strain will change the circle into an ellipse, the two perpendicular directions which remain perpendicular after the strain becf)ming the axis of the ellipse. If these lines remain parallel to their original directions, the elongations take place along them and the strain is called a pure strain. If not, the strain is compounded of a pure strain and a rotation.

As seen above, the jjrincipal axis of a strain is the principal axis of the ellipse into which the strain converts a circle. If the increase of length along one such principal axis is equal to the decrea.se of length along the other principal axis, the strain under these circumstances is called a .shear. Evidently in a shear the area of the plane itself remains unaltered. Any plane figure may be converted into a strained figure; that is, the shearing strain may be jiroduced simply by fixing one of its sides, and moving all lines parallel to this fixed side in their own directions, through spaces which are proportional distai>ces from this fixed line. The amount of this sUding motion which takes place between lines which are unit distance apart is called the amount of shear.

When a solid body undergoes a strain, a change may take place in its dimensions in one or more of three perpendicular directions. If the strain is such that all parallel lines within it are altered in

GROWTH MOTIVE FORCE 213

length ill the same ratio, the strain is called a uniform or homogeneous strain, as previously pointed out. Thus, for example, a sphere when subjected to strain is converted into an ellipsoid, a sohd every plane action of which is an eUipse. This ellipsoid is called a strain-ellipsoid. In any homogeneous strain of a solid body there are three directions at right angles to one another, which remain perpendicular after the strain. These directions are those of the three principal axes of the strainellipsoid.

Along one of these directions the elongation is greater and along another less than along any other direction in the body. Along the remaining one the elongation is intermediate. The principal axis of a strain is the principal axis of the ellipsoid into which it converts a sphere. The principal elongations of a strain are the elongations in the direction of its principal axis. According to Thomson and Tait, Any strain may be viewed as compounded of a uniform dilatation in all directions, superimposed on a simple elongation in the direction of one principal axes, superimposed on a simple shear in the plane of the other two principal axes." With this brief account of the nature of strain we may now pass on to the consideration of the effects of differential growth in intestinal development.

The most rapidly growing part of the intestine is the epithelial tube (figs. 1 to 6). In 10- to 23-mm. embryos the descending colon grows relatively more rapid in diameter than in length. The increase in diameter is due primarilj^ to the rapid growth of the entodermal epithelial tube and only partiall}' to its surrounding mesenchymal cloak. The latter is relatively passive in growth with respect to the former. It is during this early increase in diameter that the inner smooth-muscle coat is in the process of formation. The mesenchymal cells are drawn out gradually in a definite series of concentric rings. These rings appear not unlike those of the planet Saturn and the annular nebula in Lyra.

A definite centripetal force is active in the rapid, spiral growth of the intestinal epithelial tube. The surrounding mesenchymal cells arc thrown into a definite series of concentric rings accord THE ANATOMICAL RECORD, VOL. 19. NO. 4

214 EBEN J. CAREY

ing to their various densities. Those possessing the greatest density joining the outer ring in the tangential path of the force, '.vhoreas the inner rings will he composed of bodies forming a gradient of decreasing dcMisities. The cells forming the outer ring will he most elongated. Their water content decreases and viscositj^ increases.

As this concentric initial sniooth-nuiscle laj-cr becomes differentiated it tends to restrict the diametrical growth of the epithelial tube. The epithelial mitotic figures under this restriction shift their i^lanes of division from a right angle to a parallel position with the smooth-muscle colls. This shifting results in an elongation of the intestine.

In embryos 25 to 40 mm. in length, the elongation of the descending colon is more rapid in growth than that of the diameter. It is iluring this period that the outer longitudinal muscular coat is in the process of formation. The rapid growth of the epithelial tulie in length tends to elongate the peripheral undifferentiated mesenchymal cells which were not directly involved in the formation of the inner smooth muscular coat.

The differentiation of the outer longitudinal muscle coat therefore coincides, in time, with the rajiid growth in length of the intestinal ejiitheliimi. The inner smooth-muscle coat, on the other hand, is formed during the period of the rapid growth of the intestinal epithelial tube in diameter.

In this study, the initial zone of rapid growth is found in the epithelial cells. Kinetic energy is transferred from within to the surrounding splanchnic mesenchjnie by rapid spiral expansion of the entodernial epithelial tube. The less actively growing cells of the perii)heral region of the intestinal wall are elongated. Later the potential energy of the elongated cells is tran.sferred to those of theepitholium, resulting in a retardation of the growth in diameter. Inuncdiately following this retardation of diametrical growth, the period of rapid growth of the intestine in length takes place. In this development, therefore, the factor of growth motive force, as a cause in the transference of kinetic and j)otential energy, is definitely detected.

'

GROWTH MOTIVE FORCE 215

Once the formation of the inner circular muscular rings is fairly established, a resistance to growth in width is encountered by the cells surrounding the rapidly dilating lumen. These cells then grow primaril}^ along the path of least resistance in a longitudinal manner. At this stage the lontitudinal muscle cell, spherical in shape in figure 15, is elongated to a spindle-shape structure in figm'e 16.

In conclusion an interesting correlation in the development of the oesophagus in the human may be cited. This correlation was detected in the work of Jackson ('09) and in that of Keibel and Elze ('08). The former investigator studied the developmental topography of the oesophagus, the two latter the histogenesis of the oesophagus. Jackson states that the descent of the stomach is accompanied by a great elongation of the oesophagus. In a 9.4-mm. specimen the oesophagus measm-es 1.8 mm. ; at this proportion, it should measure 4.3 mm. in an embryo 22.8 mm., but its actual length is found to be 8 mm. The year previously Keibel and Elze reported that the oesophagus in 12.5-mm. embryos show a circular but no longitudinal muscle layer; in 17-mm. embryos they find a circular layer with the longitudinal layer faintly indicated. The histogenesis of the outer longitudinal layer of the oesophagus as studied bj' Keibel and Elze coincides in time with the rapid elongation of the oesophagus, due to the descent of the stomach, as recorded by Jackson.

GROWTH MOTIVE FORCE IN LIMB DEVELOPMENT

The detailed description of the direct observations made on bone and skeletal muscular development will be reserved for a subsequent communication.

When the embryo is approximately 10 mm. in length, the first indication of the limb is a bud filled with a densely packed mass of uniform mesenchymal cells. Eventually, when the embryo is 14 min. in length, a condensation of nuclei is detected in the center of the bud. This central condensation represents the primordial blastemal skeleton. It is the most rapidly moving or growing part of the hmb. This is evident by the greater number

216 EBEN J. CAUEY

of mitotic figures and bj* the relative scarcity of cytoplasm and conso(niont closely compact nuclei. As the central core of the linil) pushes forth more ra])icll}' tiian that of the ])eripheral continuous mesenchymal cells, there is a tendency for the latter to be pulled out, stretched, or elongated l)y the former. The traction force of the rapidly growing a})jiendicular core exerted ujion the surrounding mcsenchj-me is the internal stimulus of a correlated part, resulting in the elongation of the nuclei of the prenniscular mass in the direction of the blastemal skeletal growth.

From this direct observation that the cells of the premuscular mass are elongated in the direction of skeletal growth, we detect the objective evidence of the transference of kinetic energy from the zone of rapid growth to that of the relatively passive one. As differential growth continues and the growth motive force becomes more and more manifest, there is also detected a drawing out or stretching of the perii)heral syncytial cyto])Iasm in the direction of the skeletal growth. This is first shown l)y the appearance of relatively parallel rows of discrete, isolated granules which represent differences in density of the cytoplasm due to the traction to which it is subjected. This is comparable to the tendency of a viscid substance, like egg albumen, to collect in droplets if placed between two glass slides when these are separated In- a shearing force.

When the viscosity of the cytojilasm increases, on the other hand, with increased structural differentiation, these granules fuse and form a continuous condensed cytoplasmic strand known as the myofiliril. At first this myofibril is coarse, l)ut as the traction of skv'letal growtli continues it gives rise to numerous fil)rils finer in texture. Thus, there is a direct proportional increase of the cytoplasmic comjionents with continued skeletal growth. The formation of the embryonic skeletal nuisdes represents a definite reaction to the growth of the skeleton. These muscles tend to restrict the growth of the skeleton in length. This is manifesteil by an increasing condensation of the skeletal core.

This condensation is seen in the transition of the densely nucleated syncytial blastemal skeleton into the cartilaginous skeleton. The greater stability of the latter counteracts the deforma

GROWTH MOTIVE FORCE 217

tion that would naturally occur in the former as the primitive muscles begin to contract. On the other hand, with increased skeletal condensation there is presented a more rigid base, and this in turn acts as a stimulus to more definite muscular differentiation. This is detected by direct observation in the splitting up of the uniform premuscular masses into its individual muscular components. Muscular foi'ces become consequently more definitely applied and the definitive parts of the skeleton become more clearly outlined.

As the growth motive force of differential growth continues, the musculature becomes too vigorous for the cartilaginous base. The blastemal skeleton, as noted above, is supplanted by the cartilaginous one; there is now found another replacement of the cartilaginous by the osseous skeleton.

The changes which occur in a cartilaginous component of the skeleton, as the femur, in the formation of the more stable bonj" base, together with the concomitant muscular changes are as follows :

1. There is a bending of the cartilaginous femur with the con^•exity of the bow directed toward the M. quadriceps extensor. This deformation is incident to the contractilitj' of the thigh musculature and the inception of the adduction action in rotatiozi of the hind limb. This femoral strain is due to active and passive muscular stresses.

2. A strain fibrosis is detected on the weaker convex tensile aspect of the cur\ed femur resulting in the histogenesis of the primary perichondrium which subsequently encircles the shaft.

3. Concomitant with increased muscular differentiation and subsequent activity there is a progressive dehydration, increase of viscosity, and increase of total acidity (table 1).

4. Inception of necrobiosis of the cartilage cells is seen immediately underlying the initial location of formation of the primary encapsulating perichondrium. This necrotic change is ilue to the diminished blood supply caused by the restricting action of the forming perichondrium. By injection and serial sectioning methods it is revealed that all capillaries and incipient discrete \esicles, precursors of capillaries, are peripherad to the primary perichondrium.

218

EBEN J. CAREY

5. The vesiculated cartilage cells are arranged along definite curved tensile and conipressile stress lines. Previous to the bending of the femur these cells are irregularly related to one another.

6. Hyalinization of cartilaginous matrix in the central zone of the cur\eil femur is next observed.

T.\BLE 1

LENOTH or EMBRTO

TITBATION or 1 ORAM Of EUBRTONIC PREUFSCLB AND UCSCCLAR TISSUE TO .'"^ NaOH

mm.

«■

10

2 5

12

3.5

13

3.5

u

4.9

16

9.0

19

11.0

20

13.0

22

14.0

23

13 5

24

13.8

25

17.0

27

23.0

30

21.5

32

24

35

27.8

37

31

39

32.1

40

31.5

42

34.0

45

35.5

7. Calcification then takes place in the hyalinized matrix. These intergrading steps in the condensation of the matrix is incident to increased muscular growth and functional activity and to the passive resistance of the musculature to skeletal elongation.

8. .\ subperiosteal osteogenetic and constricting cellular zone is begun immediately underlying the initial zone of fibrosis on the summit of the convexitj- of the curved femoral rod. This osteoblastic constriction fjuickly encircles the shaft. This is the

GROWTH MOTIVE FORCE 219

beginning of a consecutive series of bony deposition. This bony deposit is due to two factors: first, the stimulus of the functionally active thigh muscles and, second, the stimulus of the restriction to growth at the ends of the rapidly elongating femoral rod due to passive muscular resistance. These two factors tend to stimulate the formation of the osseous skeleton in replacing the calcified cartilaginous skeleton.

From the foregoing brief account it is desired to emphasize the following :

That there is a direct transference of kinetic energy from the more rapidly growing skeleton to the less actively growing primitive musculature and a reactive transference of potential energy from the latter to the former, tending to a condition of equilibration. With the inception of functional muscular activity there is a direct transference of kinetic energy from this tissue to the growing skeleton tending to retard or alter its motion or growth. The resistance passively manifested by the muscles is an additional factor tending to inhibit skeletal growth. This fact is also noted by Holl, Schomberg, and especially by Bardeen. In this case there is a transfer of potential energy due to position from the muscles to the skeleton. This acti^'e and passive play of the muscles on the cartilaginous base resulting in a condensation of a more stable framework and the consequent more definite effect of the latter on the former is due to a direct transference of energy by conduction. This transference of energy is of fundamental importance and is produced by the motive force of differential growth.

SUMMARY Intestinal development

1. The region of most active mitosis, per mm. of cross-section, in the intestine is the entodermal epithelial tube. The mitotic figures primarilj' follow a path of a left-handed helLx.

2. The region of least active or relati\-ely passive growth per mm. cross-section is the mesenchyme, derived from the splanchnic mesoderm, surrounding the epithelial tube.

■_"_'() EBEN J. CAREY

3. The rapid oxpansioii duo to epithelial growth in a rotating spiral inaniipr of" the iiitostiiial lumoii is firoator than the activity uianifpst in the suiroundiiiK* mesenchyme. This causes a pressure in the latter lesultinR in a flattening and an elongation of the mesenchymal cells. The successive changes in .shajie of these cells through the spherical, ellipsoidal, and spindle cellular pha.ses are seen. The mesenchymal wall decreases in thickness, due to tension caused l)v epithelial tul)ular dilation.

4. The rotating spiral growth of the epithelial cell.'f causes the formation of a series of mesenchymal cellular and fibrillar concentric rings due to the centripetal force of the former.

5. The inner circular smooth-muscle cells are differentiated in the outer more condensed margins of the ring. \t these points the developing tensional stre.s.ses are greater than within the ring.

(>. The tensional stresses to which the elongated strained mesenchymal cells are subjected appear to be a dynamic stimulus to smooth-muscle differentiation.

7. The inner circular smooth-muscle coat is the first one difTerentiated and is incident to the rapid growth of the epithelial tube in diameter. The kinetic energy of epithelial growth is transferred to the surrounding inner developing annular muscle. The latter soon tends to restrict the growth of the epithelial tube in diameter. The tul)e, jjursuing the lines of least resistance, grows in length. Inuring the period of rapid growth in length the outer longitudinal musele coat is in the process of formation.

S. There is thus a definite interaction in intestinal development. We find evidence of a transference of kinetic energy from the zone of rapid growth of the epithelial tube to the less active mesenchymal wall resulting in the storage of potential energy due to ])o>ition in the latter. Subsequently a transfer of resisting potential energy from the elongated mesenchymal cells to the rapiilly growing cells of the epithelial tube. This tends to retard growth in diameter and to accelerate growth in length of the epithelial tube.

•J. The developing musculature loses water. It increases in vi.scasity and total titratable acidity.

GROWTH MOTIVE FORCE 221

10. The increase in size of the .granules in the mesenchyme is incident to tlie increase in viscosity. These granules are arranged in rows parallel to the long tixis of the elongated nuclei. The same forces at play in nuclear elongation are involved in the formation of the rows of granular fibrils. The formation of the coarse continuous myofibrils occurs at a period when the viscosity and deh.ytlration increases rapidly.

11. The following factors are intimately involved, therefore, in myogenesis:

a. Tensional stresses elicited by a force external to the differentiating myoblasts.

b. Loss of water.

c. Increase of viscosity.

d. Increase of total titratable acidity.

Limb development

1. The region of most active mitosis, per mm. cross-section in the limb is the skeletal core.

2. The region of least active or relatively passive mitosis, per mm. cross-section, is the surrounding continuous syncytial mesenchyme.

3. Potential energy is transferred from the rapidh' growing blast emal skeleton resulting in an elongation or a homogeneous strain of the surrounding continuous syncytial mesenchyme.

4. With the rapid progressi\^e extension of the blastemal skeleton more and more strain is put upon the elongating mesenchymal cells. The latter reacts upon the former continuously. There is a i)rogressive condensation of the skeleton through the embryonal to the ah'eolar or cellular hyaline cartilage stages. This gradual condensation is detected during a period when the premuscular masses are being split into the individual muscles between 14- and 18-mm. stages.

5. Between 19 and 21 mm. tlie muscles become functionally active. Limb rotation is begun during this period.

6. The longitudinal continuous nn'otibrils are differentiated between 14- and 18-mm. stages.

'222 KHEN J. CARKY

7. As the growth motive force of (hfferential growth continues, the nuisculature becomes too vigorous for the cartilaginous base. The bhistemal skeleton, as noted al)ove, is su])j)lante(l by the cartilaginous one; subsequently another replacement of the cartilaginous by the osseous skeleton occurs.

8. There is a direct transference of kinetic energy from the more rapidly growing skeleton to the less actively growing primitive musculature and a reactive transference of potential energy from the latter to tlie former, tending to a condition of ec|uilibration. ^^'ith the inception of functional muscular activity there is a direct transference of kinetic energy from this tissue to the growing skeleton tending to retard or alter its motion or growth. The resistance passively manifested by the muscles is an additional factor tending to inhibit skeletal elongation. This fact is also noted by HoU, Schomberg, and especially by Bardeen. In this case there is a transfer of potentiaL energy due to position from the muscles to the skeleton. This acti\e and passive plaj' of the muscles on the cartilaginous base resulting in a condensation of a stable frame work and the consequently increased definite effect of the latter on the former is due to a direct transference of energ}' by conduction. This transference of energy is of fundamental importance and is produced bj- the motive force of differential growth.

General deducdons from the study of myogenesis

Contractility is a fundamental ])roperty of ijrimortliul protoplasm. The protozoan, amoeba, possesses the property of contractility in all possible directions. The function of contraction in one definitive direction characterizes muscle tissue from that of unditTcrontiated and isolated organized particles of primordial protoplasm. What initiates the progressive series of physicochemical changes in primordial protoplasm resulting in an alteration of its attribute from non-specificity to sjiecificitj- of direction of contractility? This question is answered as follows:

The primordial protoplasm before differentiating into muscle tissue, must be subjected to a certain minimal homogeneous and

GROWTH MOTIVE FORCE 223

ellipsoidal strain. This strain is objectively evident by an alteration of the form of the spherical nuclei into the ellipsoidal and spindle conditions and by an elongation of the granular cytoplasm into parallel granular and continuous fibrillae. The fibrillae are arranged along lines of internal and reacting tensional stresses. The ends of the primordial protoplasm, in tension, must be attached to supports of which one, at least, is mobile. The tensional stresses are reactions to simultaneous forces extrinsic to the zone of myogenesis. The external forces cause a progressive divergence or separation of the mobile supports to which the primordial protoplasm is attached. Therefore, muscle tissue is not self-differentiating, but is dependent upon an external dynamic stimulus. As regards smooth and skeletal muscles, this stimulus is the motive force of differential growth.

Growth moiive force is any agency which tends to produce a transfer of kinetic energy, from an active to a less active group of celU, and of potential energy from a less active to an active group, in a cellular field of differential grouih until equilihriam is established.

Whether or not the end-product in muscular formation will be of the smooth or cross-striated type depends upon the intensity of the stimulus of tensional stresses to which the mesenchyme is subjected. The genesis and maintenance of muscle tissue represents a resultant or equihbration of converging factors which are active and formative during development. One of these factors is the tensional stresses to which the mesenchyme is subjected by a force extrinsic to the differentiating zone. In subsequent involution or degeneration of muscular tissue, during the prenatal or postnatal periods, this equilibrium is upset by altering or destroying the tensional reacting stress.

It is a pleasure to record my grateful acknowledgment to my former chief. Dr. H. Von W. Schulte, of Creighton University, for his encouragement, helpful interest and suggestions, and for the opportunities he has extended to me in order to complete this part of mj' studj- on bone and muscle development.

224 EBEX J. CAREY

I wish also to express my indel)tedness to Mr. M. W. Murphy, inanagor of the C'lulahy Packing Company; Dr. O. .\. Edwards, l)ri\atp veterinarian and sujjervisor of the Swift Packing Company, and to Mr. L. A. Orchard, superintendent of the .\rmour Packing Conij)any, .Soutii Side, Omaha, for their courtesies and generous permission in allowing uie to obtain unlimited numbers of pig embryos for this study.

For the beautiful clear-cut illustrations, my thanks are due to ^ladame Helen Ziska.

Finalh', for the ever ready help in completing this work, I owe my lasting gratitude to mj- wife.

LITER.\TUUE CITED

.\uiSTOTLE 1837 De Gcnpr.iti()nc Animalium, cd. Bakker; De P.irtibus .\ni malium, cd. Bakker.

1877 De .Vnima. cd. Trendelenburg, Berlin. B.\RDEEN', Charle.s H. 1910 Morphogenesis of the skeletal system. Keibel

and Mall. Human Embryology, vol. 2, p. 373.

1905 .'Studies of the development of the human skeleton. Am. Jour.

.\nat., vol. 4, pp. 265-30.5. B.\RDEEN' .\.ND Lewis 1901 Development of the back, body wall, and limbs

in man. Am. Jour. .\nat., vol. 1. B.\RDEE.N, Charles R., and Lewis, W. 11. 1901 Development of the limbs,

body-wall and back in man. .\ra. Jour, .^nat., vol. 1. Born, G. 1885 Ueber den Einfluss der Schwere auf das Froschei. .\rch.

Mikr. Anat., Bd. 24. Boveri, T. 1904 ProtopiasmadifTerenzierimg als auslosender Faktor fur

Kernverschiedenheit. S.-B. phys.-med. (ias., Wiir/.burg. Ergeb nisse iiber die Konstitution der chromati.schen Substanz des Zellkerns.

Jena. Carey, Eben J. 1917 Preliminary report on the normal unequal growth and

degeneration in the early ossification centers in the diaphyscs of

femora of the pig. .Vnnt. Rec, vol. 11. no. C.

1918 Early stages in the development of the pig with reference to the influence of muscular activity upim its ossification. .\nat. Rec, vol. 14, no. 1.

1919 On the interaction of the primary femoral ossification, thigh muscular differentiation, knee and hip-jnint formation; during the period of rotation of the hind limb of the pig (Sus scrofa). .\nat. Rec. vol. 16, no. 3.

1919 Tcratological studies, .\iiut. Rec, vol. 16, no. 2. Child, Charles Maxni.su 1915 Individuality in organisms. The University of Chicago Press, Chicago, 111.

GEOWTH MOTIVE FORCE 225

CoNKLiN, E. G. 1905 Mosaic development in Ascidian eggs. Jour. Exp. Zool., vol. 2.

Dreish, H. 1894 Analytische Theorie dcr organische Entwicklung. Leipzig.

Dreish, H., and Morgan, T. H. 1896 Zur Analysis der ersten Entwicklungs stadien des ctenophorenesis. Arch. Ent. Mech., Bd. 2.

Davenport, C. B. 1896 Studies in morphogenesis: IV. A preliminary catalogue of the processes concerned in ontogeny. Bull. Harvard Museum xxvii.

FiscHEL, A. 1895 Zur Entwicklung der vertralcn Rumpf u. Extremitatenmuskulatur bei Voglen and Siiugetieren. Morph. Jahrbuch, Bd. 23.

FiscHEL, H. 1898 Experimentelle I'ntersuchungen am Ctenophorenei. I. Arch. Ent. Mech. VI, II, III, IV ibid. VII.

FuTAMDRA, S. 1906 Ueber die Entwicklung der Facialismuckulatur des Menschen mit 27 Texabbildungen. Anat. Hefte, Bd. 30.

Harrison, R. G. 1904 An experimental study of the relation of the nervous system to the developing musculature in the embrj-o of the frog. Am. Jour. Anat., vol. 3.

Herbst, C. 1894-1895 Ueber die Bcdeutung der Reizphysiologie fiir die eausale Auffassung von Vorgiingen in der thierischen Ontogenese. Biol. Centralbl., Bd. 14, 15.

Hertwig, O. 1894 Zeit und Streitfragen der Biologie. Jena.

His, \V. 1874 Unser Korperform und das physiologische Problem ihrer Enstehung. Leipzig.

Holl, M. 1891 Uber die Entwicklung der Stellung der Gliedmassen des Meschen. Setzungsb. d. k. Akad. d. Wisi. Wein !\Iath. Xaturw. Klasse, Bd. 100, eT., S. 12. Wien.

Jackson, C M. 1908 An unusual duodenal diverticulum. Jour, of Anat. and Phys.. vol. 42, pp. 219-220.

1909 On the developmental topography of the thoracic and abdominal viscera. Anat. Rec, vol. 3, pp. 361-396.

Jenkinson, J. W. 1909 Experimental embryology. Oxford.

Johnson, F. P. 1910 The development of the mucous membrane of the esophagus, stomach, and small intestine in the human embryo. Am. Jour. Anat., vol. 10, pp. 521-561

Keibel, F., AND Elze, C. 1908 Normentafeln zur Entwicklungs geschichte der Wirbeltiere. Heft 8, S. 1-314. Jena.

Koelliker 1889 Handbuch der Gewebelehre des Menschen. S. 253.

LeW'IS, W. H. 1901 The development of the arm in man. Am. Jour. .\nat., V..1. 1.

1901 Observations on the pectoralis major muscle in man. Johns Hopkins Hosp. Bull., vol. 12.

1903 Wandering pigmented cells arising from the epithelium of the optic cup, with observations on the origin of the m. sphincter pupillae in the chick. Am. Jour. Anat., vol. 2.

1904 Experimental studies on the development of the eye in Amphibia. I. On the origin of the lens. Am. Jour. Anat., vol. 3.

1905 11. Oh the origin of the cornea. Jour. Exp. Zool., vol. 2.

22n EBEN J. CAREY

Lkwis. F. T., and Thync, F. \V. 1908 The regular occurrence of intestinal

diverticula in embryos of the i)ig, rabbit, antl man. Am. Jour. Anat..

vol. 7, pp. 505-519. LoEB, J. 1.S92 I'ntersuchungcn zur ))hysiologischen Morphologie der Thiere. M.\cCALLnM, J. B. 1S98 On the histogenesis of the striated muscle-fibre and

the growth of the human sartorius muscle. Johns Hopkins Hosp.

Hull. Mall, F. P. 1897 Ueber die Entwicklung des menschlichen Darmes und

seiner Lage beim Erwachsenen. Arch, fiir Anat. und Entw., .Supple mentband. S. 403-J34.

1898 Development of the ventral abdominal walls in man. Jour.

M(ir])h.. vol. M.

1898 Development of the human intestine and its position in the adult. Bull of the Johns Hopkins Hosp., vol. 9, pp. 197-208.

1899 Supplementary note on the development of the human intestine. Anat. Anz., Bd. 16.

1901 On the development of the human diaphragm. Johns Hopkins

Hospital Bulletin, vol. 12, and Proceedings of Amer. Assoc. Anatom.,

vol. 5, Washington. McGiLL. Caroline 1907 The histogeneis of smooth muscle in the alimentary

canal and respiratory tract of the pig. Internat. Monatschrift. Anat.

u. Phys., Bd.24.

1910 The early histogenesis of striated muscle in the oesophagus of

the pig and dogfish. Anat. Rcc, vol. 4, pp. 23-47. Meek. A. 1898 Preliminary note on the post-embryonal history of striped

muscle-fibres in Mammalia. Anat. Anz., Bd. 14 and 15.

1899 On the post-embryonal history of voluntary muscles in mammals. Journ. of Anat. and Physiol., London, vol. 33, pp. 546-608. Morgan, T. H. 1902 The dispensability of gravity in the development of the

toad's egg. Anat. Anz., Bd. 21. PFLroER, E. 1883 Ueber den Einfluss der Schwerkraft auf die Teilung der

Zellcn. Pflugers Arch., Bd. 31-33. PoPOwsKV, J. 1899 Zur Entwickelungsgeschichtc der Dammuskulatur beim

Menschen, 2 Taf. Anat. Heftc, Bd. 12. Preyer, W. 1885 Speziclle Physiologic des Embryo. Leipzig. Hecter 1896 Ueber die Entwickelung der Kaumuskulatur bein Schwein.

Anat. Hefte, Bd. 7.

1897 Ueber die Entwickelung der .Vugenmuskein beim Schwein.

Anat. Hefte, Bd. 9. RoDX, W. 1881 DerKampfder TheileimOrganismus. Leipzig. 1893 Ueber

Mosai Karbeit und ncuerc Entwicklungshypothescn. Anat. Hefte. KcssELL, E. S. 1917 Form and function. New York. ScHOMBURO, H. 1900 Untcrsuchungen der Entwicklung der Muskoln und

Knochen des menschlichen Fusses. Dissertation. Gottingen. ScHULTZE, O. 1900 Ueber die Nothwendigkeit der freien Entwicklung des

Embryo. Arch. Mikr. Anat., Bd. 4. Speuann, H. 1903 Ueber Linsenbildung bci defekter Augenblase. Anat.

Anz., Bd. 23.

GROWTH MOTIVE FORCE 227

Thoma, ]{. 1907 Synostosis suturae sagittalis cranii. Arehiv fiir patho logischc Anatomie unci Pliysiologie, Band 188. VON Baeh. Karl Ernst 1828 Ueber Entwicklungsgeschichtc der Tiere, Beo baehtung und Reflexion. Konigsberg. Wells, H. Gideox 1918 Chemical pathology. Wilson, E. B. 1896 Cleavage and mosaic work. Appendix to Crampton's

paper on lUyandssa. Arch. Ent. Mech., Bd. 3.

1904 Experimental studies on germinal localization. I. The germ

regions in the egg of Dentalium. Jour. Exp. Zool., vol. 1.

1904 Experimental studies on germinal localization. II. Experiments on the cleavage mosaic in patella and dentalium. Jour. Exp.

Zool., vol. 1.

1904 Experimental studies on germinal localization, I, II. Jour.

Exp. Zool., vol. 1. Wolff, C. F. 1759 Theoria generationis. Wiirzburg.

1768 De formatione intestinorium. Wiirzburg. Zeleny, C. 1904 Experiments on the localization of developmental factors in

the Nemertine egg. Jour. Exp. Zool., vol. 1. ZoJA, U. 1895-96 Sullo sviluppo die blastomeri isolati dalle nova di alcune

meduse. .\rch. Ent. Alech.. Bd. 1, 2.

PLATE 1

EXPLANATION OK KIliUUES

The tissue was fixed in Zenkcrs solution; the sections were eut at S/i and stained with iron-hematoxylin and pioric-aoid-fuchsin. The drawings were made with the aid of a Spencer camera htcida. Figures 1 to 6 are magnified 100 diameters.

1 Transverse section of descending voUm 10-mm. pig

2 Transverse section of descending colon 14-mm. pig H Transverse section of descending colon 20-mm. pig 4 Transverse section of desceniling colon 2o-mm. pig ij Transverso section of descending colon 31-mm. pig I) Transverse section of descending colon IC-mni. pig

AIIBREVIATIONS

dm., dorsal mesentery .</>., Meissners plexus (submucous)

cm., inner circular smooth-muscle a/)., Auerbach's plexus (intermus layer cular)

Im., outer longitudinal smooth-muscle sm., serosa

layer subm., submucosa

ml., mesenteric taenia muscle band p.m., primordial mucosae cells

X. B. — Note especially rapid increase in width of epithelial tube and the absolute decrease in thickness of mcsenchynial wall due to tension stresses elicited by the growth of the former.

228

GROWTH M(>TI\K F(M{CE PLATE 1

KBKN J. CAliEV

2

J^^- ■■■'* -^«^'>^*'

^_?/;' ^'"-'/iii-'S'

229

PLATE L'

EXrl.ANATION OF FICit'RES

7 IliRli-ptiwer drawing through iiitpstiiial wall iit region marked n - fc on figure 1. XS(1().

8 Iligh-piiwer drawing through intestinal wall at region marked a - h on figure 2 XSO().

AHHIIKVI.\TIONS

mil., mitisis

6.W., basement membrane

ni.s., meseneliynie

(/./.. granidar fibrillae

cm., circular muscle nucleus

s.m., peritoneal epitheliwiu

9 High-power drawing tlimucli iuli^l iiia! wall at region marked a - I' on figure ■\. XS(M1.

10 High-piiwer drawing thrniiuli intestinal wdl at region marked a - li on figure 4. XStH).

ahhukv lATiONs

p.m., primordial mucosae cells s.p., submucous nerve plexus /./., longitudinal muscle fibrilla. crosssection n./i.. Aucrbach's plexus

mil., mill sis

h.m., basement membrane

»!.«., mesenchyme

g.f.. granular myofil>rillae

cm., circular muscle nucleus

a.m., peritoneal epithelium

11 High-power drawing through intestinal wall at region marked a - li on figure .'). X>«X) diameters.

12 High-power drawing through inleslinal wall at region marked a - b on figure li. XS<1() diameters.

AIIHRF.VIATIO.NS

mil., mitosis

h.m., basement membrane

m.s., mesenchyme

g.f., granular myofibrillac

r.m., circular muscle nucleus

s.m., peritoneal epithelium

/).m., prim^trdial mucosae cells

.;>., submucous nerve plexus /./., longitudinal muscle fibrilla, crosssection a. p., Auerbach's plexus c.f., continuous coarse myofibrillac

230

GROWTH MOTIVE FORCE

EBEN J. CAREV

PLATE 2

10

-V

231

I'l.ATE 3

EXPLANATION OK FIGURES

13 Longitudinni reconstruction of the cross-sections nos. 45 to 94. This figure together witli the cross-sections represents a plotting of the exact hication of mitosis in the epithelial tube. Figure 13 is de])ictecl as a tube cut through the miildorsal region at 12 o'clock and lying Hat.

14 Ilcpreseuts figure 13 in graphic reconstruction; the flattened tube is folded up so that the edges of the niiddorsal cut are in apposition. The spiral paths of the mitotic figures are objectively evident. The apical region of the respective paths are globular. This globular end is always directed cephalad. The basal end of the spiral jiath is directed eaudad. The front and back aspects of the paths, as well as the cylindrical reconstruction is rei)resented by solid and broken lines respectively.

Sections 45 to 94 represent the cross sections of the epithelial tube of descending colon. Section 45 is eaudad; 94 is cephalad. The circles are numbered like a clock. Within the area enclo.sed by the two circles the dots are seen which represent the position and number of the mitotic figures. The arrows represent the direction of the spiral mitotic path which is seen to be right-handed. The predominant path, however, is left-handed. The large intestine of twenty animals was plotted. In only one was the niitntie path found to present a dexiotropic rotation.

ROWTBl MOTIVH FORCE

EDEN J. CAnET

PLATE 3

cefikalad

233

TLATK 1

KXI'LANATION OF FKlllKKS

15 Dorwivcntral section thruugh hind limh Df lO-nini. embryo pig.

ABHRKVIATIONS

m., mesenchyme eclo., ectoderm

Iti Dorsoventral section thruugh hind liml) of 14-iiim. embryo pig.

AUIIHKVIATIONS

i7., blastemal ileum b.f.. blastema] femur

IS., blastemal Ischium in., mosenohyme

d.p.m., dorsal premuscle muss b.t., blastemal tibia

v.p.m., ventral premuscle mass ecto., ectoderm

Schema of bone and muscle origin of thigh

17 Dorsoventral section through hind limb of IS-nini. eiiiliryo pig. .Stage of cartilaginous femur.

18 Dorsoventral section through hind limb of J.'j-mm. embryo pig. .Stage of inceptiim of osseous femur. Bone formatiim beginning on tensile aspect of bent cartilaginous femur (/. o. I.)

19 Dorsoventral .section through hind leg of 32-mm. embryo pig.

20 Dorsoventral section through hind limb of 50-mm. embryo pig.

AUIIHKVIATIONS

il., ilium t.p., tensile periosteum (chondrium)

i'*., ischium <•./'., comprcssih- periusleum (chon r., rectus femoris drium)

a., acetabulum v.i., vastus intermedius nuiscle

A., head of fenuir a.m., adductor magnus muscle

g.t., greater trochanter p.. patella

f.r., intermediate growing cartilage t.p.. ligamentum patellae

t.o.l., tensile osseous lamella /., fi-mur

CO./., compressile osseovis lamella I.. Iibi:i

N. B.- -The most actively growing region of the tliigh per mm. cross-section is the skeleton. This growth tends to draw out in tension the less actively growing mesenchyme which results in the elongation forming the ventral and dorsal premuscle masses a. p.m. and v.p.m., Kgure 16. With increasing tension due to skeletal growth the individual definitive muscles are formed. Concumitant with muscle formation, skeletal condensatiim is seen progressively through the blastemal, cartilaginous, and osseous stages. (See te.xt f>)r f\dl description.)

234

GROWTH MOTIVE FORCE

KBKN J. CAREY

PLATE 4

eclo

ech

f /■- ^S*^^*%'^-"'ii'^* fir'

Rcsunien por el alitor, Oscar \'. Batson. rnivorsidad dc San Iaus.

Deselect rifioaoi6n de las cintas de parafina por medio <le la eorriente do alta frecueiicia.

La cinta de parafina, al separarse de la navaja, con frecuecia se mueve, se adhiere a la navaja o cs atraida por los objetos cercanos. Esta dificultad, conocida generalinente como electrificaciAii, OS inuy inolcsta ciiando so corlan soccionos seriadas en tienipo frio y soco. La carga cstdtica os ilo caractor nogativo y estd localizada en el tejido y no en la parafina. Esta carga se doho al rozaniiento de la navaja sobre el tejido, porque si se corta un bloque de parafina sin tejido contenido en ella, no se produce cinta electrificada. La carga oloctrica puede sujirimirse y prevenirse satisfactoriamente ionizando el aire ambiente por medio do un aparato jiortatil do alta frecuencia del tipo de " rayos violetas." Se frota cl niicrotomo con esmeril, se coloca oropel sobre el soporte de la navaja y se sustituye el electrodo de vacfo del aparato de alta frecuencia, por una barra envuelta en oropel. K\ oloctrodo do oropol so dispone do tal motlo que la doscarga do la ijrocha tonga lugar a travos ilol area (}U0 rocorro la cinta al ser producida por la navaja. El aparato dobe mantonerse en marcha mientras se corte el tejido.

TraiiBlationby JiW- F Nonidcs CorniU Cnivcniity Mcdir»l Collpge, N. Y.

adthor's abstract of this paper isaubiD

llY TIIR niBLIOORAPHir SKRVICE, JULY 2fi

DE-ELECTRIFICATION OF PARAFFIN RIBBON BY .MEANS OF HIGH-FREQUENCY CURRENT

OSCAR V. BATSOX Department of Anatomy, Saint Louis University

Electrification of tlie paraffin ribbon, particularly on the highspeed rotraj' microtome, has been responsible for the great difficulties in serial work, particularly in cold, dry weather. Various methods of eliminating the trouble have been tried with indifferent success.

The problem was analyzed, first, as to the nature of the electrification; second, the source and reason for a collection of the charge; third, a means of discharging the electricity as it is formed.

The nature of the charge was determined by means of the electrophorus. The charge on the metal plate of the electrophorus is positive. The electrified paraffin ribbon is attracted to the metal plate of the electrophorus (positive) through a distance of several inches and is conversely repelled by the wax plate (negative). A ribbon possessing no charge is affected but little, so the charge on an electrified ribbon maj' therefore be said to be a negative one.

The electrification of the ribbon comes about through the friction of the block on the knife and does not occur when paraffin alone is cut. Each section produces a certain amount of frictional electricit3^ and once a charge is formed, the paraffin as a non-conductor prevents its escape except into the air, and the escape into the air is dependent on the ionization of the gas particles to carry the charge.

The solution for a de-electrification of the ribbon would therefore resolve itself into terms of air ionization to permit a discharge of the electricity as it is formed. This was first attempted by using carnotite at the suggestion of Prof. Hermann Schlundt, of the University of Missouri. A bell jar containing several ounces of radio-active carnotite was placed over the microtome and knife so that the 'active deposit' might accumulate. The

237

•2'^>^ OSCAR V. BATSON

pxppriniont proved un.succes.sful, although an elocfrifiocl ribbon lost its charge in oiic-fiftli the normal time whon exposed to carnotite.

The following procedure, however, has proved quite successful. A portable 'violet ray' high-freiiuency apparatus is employed, substituting fdi- the usual vacuum electrode a rod of wood, 8 inches long, closely wound with wire-cored Christmas-tree tinsel. The idea of using tinsel must be credited to Dr. T. (!. Lee, of the University of Minnesota. The apparatus was clamjied in position so that the tuisel electrode .stood parallel to the knife edge and about 2 inches in front of and above it. Additional tinsel wjis placed on the block holder and the knife supports. The microtome was grounded to a water pipe. The distance was adjusted to give a l)rush discharge, i.e., a distance bej'ond the possil)ility of a spark discharge, and the vibrator was set so as to give a faint ))uri)le glow from the electrode in a darkened room.

Under the.se conditions, bits of previously electrified ribbon, adhering to the knife support and block, immediately dropped to the table. No electrification of the ribbon occurred with the microtome running rapidly, while the brush discharge was taking l)lacc. Curling of the ril)bon recurred inunediately when the current was turned off. Checking on the electrophorus, it was found that both jjositive and negative plates were discharged l)y being introduced into the high-fretjuency field.

CONCMSIONS

1. Klectrilu-ation of ))arafliii ribl)on is due to a negative charge which results from the friction of the tissue on tlie knife. It accumulates because of an insufficient ionization of surrounding air.

2. The charge can l)e completely and satisfactorily removed by ionizing the surrounding air with a jjortable high-frequency ajjparatus with tinsel electrodes, and grounding the microtome.

'.i. The distance of the tinsel electrodes must be adjusted to give a faint l)rush discharge.

4. The stream of the current is through the microtome, and disagreeable sparking to the operator is absent. .\. slight odor of ozone is neither (lisagreeal>le nor harmful.

(T

n^

y

Ucsuiucn piir ol aulor, Henry Bayon.

l'niv(M'si(lante, e.s probable que el hueso anormal hallado corresponda al coracoides primitivo fusionado con sus derivaflos, cs decir, con la membrana costocoracoide y la clavfcula. Huntington cita la prosoncia do uno o dos nodulos cartilaginosos en la membrana costocoracoide. En ol sujoto de.scrito en este trabajo la mayor parte do la mombrana costocoracoide (fa.scia coracoclav icular) y ol nnisculo subdavio so han osiHcado. Una prueba mas evidente de la identidad del hueso con cl ligamento co-stocoracoides y la membrana es su |)erforaei6n por la vena cefalica. cuya dosembocadura en la vena axilar. os porotrolado normal.

TrmnslatiuD by Jus^ F. Noniilcx Cornrll Vnivcreily Medical CoUrg*. N- V.

AirXHOR S ABSTRACT OF THIS PAPER ISSUED BV THE BIBLIOGRAPHIC SERVICE, JCLY 26

A CASE OF OSSIFIED COSTOCORACOID MEMBRANE FUSED WITH THE CLAVICLE

HENRY BAYOX Department of Anatomy, Tulane University

ONE FIGURE

The subject, a negro male, with excellent muscular development, presents after reflecting the pect oralis major a quadrilateral plate of bone articulating with the sternum and extending lateralward to above half an inch from the coracoid process, to which it is united by a fibrous band. The bone is fused with the clavicle, which forms its upper rounded and expanded border; the subcla-\"ius muscle is absent and the pectoralis minor inserts at the distal end of the abnormal bone. The suggestion of Doctor Baker, mj- associate, that the condition might be connected with some abnormalitj' of the pectoral girdle is probabl}' quite correct.

In Rana catesbiana, bullfrog, the coracoid bone extends from the scapula to the sternum and is divided into two segments: a broad plate of bone below, the coracoid proper, and a slender bar above, the procoracoid, representative of the clavicle.

In the ontogenetic development of the manunahan clavicle the cartilage in which the primar^^ center of ossification is further developed is derived from the primitive coracoid. It is consequently quite probable that the abnormal bone here found corresponds to the primitive coracoid fused with its derivatives, namely, the clavicle and the costocoracoid membrane.

Huntington cites the presence of one or two cartilaginous nodules in the costocoracoid membrane. In the subject here presented the greater part of the costocoracoid membrane (coracoclavicular fascia) and the subolavius muscle have undergone ossitication. A further e\idence of the identity of the bone with

239

.MO

IlKNin HAVON

the costocoracoid ligament aiul monibraiic is its perforation by the cephalic vein, which otherwise normally drains in the axillary vein.

rcpliHlir vuin

I I'liix'-ifia-'l iKirtion o( i'<i!il<Kiinii'<iiil liimmpiil

iz^

^

kc

Resunion por ol autor, Hem y Bayou. I'liiversidad Tulane. Xupva Orleans.

Diferencias raciales y sexuales del apendice veiiiiifornie.

El ubjeto del presente trabajo es el tlesc-iil)ir las diferencias ((ue exist en entre el apendice del bianco y del negro, las cuales podrian explicar la mayor susceptibilidad para la apendicitis en la raza blanca, si es que existe tal susceptibilidad. Las observaciones efectuadas induyen diferencias sexuales y raciales en el taniano, musculatura, niimero relativo de linfocitos y criptas. y vascularizaci6n del Argano. Del examen microscAjiico de secciones transversales de cien apendices se detluce (lue las diferencias mas .salientes en las dos razas se refieren al m'unero mas elevado de linfocitos en el apendice del hombre bianco y la mayor ri(iueza vascular del niismo organo en cl negro Las estadisticas del Hospital <le Caridad de \ueva Orleans, (jue fueron consultadas iucidentalmente, parecen confirmar una susceptibilidad mayor de la raza blanca a las enfermedades de otros 6rganos linfaticos, tales como las tOnsilas palatinas y fari'ngeas.

Transliittoii by Jos/* F. Nimulca Curncll l*nivi'i>,ity MiMli«'nl OiIIorp, \. Y.

Racial And Sexual Differences In The Appendix Vermiforaiis

Henry Bayon

Department of Anatomy of Tulane University

About thirty years ago the appendix had practicalh' no history, either physiological or pathological.

Howard Kelly in his extensive work on the vermiform appendix and its diseases, recalls that only in 1824 was the appendix recognized as an organ susceptible to disease arising primarihin its own structure, although mention was made of isolated cases such as ]\Iestiviei's recorded in 1759 in which a postmortem examination revealed a pin (t)ncealed in the appendix, which had caused inflammation resulting in the death of the patient. This and other similar cases related in Kelly's work show that even in the eighteenth century the appendix was recognized as susceptible to inflammatory lesions, but it was not until 1886 that the appendix was placed in the category of organs susceptible to surgical disease. From that time the daily harvest of appendices has steadily increased. At the beginning of that period we hear Frederick Treves, one of the pioneers of appendectomy, clamoiing against the indiscriminate removal of the appendix, which he brands as a needless and illogical recklessness.

Since that time a number of speculative statements have appealed regarding the purpose of the appendix, usually more or less fanciful and sometimes positively grotesque. From the high otiice of abdominal tonsil we find it elsewhere relegated to the abject role of the ordinar}^ mechanical grease cup. In studying the minute structure of the appendix, it is true that large numbers of lymphocj'te accumulations are found within its walls, but at best these amount to little compared with similar accumulations found elsewhere in the intestinal canal and are in no way diff'erent from the solitary and aggregated lymphatic nodules.

241

242 HENRY BAYON

Nceilless to say that the grease-cup theory (imls no support from whatever aiiRlo the organ is vioweil. It evidentl}' originated in 174^ from an old theory of J. Vosse, who ohiimed that the ghmds of the cecum were not sufficient to moisten its contents antl that tlie function of the apjiendix was to provide additional secretion.

It is not the jjurposenf tlie ])resent study, however, to discuss the function of the api)endix nor the conditions which call for its removal. It was undertaken with a view to possible difTerences in .structure, both as to race and as to sex.

In considering disea.se of the appendix, the following (juestions suggested them'selves: Is appendicitis more frequent in the white race than in the negro? Is the disease more prevalent in one or the other of the sexes? .\nd if there are racial and sexual differences, is there anything in the structure of the appendix to account for such difTerences?

The first question, if records and Surgical experience are given consideration, is answered decided!}' in the affirmative. The statistics, however, on this, as unfortunately on a great many other subjects, are totally unrelial)le, even though tabulated intelligent h' and in good faith.

The eagerness displayed bj' the medical i)rofession in coming before the public, both in print and in lecture, no doubt in a great manj- instances with very laudable intent and good effect, places Avithin reach of the more intelligent hwman much of the interpretation of his own ills and jiains. He seldom ignores the signs and symptoms of appendicitis. As a result, the first tinge of pain in the right iliac region will sound a loud note of warning, followed b}' a rush to the surgeon, who at once proceeds to remove the aj)pcndix, in which postoperative examination frequently reveals little or no inflammatory change. This statement, however, is made with due regard to surgical prudence svhich takes no chances in a condition where prompt treatment means so much to the patient's safety. At this juncture it may not be inappropriate to refer to the opinion so frequently exjire.ssed, that apjiendicitis is on the increase. That the number of appendectomies has increased there can be no question, but that appendicitis is increasing is more than doubtful.

RACIAL DIFFERENCES APPENDIX VERMIFORMIS 243

In contrast with the alertness of the better classes and their readiness to part with an offending organ, is the ignorance and apathy of the poor negro concerning his disease and the counterindifference of his medical attendant. Acute indigestion or heart failure are con^-enient and readj' forms for his death certificate. Acute gangrenous appendicitis maj' have caused his death, but his tardiness in seeking medical aid or the lack of interest of his doctor, who comes in when the patient is dying or dead, are in many instances responsible for the error in diagnosis. Hence a possible flaw when records are considered, in passing judgment as to the racial susceptibility to appendicitis.

But if statistics are negative in deciding susceptibility, might there not be some structural peculiarity which would make certain appendices more vulnerable than others? Some time ago, in a casual examination of appendices in the dissecting-room, I was struck with the stout musculature of the negro organ as compared with the flabby membranous appearance of the white appendix. Obviously, a fecal stone or a foreign bodj^ would have far less chance of becoming impacted or retained in a robustly muscular appendix with active peristalsis possible than in one whose weaker walls would not only fail to rid the organ of its offending contents, but in consequence of the organ's easier distention would favor the storing up of enormous numbers of pathogenic bacteria.

Hoping to arri\-e at some tangible facts regarding structm-e which might cast some light on racial and sexual peculiarities, I have examined 100 appendices and tabulated them according to race and sex. The specimens emploj^ed comprised 53 negro appendices, 31 male and 22 female, and 47 wliite appendices, 11 nude and 36 female.

METHOD OF PREPARATION

The appendices were at first fixed in 10 per cent solution formahn, then mordanted in the following fluid:

35 per cent aqueous solution bichromate of potash 92

Formalin (40 per cent formaldehyde) 4

Glacial acetic acid 5

244 HENRY BAYON

The appendices were then imbedded and sectioned in celloidin, stained by Delafield's hematoxylin and counterstained in eosin.

LEVELS AT WHICH STAINED SECTIONS WERE TAKEN

In order to oljtain more reliable data, dissecting-room appendices were not considered. Appendices so diseased as to show disorganization or destruction of their tissues were avoided. Only recently removed appendices gathered from autopsies and abdominal operations at ("harit}- Hospital and Touro Intirmary of this city and preserved in formalin solution were used. The material included twenty-five slides of cross-sectioned a]ipentlices l)orr()wed from the pathological department of Charity Hospital. Each appendix was measured in length and in width and cross-sectioned two or three times from base toward the apex.

The average length, in all cases considered regardless of race or sex, was 9.2 cm. in seventj'-one specimens (table 1) and the average width 6.2 mm. in ninety-eight specimens. The length and width of the 100 aj)])eiidices were not all available. The length was not mentioned in the histories of the twenty-five Charity Hospital slides, and in four of the specimens prepared by myself part of the organ was missing. The width was taken fiom the mounted cross-.sections in all ca.ses except in two, the specimens having been previously opened by the pathologist for inspection.

Tallies 2 and 3 show a sexual difference in favor of the male, giving an average of 9.6 cm. (length) and 6.5 mm. (width) in the male against 8.7 cm. (length) and 6 mm. (width) in the female, tables 4 and o. the racial difference fin the two tables) show an average of 7 cm. (length) and 6.5 mm. (width) in the white and 11.3 cm. (length) and 6 mm. (width) in the negro.

It may well l)e oiijectccl that in tables 2, 3. 4, and 5 the inferences mu.st be unreliable, the nunilier of cases being too restricted. In table 1, however, which deals with the average length of the appendix, regardle.ss of race or sex, the same objection does not prevail. The slight difference in size between the male and female appendix is all that might have been expected, although that,

TABLE 1

Racial and sexual

LENGTH

WIDTH

White male . .

9 cases — ■ 8 cm. 20 cases — 11.3 cm. 37 cases — 6.1 cm.

5 cases — 11 3 cm.

11 cases — 7 mm.

Negro male

28 cases — 6 mm.

White female

37 cases — 6 mm.

71 cases av. 9.2 cm.

98 cases av. 6 2 mm.

TABLE 2 Racial, male

White male. Negro male.

LENGTH

niDTH

9 cases — 8 cm. 20 cases — 11.3 cm.

11 cases — 7 mm. 28 cases — 6 mm.

29 cases av. 9.6 cm.

39 cases av. 6.5 mm.

T^VBLE 3 Racial, female

LENGTH

WIDTH

White female

Negro female

37 cases — 6 1 cm. 5 cases — 11.3 cm.

37 cases — 6 mm. 22 cases — 6 mm.

42 cases av. 8.7 cm.

59 eases av. 6 mm.

TABLE 4 Sexual, white

LENGTH

WIDTH

9 cases — 8 cm. 37 cases — 6.1 cm.

11 cases — 7 mm.

White female

37 cases — 6 ram.

46 cases av. 7 cm.

48 cases av. 6.5 mm.

T^VBLE 5 Sexual, negro

LENGTH

WIDTH

20 cases — 11.3 cm. 5 cases — 11.3 cm.

28 cases — 6 mm.

Negro female

22 cases — 6 mm.

25 cases av. 11.3 cm.

50 eases av. 6 mm.

245

246

HENRY BAYON

together with racial differences, would seciu to otter no sohitit)n to the problem at issne. namely, structural peculiarity bearinjj; an susce|)tihility to inflannnation. The tabulations were simply included as a matter of general interest.

The field which .seemed most promising was the microscopic survey of the transverse sections. This consisted in measuring the thickness of the longitudinal and circular muscular tunics exprcs.sed in terms of microns together with noting the relative amount of h-mphocytes, fat and crypts and the vascularity of each appendix, classifying the specimens into three categories, rich, moderate anil poor, as indicated in table G.

TABI.K 6 Based upon 100 specimens

UUSCDLA

TURE

LTUPBOCrTES

F-AT

CBIPTS

VASCCIABITT

IN UICRON8

S

s

fi

O

s

P

«

e 9

£

•s

1

S

■s

b

•a c

R

1

^

L.

^

O

per

ptr

per

7per

per

5per

per

cent

ernt

cent

X. .M.-31 C.

247 B

3.50 8

16

22

62

23

32

45

19

,5.5

26

64

29

7

X. F. -22 C.

270 4

37.5 3

14

64

T2

41

18

14

36

50

54

27

19

W. .M.— 11 C.

270 4143.5 9

64

18

27

55

18

36

9

65

IS

18

64

W. F. -36 C.

241 2 392 8

47

44

9

59

29

12

62

23

15

16

21

73

A glance at the figures disproves the first impression regarding musculature. It is. therefore, quite evident that inmumitj' from ajjpendicitis in the negro, if such exists, cannot be accounted for by a stronger i)eristaltic wave. Indeed, the measurements show a preponderance of muscular tissue in the white appendix.

The racial and sexual dilTerences in the percentage ot fat conform with the general distribution of fat elsewhere in the sexes and in the two races. The negro as a race carries less fat in the average than the white, and in both races the female carries more than the male.

The dilTerence in the number (tf crypts retained is decidedly in favor of the white appendix. This would seem to indicate ie.ss

RACIAL DIFFERENCES APPENDIX VERMIFORMIS 247

susceptibility to iiifiammation. Hence, the study of structure in this particular feature, far from confirming disease statistics, offers decided opposition and is quite suggestive to the reverse.

The difficulty, however, presented by the crypts is offset very singularly by the findings regarding both the lymphocytes and vascularity. In the white appendices, 64 per cent male and 47 per cent female were found rich in lymphocytes, and 18 per cent male and 16 per cent female were found rich in vascularity. Comparing this with the findings for the negro appendix, 16 per cent male and 14 per cent female were rich in lymphocytes and 64 per cent male and 54 per cent female were found rich in vascularity.

In the cases here examined the ratio in the two races between lymphocytes and vascularity is inverted — the richer in lymphocytes, the poorer the vascularity seems a characteristic of the white appendix, whereas the reverse obtains for the negro appendix, in which the scarcity of lymphocytes corresponds with rich vascularity. From the figures the fact stands out that the white appendix is richly lymphatic and poorly vascular and the negro organ just the reverse.

In the white appendix are found two conditions predisposing to inflammation more especially of the gangrenous type — a rich supi^ly of lymphocytes indicating predisposition to inflannnation and poor vascularity favorable to gangrenous changes.

It may be objected that since the cases were tabulated regardless of health or disease, the prevalence of the appendices rich in lymphocytes might result from inflammatory action. The objection is met by the fact that, although in some cases operation was performed for appendicitis, in a great many other cases operation was performed for disease other than appendicitis, the appendectomy being performed simply as a matter of prudent routine in anticipation of possible future appendical trouble. But even if on that account, the high percentage of organs rich in lymphocytes found in the white cases be considered of negative \alue, the fact remains that these specimens show a low percentage of \-ascularity, and if inflammation alone could suggest increased lymphatic richness, it should also accentuate vascularity, which is (luite contrary to the fiiuling.

248 HENUV HAYON

Racial differences in tlie appendix suggested that corresponding differences might also exist in other diseases of the lymphatic system. Statistical inquiry into the relative number of tonsil and adenoid disease in the two races demonstrated that in 47ol) jiatients admitted into the Charity Hospital during the first three months of 1917, 2258 were negroes and 2501 were whites. In the 22r)S negro cases there were 35 tonsil cases and 8 adenoid cases. In the 2501 white cases there were 95 tonsil cases and 21 adenoid cases.

Table 7 .shows that the numl)er of tonsil ca.ses was more than twice as great in the white than in the negro and that the number of adenoid cases was twice as large in the white.

TABLE 7

22.58 negro patients. 2501 white patients

TONSIL CA8F.S

35 (0.015 per cent) 95 (0.037 per cent)

ADENOID CASES

9 (0.004 per cent) 21 (O.OOS per cent)

In these tonsil and adenoid cases figures may hold out equivocal interpretation : we are well aware that more whites than blacks are prone to l)ecome nervous al)out health conditions and the same suggestion regarding the advisabilitj' of parting with the appendix j)rcvails for tonsils and adenoids. It rests with the specialist whether the organs show sufficient evidence of disease to justify operation and the administration of an anesthetic — alwaj's a grave re.sponsibilit}'. Be that as it may, if each tonsilectomy and adeiioidertomy means disea.sed jialatiiie or pharyngeal tonsil, the unavoidable and iiidisputal)lr inference is that tonsil and adenoitl disease is more prevalent in the white than in the negro.

The .same Ciiarit}' Ilo.spital records for the first three months of 1917 show a total of twenty-three negro cases of aj)pendicitis against eighty-five white cases, ^^■ith due allowance for the doubtful trustworthiness of statistics considered from the standpoint of their face value, it may he safely assumed that when viewed in the liglit of histological findings above submitted, they

RACIAL DIFFERENCES — APPENDIX VERMIFORMIS 249

are at least ((uite suggestive of greater susceptibilit}^ of the white race than the negro to appendicitis.

Differences in the lymphatic system of the white and negro races may also be inferred from the findings of Bean and Baker, which appear in the Journal of Physical Anthropology, vol. 2, no. 1, 1919, under the title of "Some Racial Characteristics of the Spleen Weight in JNIan." 0\'er 1500 white and about the same number of negro spleens are considered, showing a decided difference in weight in favor of the white spleen.

These findings are well correlated to those submitted in the present study and seem to prove that the white race is more subject to lymphocytic stasis than the negro.

SOIMARY

1. The musculature of the white appendix is not weaker. Indeed, it seemed slightly stronger than that of the negro.

2. The female appendix is richer in fat than the male.

3. The white appendix is richer in crj-pts.

4. The white appendix is rich in lymphocj^tes and poor in vascularity and the negro appendix rich in vascularity and poor in lymphocytes.

5. The average size of the appendix is 9.2 cm. in length and ().2 mm. ill width.

6. The white appendix is shorter and wider than the negro appendix.

7. The male appendix is longer and wider than the female apjjendix.

HUMAN PAKASITOLOGY, with xotks ox Bacteuiolocy, Mycology, Lahokatouy Diagnosis, Hematology and Serology, l.y Damos Kivas, B. S. Riol. M.S., M.D., Ph.D., Uiiivcrsily of rciinsvlviinia. Illustrated. 71t> i)agps, W. B. Saunder.s Coini)aiiv. Philadelphia. Pa. 1920.

extracts from preface

A half century ago nieilieine was more an art than a science. The doors of American medical colleges stood wide open to welcome all who came as students, and if they showed a desire to learn, possessed enough elementary eilucatioii to eiiahle tlum to read their text-lmok anil write their examination papers no questions were asked as to their acquaintance with the physical and hiologic sciences.

There was no science of parasitology. Parasites were zoologic curiosities that occasionally intruded into the si)h(>re of medical activity.

Now all has changed. The necessities of commerce have led to such extensive geographic explorations that the entire surface of the earth has been explored and charted. Ethnologic investigators have uncovered the location, life and habits of many formerly unknown peoples.

The general rapid advance of scientific knowledge, especially the progress of physics, chemistry and biology, inevitably reaetetl upon metlicine, stimulating the scientific spirit, demanding research upon its obscure ]jroblems. and re(juiring a new tVpe of student whose jm'paration for medicine must include at least an elementary knowledge of the collateral and fundamental sciences.

The author has for twenty years interested himself in i)arasitology and has had the good fortune to have studied in public health laboratories at home and abroad, an<l to have served on sanitary commissions. Aftrr years of tcacliing he now endeavors to bring together tlie facts of ])arasitology in a form suital)le to the needs of the student and jihysician. The following pages reflect his personal experiences and present the facts of the sul)ject in a fonii sufficiently brief to make it a text-liook — the modern tendency is to be encyclopeilic- and sufficiently full not to omit any imjiortant fact or method.

250

',-"

THE ANATOMICAL RECORD, VOL. 19, NO. 5 OCTOBER, 1920

Resumen por el autor, Carl G. Hartman. Uuiversidad de Texas.

Los fen6nienos del parto en el opossum.

Ell oposici6n a lo que se cree generalmente, el embri6n del opossum, al final del periodo de gestaci6n, que dura diez dias, caniina por sus propios esfuerzos desde el orificio vajiinal hasta la bolsa marsupial, en la que encuentra la mama. La madre no ayuda al embri6n durante su paso desde la vagina a la bolsa, pero le lame para despojarle del liquido cori6nico, cuando sale por la vulva. Lo mismo que en el caso de las especies australianas Perameles y Dasyurus, descrito por Hill, los embriones alcanzan el canal vaginal medio no por los canales vaginales laterales, sino por un tuncl ([ue aparece de novo en el tejido conjuntivo situado entre la uretra y los canales vaginales laterales.

Translation by Joa& F, Xonides Cornell Medical College, New York

AUTHOR S ABSTRACT OF THIS PAPER ISSUED BY THE BIBLIOGRAPHIC SERVICE, SEPTEMBER 13

Studies In The Development Of The Opossum Didelpbys virginiana L.

V. The Phenomena Of Parturition

Carl G. Hartman

The University of Texas, School of Zoology

THE METHOD OF TRANSFER OF YOUNG TO THE POUCH

The literature

So far as the writer has been able to discover, there exists in the nterature only one account of the actual birth of any marsupial, notwithstanding the abundance of opossums in America and the variety of all marsupial fauna in Australia. Nor does that foremost of all students of marsupial embryology, Prof. J. P. Hill, refer to this topic, although on one occasion ('00, p. 371) he killed a specimen of Dasyurus after "one only of the young had been born." ^leigs ('47) and Selenka ('87) examined pouch young of the opossum immediately after birth, but made no observation on parturition.

The single recorded observation referred to is that of Dr. Middleton Michel, of South CaroUna ('50), who, on January 28, 1847, witnessed the copulation of a pair of opossums, and fourteen days and seventeen hours later saw the birth of the foetuses. In order to show, however, that Doctor ^Michel failed to see the actual passage of the 3'oung to the pouch, two essential paragraphs on the point at issue are here quoted:

' Parts 1 and 2 (History of the early cleavage — Formation of the blastocyst) appeared in the Journal of Morphology, volume 27, number 1, March, 1916; and Parts 3 and 4 (Description of new material on maturation, cleavage and entoderm formation — The bilaminar blastocyst) appeared in the Journal of Morphology, volume 32, number 1, March. 1919. These four parts may be obtained from the publishers.

Contributions from the School of Zoology, the University of Texas, no. 143.

The pregnant female was found standing on her hind legs; her body was much bent, and propped up against the rornor of the cage; her muzzle in immediate contact with the cloacal opening, which was red, tiunefied and distended: a young ap|)eared at the opening, and was conveyed by the mother's mouth to the pouch, or perhaps was rather licked in, as her tongue seemed busily employed within, around and about the pouch.

The young are expelled first into the vaginal cul-<le-sac, in which they remain for a short time, on the contraction of which they are forced along the vaginal canals one by one; parturition is thus ver>' much prolonged, owing to the circuitous route which the young are obliged to take, and the delay therein- occasioned between the birth of each is the object of the peculiar modification of these parts in this animal, as it affords the requisite time emjiloyed in the convej'ance of the young to the pouch and their adaptation to the teat.

It is quite clear from the language of this quotation that Doctor Michel did not actuallj- witness the migration of the embryos and that he merely guessed at the method emploj-ed by the mother, since he was not sure whether she used her mouth or her tongue. It will, moreover, be shown below that Doctor Michel was also mistaken in presuming that the young at birth pass out by way of the lateral vaginal canals. The observations recorded below indicate that the marsupial female does not actually transfer the foetuses to the pouch and that Doctor Michel's interpretation, as well as the prevailing notion in accordance therewith, is not borne out by the facts.

So7ne preliminary observations

A series of observations and experiments during the last four or five breeding seasons of the opossum had enforced the conviction that the young reach the pouch and find the teat by their own efforts and are not placed on the teats by the mother's tongue or lips, ^^h^• should it be necessary, one may ask, in the absence of actual observation, to presume such undue skill and sensitivit}- in the adult when a pure instinctive reaction on the part of the young will suffice?

On several occasions I experimented with newly born pouch young, gently removing them from the teats to which they had firmly attached themselves by means of their powerful tongues.

I quote from mj^ notes in one case (no. 301, experimented upon in the presence of Dr. C. H. Heuser, of The Wistar Institute, January 20, 1917) :

Female tied do^ii and pouch opened. Young which were removed from teats crawled about, moving hands alternately, as in swimming. Were able to crawl among hairs and find teats by their own efforts. One specimen, removed three times, found teat each time and three others found teats after wandering about.

These experiments certainly argued strongly in favor of some little independence of action on the part of these 'embryos,' a term that Doctor Meigs ('47) would have us abandon when speaking of these breathing, sanguiniferous, digesting pouch young."

On February 6, 1917, on opening specimen no. 402 under anesthesia, I was surprised to find a collapsed but very vascular uterus, as if birth had just taken place. This proved to be the case, for on remo\'ing the animal from the table I found that the entire litter of foetuses had been expelled during the operation. They were mostlj' still ali\'e, entangled in foetal envelopes and immersed in the foetal fluid. To some of the foetuses the umbilicus was still attached ; others were free, but no navel could be seen in any case. None of the foetuses, even after being freed of membranes and liquids, could crawl about, as they were apparently drowned in their own embryonic fluid. It seemed likely, therefore, that the emlsryos, on emerging from the vagina, need the assistance of the mother to lick away the fluid expelled from them, and this w-as later verified by actual observation.

Embryos near term were also removed from the uterus, freed of their envelopes, and allowed to crawl about over the mother, which they did for at least fifteen minutes.

On one occasion I removed one uterus three days before term (no. 131), and about the time that birth was to be expected from the remaining uterus I injected, some pituitrin subcutaneously, hoping to witness parturition thus brought on. But owing to the fact that abortion had pre\dously taken place, as was afterward learned, onlj' mucus was extruded from the genital orifice.

It is intorpstinp; to note, however, that after the injection of pituitrin the female Uctced out the pouch at freciuent intervals, an act which probably always precedes parturition.

The birlh of the opossum

Specimen no. 443 was broupiht to the laboratory February 2, 1920, having been captured uninjured several nights before. She was a healthy female of medium size, and In' palpation of the mammary glands, after the method which I have described at another place ('19, p. 24), T recognized her as pregnant and Hkely to give birth within several days. I removed her to my home, where she was kept under observation night and day, and the success which attended the undertaking is largely due to my wife's enthusiasm and perseverance.

The animal was i)laced just outside a window in a cage illuminated within by a red electric light, which arrangement was least disturbing to the animal as she was insulated against noises from within the room; the sight of persons moving about in the room caused little response on the part of the animal, but slight noises near the cage startled her great h'.

At 10:30 P.M., February (>, 1920, the animal showed signs of restlessness and soon began cleaning out the pouch, which she did about four times. Then began a short series of spasmodic contractions of the abdominal wall, after which she came to a sitting posture with legs extended. .\t no time did she stand on her hind legs, as Doctor Michel seems to have observed, for such

t po.sition is certainly strained and unnatural. I once had an opossum give birth while she was confined in a Inulaji sack in which she was carried to the laboratory. In this case it was assuredly' impo.s-sible for her to stand on her hind legs during parturition.

After assuming the sitting i)osture, our specimen bent her body forward and licked the vulva: however, her position at this time was such that we could not see the embryos, which very likely passed into the pouch with the fust licking of the genital opening. Hence we went to the outside where we could plainly hear her lap up the chorionic fluid; then suddenly a tinj- bit of flesh appeared at the vulva and scampered up over the entanglement of hair into the pouch to join the other foetuses, which now could be seen to have made the trip without our having observed them. Unerringlj' the embryo tra^'eled by its own efforts; without any assistance on the mother's part, other than to free it of liquid on its first emergence into the world, this ten-day-old embryo, in appearance more like a worm than a mammal, is able, immediately upon release from its liquid medium, to crawl a full three inches over a difficult terrain. Indeed, it can do more: after it has arrived at the pouch it is able to find the nipple amid a forest of hair. This it must find — or perish.

Having now satisfied ourselves as to the manner in which the 3'oung opossum reaches the pouch, we etherized the female, hoping still to find some of the embryos within the genital tract. But it happened that we had witnessed the last of the litter make the journey. The pouch contained a squirming mass of eighteen red embryos of which twelve were attached, though thirteen might have been accommodated. The remainder were, of course, doomed to starvation. Even some of these unfortunates, however, held on with their mouths to a flap of skin or to the tip of a minute tail, while several continued to move about.

With the mother under the influence of ether, we now gently pulled off a number of embrj'os from the teats in order to test their reactions. The teats had ah-eady been drawn out from about a millimeter in height to double that length, doubtless bj' the traction of the embryo itself, for the bottom of the pouch certainly presented a busy scene with each member of the closepressed litter engaged in verj^ active breathing and sucking movements.

One detached young, placed near the vulva, crawled readily back into the pouch. Two or three others regained the teats after some delaj^, and one wanderer, which lost out in the first scramble, found a vacated teat and attached itself even after twenty minutes' delay, showing that the instinct to find the teat . persists for some time. If the skin be tilted, the embryos, can be made to travel upward and even away from the pouch, for they are negatively geotropic.

For locomotion the embryo employs a kind of 'overhand stroke,' as if swimming, the head swajnng as far as possible to the side opposite the hand which is taking the jiropcUing stroke. With each turn of the head the snout is touched to the mother's skin as if to test it out, and if the teat is touched, the embryo stops and at once takes hold.

It is thus ajiparent that the opossum embryo at birth possesses not only fairly well-developed respiratory and digestive systems, but that it has attained a neuromuscular development sufficient to enable it to find its place in the pouch where food and shelter await it.

The 7iu7nber of pouch young

Most female opossums possess thirteen teats, of which usualljonlj' the posterior eleven are functional. I have often found as many as eleven pouch yovmg attached, but only in two cases as many as twelve. Doctor ^leigs ('47) on one occasion found thirteen. I have seen litters consisting of fifteen, seventeen, and eighteen newlj- born j'oimg in the pouch, with as few as seven attached to teats, and have removed from pregnant uteri as many as twenty-two normal foetuses near term. Such overproduction with consequent mortality has already been pointed out for the opossum and other marsupials (Hill, '10, '11: Hartman, '19).

Folklore

In the popular mind the generation of no animal is so shrouded in mystery as that of the opossum. From New Jersey to Texas several beliefs are current which it might be well to state at this point.

There is a wide-spread notion that copulation takes place in the nostril of the female and that the 'fruit of conception' is blown into the pouch. This superstition rests upon two observed facts: first, that the opossum penis is dichotomous and, second, that the female licks out the pouch immediately prior to parturition.

Another notion is that the pouch young is organically connected with, or 'grown to,' the teat, in fact so intimatelj^ that bleeding results from the forced separation of the pouch young. Doctor Meigs ('47) already showed that this is not the case.

Doctor ]Meigs mentions and refutes the idea prevailing in his time that the pouch young produces a teat wherever it happens to take hold of the skin in the pouch.

Finalh', it is often stated that the marsupial mother pumps milk into the pouch young. Whether or not this is true the writer does not know, but certain it is that from the very beginning the young opossum engages in active sucking movements.

THE PASSAGE OF THE FOETUSES FROM THE UTERUS

As is, of course, well known, the opossum, as a member of the order Marsupalia, possesses two uteri. These do not communicate posteriorly, but open each into a separate shallow cul de sac, on either side of a median partition. Each cul de sac communicates laterallj' with a loop, the 'lateral vaginal canal' (Hill, '97), which cur^-es laterad, then caudad and mediad, until near the midline the two canals almost touch; and from this point backward they Ue parallel until they empty into the 'median vaginal canal' (Hill, '97) or urogenital passage (Owen, '68). The lateral vaginal canals thus resemble two question marks placed face to face; the curved portions lie in the body cavity, the 'stems' are imbedded in the connective tissue of the urogenital strand. The urethra forms a third parallel tube, lying in the midline ventrad to the straight portion of the lateral A-aginal canals and emptying with them into the median vaginal canal.

In two Austrahan species Hill (Parameles, Dasj-urus; Hill, '98, '00) made the surprising discovery that the embryos at birth do not pass out through the lateral vaginal canals, but break through by a cleft-like rupture, the 'pseudo vaginal canal, directly into the median vaginal canal from the culdesac into which the os uteri opens. The new passage is described as a split in the connective tissue, at no time lined with epithelium and containing fragments of foetal membranes together with leucocvtes and maternal blood clots.

I have on several occasions demonstrated in the opossum the existence of the pseudovaginal passage discovered by Hill. In sjiecinien no. 402. aheady iiiontioiiod as aborting under an abdominal operation, one could follow a bloody trail direct into the median vaginal canal exactly as Hill had described it The hemorrhage was less severe in no. 443, the birth of whose young has been described above, but the new passage was ea.sil}- demonstrable. The organs were fixed in Bouin's fluid and sectioned. The findings are quite in accord with those of Hill. The pseudovaginal canal is seen to be simply a slit in connective tissue between the bladder and urethra voiitrally and the caudal ends of the lateral vaginal canals dorsally. In formaldehyde preparations of the organs taken from non-pregnant females such a pseudovaginal passage can with great ease be pushed through; that is, the urethra maj- very readily be separated from the parts dorsal to it. It appears quite certain that the contraction of the alxlominal and the uterine walls is sufficient to force the new passage at the tune of birth.

The embryonic envelopes are partly retained within the uterus, a fact already noted by Osborn ('87) for the opossum, and partly scattered along the median vaginal canal. None were found in tiie lateral vaginal canals either by Osborn or by the writer. It is possible that an embryo may even drag parts or all of its foetal membranes to the exterior, in which case the mother may lick it free; but my only evidence on this point is the presence of the foetal membranes about many of the embryos in the case of one abortion.

The opossum should therefore lie added to the list of marsupials which force the 'pseudovaginal canal' at parturition.

One might suppose from this that the lateral vaginal canals would pos.sess a special function. The writer believes with Hill that the}' function as rcceptacula scminis, .since in the marsupials several days elapse between copulation and ovulation. In the opossum the enlargement of the canal is one of the striking features of the prooestrus period. .\t oestrus they "have attained an enormous size and are filled to turgidity with a thin, lymi)li-like fluid. Soon after ovulation thej' shrink almost to the resting stage and are filled with cheesy masses of cpithehal cells, which remind one of a similar phenomenon described bj^ Stockard and Papanicolaou ('17) for the guinea-pig at oestrus.

ADDENDUM

Several months after the foregoing paper had been received by the editor of this journal the writer received a note from Dr. H. H. Donaldson, of The Wistar Institute, in which he stated that he had learned from Dr. N. Hollister, Superintendent of the National Zoological Park, Washington, D. C, of a pubhshed account of parturition in Macropus rufus, the deer kangaroo. The article in question is in the nature of a communicatioii by the observer, Mr. A. Goerling, to the 'Western ]\Iail,' of Perth, Australia, and was published January 3, 1913. Doctor Hollister's kindness in having the article copied makes it possible to present this interesting account to the readers of The Anatomical Record and thus render it more generally available to zoologists. The accounts of the birth of Didelphys virgiiiiana, as detailed above, and of INIacropus rufus, as reported by ^Ir. Goerling, are seen to be in perfect agreement on the one essential point, namel}^ that the young reach the pouch and find the teat by their own efforts and entirely without the assistance of the mother. It would seem, therefore, that this will be found to hold universally among the numerous species of the ]Marsupialia. The following are Mr. Goerling's notes dated December 19, 1912:

THE BIRTH OF THE KANGAROO

The question of how the young kangaroo comes into the pouch has long been looked upon as answered. According to obscivations made, the young is born and placed on the pap by its mother, and this view has been accepted In" zoologists.

On the 25th of February, 1906, 1 had the good fortune to make the most interesting and astounding obseivation. I had a number of Macropus rufus and M. cervinus in my possession, caged in varioussized cages. On the morning of the above mentioned date I was attracted by the peculiar behavior of a female M. rufus. She refused the feed placed before her; and on seeing blood marks in the cage, I

'The italics are mine.

came to the cont'lusic^n tliat the nniinal liad just given birth to a young one. Shi' was sittiinj in tliat resting ]iosition in which kangaroos can often be seen. Tlie tail pas.<eii forward through the legs, thus she was sitting almost entirely on the thick part of her tail. 8hc took no notice of my presence, although not more than three weeks in captivity, and was busy licking and cleaning herself. Presently she lifted her head, when I was astonished to see a young kangaroo clinging to the long fur about four inches below the opening of the pouch.

It moved about slowly, ven- slowly, through the fur upwards, using the arms in its progress, and conlittiuiUy moving the head from side to side, thus a.ssi.sting the upward movement. Nearly 30 minutes were required by the little wanderer to reach the top of the pouch, the last end in a semicircle. During the whole of this time the mother paid no attention to her offspring, offering no ass-istance, ami leariny it entirely to its own exertions. She then became restless; and not wishing to disturb her, I moved a short distance away, when she at once started to feed. A little later I paid another visit to her cage. She was sitting upright, the young one had disajjpeared, but the fur was still bearing evidence of the struggle, a plain visible track leading to and ending on the top of the pouch.

Now I had the explanation of a previous observation, but which I misconstrued at the time. I had a female ]\Iacropus woodwardi — Woodward's kangaroo — in captivity; and noticing blood stains in the cage. I beheved the animal was hurt. I then noticed just such a young kangaroo clinging to the fur below the pouch, and thought the mother by restless movements had dislodged it.

My obser\-ation of the 25th of Februaiy, 1006, proves that the new born kangaroo has to look after its own safety and reach the pouch mthotd the mother's as.vstance.

The anns of the new born kangaroo are strongly developed, the small hands open and close hke a cat's ])aw, and by these strong little anns and hands the young one is enabled to labour its way to the pouch, the place of safety and nourishment.

The cjuestion now presents itself, how can the young, with such a hard and firmly closed mouth, attach itself to the pap? I am convinced that at the time of birth the mouth has a wider opening and is perhaps more ela.stic than such specimens po.^.sess which are found in the pouch of the mother. Once a young kangaroo is removed from the pap, it is unable to reattach it.self.

As concluding proof that all newly born marsupials must reach the pouch by their own exertions, I mention that bandicoots, native cats and those very smallest of marsupials, the i)0uched mice, have the opening of the pouch in a reversed po.sition to the kangaroos and phalangers. I had once in my pos-scssion a ver>' small specimen of pouched mouse, having ten young ones in the pouch, each one not lugger than a grain of wheat. (Jnly through the opening of the pouch being reversed are these .smallest of boi-n mammals enabled to reach it with saftitv and without much exertion.

LITERATURE CITED

Hartman, Carl G. 1919 Studies in the development of the opossum (Didelphys virginiana L.)- Parts III and IV. Jour. Morph., vol. 32, no. 1, pp". 1-UO.

Hill, J. P. 1895 Preliminary note on the occurrence of a placental connection in Parameles obesula, and on the foetal membranes of certain macropods. Proc. Linn. Soc, New South Wales, vol. 10 (2nd ser.), part 4. 1897 The placentation of parameles (Contributions to the embryology of the Marsupialia I). Quart Jour. Micr. Sci., vol. 40, pp. .385-142. 1899. 1900 Contributions to the morphology and development of the female urogenital organs in the Marsupialia, no. 1. On the female urogenital organs in Parameles, with an account of the phenomena of parturition. Proc. Linn. Soc. N. S. Wales, vol. 24, pp. 42-82. Part I, March 29; nos. 2-5, id., vol. 25, pp. 519-532.

1900 Contributions to the embryology of the Marsupialia. Quart. Jour. Micr. Sci., vol. 43, pp. 1-22.

1900 On the foetal membranes, placentation and parturition of the native cat (Dasyurus viverrinus). Anat. Anz., Bd. 18, s. 364—373.

Hill and O'Donoghue 1913 The reproductive cycle in the marsupial Dasyurus viverrinus. Quart. Jour. Micr. Sci., vol. 59.

Meigs, Dr. Charles D. 1847 Reproduction of Didelphys virginiana. Proc. Am. Philosophical Soc, Philadelphia, vol. 4, pp. 327-330.

Michel, Dr. Middleton 1850 Researches on the generation and development of the opossum. Proc. Am. Assn. Adv. Sci., vol. 3, Charleston, S. C.

OsBORN, H. F. 1888 The foetal membranes of the marsupials: the yolk sac placenta in Didelphys. Jour. ^lorph., vol. 1, pp. 373-382.

Owen, Richard 1868 Anatomy of vertebrates, vol. 1, p. 682.

Selenka, E. 1887 Studien ueber Entwioklungsgeschiehte der Thiere. IV (1 and 2), Das Opossum (Didelphys virginiana). Wiesbaden.

Stockard, Charles R., and PAPANicoLAor, George N. 1917 The existence of a typical oestrous cycle in the guinea-pig with a study of its histological and physiological changes. Am. Jour. Anat., vol. 22, pp. 225265.

Resunien por el autor, Frank Charles Mann. Clinioa Mavd, Rochester, ^linnesota.

Psincreas accesorio.

En el present e trabajo se describen dos pancreas accesorios hallados en perros. En uno de los casos la ghindula aberrante estaba situada a corta distancia distal del ligamento de Treitz, en la inserci6n nicsentcrica del yeyuno. La glandula presentaba fomia triangular, niidiendo 27 X 20 X 15 nun. Poseia un conducto definido que desembocaba en el yeyuno. Su estructura histol6gica coiTesjionde a la del tejido pancreatico normal, pero existe una cantidad relativaniente pequena de tejido insular, y los islotes son muy pequefios.

La segunda gldndula aberrante estaba situada en la pared del duodeno, a corta distancia de la entrada del conducto pancredtico menor. Presentaba forma de disco y media 5x3 mm. Su estructura histol6gica revela la presencia de acmi y conductos normales, pero hay una ausencia casi completa de tejido insular. En este ultimo caso es interesante la estrecha relaci6n entre el tejido pancreatico y la nuisculatura lisa de la pared duodenal.

TransUtioD by Joe6 F. Xonidex Comfll Mfdiml CoIIoitc. Nrw York author's abstract of THI3 PAPER ISSUED BT THE BIBLIOGRAPHIC SERVICE, SEPTEMBER 13

Accessory Pancreas In The Dog

F. C. Manx

Assistant Professor of Experimental Surgery arjd Pathology, Mayo Foundation (Graduate School, University of Minnesota) , Rochester, Minnesota

FIVE FIGURES

Man}' cases of an accessory pancreas in man have been reported. At various times the separate reports have been collected (Opie, Ruediger, Warthin, Wiedman). An accessory pancreas has been found in the wall of the stomach, duodenum, jejunum, and ileum; in a diverticulum of the stomach, jejunum, and ileum; in Meckel's diverticulum, umbilical fistula, mesenteric fat, great omentum, hilum of the spleen, and capsule of the spleen. In some cases the accessory glands have been considered significant chnicallj- in relation to atresia of some portion of the gastro-intestinal canal, obstruction, intussusception, pancreatitis, and malignancy.

From the embryologic standpoint the accessory pancreas has attracted considerable attention and stud}'. The fact that the pancreas arises from two buds and the cells of origin are somewhat scattered seems at least partially to exjjlain the development of accessory pancreatic tissue.

There are few reports of an accessory pancreas in species other than man, although some species are believed normally to have separate pancreatic tissue in the wall of the stomach or duodenum, and the possibiUties of its embryologic development in other species are certainly as great as those in man. No reports of an accessory pancreas in the dog were found in the Uteratm-e.

During two experimental operations on dogs in our laboratory two aberrant jjancreatic glands were found. The account of the finding and the description of the two glands follows:

Dog D 93 (experiment 249-19), an adult mongrel bull, weighing 11.7 kg., was being operated on April 30, 1919, by Doc 263

tor McQuay for the purpose of developing the technic in some pastro-intestinal operations. AMiile I was demonstratinp a method of finding the first portion of the jejunum in the dog, I noted what appeared to be an accessory pancreas just below the ligament of Tritz. Since I was not aseptically prepared to operate at the time, the exact nature of the gland was not determined. The proposed gastro-enterostomy was abandoned, however, and the left ureter was sectioned and anastomosed and the gall bladder remo\ed by Doctor McQuay. The animal quickly recovered from the operation and gained in weight.

July 8, 1919, I explored the animal for the purpose of definitely determining the presence of an aberrant gland (experiment 44319). The tissue was found to be an undoubted accessory pancreas. Some measurements of the size and position of the gland were taken. M necropsj- these were found to be approximateh' correct. One small lobule, 4 bj- 2 bj- 1 mm., of the accessory pancreas was removed and fixed in neutral formalinZenker. The major pancreas was examined and found to be normal; one small lobule of it was also removed. Microscopic examination of these specimens showed both to be normal pancreatic tissue.

The animal was kept under observation, as it was planned to study the carbohj'drate tolerance and then gradually remove the major pancreas in order to determine whether or not the accessory gland would take care of the carbohydrate metabolism. The animal was pugnacious, and March 5, 1920, was killed in a fight.

The necropsy (107-20) was performed shortly after death. All tissues were well preserved. The site of the accessor j' pancreas was carefulh- examined. It was located 32 cm. from the pylorus, 11 cm. below the upper attachment of the ligament of Tritz and 5 cm. below its lower attachment. The gland was roughly triangular, with the small side of the triangle attached quite firmly to the jejummi. It measured 27 mm. along the greater side of the triangle, 20 mm. along the opjjosite side, and lo mm. across the small side attached to the jejunum. It was 6 mm. thick. It appeared to be composed of perfectly normal pancreatic tissue. A small duct, extending from the middle of the side attached to the jejunum, passed through the jejunal wall. This duct measured 2 mm. in diameter and 5 nmi. in length. On the jejunal side the duct emptied into the lumen of the intestine through a small opening.

Fig. 1 Diagram showing the rel.it ivc position of tlie accessory pancreas of dog D 93.

The major pancreas was large, weighing 45 gm. The animal was found to be normal except for a small lymphoma in the spleen, measuring 6 mm. in diameter.

MicroscojMC examination of many sections of the accessor}' pancreas showed it to be composed of normal pancreatic tissue. The acini appeared perfectly normal. A large number of islands were scattcrcil tliroufilKiiit tlic ^laml: it was noticed, however, that the islands wore very small. In most instances not more than a dozen island cells were found in one group in a section. In comparison with the islands of the major pancreas they appeared very small indeed. Other than this decrease in island tissue and iiarticularly in the size of the islands, no difference was noted between the iiiajnr paiicic;!^ ;in(l the ac('(>ssory irland (figs. 1 to 4).

Fig. 2 DrawiiiK of the accrssory iiaiirrcas in its rr'Ialion to the jcjiiiiiiin and the inrsi'ntpry in ilog D 'Xi.

Dog I) .")(>;? (experiment 200 20), a mongrel hlack and white hound, weighing 20.4 kg., was operated on March 2(1, 1!(20, for the ])nrpose of making an lOck fistula. On pulling up tlie duodenum an accessory pancreas was found 6 cm. from the pylorus on the light side of the <luodenal wall, and M 7nm. alio\e the entrance of the minor pancreatic duct into the duotlenal wall, making it about O.n cm. from the mesenteric border on the right side. The aeees.sory gl.-ind w;is disk-sha]ie(l, .'> mm. in di.imeter.

Fig. 3 Photomicrograph of the largest island found after a search through many sections of the accessory pancreas of dog D 93. It is normal, but small. X2.50.

Fig. I I'hotoinicrograph of one of the average-sized islands of the major I)ancreas of dog I) 93. Compare with figure 3. X"2oO.

Fig. 5 Photomicrograph of section of accessory i)ancreas of dog D .ilVi. Note the ahsence of island tissue and the intimate relation of pancreatic and smooth muscle tissue. X75.

and !? mm. Iliick. It was covered coinpletelj' with serosa and inihetldcci in tlie muscul;iris, hut was (|uito easily dissected out. It was ini])()ssil)le to detei-mine {jiossly wlietlicr or not a duct connected it with tlic duo<l('iium. The tissue apjieared to Ije jierfectly normal. A s])eciinen wa.s excised and fixed in formalin, and a specimen taken from the major pancreas just below the accessory gland was also fixed in formalin.

On microscopic examination the major pancreas was found to he normal, and se\eral sections of the accessory fjland showed this also to be normal pancreatic tissue. \'ery little island tissue was found. Scattered in various parts of the section were groups of a few, seldom more than six, of what appeared to he island cells. The gland had well-de\Tloped ducts; undoubtedly a duct connected it with the lumen of the intestine. The pancreatic tissue and smooth muscle tissue were intimately associated; prolongations of one dipped, tinger-like, into the other (fig. 5).

Bibliography

OiMK, K. L. 1903 The anatomy of the pancroas. Hull. .Inlins Hopkins Hosp.,

vol. 14, pp. 229-232. UuEDiOER, G. .\. 1903 .\cces.sory pancreas, .lour. .\mi. M('<I. ,\.ssn., vol. 11,

pp. 1059-1062. Warthi.v, a. S. 1904 Two cases of accessory pancreas (omentum and stomach).

Physician and Surgeon, vol. 26, pi). 337-:i.TO. Wkidmax, F. D. 1913 .\l)errant pancreas in the splenic capsule. .\nat. Hcc,

vol. 7, pp. 133-139.

Resunien por el autor. H. L. Wieman. Universidad de Cincinnati.

Obsen'aciones relativas al desarroUo temprano de la gldndula suprarrenal huniana.

Embri6n de 9 nun. 1. Las crestas siipranenales sc extienden posteriomiente desde las inenibranas pleuroperitoneales hasta las crestas genitales. 2. El unico indicio de vascularizaci6n del tejido suprarrenal esta representado por algun oorte transverso de un capilar. 3. En la region suprarrenal los ramos comunicantes se extienden ventralniente mas alia de los ganglios pre vert cbrales del siniputico, en fonna de fibras nerviosas en apariencia desprovistas de celulas nerviosas. 4. Las C(51ulas gcnninales extraregionales se presentan diseniinadas en las proxiniidades de las crestas genitales.

Embri^ii de 12 mm. Las glandulas suprarrenales estdn claraniente separadas de los tejidos ([ue las rodean. 2. La regi6n central de la gldndula es una red muy vascularizada, cuyos vasos sangufneos poseen paredes endoteliales bien distintas. 3. El lado medio de cada glandula estii en (ntimo contacto con la prolongaci6n ventral del ranio comunicante y masas de c<*lulas ganglionares. Algunas "de estas aparecen entre las fibras de la porcion distal del ramo, a lo largo del cual parecen emigrar desde los plexos celiacos y visccralfs.

Traiulntion by Joe£ F. Nonides Cornell McdimI CoUpsc, New York

ATTHOR S ABSTRACT OP THIS P.* PER ISSUED BY THE BIBLIOGRAPHIC SERVICE, 8EPTEMBP:R 13

Observations In Connection With The Early Development Of The Human Suprarenal Gland

Wieman HL. Observations in connection with the early development of the human suprarenal gland. (1920) Anat. Rec. 19: 269-280.

H. L. Wieman Zoological Laboratory, Universiiy of Cincinnati

TWO PLATES (XINE PIGrRES)

The purpose of this contribution is to call attention to certain details in connection with the development of the human suprarenal gland, because thej' happen to be clearly illustrated in the material at hand. This material consists of two human embrj^os, nos. 1 and 4 of the author's collection, which were obtained some years ago, freshty killed and fixed, from Drs. H. L. Woodward and Charles Goosmann, of Cincinnati. No. 1 had been killed in a bichromate-acetic mixture, and no. 4 in Bouin's solution. The former measured 9 mm., crown-breech, and the latter 12 mm. Both measurements were made in So per cent alcohol after fixation, so that the sizes of the living embrj'os were somewhat larger than these figures. The embrj'os were embedded in paraffin, cut into serial sections of 10 /j thickness, and stained on the slide with Delafield haematoxylin and orange G according to the method of Morris ('09). Mitotic figures abound in both emijryos. but the fixation is somewhat better in no. 1.

OBSERVATIONS

Embryo no. 1, 9 7um. The suprarenal glands are not recognizable as distinct organs, but consist of a thickening in the mesenchyme on either side of the root of the mesentery, formuig a pair of broad ridges projecting into the bodj' cavitj- from the dorsal body wall. Anteriorly these suprarenal ridges are continuous with the dorsal portions of the pleuroperitoneal membranes, while posteriorly thoy blend with the genital ridges. Laterally each is separated from the niesonephros by a distinct groove (fig. 1). Occasionally a transverse section of a blood capillary can be seen in the center of each ridge, the beginning no doubt of the central vein of the adult organ.

The ridges are made up of mesenchyme which shows no evidence of differentiation. The ramus commuiiicans divides into two at the level of the sj'mpathetic ganglion where one of the branches terminates, the other passing ventralward into the mesenchyme. The cells composing the sjnnpathetic ganglia stain more deeply than the surrounding cells, but beyond this they show no api>reciable differentiation. The ganglia lie on either side of the aorta somewhat dorsal to it. The nerve strands (axis cylinders?) are easily distinguished and followed, owing to the fact that they stain readily with orange G. The ventral branch of the ramus communicans, which is really the direct ventral continuation of the latter, loses itself in the mesenchyme of the suprarenal region. It seems to be unaccompanied by nerve cells (fig. 3). From the picture one gets the impression that the nerve fibers are pushing their way through the mesenchjTiie, blazing, as it were, a track along which the ganglion cells are to follow later.

In the posterior part of the suprarenal ridge, the genital ridge, the subepithelial region of the mesonephros, and in the mesentery, one finds large cells with clear cytoplasm and standing out distincth' from all cells (fig. 3, 4, 5). These I take to be genu cells (primary genital cells). Their wide extraregional distribution indicates that these cells undergo a rather extensive migration before reaching the germinal epithelium. This of course is in keeping with what is known about the early development of germ cells in other vertebrates.

Embryo no. .{, 12 mm. The suprarenal glands in this specimen are distinctly marked off from the surrounding tissues (fig. 2). Each one lies with its dorsal surface against the pleuroperitoneal cushion, while in close contact with its niedian side are bundles of ner\-e fibers and ganglionic clumps. Near the ventral border, a* shown in figure 2, some nervous tissue is pushed into the substance of the gland, but only to a verj' slight extent, definite immigration, according to other autliors, not taking place until a much later period.

The prevertebral sympathetic ganglion is now a very distinct mass of cells clearly differentiated from the mesenchjaiie. Its relation to the ramus comnmnicans is somewhat different from that described for the 9-mm. embryo. There is no longer any evidence of a branching in the ramus communicans at the level of the ganglion, the latter lying more directly in the path of the ramus. The ventral extension of the ramus (fig. 1) now passes directly ventralward from the ganglion (fig 2, v.r.). Among the nerve fibers of the ventral extension of the ramus can be seen two kinds of cells: 1) those distinguished by a long narrow outline with nucleus of the same shape, which are probably sheath cells and, 2) large irregular cells with yellowish cytoplasm drawn out into processes and possessing rounded nuclei. The latter are undoubtedly migrating nerve cells (fig. 7). They are larger and differ otherwise in their appearance from the nerve cells* found in the prevertebral ganglia (fig. 6), but are practically identical with the large nerve cells partially embedded in the A-entral border of the suprarenal gland (figs. 2, 8). Comparing the pictures presented by figures 1 and 2 it would seem that in the latter stage the nerve cells are in the actual process of migrating ventralward along the paths marked out bj' the nerve fibers, which alone are present in the former stage. If some of these migrating nerve cells are destined to enter the gland to form its chromaffin tissue and others to pass on to form the ganglia of the coeliac plexus, there is no way in the preparations at hand of distinguishing the two kinds. According to Souile ('03), the penetration of the cortical portion of the suprarenal by the parasj'mpathetic cells commences at the 19-mm. stage, which is of course considerably older than the one dealt with here.

The cells of the gland itself are arranged in the form of a branching network penetrated with blood-vessels, and resembling the zona reticularis of the adult organ. A distinct endothelium forms the walls of the capillaries (fig. 9). The only other indication of differentiation in the gland is the ingrowing of connectivetissue trabeculae at the periphery.

H. I-. W I KM AN

DLSCL'SSION

His, Jun. ('91), describeil a proliniinary nervc-fibcr franiowork laul out ill the form of rami fomiminicantcs, alons which tho sympathetic cells wander to form the {ganglia. Streeter (Keibel and -Mall, V. 2, p. 149) states that in human embiyos the migrating cells can be recognized in advance of the loose strands of the tip of the growing nerve which extend through the mesenchyme toward the aorta, and that by the tune a well-defined nerve trunk is established, the sympathetic cells have already completed that part of their migration, and the cells then found on the nerve trunk are sheath cells only.

In the 9-mm. embryo under discussion the nerve fibers forming the ventral extension of the ramus conniiunicans beyond the s^-mpathetic ganglia (fig. 1) may have been preceded by amigration of ganglion cells through the mesenchyme, but my preparations do not show nerve cells either among the fibers or at their distal ends (fig. 3). On the other hand, in the 12-mm. embiyo the cells found scattered along the course of the fibers are mitloubtedly nerve cells rather than sheath cells. I am therefore inclined to believe that some at least of the ganglia migrate to their final location along jiaths formed of nerve fibers. The well-known work of Harrison ( 'Oti) which .shows very conclusively that ganglion cells of amj^hibian larvae develop axis cylinders as outgrowths of the cell body, strengthens my conviction that the nerve fibers forming the pathway (kneloj) originallj' as outgi-owths from cells located in the cord. \Miether the nerve cells subseriuently found among the nerve fibers come directly from the spinal ganglia or from the prevertebral ganglia is another question. I can only say that the migrating nerve cells are larger and iliffer in outline from those found in the prevertebral ganglia.

As has been noted above, Soulie ('03) states that the penetration of the parasympathetic cells into the cortical portion of the suprarenal gland connnences at the 19-mm. stage. Zuckcrkandl (Keil)el and Mall, v. 2, p. 173) states that the elements of the migrating coll ma.sses, which are entirely or for the most part chromaftin-forming cells, are sharply distinguished from the neighboring cortical cells by their smallness and intense stain. In my preparations one cannot saj'^ with certainty whether such cells are present or not. Deeply staining cells occur bordering the nerve strands and the ganglionic masses, and these may represent the chromaffin cells, but if so they are sharply defined from the nerve cells and are more distinctly epithelial in character.

Zuckerkandl (Keibel and jNIall, v. 2, p. 171) found that the suprarenal glands are already vascularized in a 9-mm. embryo, whereas in my specimen of this age the only indication of vascularization is the occasional appearance in the suprarenal ridges of a cross-section of a blood capillary, which simply means that my embryo is younger than his, though both are the same length. In the 12-mm. embryo of my collection delicate endothelial capillaries form a xevy rich vascular network involving practically all of the gland except the cortical region. The central vein is not visible.

Hoffmann (93) and others have shown that the primordial germ cells are distinct from the elements making up the geniiinal epithelium of the gonad and that they exist a long time before the appearance of the latter. More recently, Swift ('14) has traced the history of the primordial germ cells of the chick from their origin in a specialized region of the germ-wall entoderm just at the margin of the area pellucida. These cells are carried by their own movement and later by that of the blood to all parts of the embryo and vascular area until in embryos of twentysix to twentj'-nine somites thej'^ are found in the splanchnic mesoderm near the radix mesenteric With the formation of the gonad they gradually jiass to that organ. Fuss ('11) describes extraregional germ cells in a human embryo aged four weeks. He finds them in the mesentery directly under the peritoneum, but not in the germinal epithelium. According to his description, they are large cells of rounded outline, with clear cytoplasm and distinct nucleus. The cells measure 19 to 20 m i» diameter and the nuclei 12.75 ix.

In my 9-mm. embryo, which is somewhat older than the one studied by Fuss, I have found cells resembling the one pictured

274 H. L. WIEMAN

by Fuss in his Hpuro and corresponding in e\-cry way to those described in his text, except that the measurements I have made are somewhat less than his. Likewise I find the distribution of these primitive germ cells to be somewhat wider than he found, and in my preparations some of the cells have approached verjclose to the germinal epithelium (fig. 4). The 12-mm. embryo did not prove favorable for the study of these cells, so that I have no data on the range of distribution at this later stage. My observations on the 9-mm. embryo corroborate the statements of Fuss, which indicates that the germ cells of man like thoso of other vertebrates are characterized by period of migration in the early part of their history.

SUMMARY 9-mtn. embryo

1. The suprarenal ridges extend from the pleuroperitoneal membranes posteriorly to the genital ridges.

2. The only indication of vascularization in the suprarenal tissue consists in an occasional cross-section of a capillary.

3. In the suprarenal region the rami communicantes extend ventrally beyond the prevertebral .sympathetic ganglia as ner\'e fibers apparently free of nerve cells.

4. Extraregional germ cells are found widely scattered in the neighborhood of the genital ridges.

12-mm. embryo

1. The suprarenal glands are distinctly marked off from surrounding tissues.

2. The central region of the gland is in the form of a network, and is highly vascular, the l)lood-vessels having distinct endothelial walls.

3. The median side of each gland is in close contact with the ventral prolongation of the ramus conimunicans and masses of ganglia cells. Some of the latter are found among the fibers of the distal part of the ramus along which they seem to be migrating to form the coeliac and visceral plexuses.

LITERATURE CITED

Fuss, A. 1911 Ueber extraregionare Geschlechtszellen bei einen menschlichen

Embryo von vier Wochen. Anat. Anz., Bd. 39. Harrison, R. G. 1906 Further experiments on the development of peripheral

nerves. Am. Jour. Anat.. vol. 5. His, W., JON. 1891 Die Entwicklung des Herznervensystems bei Wirbeltiere.

Abh. d. math.-phys. Kl. d. Kgl. Sachs. Ges. d. Wiss., Bd. 18. Hoffmann, C. K. 189.3 Etude sur le developpement de I'appareil urogenital

des oiseaux. Verh. d. Kgl. Akad. v. Wetenschoppen. Amsterdam,

vol. 1. Keibel and Mall 1912 Manual of human embryologj-. Philadelphia. Morris, J. T. 1909 A note on orange-G counterstaining suggesting a useful

method in the management of embryonic tissue. Anat. Rec, vol. 3. SouLi£, A. H. 1903 Recherches sur le developpement des capsules surrenales.

Journ. de I'Anat. et de la Phj-siol., vol. 39. Swift, C. H. 1914 Origin and early history of the primordial germ cells in the

chick. Am. Jour. Anat., vol. lo.

DESCUIPTIOX OF I'lCilUES

Figs. 1 ami 2 are camera drawings made at table level with Zeiss ocular 2- and l(j-nuii. objective. The remaining figures were made with Zeiss ocular 4- and 2-mm. objective. .\11 figures have boon somewhat reduced in reproduction.

ABBREVI.\TIONS USED IN FIGURES

6.1'., blood-vessel P-c-, plcuroperitoncnl cushion

e.c endothelial cell s.g., prevertebral sympathetic gan g.c. primordial germ cell glion

g.r., genninal ridge s.r., suprarenal ridge

H.c, nerve cell v.r., ventral continuation of the ramus

ii.f.. nerve fiber communicans

PL.\TE 1

EXPL.VXATIOX OF FIGURES

1 Transverse section thro\igh suprarenal region of 9-mm. embrj-o.

2 Transverse section through suprarenal region of 12-mm. embryo.

3 Enlargement of portion of ventral continuation of the ramus communicans of figure 1.

4 Enlargement of portion of germinal ridge of figure 1, showing a primordial germ cell near the germinal epithelium.

a Enlargement of portion of subepithelial portion of the suprarenal ridge of figure 1 also showing a primordial germ cell.

27^.

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277

PLATE 2

EXPLANATION OP FIGURES

6 Enlargement of portion of the prevertebral ganglion of figure 2.

7 Enlargement of the ventral continuation of the ramus communicans of figure 2.

8 Enlargement of the ganglionic mass embedded in the ventral border of the suprarenal gland uf figure 2.

9 Enlargement of the central portion of the suprarenal gland of figure 2, showing the capillary structure.

PLATE 2

Resimioii ]ior los autores, George B. Wislocki y Tracy Jackson

Putnam. Escuela Medica Harvard, Boston.

Xota sobre la anatoniia de las areas postremdtieas.

Las areas postrenidticas son niasas de tejido situadas en el extremo caudal del cuarto ventrfculo: estdn compuestas de cclulas de neuroglia y estan niuj- vascularizadas. Al fusionarse foniian el techo del canal central de la medula. Estdn cubiertas de delieadas c<'>lulas eiiendiniarias aplanadas, cjue difieren del epitclio cjue tapiza interiomiente el resto del cuarto ventriculo.

En las areas po.strematicas del honibre se han hallado celulas nerviosas, designadas eon el nonibre de niicleos postremdticos. En los animales no se han encontrado cclulas nerviosas en estas regiones. La rica vascularizaci6n de estas areas es un hecho descrito repetidas \-eces. Los vasos provienen de las ranias piramidales de las arterias cerebelosas inferiores. No se sabe nada acerca de la significacion funcional de estas estructiu'as. Las areas postrenniticas se tinen intensaniente con los colorantes vitales, J' este hecho es sorprendente si se tiene en cuenta que todas las demas jjartes del sistema nervioso central, con excepci6n de la hip6fisis, no se tinen vitalincnte. La (•oloraci6n de las areas puede explicarse por la acuniulaci6n de mol^culas del colorante en las cclulas del tejido conjuntivo situadas en las vainas de los vasos sangufneos.

Transliitiou liy Joti F. Nonidcs Cornell McUiral College, New York

acthor'6 abstract of this paper issued by the bibliographic service, september 13

Note On The Anatomy Of The Areae Postremae

GEORGE B. WISLOCKI and TRACY JACKSOX PUTNAM

Laboratory of Surgical Research, Harvard Medical School

The earliest investigators of the behavior of the benzidine group of A'ital dyes were impressed by the fact that the normal central nervous system remained unaffected by these substances. The choroid plexuses alone were deeply stained, and it was thought that they were responsible for the failure of the dye to enter the cerel^rospinal fluid. The only portion of the brain which was observed to stain grossly, aside from the choroid plexuses, was the hypophysis. The dj'e appeared in tliis organ principally in the pars anterior.

On examining the tissue of the brain under the microscope, it was discovered, however, that it is not absolutely devoid of stam, since granules of dye-stuff were occasionally discovered in connective-tissue cells of the meninges, in the adventitial sheaths of the cerebral vessels, and in the capsule cells of the spinal ganglia. In the true nerve elements vital-dye granules were never observed under normal conditions.

On examining the brains of a varietj of animals after repeated injections of trypan blue we noticed in the gross two bilateral areas at the caudal end of the lateral walls of the fourth ventricle which were quite as deeply stained as the adjacent choroid plexus. These areas were found vitallj' stained in several monkeys besides in a series of dogs, cats, and rabbits, so that there remained no doubt as to the constancy of the phenomenon (figs. 1, 2, and 3). No mention has been made of the behavior of these areas by either Goldman (1, 2, .3) or ^MacCurdy (4), to whom we are indebted for our knowledge concerning the distribution of vital dyes in the central nervous system. A possible reason why this staining may ha\'e been o\'erlooked by Goldmann is that he worked upon mice and rats in ^\hich the areas would necessarilj' be vevy

2S1

2S2 GEORGE B. WISLOCKI AND TRACY JACKSON PUTNAM

minute. In the species of large anijimls studied by us the areas could hard!}- fail to attract attention. An investigation of the anatomy of the caudal end of the fourth ventricle showed these spots to be the areae postremae.

The lower end of the calamus scriptorius is only briefly described in most text-books of neurology, but it has been the object of special study in the human brain by several investigators, particularly Blake (5), Wilson (6), and Street er (7).

The areae or eminentiae postremae, so named by Retzius, are paired mounds of loose, vascular tissue which overlie the caudal third of the nucleus vagi and protrude into the lumen of the fourth ventricle. At their superior extremities the areas lie just ventral to the line of attachment of the choroid tela. Caudally they converge and eventually fuse in the midline to form the roof of the central canal. A tiny pocket, the suprapostremal recess, exists, as Blake has observed in many animals, between the roof of the central canal and the roof of the ventricle or the obex.

Wilson (6) has described and pictured the A-ariations which occur not infrequently in this region in the human brain. In some specimens he noted that the areae postremae fuse to form the roof of the central canal. In these instances a suprapostremal recess is formed, as in animals, between the areae postremae and the obex above. In other specimens, however, the areas fail to coalesce in the midline, and consequently the obex forms the dorsal wall of the central canal at its emergence into the ventricle. In the latter cases the eminentiae postremae are seen in section as bulgings in the lateral walls of the mouth of the canal.

In serial sections the minuter rclatiouf^hips of the areas may be obser\-ed. Near their upper poles they appear as low elevations projecting into the rhomboid fossa, bounded mesially and below by the alae cinereae and extending laterally to the line of origin of the taenia. Midway between their poles, in the region of their greatest development, they appear as two prominent masses bulging into the lumen of the ventricle and overlying the dorsal nuclei of the vagus nerves. A band of dense neurogliar tissue, the so-called funiculus separans of Retzius, is conspicuous in

NOTE ON ANATOMY OF AREAE POSTREMAE 283

this region. It separates the areae postremae from the alae cinereae which He beneath and mesial to them. In sections taken farther back, it may be observed how the areae postremae gradually converge and finally fuse, enclosing a space between them and the ventricular floor, the orifice of the central canal. The entire surface of the areae postremae is covered by a delicate, flattened epithelium, and differs in this respect from the rest of the ventricle which is covered by cuboidal or columnar ependyma. The tissue of which the eminentia postrema is composed, consists of a loose network of neuroglia through which runs a rich plexus of arterioles and capillaries. The arterioles are surrounded by perivascular sheaths composed of connective-tissue cells. In addition to the vessels, fibroblasts, and neuroglia cells which were observed by Streeter (7) and Blake (5) , the presence of neurones has been described in human material by Wilson (6). He suggests that these nerve cells be designated the 'nucleus postremus.' He also states that Stilling used the term 'Accessoriuskern' to designate the area postrema, and that the latter observer may therefore have been aware of the presence of nerve cells in that region We have confirmed Wilson's observation in several human brains, but have been unable to find nerve cells in preparations from any of the animals which we have examined. The embryology of the area postrema has occasioned some discussion. Blake, who is apparently the first writer to investigate the subject, believes that it is part of the remains of the secondary rhomboid lip of His, in common with the obex and the ligula. As we have seen, however, the eminentia postrema is quite distinct from both these structures, which Blake's own illustrations also show. In his figm-e 28, the area postrema, marked 'secondary rhomboid lip,' is some distance mesial to the attachment of the velum. Elsewhere in the same paper, Blake speaks of the primary rhomboid lip as fusing to "produce a bridge of nervous matter over the emergence of the myelocoele into the fourth ventricle," which is doubtless the interpostremal fusion in this region. Wilson's conception seems much more tenable. He considers the area postrema as a part of the alar lamina of His.

THK aN.\TOM1CAL RECORD, \0L. 19, NO. 5

284 GEORGE B. WISLOCKI AND TRACY JACKSON PUTNAM

Wp liavo ptiicHcd two human onibryos from the Harvard Embrj-ological Collection. In the younger of these, a specimen of 40 mm., the area postrenia could barely be made out as a spot of loose, undifferentiated neuroglia tissue, covered with flat ependyma, at the point of emergence of the central canal into the ventricle. In the other, an embryo of 78 nmi., the eminentia postrema was perfeeth' distinct, and displayed all the characteristics of form and structure which mark the adult area, even containing a few nerve cells. In both specimens, the area was at a considerable distance from the roof of the ventricle. In the older one the heaped-up epithelium of the rhomboid lip was to be seen, entirely distinct from the flattened ependyma of the area postrema mesial to it.

The vascularity of the eminentia postrema has attracted the attention of all observers. Haller (8), in his paper on the comparative anatomy of the rhomboid fossa has described its vascular connections. It is supplied from the pyramidal branch of the inferior cerebellar artery (first described by Duret) by three or four long, slender, anastomosing trunks. The principal arteries run along the outer border of the area, and send many arching arterioles transversely across it, from which a plexus of capillaries drains into a set of venules along its mesial edge. The vessels of the eminentia postrema have no connection with those supplj'ing the choroid plexuses and the velum. The blood supply of the areae postremae in the dog's brain is illustrated in figure 4.

We have sectioned the calamus region in a number of vitally stained animals (one monkey, two dogs, two cats, and a rabbit in serial sections) and have examined the areae postremae. Trjpan blue was the vital dye employed. Its distribution was alike in all the species. It was observed to occur abundantly as blue granules in many of the connective-tissue cells of the 'adventitial cell' type which invest the small arterioles and capillaries of these richly vascular areas. Particles of dye were rarely observed in the endothelium of the vessels. None was found in the neuroglia cells or in the nerve elements of the adjacent ala cinerea. It is interesting that these areas are the only intrinsic part of the central nervous system which possesses sufficient mesodermal tissue to stain deeply with vital dyes.

NOTE ON ANATOMY OF AREAE POSTREMAE 285

Repetition of some of Weed's (9) experiments, in which a sohition of potassium ferrocyanide and iron-ammonium citrate was introduced into the ventricles, failed to demonstrate any absorption in the region of the areae postremae.

The abundant blood supply of the areas, the beha\'ior of trypan blue toward them, and the fact that they are covered by an extremely low ependyma raises the suspicion that the areae postremae have some function in the transmission of fluid from the blood stream into the cerebrospinal fluid. The further elucidation of this point would be extremely interesting.

LITERATURE CITED

1 GoLDMANN, E. 1909 Beitr. z. klin. Chir., Bd. &4, S. 192-264.

2 1912 Arch. f. Psychiat., Bd. 1, S. 595-597.

3 1913 Arch. f. klin. Chir., Bd. 101, S. 735.

i MacCurdt, J. T. 1917 Psychiat. Bull., vol. 2, p. 1.

5 Wilson, J. T. 1906 J. Anat. and Physiol., vol. 40, pp. 210-241, 357-386.

6 Streeter, G. S. 1903 Am. Jour. Anat., vol. 2, pp. 299-313.

7 Blake, J. A. 1900 Jour. Comp. Neur., vol. 10, pp. 79-108.

8 Haller, G. 1914 Arch. f. Anat. u. Entwcklngsgesch., S. 213-256.

9 Weed, L. H. 1914 J. Med. Research, vol. 31, pp. 40-42.

PLATE 1

DB8CRIPTIOX OF FIOCBES

1 Dorsal view of the medulla of a rabbit with the roof of the ventricle removed showing the choroid plexuses and the interior of tlic rhomboid space. The animal has received repeated injections of tryjian blue. The choroid plexuses and the areae postremae are deeply stained.

2 Medium sagittal section of the same specimen.

3 Cross section through tlie area postrema on the right side.

4 The blood vessels of the calamus scriptorius of a dog injected with india ink. The rich anastomosis of blood vessels in the areae postremae is clearly shown.

a.p., areae postremae c.p., choroid plexus p.i.c, posterior inferior cerebellar arteries

286

NOTE ON ANATOMY OF AREAE POSTREMAE

GEORGE B. WIHI.OrKI AND TK\CY JACKSON PITNAM

PLATE 1

1 M^^^P

^^^^^H^BB

287

Kosuincii p<ir el alitor, Alexander I'otiuukcvitcli. I'liivcrsidail Yale, New Haven.

l.a iinificacinu dc la inici'ofotojirafia.

I. a microfotografia puede simplificaise y al niisnio tiempo haeerla mas fieiitifica por im procoso do uiiificaciAii dolosaparatos Para (ihteiior este fin todas las partes del aparato niicrofotoKiafii'o dehen disponeiso do un inodo especial. Despuos de osto dol)on i)repar.irsi- ties tal)las do datos, confonne so indica on el toxtt). una do oUas para los auniontos, la <»tra para los facturos do exposicion y ima toroora para los fact ores rolacionados con los filtros de rayos luminosos.

El use de estns cuadros ahrovia el tionipo de trabajo y la pordida do material, oliminando todos los errores fluctuantes y d;in<lolos valoros pormanontos. De este modo se aumenta considerablemento la eficacia del aparato. Las mejores conibinaciones do plaoas y filtros para rayos ban sido dotorminadas mediant o i)ruobas y se tlosoriben para un cicrto niimcru de coloraciones senoillas y dobles de use comun.

Truii>'lutiun by Jod^ F. NuiiidfS Corn*')! Mcdtnil CollrRc. Xfw York

AlTHOIt S ABSTRArr OF THIS PAPKR ISSt'ED DY THK UlULIOaRAPHIC SERVICE, St:Pn:MBI::R 13

STAXDAHDIZEJJ .MlCROPHOTOtiKAPHY

ALEXANDER PETRUNKEVITCH Sheffield Scienlific School of Yale University

AD\ANTAGES OF STAXDARDIZATIOX

^^'hile the trend of the manufacturer has alwaj's been to introduce as much standardization as possible into his methods of production, the scientific investigator has held strangely aloof from anything that might restrict the freedom of his indi\-idual effort. The reason for this lies in a partial misconception of the principle of efficiency as applied to science. The feeling of aversion for an}' standardization has been carried so far that freedom in the selection of methods and the consequent desire to avoitl any limitation in the use of apparatus are causing the loss of more time than one would like to admit. None would nowadays expect a photographer to make his own j^lates or paper. Sensitizing plates to various rays or increa.sing their rapidity in the laboratory would be futile, for one can obtain on the market the desired product. At the same time the majority of microphotographic apparatus are made on the principle of a universal tool, to be used as it may please the photographer at the time, who sets up or dismounts the apparatus on every occasion when he works with it. The intensity of the light may be increasetl or diminished by an almost endless combination of adjustments in several parts, such as the source of ligiit, the substage, the diaphragms, the rayfilters; the desired magnification may be obtained by the use of the one or the other combination of oculars and objecti\es: objects may be photographed with the camera in an ujiright or a horizontal position, etc. What is the result? Not only a tremendous lo.ss of time due to constant rearrangement of the apparatus and to measuring of the magnification, but an unavoidable variation in the iiuality of the negatives

289

200 ALEXAXDF.R PETUrXKEVITi'Tl

and an utter iniiwssihilityof duplicating negatives or of obtaining identical magnification after the lapse of a few days or even hours, if the ap|)aratus has nieanwiiile been deranged.

The latter statement may seem like an unwarranted assertion to anyone who has not had sufficient experience in ph<it()graphie measm-enient. Yet, unfortunately, it is ([uite true. In figuring the magnification, especially when it comes to higher i)owers, it is practically impossible to determine with absolute accuracy when the scale is focused, and the possible error is (piite sufficient to make an appreciable difTerence in size. It means simply this, that within given limits there is always an error in the stated magnification and that this error cannot be overcome by practical means. But in standardizing the individual apparatus as will be explained below, we can fix the erroi' so that it always will remain the same. If w(> were to make photographs of a long series of sections we would have at least the same magnification in every case, while under other circumstances the error itself would present a variable.

To be practical, the methods of standardization not only have to accomplish theiij)ur|)ose.l)uf must b(> simple. l~^ome books gi\-e long formulas, the application of which is troublesome and does not give reliable results. A certain amount of derangement in the apparatus will always be ima voidable. If we are to use eom])licated mathematical calculations every time we want to obtain a given magnification, we defeat oiu' own purpose. From the point of view of theory, the methods of standardization applied by me may appear perfunctory; from the point of \iew of results obtained, the}' leave nothing to be desired. They do not remove the errors themselves, but the sources of errors, by making errors constant. .\nd they allow of very rapid work of high ((uality. At the Osborn Zf)ological Laboratory where I have worked out the method of standardization and used the apparatus for considerable time, we are able to make a fine negative of any microscopic slide stained by one of the forty-odd stains commonly in u.se here and at any of the thirty-five different magnifications ranging from 12 to :i()(M) diameters, without making any calculations or measurements whatsoever except a simple imiltiplication

STANDARDIZED MICROPHOTOGRAPHY 291

of two factors given in special tables. We are able to turn out a finished negative in less time than it would take to find the necessary extension of the bellows for the desired magnification and we can change from one given magnification to another in a few moments. Should the apparatus for some reason ha\'e to be temporarily dismantled, it can be again reset, although this of course would take considerable time. The maximum of efficiency is attainable only through fixation of parts.

CHOICE AND ARRANGEMENT OF APPARATUS

Not every microphotographic apparatus is suited for standardization. There are several essentials without which standardization becomes impossible. These are: a rigid bed consisting of one unit; a source of light of permanent intensity; graduated scales for all mobile parts; a set of rayfilters of permanent colors and known wave-lengths. An examination of the majority of microphotographic cameras made by the leading manufacturing concerns of all countries has shown that very few, indeed, may serve the purpose. Thus the largest cameras made by both Zeiss and Leitz in Germany are as if intentionally constructed in such manner as to preclude standardization. Of the British cameras, that made bj' Baker comes up to the requirements; while in this country the same may be said of the large horizontal camera manufactured by the Bausch & Lomb Company, that model which does not allow the raising of the bellows into a vertical position. As described in their catalogue, the camera has one very important defect which, however, the manufacturers remedy on request, and this is a single holder for raj-filters instead of two, as is imperative whenever one has to use monochromatic light of highly limited wave-length. With this correction and with additional scales engraved on parts of which I shall speak below, the camera proved to be quite suitable for the purpose in question.

A few words about the microscope may be in place here. The stand must be of a regular microphotographic model. From a practical point of view, the choice of lenses at present is largely

292 ALEXANDER PETRUNKEVITCH

a matter of taste. We use Apochromats 16.0, 8.0, 4.0 and oil immersion 2.0. The best oculars to be used are so-called projection-oculars 2 and 4 as manufactured bj' Zeiss, since they give a flatter field. For small mafniifications the micro-tessars are best. A\'hcn they are used in place of an objerti\c, the substage has to be removed. If possible, the microscope should be with sliding objective changers instead of a revoK'ing nosepiece. These changers are made so as to allow the adjustment of the objectives to cofocal length. There have to be as many changers as there are lenses, and the lenses once screwed in and adjusted should not be again removed, as that would result in an appreciable change of magnification. For the same reason the stand must never be removed from the support to which it has been fastened, nor must the centering be deranged. This necessitates examining the microscope slide for the part to be photographed in a rather awkward position with a consequent loss of time. The difficulty may be overcome by a special construction allowing the replacement of the microscope in the identical position after its removal for the purpose of focusing. But in absence of such a contrivance, the renioval of the .stand is not permissible under any circumstances. Correct centering of the microscope reciuires a great deal of time, much more than the loss due to inconvenience in focusing. The support for the microscope is also movable along the bed, and when the microscope has been once centered it becomes necessarj' to record the exact division on the scale of the bed at which the support has been fastened. This gives a guaranty that in case the apparatus has been dismantled, it may again be assembled without any change in the values of the tables.

THE LIGHTING SYSTEM

^^'hateve^ the source of light and the system of condensing lenses, the intensity of light must remain the same for a given record. With other words, the lighting system nuist be of such a kind as to allow exact recording and returning to each given combination within the shortest time, without any measurements or calculations whatsoever and in the simplest manner possible.

STANDARDIZED MICROPHOTOGRAPHY 293

This can be accomplished only if every movable part is provided with an arrow or a pointer and its position recorded on a corresponding immobile scale. If the source of light be a carbon arc, it is best to select once, by experhnenting, the most satisfactory distance of the arc from the lens and mark the position of the carbon-holder by means of a transverse line scratched or engraved on the immobile bed of the holder. Still better, to make a ring of a flat strip of heavy copper and rivet it in such a position that the arc is in the correct position when the carbon-holder abuts against the copper ring. This precludes all mistake, is easily done, and requires nothing but the commonest tools. The arc light as furnished by the Bausch & Lomb Company, even under such circumstances, is not a permanent source of light, but the variation in intensity, if the arc is watched, is not sufficient to impair seriously the quality of the work.

All diaphragms must be graduated, for which purpose it is best to measure the diameter of the opening at full stop and engrave lines showing when the diaphragm is closed to one-half its diameter, to one-fourth its diameter and so on. The diaphrams of the microscope must also be graduated in the same manner.

It is absolutely indispensable that the position of the microscope substage should also be recorded. For this purpose the arm carrying the substage should be graduated. That position in which the substage is brought as far as possible toward the objective is most conveniently designated as the zero of the scale, and the scale itself may be metric or English or quite arbitrary, provided the divisions are well marked. Even, bright illumination is obtained by placing the substage condenser in the position which gives critical illumination, and which may be more or less easily found by racking the substage nearer toward or further away from the objective. What is desired in practice is the simultaneous focusing of as many structures of an object as possible. In a photomicrographic instrument provided with a complete condensing system, such as used in the Bausch & Lomb apparatus, this so-called 'depth of focus' is most easily increased by racking the substage away from the objective. The optimum position of the substage may be judged by an examination of the

294 ALEXANDER PETUUXKEVITCH

image of a slide on the ground-nlass. Any further inerease in the distance of the snbstage will result in a decrease in light intensity and loss of definition. The optimum position of the substage is different for every objective. The lower the magnifying ])ower of the objective, the greater will be the distance of the substage from the objective. Once the optinmm i)osition has been determined for every objective, it must be recorded.

HOW TO I'REPARE A TABLE OF MAG\IFIC.A.TIONS

The first step in the preparation of a table of magnification is the choice of magnifications desired. If the oculars used are of the common compensation kiiid. the determination of magnifications is so simple that anj- number of magnifications may be recorded. All one has to do is to determine the position of the ground-glass carrier for two magnifications at the extreme ends of the lied, let us say for 100 and 500 diameters. The intermediate positions may be derived l)y a simple calculation, remembering that for a given optical system the magnification is in direct ratio to the extension of the bellows.

The use of projection oculars precludes, however, the apjilication of such a simple method. These oculars are supplied with a correction scale which must be used if the oculars themselves are used at all. The 'raison d'etre' of such oculars is their greater flatness of the field which is obtainable only by the use of the correction scale. Zeiss furnishes a formula which may be used to find the necessary correction for a measured extension of the bellows. Unfortunately, there are two reasons why such a procedure is inapplicable in the case of a standardized instrument. First, it requires in every case the measurement of the extension of the bellows and, .second, the magnification itself is changed by the adjustment of the correction scale. A\'ith other words, if we were to prepare a magnification scale by the method used for conmion or compensation oculars, we would find, on correcting the field of the projection ocular, that this has resulted in a change of the magnification and that to obtain the desired magnification we have to measure it instead of simply setting the bellows to a given scale. This means, therefore, that the preparation of a

STANDARDIZED MICROPHOTOGRAPHY 295

magnification table for use with projection oculars is not a simple process of calculation and requires careful measurements.

It is most convenient, therefore, to select a list of magnifications which are most desirable and which will prove to be sufficient in the majority of cases. The next step :s to find the proper position of the bellows for each magnification given, for each combination of objective and ocular. This can be done by the use of a stage micrometer, such as furnished by any reliable optical companj^ and an exact millimeter scale by means of which the image of the micrometer scale on the ground-glass may be measured. After the bellows have been extended to give approximately the desired magnification, the projection ocular is corrected by the turning of its graduated disc until the edge of the visible disc of light on the ground-glass is quite sharp. This position is recorded in the table. Next the carrier of the groundglass is moved nearer or further away from the microscope until the millimeter scale shows that the desired magnification has been obtained. Of course, the micrometer scale must be in focus. The position of the ground-glass carrier on the bed maj' now be recorded. If it is difficult to decide when the micrometer scale is in focus, the process maj' be repeated several times and the mean of the observations used for the record. It is tedious work, but it pays in the end, because it need never to be repeated. In the table, corresponding with each magnification two figures should therefore be given, one showing the position of the correction disc in the projection ocular and the other the position of the ground-glass carrier on the bed. Such a table naturally has value only for the given combination of stand, objective, ocular, and bed, and would be of no use if reproduced here. Each manufacturer, however, followmg these instructions, could easily prepare and furnish such a table for a standard equipment .

In preparing the table of magnifications one must bear in mind that the objectives give best definition at a given length of the tube, usually 160 mm. The use of a revolving nosepiece requires the extension of the microscope tube to only 145 mm., because the nosepiece itself measures 15 mm. The use of slid THE ANAIOMICAL RECORD, VOL. 19, NO. 5

291) ALEXANDER PETRUNKE\aTCH

iiifi rliangprs requires an extension of only 140 mm., because the clian^ers measure 20 mm. Siioukl the extension become deranged during the work, the magnification value would also change. To prevent this in the most efficient waj', a ring should be made from a strip of flat copper and placed permanently on the microscope tube. The width of the ring may be made of the correct size by filing it down until the tube is in its proper position when firmly moved against the ring. Once placed on the tube, the ring should be left there permanently.

In my table I have twelve vertical columns, each for a different combination of objective and ocular. The magnifications are given in a special cohnnn on the left of the table. Each vertical column has two subdivisions, one for the ocular correction, the other for the ground-glass carrier. The figures of each col\min interlap with the figures of the next coliunn, because the .same magnification may be obtained by the use of two or three different objectives and oculars with an increase in the length of the bellows, thus permitting a choice of the most suitable combination in each individual case. For example, if definition is most important, the inunersion lens may be used with a lower ocular and shorter extension of the bellows. Where, on the other hand, depth of focus is more important than definition, the same magnification may be obtained by using an 8-nmi. objective with a more powerful ocular and longer extension of the bellows. If for some reason, after having examined one combination, one is not satisfied with the result as shown in the image on the ground-glass, it takes but a few seconds to change the combination and to try out several other combinations for the same magnification. Imagine what labor it would entail if we had no table by which to go in such a case!

HOW TO PREPARE A TABLE OF EXPOSURE FACTORS

Only in very rare instances microphotographs can be made without the use of rayfilters. Since the object of a microphotograph. barring a few exceptions of which I shall speak later, is to show as much detail as can be obtained, it is absolutely neces

STANDARDIZED MICROPHOTOGRAPHY 297

sary to know the best combination of rayfilter and plate to be used in each indivichial case. It would be possible to prepare a single table from which one could find not only this combination, but the necessary exposure in seconds for each given magnification. But such a table would require so many vertical and horizontal columns, that it would defeat its own object of shnplifjdng the procedure. It is quicker to find two factors, one in each of the two small and simple tables, and to compute the necessary exposure by a multiplication of these factors. This can be accomplished if one of the tables shows the exposure factors for all given magnifications without any rayfilter and the other shows the factors for all combinations of plates and ra^^filters.

The relative speed shown for dry plates in various photographic manuals and exposure meters naturally refers only to exposures in daylight with a common photographic camera and a lens of a given aperture and focused on infinity. I have compared and controlled several of these tables, and having selected the most important brands of plates am giving here, for the convenience of the reader, a table showing the relative exposure factors or speed of such plates, assuming that the speed of the Standard Orthonon plate equals 1.

Relative exposure factors or speed of photographic plates in daylight loithout rayfilter

Regular plates

Cramer's Crown 1

Marion Record J

Seed Graflex i

Seed 27 gilt edge f

Seed 30 i

Seed 26X f

Seed 23 3

Stanley 1

Orthochromatic plates

Cramer's Instant Iso 1

Cramer's Mediu ii Iso 2

Seed L Ortho J

Seed C Ortho 3

Standard Orthonon 1

298 ALEXAXDER PETHVXKEVITCH

Paucliroinatic plates

Cramer's Trichromatic 3

Cramer's Spectrum 3

Seed Panchromatic 3

Wrattcn M 1

Slow plates for special work

Cramer's Contrast (green label) 6

Seed Process 12

Lanternslide, Eastman 60

Lantcrnslide, Imperial Special 36

Lantprnslide, Seed 36

Lantcrnslide, Standard, blue label

Lantcrnslide, Standard, white label 18

Plates for color photography

Lumiere's Autochrome with Lumiere's rayfilter "tl

Hess-Ives Iliblock '. 60

Paget direct colour, with screen and rayfilter 24

As in the preparation of the magnification table, so in the preparation of the talkie of exixisure factors for the given magnifications one cannot be guided by the shiiple rule that exposure stands in direct ratio to the square of magnification. This rule is of great help in preparing the table for a single system, where nothing but the ocular or the extension of the bellows is changed. But when it comes to the use of another objective, two new factors must be taken into account . It is well known that exposure \ar ies as .■ ,■. . .. of the objective, and this formula does not applv (N. A.)«

to oil-immersion objectives. ^loreover, it is desirable to use the optimimi position for the substage condenser and this position, as explained in the paragraph on the lighting .sj-stem is a different one for every objective.

The best way to proceed is, therefore, to ascertain by actual exposure the time of correct exposure for a given magnification for each objective at the optimum position of the substage. Once these are obtained the correct exposures for all other magnifications for each system maj" be calculated. For example, if you have found that the correct exposure for an Orthonon plate at

STANDARDIZED MICROPHOTOGRAPHY 299

100-diameter magnification obtained by the use of an objective apochromate 16 mm. in combination with a projection ocular 2 and optimum position of the substage condenser at mark 5 of your scale is 0.04 second, then the exposure for the same combination at 400-diameter magnification, even if that magnification has been obtained bj' the use of ocular 4, will be 0.64 second.

Unfortunately, it is by no means easy to decide what is a correct exposure. To ascertain it as nearly as possible it is imperative to use tune and temperature development and fractional exposm-e. My experiments were made with the following developer which has manj^ good qualities, does not stain the fingers or the plate, but must be used fresh in every experiment, since the time of development increases considerably with the use of the developer.

Pyro-acetone developer Solution A

Water 500 cc.

Oxalic acid 1 gram

PjTogallic acid 30 grams

Solution B

Water 1000 cc.

Sodium sulphite, dry 120 grams

For use take

Water 120 cc.

Solution A 15 cc.

Solution B 30 cc.

Acetone 6 cc.

If the mixture has a temperature of about 18.3 to 18.8°C. (65 to 66° F.), then the image of a correctly exposed plate will appear in fifteen seconds and the development will be completed in six minutes from the time the plate was immersed in the developer. Fractional exposure consists in making four different exposures on the same plate in such a manner that each following exposure is twice as long as the preceding one. These exposures may be represented as a, 2a, 4a, 8a. To make such an exposure, the

300 ALEXANDER PETRUNKEVITCH

slide of the plate-holder must he marked with three parallel lines dividing the plate in four ciuarters. The slide is opened and the plate is exposed n seconds (or fractions of a second). Now the slide is moved in one quarter and the plate is exposed again a seconds (or fractions of a second), ^^'hen moved in two quarters the exi)osure should he 2a and when the plate-holder is moved in three quarters the exposure should be 4a.

The choice of an object to be photographed is also important. A stained section will not do and it is advisable to use a slide which will permit the use of both low- and high-power objectives. I have used the Diatome Arachnodiscus and a thin section of human bone. The time of the appearance of the four images in the developer will at once indicate which exposure is nearest to be the correct one. It is advisable to control the experiment by making another fractional exposure at a higher magnification.

The completed exposure table will consist of as many vertical columns as there are objectives in the outfit, and for each of these columns the optimum position of the substage must be indicated at the top of the columns. A special cohmin on the left of the table will contain all magnifications as accejited in the magnification table.

HOW TO PREPARE A TAHLE OF HAYIILTER-PLATE FACTORS

The choice of rayfilters is not entirely a matter of taste. While one can use fluids in special containers, it is simpler and better to buy a set of dry rayfilters from a reliable firm with stated regions of light transmitted. Such filters are more permanent and easier to use. It is not advisable to make dry rayfilters in the laboratory unless the laboratory is provided with instruments which permit the preparation of identical rayfilters at any time in case of inadvertent damage, since a variation in the region or in the intensity of light transmitted would affect the exposure. At the O.sborn Zoological Laboratory we have accepted as a standard cfiuipmcnt for all photograjihic work Cramer's photom^crographic rayfilters. There are ten of them and s'ingly or in combination they transmit the following regions:

STANDARDIZED MICROPHOTOGRAPHY 301

1 A-6350 3+4 6920-5840

2 A-6100 3+7 5900-5800

3 A-5S50 3+8 A-7000

4 A-5400 4+5 6870-5525

5 A-5250 4+7 5900-5660

6 A-5100 5+7 5900-5400

7 5800-5000 5+8 5530-5350

8 5200-3950 6+7 5900-5150

9 5200-3500 6+8 5350-5150

10 Visual luminosity 6+9 5600-5200

7+8 5200-5000

7+9 5300-5100

The Wratten '^I' filters transmit somewhat different regions, as shown in their booklet.

If all plates were equally sensitive to the same regions of the spectrum, the same factors would apply for all makes. But experience shows that one brand of plate may be twice as rapid as another in daylight yet be considerably slower with a special rayfilter. Thus the Standard Orthonon is twice as rapid as Cramer's Medium Iso in daylight, and four times as slow in green light in the region 5200-5000. When it comes to the use of red light, nothing but panchromatic plates can be used. The Wratten 'M' plate answers this purpose adm'rably, but for orange, yellow, and blue light the Orthonon plate is preferable if for no other reason than greater ease and safety in handling it. For green light we use Cramer's Iso Medium or Instantaneous Iso.

To find the correct rayfilter-plate factors it is necessary to use the same slides as were used in the preparation of the table of exposure factors without rayfilter. Fractional exposure with a rayfilter will easily show how much the normal exposure must be prolonged to obtain the same results. A separate exposure experiment must be made for every rayfilter or combinations of rayfilters and plate. Thus was the following table of RP factors obtained, but naturally it is good only for the Cramer rayfilters.

302

ALEXANDER PETRUNKEVITCH

Table of R-P factors for use with Cramer's photomicrographic rayjilters and dry plates. The unit of comparison is the normal exposure for a standard Orthonon plate irithoul rayfilter. The figures are good only when the light is an open arc

CHAUEB's BATriLTER. SINQLE OR COUBIKATION

or TWO

8TANDAKD ORTHONON PLATB

WBATTEN U PLATE

cbauer'b uedicu

wo PLATE

CBAUEb's 1K9TANT ISO PLATB

1

250

2

30

3

500

• 15

4

30

50

5

15

6

10

7

60

8

15

9

10

5

10

3+4

600

15

.

4+5

30

4+7

1000

400

5+7

250

100

5+8

2000

600

250

6+7

100

6+8

1000

150

7+8

2000

500

250

Without rayfilter

1

2

1

THE CHOICE OF THE RAYFILTER COMBINATION

The choice of a rayfilter will naturally depend upon the results to be attained. At times it may be desirable to get as much contrast as possible regardless of the loss of detail, especially' if some single structure should be shown clearly. In such cases a rayfilter which makes the struct ine appear black to the naked eye, i.e., a rayfilter which absorbs all rays transmitted by the structure to be photographed, is the one that will give the best results. If the section has a counterstain, if for example the stain employed was haematoxylin-eosin, and it is desired to show onlj* the structures stained with haematoxylin, then an eosincolored rayfilter which will transmit all rays of that color may be used with advantage. In the majority of cases, however, the photogiaph will be nmch more satisfactorj-, if the contrast is less, but the detail greater. To find the right combination that will answer

STANDARDIZED MICROPHOTOGRAPHY 303

this purpose is not an easy matter. One may be helped by an examination of each staining fluid through a direct vision spectroscope, but the final decision has to be derived from an actual exposure. It will be also found that an examination of the image on the screen with different ray filters will be of great help. In case of doubt, two or three different combinations may be tried and the negatives compared. In the following table is given a list of the commonly emploj'ed stains and the best combinations of plate and ray filter for each.

CORRECT EXPOSURE

The exposure factor multiplied by the R-P factor will give the correct exposure in seconds for the given combination of stain, rayfilter, objective, substage position, and magnification as indicated in the tables. If care is exercised not to overlook a single one of these conditions and to see to it that the source of light is also in its proper place, the only element unaccounted for remains the microscopic slide itself. The quality of the tissue, the intensity of the stain, the thickness of the section, play no inconsiderable part in the determination of the correct exposure. If the tables are prepared from a very thin and transparent section, the deviation in exposure of thick sections will be great. It is therefore advisable in standardizing the apparatus to use either 'medium thick sections, or else to take the mean of two figures obtained from an exposure of a very thin and a very thick section under identical conditions. No satisfactory rules can be formulated in regard to the transparency factor of the microscopic section, but the student will rapidly learn the necessary increase or reduction in tlie time of exposure.

As a rule, correct exposure gives the best results. Under circumstances, however, overexposure is desirable and even indispensable. Just as in a brilliantly sunlit room one obtains a much better picture of details if one gives long exposure and develops the plate with a restrainer, so in microphotography details may be brought out by overexposure when some parts of

304

ALEXANDER PETRUNKEVITCH

Table showing the betl combination of dry plale and rayfilter for stains in common use, spectral regions transmitted and the R-P factors

STAIN

PLATE

CRAUER'8

RAT PILTER

SPECTRAL REGION

B-P

PAcroa

None

Orthonon

None

Entire spectrum

I

None

Orthonon

10

Entire spectrum

5

Acid green+safranin

Instant Iso

Orthonon

4+7

5900-5660

400 1000

Anilin blue

Orthonon Medium Iso

4

A-5400

30 50

Anilin blue+safranin

Orthonon

5

A-5250

15

Azur II

Wratten M Orthonon

3

A-5850

15 500

Bielschowsky's silver

Instant Iso Orthonon

5+8

5530-5350

250 2000

Bismark brown

Orthonon

8

5200-3950

15

Bleu de lion

Instant Iso Orthonon

4+7

5900-5660

400 1000

Carmalum

Instant Iso Medium Iso

5+8

5530-5350

250 600

Carmine (all stains, acid, alum.

Instant Iso

5+8

5530-5350

250

borax, para, picro. etc.)

Medium Iso Orthonon

600 2000

Erythrosin+cyanin

Orthonon

7

5800-5000

60

Eosin

Instant Iso Orthonon

6+8

5350-5150

150 1000

Fuchsiu

Instant Iso

6+8

5350-5150

150

Orthonon

«

1000

Gentian violet

Wratten M Orthonon

3

A-5850

15 500

Gentian violet+safranin

Medium Iso Orthonon

5+7

5900-5400

100 250

Giemsa'a

Instant Iso Orthonon

4+7

5900-5660

400 1000

Gold chloride

Instant Iso Medium Iso Orthonon

5+8

5530-53.50

250

600

2000

Ilcmalum

Medium Iso Orthonon

5+7

5900-5400

100 250

Hacmatoxylin (all stains Boehmer's,

Medium Iso

5+7

5900-.5400

100

Delafield, Ehrlirh, iron, etc.)

Orthonon

250

STANDARDIZED MICROPHOTOGEAPHY

305

STAIX

PLATE

Cramer's

RATFILTER

SPECTRAL REGION'

R-P FACTOR

Haematoxylin+boraxcarmine, con

Medium Iso

5-h7

5900-5400

gored, eosin, erythrosin, orange

Orthonon

G, picrocarmine, tetrabromfluor

escic acid

Haematoxylin+safranine

Orthonon

5

A-5250

15

Indigo carmine

Wratten M Orthonon

3

A-5850

15 500

Iodine green

Wratten M

1

A-«350

250

Iodine green + acid fuchsin

Instant Iso Orthonon

6-1-8

5350-5150

150 1000

Methyl green

Wratten M

1

A-6350

250

Methyl green+acid fuchsin

Wratten M

3-F4

692O-5S40

15

Methyl violet

Wratten M Orthonon

3

A-5850

15 500

Methylen blue+eosin, Romanow

Instant Iso

4-K7

5900-5660

400

sky, Wasielewski, etc.

Orthonon

1000

Mallory's

Instant Iso Orthonon

4+7

5900-5660

400 1000

Magdala red + anilin blue

Medium Iso Orthonon

5-1-7

5900-5400

100 250

Nigrosin

Orthonon

5

A-5250

15

Orange C

Orthonon

8

5200-3950

15

Picric acid

Orthonon

8

5200-3950

15

Rose Bengal

Instant Iso Orthonon

6-1-8

5350-5150

150 1000

Safranin

Instant Iso Medium Iso Orthonon

7+8

5200-5000

250

500

2000

Safranin+acid green, light green

Instant Iso Orthonon

4+7

5900-5660

400 1000

Safranin+gentian violet, picric

Medium Iso

5+7

5900-5400

100

acid, waterblue

Orthonon

250

Safranin+haematoxylin

Orthonon

5

A-5250

15

Silver impregnation

Instant Iso Orthonon

5+8

5530-5350

250 2000

Sudan III

Instant Iso Orthonon

6+8

5350-5150

150 1000

Tetrabromfluorescic acid

Instant Iso Orthonon

6+8

5350-5150

150 1000

Toludin blue+erythrosin

Instant Iso Orthonon

4+7

5900-5660

400 1000

Vesuvin

Orthonon

8

5200-3950

15

Victoria blue ■

Wratten M Orthonon

3

A-5850

15 500

306 ALEXANDER PETRUNKEVITCH

a section are niurh more transparent than others. In overexposing a plate it is advisable in such cases to know the exact ratio of overexposure as the restrainer should be used in strict conformity with that ratio. The pyro-acetone developer of the formula given above lends itself admirably to such work. I ha\p made a series of exjioriments in which the correct exposure was first carefully ascertained for a given microscopic slide, and the exposure then increased twice, four times, eight times, sixteen times, thirtj'-two times, sixty-four times, one hundred twenty-eight, and two hundred fifty-six times. IMeasurcd ([uantities of potassium bromide were added to the developer and fractional exposure used to see the results more clearly. The plates were left six minutes in the developer. A similar series of plates was left seven minutes and a third eight minutes. The best negatives were noted and a fresh plate was exposed same length of time and developed in the same manner as a control. Thus several formulae were obtained, each giving excellent results for the given overexposure. Those who have seen my negative which was overexposed about 130 to 150 times and then developed with the restrainer agree that aside from its j-ellowish color one would never guess that the plate was overexposed.

a. Pyro-acetone developer for plates overexposed 4 times:

f Water 120 cc.

Nonnal developer J Solution .\ 15 cc.

] Solution B 30 cc.

[Acetone 6 cc.

10 per cent potassium bromide 1 cc.

Develop 6 minutes at 65° F.

6. Pyro-acetone developer for plates overexposed 8 times:

Normal developer as above

10 per cent potassium bromide. 2 cc.

Develop 8 minutes at 65°F.

c. Pyro-acetone developer for plates overexposed 16 times:

Normal developer as above

10 per cent potassium bromide 10 cc.

Develop 8 minutes at 65°F.

STANDARDIZED MICROPHOTOGRAPHY 307

d. Pyro-acetone developer for plates overexposed 32 times:

Normal developer as above

10 per cent potassium bromide 20 cc.

Develop S minutes at 65°F.

e. Pyro-acetone developer for plates overexposed 130 to 150 times:

Normal developer as above

Potassium bromide (powder) 4 grams

Develop 8 minutes at 65°F.

New Haven, Connecticut April 19, 1920

-^

K'

^

THE ANATOMICAL RECORD, VOL. 19, NO. 6 NOVEMBER, 1920

Resuinen pnr ol iuitor. Frank lilair Hanson. T'liivorsidad Wat^hinglon, .Saint Loui!<.

La historia de los estados mds tempranos de la clavfcula humana.

La literatura soI)re la clavicnla contiene tres teorias sobre el orfgen de dicho hueso. Se ha considerado eonio un hueso puramente cartilapinoso. como un hueso jMii'ainente derniico y conio uii eleniento niLxto, que contiene porcioncs caitilaKinosa-s y d^niiicas. Puesto que el I'llthno trabajo sobre este punto (1918) intenta resucitar la teorfa expuesta en el pruner trabajo sobre la clavfcula (1864), el prohleina fiuoda sin resolver, ahierto a nuevas investigaciones.

El autor ha estudiado los estados mas tempranos del desarroUo de la clavicula humana en una extensa serie de embriones liumanos del Laboratorio Carnegie de Embriologia, confirniando la opini6n que considera a la clavicula como un eleniento rjue se osifica en BUS primeros estados como un hueso puramente d^rmico, al cual se agrega el cartflago en estados ulteriores. pero sin significaci6n morf()16gica.

Traiulation by Jo»^' F. N'onidps Cornell Medical Collpgo. New York

ADTBOR 8 ABSTRACT OF THIS PAPER ISSCED BY THE BIBLIOGRAPHIC SERVICE. OCTOBER 4

The History Of The Earliest Stages In The Human Clavicle

Frank Blair Hanson

Department of Zoology, Washington University, Saint Louis, Missouri

FOuR PLATES (THIRTEEN FIGTJBES)

INTRODUCTION

The clavicle is one of those elements of the human skeleton concerning which the last word has not yet been spoken.

Beginning with Gegenbaur in 1864, an enormous literature has arisen, the earliest of which would be now of historic interest only, were it not for the fact that the most recent paper on the clavicle (Huntington, '18) attempts to restore the old Gegenbaurian hypothesis of a cartilaginous precoracoidal core in the human clavicle, thus opening again an old controversy on the origin of the clavicle as a dermal or cartilage element.

The point of interest, then, in this present paper is whether the human clavicle originates in cartilage or as a dermal element or is derived in part from both cartUagmous and membranous elements.

Gegenbaur ('G4) considers the clavicle in man to be a pure cartilage bone; Broom ('99) and Fawcett ('13) claim that the cartilage present has no morphological significance and that the clavicle is as purely a dermal bone as is the dentary; while Paterson ('02) and FitzwUliams ('10) combine these two views, holding that the clavicle is of dual origin, its inner end being formed in cartilage and its outer as a dermal element.

This confusion in the literature of the clavicle is reflected in the text-books of hiunan anatomy and puts new and uncalled-for difficulties in the by no means rosy pathway of the first-year medical student.

309

310 FRANK BLAIR HANSON

THKORIES OF CLAVICULAR ORIGIN

CJegenbaur ('04) thought that he had found the human clavicle developing in cartilage, and ]irohably with the anuran shouldergirdle in mind, claimed that the cartilage jMesent was a remnant of the old precoracoid, thus determining the character of the clavicle as a cartilage bone. It is certainly true that in the frog the precoracoid does enter into and constitute the core of the clavicle, which is overlaid on tlie anterior side by a membranous element, and it is also true that in many of the mammals the clavicle contains a relatively large amount of cartilage at a fairly early stage. In man the cartilage is of a peculiar kind called by Mall a 'precartihiginous tissue' (figs. 4 to 6).

Ciegenbaur has been supported in his view of a precoracoidal contribution to the clavicle by Huntington ('18), and in a private communication to the author concerning the matter Huntington states his position not only on the clavicular complex, but also on the entire shoulder-girdle as follows:

this structure (shoulclcr-girdle) as a whole represents all the various possihlc conil)inations which result from the fact that it develops by the union of two originally ilistitict and separate elements, the exoskcletal and the primordial cartilaginous girdle, in different degrees in different types.

As regards thf ciaviole the diffcront prn|ioi-tional amounts of the dermal and cartilaginous contribution is well shown in the different vertebrate clas.ses. The process of envelopment of the jirocoracoid by the clavicle is developed to a widely varying degree in individual Anure types, up to the complete replacement of the cartilage by an element originally dermal in origin.

In the above statement of Huntington's is a somewhat plausible explanation of the widely different views expressed as to the constitution and homologj- of the clavicle. Two distinct elements, exoskeletal and cartilaginous, have contributed to it unequally in different classes of vertebrates, and even in different genera of the same class. This is apparently the case in the Amphibia and Reptilia, where the cartilaginous and dermal elements vary from a nearly pure precoracoidal cartilage bone to a purely denual bone such as that found in many of the reptiles.

EARLIEST STAGES IN HUMAN CLAVICLE 311

The hypothesis of Gegenbaur and Huntmgton has much to recommend it at first sight and does seem to account for the variations met \\ith in the clavicle of the different groups of vertebrates by the inclusion of a greater or lesser amount of the cartilaginous precoracoid into this element. Assuming that the coracoid process of man is the homologue of the metacoracoid or posterior coracoid of Permian reptiles and the precoracoid to be the cartilaginous part of the clavicle, a most direct and beautiful homology can be drawn between the shoulder-girdle complexes in the frog and man, for which comparison examine figin-es 1 to 3.

However, as Watson ('17) remarks, the anuran shoulder-girdle is of totally unknown ancestry, and the group as a whole being characterized by extraordinary specialization, any comparisons between the frog and other forms are \'ery hazardous and should receive most careful checking and corroboration. And this is especially true in a comparison with the human shoulder-girdle so long as the homology of the coracoid process is still in doubt. Further on I shall attempt to show that the coracoid process is the homologue of the precoracoid rather than the metacoracoid, and, if this be true, the theory of Gegenbaur and Huntington is no longer tenable.

Broom ('99) was the first to cast doubt upon Gegenbaur's hypothesis. He claimed that, while cartilage was present in the clavicle, it did not appear until after ossification had begun in the dense connective tissue, and concluded therefore that the clavicle was a purely membrane bone. Broom examined a number of marsupials, reptiles, and other Tetrapoda, including man, and found that in all these ossification of the clavicle preceded the appearance of true cartilage cells.

Mall ('06) studied by the Schultze method of clearing, the ossification centers in an extensive series of human embryos less than 100 days old. He was the first to announce the dual orighi of the clavicle from two distinct centers of ossification, a medial and a lateral. Mall did not, however, give an opinion on the significance of these two centers.

Fawcett ('13) examined a series of human embrj-os sectioned transversely and otherwise, and found m serial sections the two

312 FRANK ULAIR HANSON

centers of ossification Mall had seen in cleared specimens. Ossification hefjan in the outer end of the inner half of the clavicle anil in the inner end of the outer or acromial part of the clavicle. No cartilage cells were present until after the appearance of these two ossified centers. At this stage the inner and outer parts of the clavicle had no connection, but were separated in* the investing perichondrium. In the 19-nim. stage (crown-rump measurement) a bony bridge develops and connects the two centers (figs. 6 to 9).

Another miportant point made by Fawcett is that the connection of the coracoid-clavicular ligament is always with the acromial half of the clavicle, and not, as Fitzwilliams ('10) thought, with its sternal end. In cases of cranio-cleido-dysostosis Fitzwilliams found a ligament connecting the inner part of the clavicle with the base of the coracoid process. He identified this as the coracoid-clavicular ligament and urged that it was in cases of this disease a prolongation of the coracoidal contribution to the sternal part of the clavicle. That Fitzwilliams is incorrect in his identification of this ligament is beyond all doubt, as is shown \-ery clearly in figures 6 and 7. In all the specimens I have examined in the Mall Collection, the coracoid-clavicular hgament extends from the acromial half of the clavicle to the coracoid process, and Fawcett found the same thing in his material. Watson ('17) pubhshes a photomicrograph of a cross-section through the shoulder region of the marsupial Trichosurus, which shows that in this group also, as in the primates, the coracoid-cla\ncular ligament is attached to the acromial part of the clavicle.

It is admitted by all investigators that at a comparatively early stage cartilage does appear in the clavicle in considerable Cjuantity and contributes to the ossification process. The question seems to hinge on the amount and character of the cartilage present and whether this has morphological significance such as is attributed to it by Gegenbaur, Huntington, Fitzwilliams, and Paterson or is merely a neoinorph comparable to the cartilage in the mandible and other membrane bones (Broom, Fawcett, Watson).

EARLIEST STAGES IN HUM.\N CLAVICLE 313

Paterson has a number of papers on the shoulder-girdle and has briefly stated his views on the homology of the clavicle in his 1902 paper as follows: that the clavicle possibly contains more than one morphological unit (judged by its ossification, directly in the outer part, indirectly through cartilage in the inner part).

FitzwOhams ('10) also maintains that there are two distinct elements im-olved in the origin of the clavicle, one is a dermal element and is confined to the outer half of the clavicle, while the other is cartilaginous and represents the precoracoid of the lower forms. His arguments for the dual origm of the clavicle are the most complete and strongest on that side of the ciuestion. They may be summed up as follows:

a. There are two centers of ossification present in the clavicle, and this may well indicate that the bone is a composite one and maj' be traced back to dissmiilar elements in lower forms.

b. It is pointed out that the inner end of the element is a round bone, and here is found the greater amount of the cartilage present. Round bones are, in general, cartilage bones, and this argues in fa^-or of the inner half of the clavicle being of cartilage origin. On the other hand, the outer half is flattened and has more the characteristics of the flat bones of the skull which are membrane bones. The first center of ossification also appears in the outer half and is well advanced before cartilage appears.

c. The disease known as cranio-cleido-dysostosis attacks membrane bones principally, and when present in the clavicle the outer part is visuall}' the one affected, while the inner half remains normal. This again points to the inference that the outer half of the clavicle is of membranous origin, the inner half cartilaginous.

(/. There is, after all, a rather large deposit of cartilage present in the developing clavicle, and as this cartilage enters into and becomes a part of the bony product, it may have had an ancestral history.

e. The above points are emphasized by the known conditions in the Anura, where the precoracoid becomes the cartilaginous core of the investing dermal tissue, the two elements quite clearly imiting to form the anuran clavicle.

314

FRANK BLAIR HANSON

/. The clavicle, therefore, according to this point of view, is the result of two interacting tissues, one a dermal element and the other cartilage, which contribute unequally in the different classes of vertebrates to this structure, so that investigators finding one or the other elements greatly in excess in the form immediately under observation were led to take such divergent views as above indicated.

The three theories of clavicular origin now in the literature are set forth with their respective sponsors in the following table:

CARTILAOINOt'S CLAVICLE

DERMAL CLAVICLE

MIXED

CARTILAGISOrs

AND DERMAL

CL-WICLE

Broom ('99)

•

Fawcett ("13)

Fitzwilliams ('10)

•

Gegenbaur ('64)

Gotle (77)

HofTman (79)

Huntington ('18)

Paterson ('02)

«

Watson ('17)

OBSER^'ATIONS

Recently I have had the privilege of examining the cleared specimens of hiuiian embryos ui)on which !MalI ('00) based his paper on ossification centers, and also have studied the earliest stages of the clavicle in the splendid collection of serial sections of human embrj'os in the Carnegie Laboratoiy of Embrj'ologj' at the .Johns Hopkins Medical School.' My purpose was to detennine, if possible, between the view of Broom and Fawcett that the human clavicle is a pure membrane bone, and that of other in\estigators who see in the clavicle a persisting remnant of the old precoracoid.

' It is my pleasure to acknowledne the courtesy extcndetl me by Dr. George L. Strcotcr, of the Carnegie Laboratory of Kmbryologj-, in placing the facilities of the laboratory and the series of human embryos in his charge at my disposal during the summer of 1919.

EARLIEST STAGES IN HUMAN CLAVICLE 315

So far as I am aware, there was no prejudicial bent of mind toward either theorj^, and I am not committed to either side of the controversy by any statement in mj^ published papers on shoulder-girdle problems.

The result of my examination of all the evidence available may be summed up briefly as follows:

A. The material at my command, the jMall Collection, than which there is no better or larger collection of human embryos anj^vhere to be found, confirmed in all essential particulars the observations of Broom and Fawcett. Ossification begins approximately about the thirty-ninth day and is by two distinct centers, one in the lateral half and one in the medial half of the clavicle. At this time the bony centers are surrounded by the 'peculiar precartilaginous tissue,' which certainly is not hyaline cartilage. It seems quite clear that the earliest stage of ossification in the clavicle, both in its medial and lateral halves, is a dermal ossification, and that cartilage is entirely lacking at the time of the appearance of the two centers of bony tissue. This one fact was sufficient to justify Broom and Fawcett in excluding the precoracoid as a morphological element of the human clavicle (figs. 10 to 13).

B. In addition to the confirmation abo\'e, my special contribution to the subject consists in an attempt to show that the precoracoid has a history so different from that contemplated by those who see in the cartilage the old precoracoid, that this cartilage could not possibly be that element. I have traced the history and homologies of the precoracoid recently (Hanson, Anat. Rec, vol. 19), and the conclusions therein set forth may be recapitulated briefly here.

1. It has been shown by Broom for Australian marsupials, and the author for the .American opossum, that in the embryo and fetus of these forms the shoulder-girdle consists of a scapula, clavicle, and two coracoid elements, one of which, the posterior (fig. 2) , extends from the scapula to the sternum and is comparable directly with the coracoid of the monotremes. The anterior element of the marsupial fetus is a broad fan-shaped sheet of mesenchyme, of short duration in embryonic life, and is the homologue of the epicoracoid of monotremes.

316 FRANK ni.AIH HANSON

2. Devclopinent shows that the posterior of the two coraooid eleniPHts of tlip fetal marsupial pirdle beromes the small rudimentaiy coracoid process attached to the scajKila in the adult, which process undoubtedly is homologous with the same-named process in man. This gives a clear line of genetic relationship from the coracoid jirocess of man to the posterior element in the girdle of the monotremes.

3. CJregoiy and Camp ('18) and the author have shown that the conditions in the monotrcme girdle are so clearly reptilian in character and apjiroximate so closely in every respect to the structure of the girdles in Sphenodon and lizards that genetic relationship and homology exist between them.

4. Williston ('ID has practically demonstrated that the coracoid of living reptiles is derived from the anterior bony coracoid element fprecoracoid) of Permian reptiles.

5. Therefore, if the coracoid process of man is the same element as the posterior coracoid of monotremes, and this latter is directly comparable with the posterior of the two coracoids of Sphenodon and lizards, which is in turn a derivative of the precoracoid of Pennian reptiles, then the coracoid process of man ecpials the anterior bony element of Permians, and the precoracoid is the true coracoid.

6. It seems to be pretty well established that the coracoid process of placentals is a precoracoid, so that this bone is fully accounted for without reference to the clavicle. It might be suggested that the part of the precoracoid which has aborted is the piece found in the clavicle, but it has been shown clearly by Broom that the clavicle is fully formed and contains its maximum amount of cartilage long before the degeneration of the precoracoid, i.e., the fully formed precoracoid extending from scapula to sternum (fig. 2) persists for a considerable time after the ossification of the clavicle has begun and the cartilage at its ends is present. The two, fully formed clavicle and precoracoid, are in marsupials coexistent and separated by a consideral)le space. There is, therefore, no way for the cartilage of the precoracoid to enter the clavicle in mammals.

EARLIEST STAGES IN HLTJIAX CLAVICLE 317

CONCLUSION

The fact that the cells in the early clavicle are clearly not hyaline cartilage cells, but a peculiar tissue of which little seems to be kno-nii, coupled with the demonstration by the author that the well-developed clavicle and complete precoracoid extending from the scapula to the sternum are coexistent in the embryo, and the stages of the degeneration of the precoracoid having been followed completely in marsupials by Broom, excluding the possibility of the entry of precoracoidal tissue into the clavicle, apparently indicates that there are pretty solid grounds for considering the human clavicle to be a purely dermal bone.

LITERATURE CITED

Broom, R . 1899 On the development and morphology of the marsupial shoulder

girdle. Trans. Roy. Soc. Edinb.. vol. 39, pt. III. pp. 749-770. F.iwcETT 1913 The development and ossification of the human clavicle.

Jour. Anat. Physiol., London, vol. 47, pp. 225-234. (Fawcett's initials

not given in his paper.) FiTZ^\'iLLi.\MS, D. C. L. 1910 Hereditary cranio-cleido-dysostosis. The Lancet,

Nov. 19, 1910. Gegexbaur, C. 1864 Ein Fall von erblichem Mangel der Pars acromialis

Claviculare, mit Bemerkungen tiber die Entwickelung der Clavicula.

Jen. Zeitsehrift, Bd. 1. GoTTE, A. 1877 ^Morphologie des Skelettsystems der Wirbeltiere: Brustbein

und .Schultergiirtel. Arch. f. Mikr. Anat., Bd. 14. Gregory, \V. K., and Camp, C. L. 1918 Studies in comparative myology and

osteology. No. III. Bull. An. Mus. Nat. Hist., vol. 38. Hoffman', C. K. 1879 Zur Morphologie des Schultergiirtels und des Brust beins bei Reptilien, Vogeln, Saugetieren, und dem Menschen. Nied erland. Archiv. f. Zool., vol. 5. Huxti.xgtox, G. S. 1918 Modern problems of evolution, variation, and inheritance in the anatomical part of the medical curriculum. Anat.

Rec, vol. 14. no. 6. Mall, F. P. 1906 Ossification centers in human embryos less than 100 days

old. Am. Jour. .4inat., vol. 5. Paterson, a. M. 1902 Development of the sternum and shoulder girdle in

mammals. Brit. Med. Jour., vol. 2. Watson, D. M. S. 1917 The evolution of the tetrapod shoulder girdle and

forelimb. Jour. Anat., vol. 52, pt. 1. WiLLisTOx, S. W. 1911 American Permian Vertebrates. University of Chicago

Press, Chicago.

PLATE 1

KXPI.ANATION OF FIOUKES

1 Shoulder-girdle and lateral half of sternum and epicoracoidal cartilages of the bull frog. The precoracoid becomes the cartilaginous basis of the clavicle. In this form the clavicle is derived from two sources, the precoracoid and the dermal ossification.

2 Reconstruction of the shoulder-girdle of a marsupial fetus. Note that the coracoid reaches to the sternum. This is the same coracoid that a little later in development aborts, the only remains of which is the rudimentary coracoid process attached to the anterior side of the neck of the scapula. The complete coracoid is present, however, long after the clavicle is fully ossified, and if this element (coracoid) is the precoracoid, as I hold, there is no possibility of its contributing to the cartilage of the clavicle. After Broom.

3 Schematic diagram of shoidder-girdle of man. Compares pretty closely with figure I of the anuran shoulder-girdle. However, the resemblance is superficial only (see text) and not genetic. After Huntington.

.ABBREVIATIONS

Ac, acromian

CC, costocoracoid ligament

CI, clavicle

Ct, coracoid

ECr, cpicoracoid

Ep. sternal epiphysis of clavicle

Hu, humerus

Ic, interclavicular ligament

Oas, OS suprasternalia

OSl, omosternum

PCt, precoracoid

i?', first rib

Sc, scapula

SSc, supfascapula

SI, sternum

31S

EARLIEST STAGES IN HUMAN CLAVICLE

FRANK BLAIR HANSON

PLATE 1

PLATE 2

EXPLANATION OF FIGURES

4 to 9 A series of stages showing the ossi6cation of the clavicle from two distinct centers. Note that the coracoid-clavicular ligament is attached to the acromial half of the clavicle. This series of figures is modified after Fawcett and checked in all particulars by a careful examination of a large series of human embryos.

ABBREVIATIONS

B, ossification center

Br, bridge of connective tissue between two parts of clavicle

C, cartilage

CC, young cartilage cells

C CI Lig, coracoid clavicular ligament

CT, connective tissue

DT, deltoid tubercle

O, bony bridge, connects two centers

PC, procartilaginous tissue

320

EARLIEST STAGES IN HUMAN CLAVICLE

PLATE 2

FRANK BLAIR HANSON

^^'—^

•■^n^^k^^.

9 321

PLATK 3

EXl'LANATION OF FIGUKES

10 Photomicrograph of developing clavicle, showing two centers of ossification. This and the following three photomicrographs are introduced to show several stages of the developing clavicle as it actually appears under the microscope. Together with a large number of others, they constitute the basis for the schematic figures 4 to 9 and the conclusions reached in this paper. Series 240, slide 26, section 1. X 29. Mall Collection, Carnegie Laboratory of Embryology.

11 Older stage than above. Outer half of clavicle fully ossified, inner half lags in ossification process and more cartilage is present in this part. Ossification is ectochondrial. Series 460, slide 1^, section 7. X 29. Mall Collection, Carnegie Laboratory of Embryology.

CI, clavicle

322

EARI.IKST STAUES IN HIMAN CLAVICLE

FRANK BLAIR HANSON

TLATE 3

323

PLATE 4

KXPI-AXATION" OF FIGCRES

IJ 'I'lir Iwd piirts of the clavicle arc bcginniriK to fiiso. Series 1324, slide 26. section ti. X 55. .Mall Collection. C'arncftie Laboratory of Kinhryology.

13 Photomicrograph of (leveloping clavicle, showing acromial center of ossification well estalilishetl antl inner center just heginiiing anmml the lower outside e<lge of (•lavi<'le. an ectochoriilrial ossihcation. Series 240, slide 2t), section S. X 48. .Mall Ccdlcction, Carnegie Laboratory of Kmbryology.

CI, clavicle

324

EARLIEST STAGES IX HUMAN CLAVICLE

FHANK ni.AIH HANSON

PLATE 4

<w'^

'r J^^::

325

Resumcn ]ioi- el autur, Frank Blair Hanson. I'niversichul Washinjiton, Saint Louis.

K\ ])ri)l)l(Mna del coracoides.

El enibri6n del opos.suin aniericano, Didelphys virginiana posee mi roracoides, (|U0, lo inisnio ((Vio en los nionotrenias. so oxtiendo hasta el esternon, uniendose eon el en mi jiunlo situado entro la clavicula y la priniera costilla. Esta ultima .se atrofia y deja un pe(iueno proceso rudimentario. conocido en el adulto con el nunihre de proeeso coraeoideo.

A la parte ilescriptiva sigue una discusi6n de la homologia del proceso coraeoideo del hombre, esforzandose el autor en demostrar ([ue el jiroceso coraeoideo del lionihre es el honi6logo del precoracoides de los reptiles f6siles del Permico.

TnluUtion by Jovt F. N'onidei Cnrndl Medical Collse, New York

ACTBOR 8 ABSTRACT OF THIS PAPER ISSUED BY THE DIBUOGBAPBIC SERVICE, OCTOBER 4

THE PROBLEM OF THE CORACOID

FRANK BLAIR HANSON

Department of Zoology, Washington University, Saint Louis, Missouri

TWO PLATES (seven FIOUREs)

INTRODUCTION

The phylogeny of the coracoid presents one of the most fascinating and elusive problems of vertebrate morphology. The literature is extensive. The number of conflicting theories and the confusion of the nomenclature is hardly paralleled in the history of anj' other vertebrate structure. This is due, in part, to its long historj^, occurring as it does in the Elasmobranchii and found in everj^ group of animals from the dogfish up to man; also, in part, to the radical character of the modifications undergone in the different groups through adaptations to structural and functional demands. A long history of structural changes in a region of progressive functional differentiation, and, complicated fm-ther by the presence of both dermal and cartilage bones, gives an ideal situation for exactly what has happened in regard to our knowledge of the coracoid.

One is at times disposed to pigeon-hole this problem among the insolubles, or at least await patiently and in silence for the somewhat remote possibility of turning up some new evidence from paleontological specimens j-et to be collected.

However, this is one of those haunting problems that refuses to be pigeon-holed, and, once infected by its appeal, the investigator finds himself returning to i' again and again.

DIFFICULTIES OF lENCLATURE

As indicated above, the mericLiture of the coracoidal elements of the different gmnjis is terribly involved and confusing. Different authors appl- " name to very different struc tures, and again diffc ~ to the same structure.

327

THK ANATOMICAL RECOl.i'. VOL. 19. tiO.'i

32S FRANK BLAIR HANSON

In reading the literature on the subject it is necessary, first of all. to ascertain just which element each author has in mind when usiiifi the terms metacoracoid, coracoid. opicoracoid, precoracoid, prociuacoid, and subcoracoid. As an examj)lo of this, (\ivier in 1820 applied the term 'epicoracoid' to the anterior coracoidal element in monotremes. W. K. Parker and others use this same term in si)eaking of the cartilaginous element on the ventral ends of the coracoids in the frog, alligator, etc., while by Case, Williston and (Jregory this same term is used to designate the unossified element found in some fossil i-ejitiles anterior to the two ossified coracoids. A few remarks maj- clear up the matter somewhat.

In the first place, the term 'epicoracoid' was first given to the anterior element in the monotremes, and by priority should be retained in this connection. The ventral median cartilages of the coracoids of the frog, alligator, etc., have no claim to this name except through the usage of Parker ('67). These cartilages might better have the term 'infracoracoid' applied to them, which woulil be a suitable and descriptive term and would pair well with the corresponding dorsal cartilage, the supascapula.

Second, the term 'subcoracoid' may now be discarded. It was formerh- applied to the small element on the anterior side of the glenoid fossa in man, and, as its name indicates, was thought to be a vestigial coracoid element. There is now general agreement (infra) that this small bone is a neomorph and not of phylogenetic interest. This dispo.ses of one term from the list

Third, the terms 'precoracoid' and 'procoracoid' are synonj'mous, some authors preferring one and some the other, while a few u.se them interchangeably. By pre- or pro-coracoid is unilerstood the anterior of the two ossified elements of Permian leptiles, but not the most anterior of all, which is a cartilaginous epicoracoid (infra).

Fourth, 'metacoracoid' is the name given by Williston to the most posterior coracoid of the Permian reptiles.

Fifth, the .simple term 'coracoid' has been so long applied to the coracoid process of man. that it must be retained in this service and its ancestry sought either in the metacoracoid or jirecoracoid of Permian fossils.

THE PROBLEM OF THE CORACOID 329

If Broom and Watson are correct in their contention that the metacoracoid of Permians is the homologue of the coracoid process of man, then the metacoracoid is the true coracoid. On the other hand, if the arguments set forth in this paper are valid, the precoracoid is the true coracoid of man.

An examination of the shoulder-girdle of Moschops (fig. 5) will give the correct names of these coracoid elements and then* relations to one another when all are present.

THE MARSUPIAL CORACOID

Broom ('97, '98, '99, '02, '12), in a series of papers on the shoulder-girdle of the Australian marsupials, has demonstrated that in all the genera studied by him the coracoid extends to and connects with the sternum during earl}' developmental stages.

This embryonic coracoid extends from the anterior part of the glenoid cavity to a position on the sternum between the clavicle and first costal cartilage. In the earliest stages there are no sutures between these parts (scapula, coracoid, sternum) , but the whole is one continuous mesenchymatous and later precartilaginous mass.

The adult marsupial has onh' a small rudimentary coracoid process (fig. 7) attached to the scapula, not relatively larger than in the higher mammals and man. The transition between the condition in the embryo and that in the adult form is, according to Broom, by a process of degeneration, begmning near the middle poiiion of the fetal coracoid. This progresses in each direction, completely destroying the sternal half, but only incompletely destroying the scapular half, leaving the well-known rudimentary coracoid process of the adult attached to the anterior side of the neck of the scapula.

This embryonic coracoid of the marsupial has on its anterior border a 'fan-shaped cellular element' which does not participate in the glenoid and is of even shorter duration than the posterior element. Broom considers this anterior element to be an epieoracoid and homologous to the element in the monotremes known by this name and having precisely the same shape, position, and relations.

330 FR.\NK BLAIR HANSON

The posterior fetal coracoid of the marsupial has exactly the same position and relations to the scapula, clavicle, and sternum as has the posterior coracoid in monotremes, and the two are quite certainly homologous.

It appears from this work of Broom that the embryonic shouldergirdk of the Australian jnarsupial is identical with the adult (jirdle of the monotreme. I state this strongly at the outset because of the bearing it seems to have upon the whole question of the homology of these elements. In this identity is wrapped up one of the clues to the homology of the coracoid process of man.

Formerly it was impossible to pass from the reptilian-like girdle of the monotremes, with its coracoid complete from scapula to sternum, up to the girdle of the adult marsupial, and higher mammals, with a mere rudimentary process attached to the scapula. The development of the marsupial, however, demonstates in the clearest manner how the coracoid process of the adult passes through a monotreme-like stage with a coracoid extending from sternum to scapula, and how by absorption and degeneration all is lost except the small process on the adult scapula.

Since the work of Broom has an important bearing upon the solution of the long-vexed question of the phylogenj* of tlie coracoid process of man, the question may arise whether his observations and interpretations are correct. Watson ('17), a very careful worker, has verified Broom's lesults in at least one species of marsupial, Trichosurus . Watson made reconstructions in wax of the parts under discussion and showed that conditions were exacth' as describetl by Broom.

Recently I have had the opportunity' to examine several series of transverse and frontal sections of Didelphys virginiana, the American opossum, and have found that in our native marsupial as in his Australian relatives the coracoid is a solid bar of mesenchyme and later of young cartilage cells, extending without sutures from the scapula to a point on the sternum between the clavicle and first rib (figs. 1 and 2).

' My apprcriiitiiin is licrdiy expressed to Dr. .J. L. Rremcr, of the Depnrtnient of .Vnatomy of the lliirvurd .Medical School, for the ijrivilcge of examining the marsupial slides in the Harvard Embryological Collection.

THE PROBLEM OF THE CORACOID 331

In older stages the coracoid has parted company with the sternum, and that process of absorption, described by Broom for the species studied by him, has begun, which will eventually leave it in the adult but a mere finger-like projection on the anterior neck of the glenoid (fig. 7).

Since the shoulder-girdle of the American opossum was found to be in all essential aspects the exact counterpart of the anterior girdle in its cousins of Australia, no detailed description is necessary here, and I may proceed at once to the discussion of the homology of the coracoid process of man.

THE HOMOLOGY OF THE CORACOID

Broom ('99) in describing the shoulder-girdle of a 17-mm. mammary fetus of the marsupial Trichosurus, saj'S of the coracoid that it is of "much the same absolute size as in the 14.8 mm. stage, and is thus considerably smaller relatively." Broom's work on many species of marsupials shows that as development proceeds the coracoid which once reached the sternum in the embryo and fetus is in the adult only a small process attached to the scapula.

I have observed much this same thing in higher mammals where the coracoid process is relatively much larger in the embrj-onic stages than in the older fetal stages. Even in the pig, which in the adult has no coracoid process, a small coracoid is present in the embryo and diminishes in size with development. This is also strikingly true in the mouse and human embryos.

Broom has demonstrated conclusively that the coracoid process of adult marsupials is a persisting rudiment of the coracoid which in the fetus extends from the scapula to the sternum. The coracoid of marsupials, therefore, is homologized definitely with the coracoid process of higher mammals and man on the one hand, and with the posterior of the two coracoid elements in the montremes, for in all their morphological relations the two coracoidal elenients of the fetal marsupial can be compared directly with the two coracoids of the monotreme. Thus the homologies of the manunalian coracoid maj^ be stated as follows : the anterior and posterior elements of the monotreme girdle are the epicoracoid and coracoid, respectively'; and these are the

332 KRAXK BLAIR HANSON

homologues of the two similar elements found by Broom in Australian marsupials; and the author in the American species.

The anterior of these two elements (epicoracoid) in the monotremes is a permanent feature of the adult skeleton, but disappears in the adult marsupial and does not reappear in higher forms. The posterior element, the coracoid, is a stout element in the monotremes and is present in the adult as in the fetus, while its marsupial homologue is the exact counterpart in the fetal condition, this later gives way through degeneration to the relatively small element (fig. 7) attached to the scapula in the adult. The coracoid process of mammals is, therefore, the homologue of the strong posterior coracoidal bar which connects with the sternum in the monotremes. That this is the correct view of the coracoid homologies between monotremes and marsupials and higher orders of manunals probably will not be seriously questioned.

In passing from the monotremes to the reptiles there is a variety of opinion which is quite revealing of how little after all we have gra.sped of the real phylogeny of the maminals.

Broom derives the present-daj- reptiles from a line of Permian ancestors in which the posterior coracoid was gradually lost, leaving the coracoid of Sphenodon. hzards, and the single coracoid of the alligator as the homologue of the anterior coracoid element of the Permians. He, then, derives the manunals from another line of Permian stock in which just the reverse process occurred, i.e., the anterior element now is thought to be the one lost and the postericjr retained and homologous with the posterior element of monotremes and the coracoid process of other mammals.

Williston ('ID admits the possibility, and even the probahiUty, of two divergent lines of evolution, one in which the posterior coracoid is lost and leading to present.-day reptiles, and one in which the anterior coracoid is lost, leading to the mammals, and he also points out that the absence of the coracoid foramen in the mammals may indicate that this has been the case. However, ^^'illiston is very positive that the coracoid of Lacertilia, Dinosauria, Crocodilia, etc., is absolutely identical with the cora

THE PROBLEM OF THE CORACOID 333

coid of Seymouria and Varanosaurus, which is without doubt the anterior coracoid. He says:

there cannot be_ the least doubt but that the posterior hone, the socalled coracoid, is unossified in Se>nnouria, as in Varanosaurus. . . . The coracoid of all these forms consists exclusively of the anterior element, the so-called procoracoid. That this bone has entirely disappeared in all later reptiles, fjiving place in its entirety to another bone, here unossificd, with like attachments, and with its perforating supracoracoid foramen in the same position, I cannot believe. It seems to me utterly improbable that the coracoid as ossified in the SejTnouria and Varanosaurus is not identical with the bone supposed to be (without proof) the fused coracoid and procoracoid of LacertiUa, Dinosauria, etc., . . . . the only thing I wish to in.sist upon is that the coracoid of SejTiioiu-ia and ^aranasaurus is absolutely identical with the coracoid of the Lacertilia, Dinosaiuia, Crocodilia, etc.

Again discussing this same point under the genus Varanosaurus, Williston says:

the absence of a posterior bone in this genus, as in Sejanouria is remarkable. The whole pectoral girdle of Varanosam'us has an almost absolute superficial identity with that of the lizards. Under the usual interpretation, however, the large ossified coracoid of Varanosaurus, with its close resemblance to the coracoid of Varanus, for instance, in its supracoracoid foramen and fenestra, is the metacoracoid. In other words it is assumed that the coracoid of Varanosaiuus has disappeared gradually by the encroachment upon it of the posterior bone, the so-called true coracoid, which here in tliis genus was so degenerate that it no longer was even ossified. It seems to me that the utter al3sence of any proof that such has been the course of evolution in the pectoral girdle of reptiles — for no intermediate form has ever been discovered, no form in which the posterior bone has even reached as far forward as the supracoracoid foramen — is sufficient to throw great douljt upon the hypothesis, a doubt that becomes quite conclusive in the proof afforded liy the various specimens of these and other Permian reptiles.

It is a curious fact also that a posterior coracoid bone has never been observed in any temnosjiondyl, though the sutviral division bet\^^een the scapula and coracoid I have observed in specimens referred to Aspidosaurus to be quite as in Seymouria.

^^'iUiston's work is quite conclusive in homologizing the coracoid of Sphenodon, lizards, and crocodiles with that of the anterior element (pre.coracoid) of Permian reptiles.

334 FRANK BLAIR HANSON

Is it possible to pass from the lizards and Sphenodon to the numotromes? is the question now facing us. For if we accept the above arguments on the homology of the posterior element of monotremes with the coracoid process of mammals, and also assent to \\'illiston's view that the single coracoid of lizards and Sphenodon is the homologue of the precoracoid of fossil reptiles, then liy i)ridging the gap between monotremes and living reptiles we shall have completed the homology of the coracoid from early Permian reptiles up to man.

Gregory and Camp ('18) have comjiiled the evidence or given the basis for this latter homologj- between monotrenes and living reptiles. In the first place, it has been shown that the single coracoid of Sphenodon "gives origin on its ^•entral surface to a group of nmscles comprising the biceps and the three branches of the Coracobrachialis, which group appears to be preciselj* homologous with a similar group of muscles carried by the ventral surface of the coracoid of monotremes." The subcoracohumeralis of Sphenodon arises on the dorsal surface of the coracoid and is homologous with the similarly placed muscle, subcoracoideus, of the monotreme. As far as evidence from muscle goes, the coracoid ( = precoracoid) of Sphenodon is identical with the coracoid of monotremes. Secondlj-, the epicoracoid of Sphenodon and the lizards is widely excluded from the glenoid exactly as in the monotremes and the emijryos of marsupials. The relations of the epicoracoid to coracoid, clavicle, and interclavicle are also identical in monotremes and living reptiles, and in each the ventral surface of the epicoracoid carries the anterior part of the supracoracoiil muscle. Comparison of the monotreme coracoid with that of the alligator shows practically the same thing. While there is onh' one coracoidal element ( = precoracoid) in the alligator, (Iregorj' thinks that with the loss of the clavicle in this form there undouiiteilly also was lost a membranous epicoracoid which lay l^etween the interclavicle and the coracoid. If this should prove to be the case, the identit}' between the monotreme girdle and that of the Crocodilia is quite complete.

In general, to quote again from Gregorj' and Camp ('18), "the whole complex of relations of the epicoracoid and coracoid

THE PROBLEM OF THE CORACOID 335

of monotremes to each other and to the scapula, clavicle, and interclavicle, is practically identical with the relations of the same set of elements in lizards and Sphenodon" (figs. 3, 4, 5, and 6).

There is, then, considerable evidence for comparing directlj' the coracoid of monotremes with that of living reptiles, and, as shown above, Williston, Broom, Gregory, and Watson unite in homologizing the single coracoid of crocodiles and Sphenodon and the posterior element in lizards with the precoracoid of Permian reptiles.

If this reasoning is valid, then the coracoid process of man is a precoracoid and the homologue of the single coracoid of such Permians as Seymouria and Varanosaurus, and likewise homologous to the anterior element of those Permians which possess two bony coracoids.

Another question yet remains to be disposed of. If the coracoidal elements of the monotremes, Sphenodon, and the lizards are the homologues of the anterior element of Permian reptiles, what is the phylogeny of the so-called anterior element or epicoracoid of living reptiles and monotremes? Only one explanation has been offered, and that by Gregory and Camp, to the effect that in such a Permian as Moschops (fig. 5) and probably in others, there was really an epicoracoidal cartilage present between the precoracoid and the clavicle and interclavicle. At least in fitting the bones of the shoulder-girdle of Moschops together, it was found that there was a space between the clavicles, interclavicle, and precoracoids which must have been filled by the epicoracoids as in Sphenodon, lizards, and monotremes. The same thing is indicated in Eryops. As shown above, the epicoracoid, often appearing transiently as an embryonic structure in the marsupial, disappears from all higher forms.

This means, of course, that according to Gregory there were oiiginally three coracoid elements — metacoracoid, precoracoid, and epicoracoid — lather than the two usually considei-ed. The admission of a third coracoid (epicoracoid) is denied by Watson, who says (in a private letter) "that the presence of a distinct ossified 'epicoracoid' (as a third anterior element) in Permian vertebrates has never been proven."

336 FR.\NK BLAllt HANSON

While the existence of a third epicoracoidal eloinetit has not been proved bj' the demonstration of an actual specimen from Permian strata, there are several strong indications that such might have been the case. One of these has already been mentioned, namely, that in the Permian Moschops between the precoracoid, clavicle, and interclavicle, there is a space directly comparable with the one filled by an epicoracoid in the lizards and Sphenodon. Since the epicoracoid is a broad thin plate of membranous tissue, it naturallj- would be lost in the process of fossilization. Other evidence that the epicoracoid was a fairly constant element of Permian reptiles is furnished by Case ('07, '11a, 'lib). Describing the skeleton of Dimetrodon dollovianus, he says, "the procoracoitl teiininates anteriorlj- in a thin, straight edge, which shows signs of having borne a heavy epicoracoidal cartilage." Dimetrodon has an ossified coracoid and a precoracoid, and if Case is correct, it also carried a heavy cartilaginous epicoracoid on the anterior edge of the precoracoid. Since the cartilage would not be preserved, we have probably as near a demonstration of the presence of three coracoidal elements (metacoracoid, precoracoid, and epicoracoid) in Perniians as will ever be obtained. That this is not an isolated case is shown in two other illustrations taken from Case.

Describing the genus Diadectes Cope, Case ('11 a) saj's of the shoukler-girdle, 'the coracoid and precoracoid are not separated from the scapula by suture. The anterior edge (of

the precoracoid! is nearly straight and shows the attachment of a carlilaginou.'i epicoracoid of considerable size." And again, Case ('11 b), quoting Cope's description of Eryops megacephalus, gives the following account of the girdle: the coracoid is but little incurved; its internal border is convex, and is roughened as though for cartilaginous attachment. Its superior portion forms a convex continuum with the scapula. The direct line or external face of the scapula extends in a nearly plane surface to the glenoid cavity, embracing a perforating foramen above the latter, precisely as in the Peljcosamia. Its surface is continuous anteriorly with a wide expansion forwards, whose fine inner border is continuous with that of the coracoid. This plate doubtless

THE PROBLEM OF THE CORACOID

337

includes a third element, but its borders are not preserved, on account of the obliteration of the sutures. It is probably epicoracoid, as in the Peh'cosauria.

From the foregoing, it is apparent that in several groups of Permian reptiles and in the primitive Eryops, there is considerable evidence to support the theory of a third coracoidal element — the epicoracoid in front of the precoracoid.

The following table shows the presence or absence of these several coracoidal parts in fossil and living forms according to the interpretation of the homology of the coracoid herein set forth.

METACORACOID

PRECORACOID

EPICORACOID

Eryops

♦

Seymouria

Varanosaurus

Sphenodon

Lizards

Alligator

Marsupial fetus

Marsupial adult

Man

= element is present. While the above table is not in any sense a phylogenetic one, it shows that in se^'eral groups of Permian fossils, relatives to the ancestors of the mammals, three coracoidal elements were present, and by the dropping out of either the most posterior element {metacoracoid) or the most anterior element {epicoracoid), or both of these elements, all the variations met with from Permians to man are explicable.

The relations and homologies here set forth will stand regardless of what disposition is finallj- made of Gregorj-'s "epicoracoid or third coracoid element," for the homologies of the coracoid all hinge upon the precoracoid as the constant and vital factor in the phylogenetic succession.

338 I-KANK ULAIU IIAX.SOX

The epicoracoid maj' be, for all anyone has shown to the contrary, merely a neoniorph, like the subcoracoifl, with no morphological signiticance. Regarilloss. then, of the fate of the epicoracoid, the following homology apparently is established, namely, that the pncoracoid of Permiaus = coracoid of lirincj reptiles = coracoid of monolremes — coracoid of marsupials = coracoid process of trian.

It is at once apparent that the precoracoid of Permian reptiles is the constant factor in the situation. Since, as shown by Williston, this element (precoracoid) is the one preserved and known as the coracoid of Sphenodon, lizards, and the alligator, the term coracoid is correcth' applied only to the homologues of the precoracoid. Gregory and the author have argued for the homology of the girdles of Sphenodon and lizards with that of the monolremes, and Broom and the author have shown that the conditions in the nionotremes are directly comparable with the fetal girdle of the marsupials, therefore, the two elements of the girdle in the fetal marsupial (coracoid and epicoracoid) are homologous with the same two elements in the lizard and Sphenodon. But these elements of Sphenodon and the lizards are demonstrated by Williston and Case to be the homologues of the precoracoid and cartilaginous third element (epicoracoid) of Permian reptiles. Therefore, again, the two elements of nionotremes and fetal marsupials are homologues of the precoracoid and cartilaginous epicoracoid of Permian reptiles, and not to the precoracoid and metacoracoid, as assumed by Watson and Broom.

In the fetal marsupial the epicoracoid is embryonic onh', the coracoid aborts except for a small rudimentary process attached to the scapula, which is undoubtedly the homologue of the samenamed element in higher mammals and man. Therefore, once again, the coracoid process of man is a precoracoid and the homologue of the precoracoid of fossil reptiles.

It may be objected that the precoracoid of Permian reptiles, and its homologue in li\ing reptiles, carried a foramen and nerve. This is not present in nionotremes, anil we must assume it to be lost here. This is not a serious objection, as the foramen is also absent from the coracoid of many birds, which coracoid is without fjuestion the homologue of the precoracoid.

THE PROBLEM OF THE COR,\COID 339

Also it may be pertinent to ask, if the coracoid process of placental mammals is the posterior element of Permians, how did it get to the anterior side of the glenoid? It is hard to imagine any rotation or migration of this element which would bring it from a position distinctlj^ posterior of the glenoid to its present distinctly anterior position.

THE SUBCORACOID

The subcoiacoid center of placental mammals has been homologized by Howes ( '93) , Lydekker ('93) , and others to the metacoracoid of Permian reptiles. Thej' regard the subcoracoid center of mammals as the vanishing vestige of the metacoracoid. Gregory ('15) and also Williston formerly accepted this homology, but Gregoiy ('18) has reconsidered this element and now beUeves it to be a neomorph or cartilaginous epiphj-sis and without morphological significance.

Hanson ('19), in studying this subcoracoidal element in the pig (an animal lacking the coracoid pfocess), came to the conclusion that this center of ossification in the pig was an epiphj'sis.

The subcoracoid always occupies the anterior portion of the glenoid, just behind the coracoid process. The posterior part of the glenoid in mammals is formed by the lower end of the scapula. To accept the subcoracoid element as the last remainmg rudiment of the metacoracoid, it would be necessarj^ to assume that in some way there was a rotation of the scapula so that the posterior side of the glenoid in Permian reptiles is now the anterior side of placental mammals, or else in some manner that this center has migrated across the glenoid cavity anteriorly to its present position. Either of these explanations puts our credulity under a rather heavy strain.

Gregory and Camp ('18) also point out in this connection that the subcoracoid "is located at the anterior end of the glenoid ligament where the latter is continuous with the tendon of the biceps .... as the intrascapular position of part of the biceps is undoubtedly a neomorph in the placentals, we suggest that the appearance of a subcoracoid is also a neomorph."

340 FRANK ULAIU HANSON

Broom was the first to suggest that the subcoracoid was an epiphysis, and not part of the coracoid complex.

SIM.MAKY

1. It has been shown bj* Broom for Australian marsupials and the author for the American opossum that in the embryo and fetus, the shoulder-girdle consists of a scapula, a clavicle, and two coracoidal elements, one of which, the posterior, extends from the scapula to the sternum and is comparable directly with the coracoid of monotremes. The anterior element of the marsupial fetus is a broad fan-shaped sheet of mesenchyme, of short duration in embryonic life, and is the homologue of the epicoracoid of monotremes.

2. Development shows that the posterior of the two coracoidal elements of the fetal marsupial girdle becomes the small coracoid process attached to the scapula in the adult, which process undoubtedly is homologous with the same-named process in man. This gives a clear line of relationship from the coracoid process of man to the posterior element in the girdle of the monotremes.

3. Clregorj' and the author have maintained that the conditions in the monotreme girdle are so clearly reptiUan in character and approximate so closely in every respect to the structure of the girdles in Sphenodon and the lizards, that genetic relationshij) and liDUiology exists between them.

4. Williston has practically demonstrated that the coracoid of living reptiles is derived from the anterior bony element (precoracoid) of Permian reptiles.

5. Therefore, if the coracoid process of man is the same element as the posterior coracoid of monotremes, and this latter is directly comparable with the posterior of the two coracoids of Sphenodon and lizards, which is in turn a derivative of tiie precoracoid of Permian reptiles, then the coracoid process of man equals the anterior bony element of Permians, and the precomcoid is lltf true coracoid.

6. The subcoracoid of placental mammals is not a coracoid element at all, but an epiphysis, and does not enter into the problem of the coracoid.

THE PROBLEM OF THE CORACOID 341

LITERATURE CITED

Broom, R. 1897 On the existence of a sterno-coracoidal articulation in a fetal marsupial. Jour. Anat. and Physiol., vol. 31.

1898 Description of shoulder-girdle in an 8.5-mm. embr}-o of Trichosurus (not exact title). Proc. Linn. Soc. N. S. W.

1899 On the development and morphology of the marsupial shoulder girdle. Trans. Roj'. Soc. Edinb., vol. 39, pt. 3.

1902 On the early condition of the shoulder girdle in the Polyproto dont marsupials Dasyurus and Perameles. Linn. Soc. Jour. Zool.,

vol. 28.

1912 The morphology of the ooracoid. Anat. Anz., Bd. 41. C.\sE, E. C. 1907 Revision of the Pelyeosauria of North America. Carnegie

Institution of Washington, Pub. no. 55.

1911 a A revision of the Cotylcsauria of North America. Carnegie

Institution of Washington, Pub. no. 145.

1911 b Revision of the Amphibia and Pisces of the Permian of North

America. Carnegie Institution of Washington, Pub. no. 146. (iREGORY, W. K., AND C.^MP, C. L. 1918 Studies in comparative myology and

osteology. No. III. Bull. Am. Mus. Nat. Hist., vol. 38. H.^xsoN, F. B. 1919 The ooracoid of Sus scrofa. Anat. Rec, vol. 16. Howes, G. B. 1893 On the ooracoid of the terrestrial animals. Proc. Zool.

Soc. London. Lydekker, R. 1893 Notes on the ooracoidal element in adult sloths, with

remarks on its homology. Proc. Zool. Soc. Parker, W. K. 1867 A monograph on the structure and development of the

shoulder girdle and sternum. Ray Society, London. Watson, D. M. S. 1917 The evolution of the tetrapod shoulder girdle and forelimb. Jour, of Anat., vol. 52. WiLLisTON, S. W. 1911 American Permian vertebrates. University of Chicago

Press.

ABBREVIATIONS

Ar, acromian CI, clavicle Cleith, cleithrum Cr, coracoid ECr, epicoracoid 01. glenoid Hti. humerus

ICl, interclavicle MCr, metacuracoid PCr, precoracoid PSl, presternum Sc, scapula SSc, suprascapula St, sternum

PLATE 1

EXPLANATION OF FIGURES

1 Transverse section of the shoulder-girdle and sternum of a 7.5-mm. embryo of Didclphys virginiana. Scapula and coracoid continuous at glenoid Coracoid extends to and unites with the sternum. Series 924, slide 3, section 35, Harvard F^mbryological Collection.

2 Frontal section of the shoulder-girdle and sternum of 11.5-mm. embryo of Didelphys virginiana. This section shows the connection of the large coracoid with the sternum, but is cut in such a plane as to exclude the scapula. Series 6127, slide N, section 5, Harvard Kmbryological Collection.

342

THE PROBLEM OF THE CORACOID

FRANK DLAIR HANSON

PLATE I

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343

THE ANATOMICAL RECOKD, VOL. 19, NO. f

PLATE 2

EXPLANATION OF FIGDBES

3 Shoulder-girdle of iguana. Modified after Parker and Gregory.

4 Shoulder-girdle of Sphenodon. Modified after Gregory and C.imp.

5 Shoulder-girdle of Permian Moschops. After Gregory and Camp.

6 Shoulder-girdle of the monotreme, Ornothorynchus.

7 Shoulder-girdle and anterior part of sternum of the marsupial Petrogale xanthopus. Note small rudimentary eoracoid process and compare with coracoid in figures 1 and 2.

344

THE PROBLEM OF THE CORACOID

FRANK^BLAIR HA-NSOX

PLATE 2

345

Resumen por el autor, Homer B. Latimer. Universidad de Nebraska.

Peso de las visceras eii la tortuga.

Veintii'in machos y una hemhra ilo la tortuga de Cumberland (Chrysemis elegans) fueron empleados en el presente trabajo. Despu^s de cloroformizados se pesaron, disecandoles a continuaci6n y extrayendo las vfsceras, que se pesaron, en frascos de pesar con tap6n de vidrio, en una balanza qufmica que podia apreciar diferencias de una d^cima de miligramo.

El peso ordinario de las visceras expresado en tantos por ciento del peso total cs el siguiente: el coraz6n, 0.31; el bazo, 0.21 ; los pulmones y triiquea, 1.07; el tubo digestive sin su contenido, 6.23; el higado, 5.43; el pancreas, 0.15; los rinones, 0.31 ; y los testfculos 0.23 por ciento, o sea un total de 13.74 por ciento del peso total del cuerpo.

Cuando se emplearon los pesos absolutes del cuerpo y de cada 6rgano para determinar el coeficiente de variabilidad, el autor hall6 ciue el peso del cuerpo posee un coeficiente menor que el de cualquiera de los 6rganos. Los 6rganos que poseen un coeficiente de variabilidad mener son generalmente los 6rganos con un coeficiente mas alto de correlaci6n con el peso total ilel cuerpo. Natiualmonte, los coeficientes de variabilidad de los 6rganos son mas pequenos cuando en vez de los pesos absolutes se emplean los pesos en tantos por ciento. Estos ultinios se obtienen reduciendo los absolutes a un por ciento del peso total del cuerpo.

Tniulstion by loat F. Nonidoi Cornrll Medicnl CoIIpcp, New York

THE WEIGHTS OF THE VISCERA OF THE TURTLE

HO-MER B. LATniER Department of Zoology, University of Nebraska

The frequent use of the tui'tle for laborator}- purposes and the lack of quantitative data on the size of the tiu'tle viscera has made it seem worth while to determine the weights of the viscera of the turtle. Another thing which suggested this problem was the question of the effect of the weight of the turtle shell on the percentage weights of the organs. The only published quantitati^'e work on the turtle viscera of which I am aware is the report of Welcker and Brandt ('03) upon a single female specunen of Testudo graeca. The brain and spinal cord of each turtle were remo^•ed. measured, and weighed, and this data will be combined with similar data from other forms and published later.

MATERIAL AND METHODS

The specimens used in this investigation were twenty-one male and one female Cumberland terrapins (Chrj-semj-s elegans), three Southern musk turtles (Aromochelys tristata), one male and two females, and one male specimen of Lesueur's terrapin (Malacoclemmys lesueurii). The turtles were killed with chloroform. The small turtles were weighed on a chemical balance sensitive to a tenth of a miUigram, the larger turtles, the Cumberland terrapins, were weighed on a laboratorj- balance sensitive only to a tenth of a gram. The viscera were carefully dissected out and immediatelj' put in ground-glass-stoppered weighing bottles after all the excess blood had been allowed to drain off. The lungs and trachea were weighed together, the trachea being severed at its attachment to the pharj-nx. The oesophagus was cut away

' Studies from the Zoological Laboratory of the University of Nebraska, no. 126.

347

348 HOMER B. LATIMER

from its attachment to^the pharynx and the large intestine was severed at its opening into the cloaca. The entire tract was removed with as little of the surrounding fat and the mesenteries as possible. The stomach and intestines were opened and the contents removed. WTiat little material there was in the intestine could usually be forced along the intestine by gentle pressure until it coukl Ije removed at the end or at one or two incisions. All the other viscera were removed in a sunilar manner with as little of the mesenteries and fat as possible. The net body weight and the percentage of loss were not determined as thej' were for the frogs (Latuner, '20), but in other respects the same plan, which was described in the previous papei', was followed in the dissection and weighing of the turtles.

The twenty-two Cumberland terrapins were received from a Chicago dealer, and the fact that but one of the twenty-two was a female is interesting. They were kept in a tank with free access to running water in a room with a temperature slightly lielow the usual laboratory temperature. The first turtle was killed and studied December 23, 1919, or soon after they were received. The last one was killed January 26, 1920. The}' received no food during this time, and when killed only small masses of fecal material were found toward the caudal end of the intestines. Thej"^ all had ample quantities of fat in the mesenteries, showing that they were in good condition.

PERCENTAGE WEIGHTS OF THE VI.SCERA

Table 1 A gives the total weight in grams of each of the twentyone male Chrysemys elegans and the weights of the viscera of each turtle expressed in percentages of the total bod)- weight. Sections B, C, and D give the same data for the one female Chrysemys elegans and for the other turtles. The weights of the digestive tract are for the empty tract. There was so little material to be removed that no correction was made for this in the total bodj'-wcight.

Table 2 will facilitate comparisons between the turtles and other species. It shows the averages of the percentage weights

WEIGHTS OF THE VISCERA OF THE TURTLE 349

of the various organs of the turtles and the same data for the other forms. The first line gives the a^•erage percentage weight of the organs of the twenty-one male turtles (C. elegans). The second line gi^■es the averages for the three Southern musk turtles, and the third line the percentage weights of the viscera of the one Lesueur's terrapin. The data for the first three lines are taken directly from table 1 . The percentage weights for the Testudo graeca are taken from the report of ^Yelcker and Brandt ('03) and are for a single female specimen. The next two lines give the average percentage weights of the organs of the ten male and nineteen female frogs (Rana pipiens) from a previous paper (Latimer, '20). The percentages of the rat viscera are those given bj- .Jackson ('13) for one-year-old male white rats. The last line gives the data on the human organs as given by Vierordt ('06). The last column of the table shows the totals of the percentage weights for all the viscera of each species. These were determined from the four-place decimals of the complete tables, and consequentlj- the sums are sUghtly larger than the sums of the two-place decimals gi^•en in this table. It is obviously impossible to place much weight on the figures in the second, third, and fourth lines, for these three lines represent altogether but five specimens.

In comparing the twenty-one male turtles with the frogs it is apparent that each of the organs of the turtle is heavier than the same organ of the frog, with the exception of the heart and the kidneys.

Heart. The heart forms a smaller percentage weight in the turtles than in any of the other forms. Joseph ("08) suggests that the relative size of the heart is correlated with the activity of the animal. This would place the turtle at the bottom of the list as far as activity is concerned, and the Chrysemys elegans would be more active than the other three species of turtles, if we may be permitted to judge from the xQvy small numbers. The percentage weights of the heart for the frog, the rat, and the human are nearh' the same.

Spleen. The spleen is the most variable organ not onh^ in comparing the eight species listed in this table, but in comparing

350

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WEIGHTS or THE VISCERA OF THE TURTLE

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352

HOMER B. LATIMER

the indi\idual twenty-one male turtles and the twenty-nine frogs. It is thirteen times heavier in the rat than in the three musk turtles.

Lungs. The weights of the lungs in terms of percentage of the total bod}' weight are heavier in the turtle than in the frog. In weighing the turtle lungs the trachea is included. This might account for the difference, but the turtle luiiij is a more complicated structure than the simple sac-like lung of the frog. No separate weighings of the trachea were made.

Digestive tract. The digestive tract in the Cumberland terrapins, Testudo graeca, and the white rat is much heavier than the

TABLE 2 Shounng the average percentages of the viscera for the following species

C. elcgans

Musk turtle

Lesupur's terrapin

Test, graeca

Male frogs

Female frogs

White rat

Human

BEABT

SPLEEK

LUNOS

DIOE8TIVE TRACT

LITER

■PANCREAS

KIDNETS

0.31

0.21

1.07

6 23

5 43

0.15

0.31

0.28

003

0.92

338

2.40

0.14

0.27

0.24

0.18

1.14

3 11

3 75

0.13

24

0.23

10

1 71

5.68

5.78

14

62

0.43

0.18

0.85

3 50

2.80

09

0.43

0.47

16

76

3 77

2.88

09

0.47

0.45

,39

93

5 1

4.42

95

46

25

1 50

2 06

2.75

0.15

0.46

13.74 7.45 S.83

14 26 S 31 S 63

12 25 7 63

percentage weights in the other forms. The lower percentages in the frogs, the musk turtles, and Lesueur's terrapin may have been due to the fact that they were kept in the laboratory for some time before being killed. The Cumberland terrapins were kept in the laboratorj' for only a little over one month, and that was during the winter time, wliile the frogs and the other turtles were kept for a longer time and during the sunmier. It is interesting to note that the percentage weight of the himian digestive tract is the lowest and that of the Cumberland terrapin the highest, or a Httle over three times the percentage of the hiuuan digestive tract.

Liver. The variation in the percentage weights of the liver in comparing one form with another seems to parallel the varia

WEIGHTS OF THE VISCERA OF THE TURTLE 353

tion in the digestive tracts. The human, the Testudo graeca, and Lesueur's terrapin are the onh- forms in whieh the Hver is heavier than the digestive tract. Only fi^'e of the twenty-one male turtles had a liver with a heavier percentage weight than the digestive tract.

Pancreas. The pancreas forms nearly the same per cent in all forms except the frogs, where it is much less.

Kichieys. The kidneys show a marked variation, the kidneys of the rat being 3.95 times heavier than the kidnej-s of the Lesueur's terrapin. The kidneys of the three terrestrial forms, the rat, the human, and the Greek tortoise, are heavier than the kidnej^s of the aquatic forms. The adrenals were included in the weights of the kidneys of the turtles which I weighed, and of the frogs.

A comparison of the svnns of the percentage weights of the viscera of the turtle (C. elegans) and the frogs is interesting, the former being 1.6 times heavier than the latter. This means that either the organs of the turtle are relatively larger than those of the frog or that the better-developed musculature or other parts of the frog more than compensate for the shell of the turtle. The sum of the percentages for the human most nearly resembles the sum of the percentages of the musk turtles, which were undoubtedly undernourished, due to their prolonged period in the laboratory, and the normal healthy rats resemble more closely the sum of the percentages of the turtle. If we omit the one specimen of the C4reek tortoise, we find the viscera of the Cumberland terrapin the heaviest, with the weights of the viscera of the white rat a close second.

COEFFICIENTS OF VARIABILITY

In table 3 are shown the coefficients of variability of the percentage weights of the viscera of the twenty-one male C'lunberland terrapins and of the ten male and nineteen female frogs. The coefficient of ^•ariation and the probable error of the coefficient of variation for the turtles are taken from table 1. The coefficient of ^-ariation and the probable error of the coefficient of variation for each organ of the frogs were computed from the

354

HOMER B. LATIMER

data given in table 2, page 39, of the report of the frog viscera (Latimer, '20), which gives (lie jiercentage weights of the viscera of the chloroformed frogs. Rana pipiens. In Hnding the standard deviation, the coefficient of variation and coefficient of correlation and the jirohalile errors of each of these, Pearson's formulae, as given h%- Davenjiort ('04), were used. A six-place logarithm tal)le and the tal)le of sfjuares given Ijy Davenport ('04) aided in the computations. .\11 the results were checked.

This table shows the turtle spleen with a coefficient of variation of 33.40 ± 3.85 or four times that of the digestive tract. The frog spleens have a still higher variability, or 71.0 ± 15.1

TABLE 3

Coefficient vf variability of percentage weights

UALE TURTLES

Digestive tract 8. 05 ±0 84

Liver 9 42±0 ftS

Heart 10 S3 ±1 '27

Kiilney 12 -Jli^l 31

Pancreas 23 12 ±2 47

Lungs 27 03±2 91

Spleen 33 46 ="=3 So

Testes 35 «5±4 15

UALK FROGS

Kidney 11.5=1=1.7

Digestive tract 12 6±1.9

Heart 13 4=^2.

Liver 15 4=^2.3

Lungs 17 7^2.7

Pancreas 22.2=*=3.5

Testes 47.2=*=8.5

Spleen 71.0=^15.1

FCUU.E rnoca

Kidney 12. 9=*= 1.4

Liver 19 6±2.2

Lungs 20 7=^2.3

Digestive tract21 .C=*=2.4

Heart 22 2=^2.5

Pancreas 24.5 =^2.8

Ovaries ;.52.1 =»=7.0

Spleen 64 7 ±9.6

for the male and 64.7 ± 9.6 for the female frogs. This it will be .seen is greater than the coefficient of variation of either the testes or the ovaries of the frog. The low coefficient of variation of the digestive tract of the turtle is noticeable, due possibly to tlie lack of food for a similar length of time and uniform conditions of temperature and so forth. The kidney, which is fourth in varial)ility in the turtle, ranks first with a \ariability of 11.5 ± 1.7 in the male and 12.9 =fc 1.4 in the female frogs. The l)ancreas seems to ite about the same in all three columns, with a coefficient of variation of 23 for the turtles, 22 for the male frogs, and 24 for the female frogs. The ovaries, as might be expected, show a greater variability than do the testes, and both gonads of the frogs show a greater \ariation than do the testes of the

WEIGHTS OF THE VISCERA OF THE TURTLE

355

turtles. The heart is third in two cohunns and fifth in the third, the kings are sixth in order of the increasing coefficient of variability in the turtle, fifth in the male frogs, and third in the female frogs.

Table 4 gives the data for the weights of the organs in grams; A gives the data for the twenty-one male turtles and B for the

TABLE i

Showing average weights, standard deviations, and coefficients of variability, computed from the actual weights of the organs in grams

AVERAGE WEIGHT

STANDARD DEVIATION

COEFFICIENT OF VARIABILITT

A. Twenty-one male turtles

Body weiglit. . . .

Heart

Spleen

Lungs

Digestive tract.

Liver

Pancreas

Kidneys

Testes

688.9-1001.1

2. 0858-3. 2-162

l.Oail-3.7120

6 5932-17.2002

41.0200-67.7790

30 5501-61.9637

9410-2.4125

1 9441-3 8076 1.0.537-3.7801

S9.6S5 0.292 0.699 2.435 6.901 8 993 0.338 0.447 0.669

10.67 ± 1.12 11.06 ± 1.16 38 .36 ±4. .54 27.22 ±3.03 13.19 ± 1.39 19 66 ±2.12 25.65 ±2.84 16.76 ±1.79 34.58±4.00

B. Frogs (male and female together)

Body weight

Heart

Spleen

Lungs

Digestive tract.

Liver

Pancreas

Kidneys

37.4643

0.1743

0.0626

0.3003

1.4073

1.0945

0.0372

0.1735

24.9561-56.7866 0.0925-0 3473 0176-0.1604 0.1360-0 5500 662.3-2 .5770 5299-2 2951 01.38-0.0670 0990-0 2762

7.056

0.053

0.037

0.091

0.489

0.382

013

0.044

18.83 ±1.72 30.41 ±2.93 59.95 ±6.96 30.57 ±2.91 34.77 ±3.43 34.97 ±3.45 35.43 ±3.51 25 89 ±2 44

ten male and nineteen female frogs taken together. The first column gives the average weights, the second the range or the lowest and highest weight, the third column gi\-es the standard deviation, and the fourth column, the coefficient of variability and probable error of the coefficient of \-ariability for each organ. In preparing the data for table 3 each indi\idual organ of each specimen was reduced to a percentage weight of the total body

356 HOMEIl B. LATIMKR

woinht of the animal, and so any variation in the weights of the organs duo to a variation in the size of the s])Pfiiiipn was eliminated. In tal)lo 4 the actual weights of each oigan were used in the computations. This naturally would make the coefficients of variability larger when the absolute weights are used than when the percentage weights are emploj-ed, and is evident from a comparison of taljles .3 and 4. It is an interesting fact that the total body weight for both the turtles and the frogs has a lower coefficient of \arialiility than any of the individual organs. Since the entire animal varies less than any of the individual organs, it would seem that there might be some reciprocal relationship between at least some of the organs, but as will be explained below nearly all the correlations are positive (table 5).

The turtle heart has nearly the same coefficient of variability in each table, 10.83 for the percentage weights and 11.06 for the absolute weights. The digestive tract comes second in order of increasing coefficients of variabilitj' of the viscera, with a coefficient of 13.19 in this table compared with a coefficient of 8.05 in the preceding table. The kidneys of the frogs still retain their position as the least variable in the list of the organs of the frog, and the spleen is the most varial)le, having a coefficient of 38.36 for the turtles as compared with 33.46 for the percentage weights. The pancreas and lungs are about the same, but all of the other organs of the turtle have a liigher coefficient of variability in talile 4 except the testes and for this organ the percentage weights give a coefficient of variation of 35.65 db 4.15, and the al)solute weights a coefficient of 34.58 =fc 4.00. This is probably due to the fact that there is practically no correlation l)etween the weight of the testes and the total body weight (table 5), and consequenth' the reduction of the absolute weights of the testes to a percentage of the body weight would not give even as constant a series as the absolute weights themselves. The greatest increase is fountl in the liver of the turtle. It has a coefficient of variability in the tal)le of percentage weights of 9.42 ± 0.98 and 19.66 ± 2.12 in the table of absolute weights. The hver has a rather close correlation with the body weight (table 5), and so although it is a rather variable organ, reducing its weight to a

WEIGHTS OF THE VISCERA OF THE TURTLE 357

percentage of the total body weight reduces its variability. The pancreas and lungs, which are about the same in tables 3 and 4, have a low coefficient of correlation with the total body weight and consequently reducing them to a percentage basis makes but little difference with their coefficients of variation.

The same relationship between the coefficients of variabilitj(tables 3 and 4) and the coefficients of correlation of the various organs with the total bodj^ weight (table 5) holds good for the frogs as well as for the turtles. For all of the organs of the frog except the spleen, the coefficients of variability for the percentage weights is less than the coefficients for the absolute weights, and for all of these organs table 5 shows a rather good coefficient of correlation with the body weight. The spleen has a negative correlation of 0.064 and its coefficient of variation for the twentj'-nine male and female frogs taken together and usmg the absolute weights of the spleen is 59.95, but when the percentage weights are used the spleens of the male frogs have a coefficient of variability of 71 and the female a variation of 64.7.

COEFFICIENTS OF CORRELATION

The coefficients of correlation of the absolute weights of the individual organs and the total body weight for the twentj'-one male turtles and the ten male and nineteen female frogs, taken in one group, aie given in table 5. As has been suggested above, the organs having a close correlation with the total bodj' weight have a lower coefficient of variation when the percentage weights are used than when the absolute weights are employed.

The correlations between the body weights and the individual organs seem to be a little closer for the frogs than for the turtles. The body weight and the pancreas of the frogs have a positive correlation of 0.909, while in the turtles the correlation of the same organ and the body weight is but + 0.391 and the highest coefficient of correlation is + 0.794 for the digestive tract and the body weight of the turtle. The onh^ negative coefficient of correlation of any of the organs with the body weight is that of the spleen of the frog. The testes, lungs, and pancreas of the turtles have \-ery low coefficients of correlation with the bodjweight.

308

HOMER B. LATIMER

In table 5 B are shown the coefficients of correlation between some of the organs, both for the turtles and for the male and female frogs. As in the preceding part of the table the correlations are closer for the organs of the frogs, the digestive tract and kidney having a correlation of + 0.875, while the same organs

TABLE 5 Coefficients of correlation

TWENTY-OSE MALE TURTLES

TWEKTT-XINE rSOOS (UALE AND FEMALE)

A. Correlations with body weight

Body weight and digestive tract + 794 ± 054

Body weight and liver -(- 0.632 iO.OaS

Body weight and kidneys + 613 ±0 09S

Body weight and heart + 535 ±0.105

Bodj- weight and spleen + 0.432 ±0.119

Body weight and pancreas -(- .391 ± 1.56

Body weight and lungs + 0. 158 ± . 143

Body weight and testes -i- 0.089 ±0.146

Body weight and pancreas + 909 ±0.021

Body weight and digestive tract + 0.866 ±0.031

Body weight and kidneys + 0.863 ±0.031

Body weight and liver.+ 845 ± 035

Body weight and

lungs + 0.733 ± 057

Body weight and heart + 0.665 ±0.069

Body weight and spleen - O.O&l ± 0.124

B. Correlation of organs

Liver and spleen +

Liver and kidneys +

Liver and pancreas. . .+ Digestive tract and

kidneys +

.•spleen and pancreas. .+ Digestive tract and

liver +

Digestive tract and

heart +

Digestive tract and

spleen +

Lungs and kidneys. . .+ Lungs and heart +

731 ± 008

.64S±0 ()S5

626 ±0 089

619 ±0 090

.4.-)2 ±0 117

362 ±0 127

.254 ±0 137

.253 ±0 1.37

228 ±0.139

.143 ±0 144

Digestive tract and

kidneys + S75 ± 029

Digestive tract and

heart + 0.858 ± 0-15

Digestive tract and

liver + 0.725 ±0 059

Pancreas and liver, . . . + 0.657 ± 071

Kidneys and liver + 6.>1 ± 071

Kidneys and lungs + 0.530 ± 090

Heart and lungs + 396 ± 105

Pancreas and spleen.. .— lOS ± 123

Liver and spleen 0.0

Digestive tract and

spleen - 025 ± 125

WEIGHTS OF THE VISCERA OF THE TURTLE 359

of the turtles have a positive correhitioii of but 0.619. The three highest coefficients of correlation between the organs of the turtles are between the liver and spleen, liver and kidney, and the liver and pancreas. The three closest correlations in the frog viscera are the digestive tract and kidney, digestive tract and heart, and the digestive tract and the li\'er. All the coefficients of correlation are positive for the turtle ^•iscera, although some of them are very low, but for the frog viscera tw^o of the correlations are negative, although low and one is zero. The liver and spleen of the frogs have a coefficient of correlation of zero, and yet for the same organs in the turtle we find the highest correlation of any of the organs, or + 0.731. The two negative correlations for the frog viscera are the spleen and pancreas and the spleen and digestive tract. Both of these correlations are low in the turtle viscera.

Sr.M.MARY

1. The heart of the male turtles (C. elegans) forms 0.31 per cent of the total body weight. It has the lowest coefficient of variability of any of the organs, or 11.

2. The spleen ec[uals 0.21 per cent of the total body weight and is the most varialile of the organs, having a coefficient of \ ariability of 38.

3. The lungs which compose 1.07 per cent of the total weight of the turtle Ivdve a coefficient of variability' of 27.

4. The digestive tract forms 6.23 per cent of the body weight and it has a coefficient of variabilitj' of 13.

5. The liver is second largest in percentage weight. It forms 5.43 per cent of the weight of the body and has a coefficient of variability of 19.

6. The ijanci'eas, with a coefficient of variability of 25, forms but 0.15 per cent of the total weight of the turtle.

7. The kidneys form 0.31 per cent of the body weight and have a coefficient of variability of 16.

8. The gonads are less variable than the spleen, for the}' have a coefficient of variability of 34 and they foiin 0.23 per cent of the total body weight.

THE ANATOMICAL HECOIID, VOL. 19, NO.

H(t(» HOMKR B. LATIMER

HIUI.KKIK \|■|1^

11 \\ KM'oliT. {". 15. lull Sliilistioiil iiu-lli<iils « itii s| i:il nlC retire ti) liinlnpicnl

v:iri:iti'iM

DdNAi-DsoN, II. 11. I'.tl.') Tlic i;il. .Mi-moir.-i 111' Tlic WL-^hir In.stiliiU', no. 0.

H.AT.M, SillNKisHi 1913 On till- weight of the nhdominal uiiil tilt- thoracic viscera, the sex Khinds. iliietless glands and the eyelialls of the albino rat (Mils norv. albinus) aerording to body weight. .\iu. Jour. Anat., vol. 15, p. S".

J.\CKSON, C. M. 19(19 Oiillir iireiiatal growlli of (lie Ihiukiii limly atul tlie relative growth of the various organs and parts. Am. Jour. Anat., vol. 9. p. 119.

191:? Postnatal growth and variability of the body antl of the various organs in the albino rat. Am. Jour. Anat., vol. 15, p. 1.

J.^CKSON, C. M., AND LowREY, L. CI. 1912 On the relative growth of the component parts (head, trunk, and extremities) and systems (skin, skeleton, musculature, and viscera) of the albino rat. Anat. Hec, vol. 6, p. 419,

JosKPii, Don U. 19I1S The ratio between the heart-weight and the liody-weight in various animals, .lour. Kxp. Medicine, vol. 10, p. ."«21.

I,\Ti\iKH, H. H. 19_'(1 The weights of the viscera of the common frog. Anat. Hee., vol. IS, p. ;}5.

ViKHOUDT, H. 19(K) Anatomische, physiologische and pliysikalisehe Daten und Tabellen. 3. AuH. Jena (cited by Jackson, '09).

Wku'KKII, Hkkmann, und Uk.vndt. Alex.wdkr 1903 Gewiehtwerthe dur Kiirperorgane bei dent Menschen \md den Thieren. .\rchiv. fiir Anihropologie. Hd. 2S.

YtLE, (I. Idnv 1912 .\n introduction to the theory of statistics.

^

^\o^

Resmiien por el autor, Otto F. Kampnieier. Univorsidad de Illinois.

La circulaci6n colateral en un case de oclusi6n completa del orificio ■ de la vena cava superior.

El orificio de la vena precava y de la mayor parte de la camara atrial de un coraz6n humano apareclan obstruidos a consecuencia de la fnnnaciAn de un gran trombus en el atrio derecho, sufriendo dicho trombus una calciticacion subsiguiente.

Los cambios resultantes en la direcci6n y marcha de la corriente venosa pueden resvmiirse brevemente del mode siguiente: Toda la sangre (|ue \uelve al corazon desde la porci6n del cuerpo situada sobre el diafragma, excepto la procedente de las venas coronarias, tenia cjue descender, principalmente por el sistema de las venas azigos, a la cavidad abdominal, donde penetraba en la postcava. La direcci6n de la corriente .sangufuea en el sistema de las venas azigos, era pues, completamente contraria a la direcci6n de la misma corriente en el cuerpo normal. Estas modificaciones se han expresado mediante dos esciuemas que acomi)anan al trabajo.

TraiulatioD by Jos£ F. Nonidez Cornell Medical College, New York

ACTHOR 9 AnsTHACT OF THIS PAPER ISSUED DY THE BIBLIOanAPinC SERVICE. OCTOBER 4

The Collateral Circulation In A Case Of Complete Closure Of The Mouth Of The Superior Vena Cava

OTTO F. KAMPMEIER

Department of Anatomy, College of Medicine, University of Illinois, Chicago,

Illinois

TWO FIGURES

The case, here described, is that of a negress of middle age, who died of pneumonia in the course of chronic mania. The body was muscular and well nourished; of short stature, being less than five feet in height, it weighed 150 pounds. Surface examination showed a large ulcer on the lower lateral side of the right leg. This character and certain of the internal abnormalities found later led one to suspect syphilis, which diagnosis was subsequently substantiated by the woman's clinical history at the insane asylum' where she had been confined. The records re^'ealed that she was a prostitute and a criminal ; she committed murder, evidentlj' in a fit of madness, for she was placed in a hospital for mental diseases (1901) and, fourteen years later (1915), was admitted to the asylum for mentally diseased. The clinical data further showed that she had been under syphilitic treatment for years.

During the dissection- of the cadaver, a considerable number of abnormalities were observed, chief of which were those of the heart, to be described presently, also a large fibroid of the uterus, a fairly large lipoma of the back in the lumbar region, softening

' Asylum for Mentally Diseased in Wauwatosa, near Milwaukee, Wisconsin. I thank Dr. F. W. Beutlcr. director of the institution, for looking up the records of the case.

' The dissection was carried out by two of my students, Messrs. J. A. Blair and A. J. Raymond, at the Marquette School of Medicine, Milwaukee, and the figures were copied from my diagrams and prepared for publication by Mr. L. Massopust, the artist of the school.

301

362 OTTO F. KAMPMEIER

of a large part of one lobe of the cerebrum (which apparently was not due to postmortem changes following imperfect preservation), marked oircidatorj- deviations, chiefly of the veins, and a number of easily recognizable muscular anomalies, especially of the upper extremity. In fact, the students in the dissecting laboratory claimed everything was wrong with her."

\Mien the heart' was examined and studied, the major portion of the right atrium as well as an extensive area of the aortic arch was foimd to be bonj' hard. On laying open the chambers of the heart, it was discovered that not only the entire wall of the right atrium, except where the inferior vena cava and coronary sinus entered, but also the entire interatrial septum was composed of a thick, compact 'osseous' tissue. Moreover, this tissue had extended far up through the anterior or ventral wall of the root and arch of the aorta and had invaded the atrioventricular septa partly surrounding the tricuspid and mitral valves, ^^'hat was most remarkable about this calcified tissue was its great thickness, in many places measuring from 6 to 8 cm. (2 to 3 inches) across. Even though the ventricular walls, except the atrioventricular septa, were for the most part free from the sclerotic deposit, it is a mystery to the writer how the contractions of the heart could have been sufficientlj' complete to propel the vascular stream throughout the body. The most notable change occurred in the right atriinn. Here the sclerotic layer had become so massive as to have occluded the major part of the atrial chamber, shutting off entirely the superior vena cava, but leaving a lumen approximately as wide as that of the inferior vena cava for the passage of the blood from the latter vein and the coronary sinus to the tricuspid portal. To give actual dimensions, the average thickness of the sclerosed interatrial septum was about 3 cm. (!', inches), while that part of the bony wall situated between the end or origmal mouth of the superior vena cava and the remnant of the atrial cavity was no less than 5.5 cm. (slightly more than 2 inches). The latter relations are indicated in figure 1.

•This specimen, numbered .M. 344, is in the Museum of Pathology of Marquette Medical SchoDJ.

COMPLETE OCCLUSION OF MOUTH OF PRECAVA

363

The excessive encumbrance to the heart of the sclerosed areas just pointed out had produced a compensatory h3'pertrophy of the remainder of the heart, although perhaps not to the degree one should expect. The ventricles were somewhat dilated, their muscular walls were correspondingly thick, and the beginning of the aorta was at least twice as wide as in the normal individual. Besides the pathological features already pointed out, the intimai

pulmonary veit\ left eiii'ium

Inferior vent, cftva

mouth of coi"onM>y sinus

iricuspid valve

Fig. 1 Semischematic sketch of the right upper portion of the heart, showing one half of the right atrium cut away and illustrating that part of the massive sclerosed thrombus, situated between the orifices of the venae cavae and occluding most of the atrial chamber. Approximately one-half natural size.

or lining of the aortic arch was beset with numerous rough or thin, scaly, bony patches.^

A section of the sclerosed wall of the light atrium was prepared for the microscope, which showed definitely, according to Professor McJunkin,^ that it represented an organized thrombus.

Besides the sclerotic patches on the inner surface of the aorta, there were also little pits or depressions and small, parallel ridges, which I believe are considered indicative of syphilis. In a fixed specimen, however, such depressions and elevations must be taken with reserve.

' Prof. F. A. McJunkin, formerly of the Department of Pathology, Marquette School of iMedicinc, now of the Department of Pathology, Washington I'niversity Alcdical School, St. Louis.

364 OTTO F. KAMPMEIEU

In structure it displayed dense fibrous tissue which had undergone widespread calcification. There were certain peculiarities v.hicli suggested syjihilitic lesions as a possililo initial cause of the thrombus formation. Perhaps it is more likely, however, that the latter began from a secondary infection of some sort, possibly streptococcic in origin, producing a thrombus which arose on the atrial wall itself, or, carried thither from a distant part of the bod}', became adherent and, gradually growing larger bj' successive depositions of fibrin, eventually blocked the cavity as demonstrated.

The complete closure of the mouth of the superior \ena cava by the atrial thrombus consequently led to extensive modifications in the course and direction of the venous flow from the upper jiarts of the body to the heart, as illustrated in the diagram, figure 2. These changes may be brieflj' summarized as follows: 1) All blood returning to the heart from the body above the diaphragm, except that from the coronary veins, was forced to descend to the abdominal cavity, where it discharged into the inferior vena cava. 2) The direction of the blood stream in the azygos system of veins was the exact reverse of that in the normal body. The.se points are expressed in the diagram (fig. 2) by arrows.

Much of the venous drainage of the head and arm flowed directly into the azygos and hemiazygos veins through the anastomoses of the right and left supreme intercostal and accessor}' hemiaz\'gos veins with the innominate and vertebral veins. The remainder passed into the superior vena cava, but being unable to enter the right atrium on account of the occlusion of its orifice, it was deflected into the mouth of the azygos vein. From here this blood stream, in conjunction with that coursing through the right supreme intercostal, continued downward in the azygos vein; some of it, however, was turned to the left side through the hemiazygos, thus in direct opjjosition to the normal course of the flow. All blood pa.ssing through the entire extent of the azygos, and most of the blood of the hemiazygos poured via a pair of anastomoses into the interior vena cava innncdiately below the diaphragm and at the level of the entrance of the

V. iueularis exteri ■^ dextr

COMPLETE OCCLUSION OF MOUTH OF PRECAVA

V

365

2rr\a ra

V. subclavia dextra

V. cava superioi V. irvtercostalis suprema dextra

V. azygos

Remnant of right

atrial cavity

V. intercostalis 6 V. cava infei

Diaphragm Vv-hepaticae

Vlumbalis I

V. iliaca communis

V. iliaca externa dextra

•V. iugularls interna J Sinistra

-V.anonyma sinistra

-V. intercostalis suprema sinistra

■Sclerosed thrombus in right atrium

Cor

■V. hemiazygos accGSsopia

V. hemiazygos

— Diaphragnn

V. renalis sinistra

V. lumbalis ascendens

V. sacralis media ■V. hypogastric a

sinistra

Fig. 2 Diagram showing the closed mouth of the superior vena cava and the resultant modifications in the course and direction of the venous blood stream.

3()tt OTTO F. KAMPMEIER

hepatic \-eins. These anastomoses, which when present in the normal individuals are niinutp and relatively vmunportant, had become very mvich distended bj- the demands put upon them. Some of the blood stream of the hemiazygos continued still farther down through the abdominal cavity to emptj' into the inferior vena cava partly through the left renal vein and partly through the left first lumbar vein.

The valves which are usually assmned to be present in the proximal segment of the azygos vein apparently offered no obstacle to the reversal of the vascular current flowing through it. But such valves do not always exist, and \\hen existent are "nicht schlussfiihig,' according to Spalteholtz (Handatlas der Anatomic, Bd. 2). Valves which are unable to close the lumen jjerfectly lose their value in determining the direction of the flow when the caliber of the vessel becomes greatly expanded, as occurred in the case of the azygos under consideration.

Besides the deep and important collateral pathways already mentioned, it is possible that much of the superficial haemal drainage of the thoracic wall, which normally discharged into the axillary, subclavian, and innominate veins through the thoracolateral, internal mammary and other smaller veins, was in this instance absorbed by the thoraco-epigastric and the superficial and deep epigastric veins to be carried to the femoral and iliac veins and thence to the inferior vena cava.

r'

Resumcn pnv pi autor, Edgar D. Congdon.

Un seno paranasal supemumerario.

La cavidad situada niediuliuonte en la regi6n de la fosa incisiva y los canales del mismo nonibre de un adulto, presentaba fomia ovoidea y posei'a una capacidad de unos 3 centimetros. Su pared 6sea no era completa por debajo, mientras que por encima se continuaba con las ca\'idades nasales niediante los cortos canales incisivos.

La foniiaci6n de esta cavidad debe atribuirse probablemente a la fu.si6n inconipleta de los procesos nasales medio y lateral, asf como a la actividad fonuadora de senos del epitelio respiratorio, que ocupa nonnalmente el extreme superior de los canales incisivos en vfas de desarrollo.

Translation by Jo«£ F. Nonidcx Cornell Medical College, New York

author's abstract op this paper issued bt the bibliographic service, november 15

A SUPERNUMERARY PARANASAL SINUS

E. D. CONGDON Department of Anatomy of the Leland Stanford Junior University Medical School

ONE FIGtTRE

The cavity shown in the accompanying figure was found by a student while making a sagittal section of an adult head. It is medially placed and extends upward from the region usually occupied by the incisive fossa. It is of a regular ovoid form, 9 mm. in height, 5.5 mm. in anteroposterior diameter, and its width is 8.5 nmi. if 2 nun. be allowed for the section removed by the saw. Its interior is lined by a smooth membrane which contained a cyst in the right-hand wall 2 mm. in diameter, whose contents was evidently mucoid in nature. A small deposit of similar appearance lay upon the floor of the cavit3\

The bony wall of the space contamed above a pah of symmetrically placed short passageways, one of which opened into each nasal cavity, where their location and contents of nerves and blood-vessels identified them as the upper ends of incisive canals. At the palatine end bone was lacking over an area several millimeters in diameter, but the gap was filled upon either side of the saw cut by the membrane lining the cavity and the layers investing the bone of the palate. No communication into nose or mouth was found.

Upon microscopic examination the lining membrane proved to be largely fibrous, but covered on the inner surface bj' a thin layer of colmiinar epithehmii whose precise structure could not be made out because of maceration.

The frequent presence of abscesses m the alveolar process makes it necessary to consider the likelihood of a i)athological origin of the cavity. The neighbormg bone and teeth seemed sound. The osseous and membranous walls showed no deteri 3G7

368 E. D. CONGDON

oration other than the maceration of the epithelium, and this was judf;;ed to have t!\kon place after death.

The region of the incisive fossae was examined in 128 paired and single maxillae in a search for other cavities similar to the one under discussion. The fossae not infref|uently bear a slight resemblance to it, as they may be deeper than wide and somewhat narroweil at their inferior end. Thej' are, of course, much smaller and usually of slightly irregular outline. Two of the series, however, show a distinct reseml)lance to it in the regularity and roundness of their contour, though they dilTer in being but slightly constricted below. There is a remote possibility, then, that they also may have contained cavities lined with mucoperiosteum.

The continuity of the bony cavity with the incisive canals in our specimen is an indication that it may have been related to tliem in de\elo]iment. Leboucfi ('81) agrees with the observations of Durscj' ('69) and His ('01) whose work was accessible only in references from other writers, that the bony incisive canals surround in the embryo an epithelial tube called the incisive duct wliich is the result of a reopening of a part of the originally free conununication between the spaces above and lielow the i)alatine processes. For a time after the median nasal and the palatine portion of the maxillary processes have fused, the duct, though closed, is represented by an epithelial cord continuous with the lining of the nose and mouth. The lumen of the incisive duct which develops in this cord usually disappears a second time permanently before birth.

It .seems probable that the cavitj' here described had its beginning either in the incisive ducts or the passageway from which they are derived. If it arose from one or both ducts, it must have undergone a subsequent enlargement, and shice it is lined with columnar epithelium which was probably once continuous with the nasal cavity, it would have claim to classification as a paranasal sinus. This inter})retation encounters the difficulty that the connection of the l)ony cavit\- witli linth incisive canals must have been the result of a fusion of their lumina — a process rare in sinus development.

A SUPERNUMKRARY PARANASAL SINUS 869

It is more probable that the cavity came into existence as a result of a failure in the meeting of the median nasal and the maxillary processes in this region so that a single large space remained where the lower parts of the incisive ducts usually developed. If this supposition is correct, both a change in the form and an increase in the size of the cavity must have occurred, since a space left between three rounded processes would not have an ovoid form and it could not have equalled in size this cavity of the adult bone. A possible difficulty for either explanation is that the columnar epithelium extends close to the

Right half of siuus at (a) exposed bj- a median sagittal saw cut. X 1

oral surface of the maxilla, while Leboucq found that it gave wa.y in the incisive ducts to the pavement type midway in their course. The exact position of the boundary line is probably not significant, however, since the corresponding transition zone also varies considerably in the luisopharviix.

Works upon j)alatiiie malformations and upon the development of the incisive ducts were consulted, including Leboucq ('81), Merkel ('92), Le Double ('9G), and His ('01), without finding any reference to a cavity in this region. The studies of the paranasal sinuses by Zuckerkandl ('82), Gruber ('SS), Onodi ('07, 'OS), Underwood ("07), and Sliaeffer ('10 and '10 a) do not de

.'{7(1 K. I). CONflUON

scribe a sinus here. Ilicic is a siiifilc iccorii i>| a similar caxity hy Meyer ('13).

In l>is specinuMi tiic ]i(isitii)ii was also inetliai ami the bony wall connected with the osseous enclosincs of the nose by short incisive canals, but there was no connnunication with the oral cavity. The tiiniensions of the cavity were so considerable (l.ti mm. X 1.3.") mm. x 2:2 mm.) that the walls were flattened apainst various areas of the surrounding compact bone, givinp; it decidedly the a])pearance of a siiuis. A smooth lining membrane was present. Xo openinti into nose nr niDulii was fdund. I'rofcssor Meyer concluded that it was a ])aranasal siims in a very umisual situation and called attention to I'nderwood's description i'()7) of a sinus similarly ])laced in the chimpanzee.

The characteristics of the cavity found by Professor Meyer and of the subject of the preceding description are so similar that in the writer's opinion the two must have had a similar origin. The dimensions of the cavity in Professor Meyer's specimen are much greater than ))ossible for an unmodified gaj) left In- the medial nasal and maxillary |)roce.s.ses. The jjrobable independence of the two from the nasal cavity at all .stages of their ilevelojjmental history sets them ajiart from the paranasal sinuses more in apjiearance than in reality since the evidence points to their origin from a membrane that was once at least in continuity with ihc nasal lining and similar to it in character.

A SUPERNUMERARY PARANASAL SINUS 371

LITERATURE CITED

DuRSEY, E. 1869 Zur Entwicklungsgeschichte des Kopfes. Tubingen.

His, \V. 1901 Beobachtungen zur Geschichte dor Xasen- und Gaumenbildung beim menschlicben Embryo. Abt. med.-phys. Kg'l. Sachs. .\kad. Wiss. Bd. 27.

KiLLiAX, G. 1904 The accessory sinuses of the nose. Jena.

Leboucq, H. 1881 The canal naso-palatin chez rhomme. Arch, de Biol., T 2

LeDouble. A. 1906 Traitfi des variations des os de la face de I'homme. Paris.

Merkel, F. 1892 Jacobsonsches Organ und Papilla palat. beim Menschen. Anat. Hefte., erste Abt.

Meter, A. W. 191.3 Spolia Anatomica, Part 4. Jour. Anat. and Physiol., vol. 48.

OxoDi, A. 1907 Beitrage zur Keuntniss der Xasennebenhohlen. Arch. f. anat. Physiol., Anat. Abt. 1908 Nebenhohlen der Xase. Wien.

ScH.\EFFER, J. 1910 The sinus maxillaris and its relations in the embryo, child, and adult man. Am. Jour. .\nat., vol. 10. 1910 a The lateral wall of the cavum nasi in man with especial reference to the various developmental changes. Jour. Morph., vol. 21.

UxDERWOOD, A. 1909 .\n inquiry into the anatomy and pathology of the maxillary sinus. Jour. Anat. Physiol., vol. 44.

Zdckerk.^xdl, E. 1882 Normale und pathologische .A.natomie der Nasenhohle und ihre pneumatischen Anhange. Wien.

THE AN.VTOMICAL RECORD, VOL. 19. NO. I

Resiiinen por el autor, Clarence Lester Turner. Colegio Wooster.

Un medold do eora de uii enibri6n humano en el estado

presomitico.

Kl onihri6n descrito en el presente trabajo es un embri6n humano nonnal en el estado que precede a la aparici6n de los somitas. El autor le designa con el nombre de "6vulo de Mateer", en honor del Dr. H. N. Mateer, de Wooster College, quion le obtuvo y conserv6.

El embri6n mide pr6xunamente un milimetro de longitud, y presenta en buen estado de conservaci6n el disco enibrionaiio, amnios, corion saco vitelino y pedunculo del cuerpo. Es sumamente notable por estar contenido en un 6vulo que tambien enoierra im embri6n gemelo en \nas de degeneraci6n.

La serie de dibujos, trazados con ajiida de la ctimara clara, cjue aconipana al texto representa los contornos de todos los cortes, que pasan por el disco embrionario, amnios, saco vitehno, alantoides y pedunculo del cuerpo. Los cortes median 10 micras de espesor, y los dibujos los ropresontan aiunentados oO dianiotros. Si dichos dibujos so aumontan al doble de su tamano mediante la proyecci6n o la fotograffa, pueden trazarse sobre placas de cera de un milfmotro do espesor, y el modelo asi obtenido representani una rescontrucci6n aunientada uniformemente 100 diiinietros en las tres dimensiones.

Tranaljitifin by .Itn*^ F. Nonidti Cornell MMliral Colir(c, New York

althor's abstract of this paper issued bv the bibliographic service, november 1

A Wax Model Of A Presomite Human Embryo

Clarence L. Turner Biological Laboratory of Wooster College

Eighty-One Figures

Introduction

The presomite human embrj'o figured in this article has been fully described bj' Prof. George L. Streeter, of Johns Hopkins University, in a recent monograph ('19) and the twin formation of the same ovum in a shorter article ('19). He has designated the embryo as the Mateer Embryo after Doctor H. N. Mateer, of Wooster, through whose efforts it was preserved. It is not the purpose of this paper to attempt to repeat any of the work done, but to present a series of drawings representing all the sections through the embryo and the yolk sac. Such a series of drawings makes it possible for every laboratory in which the wax-plate reconstruction procesg can be carried out to have a model of this embryo for study. The series should also prove of value to classes in embryology, even though the plane of sectioning is verjr obhque.

The writer is greatlj' indebted to Doctor Mateer, the owner of the embryo, for a loan of the specmien and for his generous consent in peiTnitting this series of drawings to be published. Several models were constructed, and this series of drawmgs was prepared in the Biological Laboratory of Wooster College.

THE EMBRYO

The age of the embryo was placed by Doctor Streeter at about seventeen days. The embryonic shield is approximately 1 mm. long and 0.75 mm. wide at its greatest width. Both the embryonic shield and yolk sac are surrounded bj' a thin laj-er of mesoderm and the entire vesicle is attached to the chorion bj' the body stalk. All the sti-uctures, with the possible exception of the allantois, are apparently quite normal.

373

374 CLARENCE L. TURXER

' .1 . Enibnjoii ic sh ieUl

The embryonic shield is oval in shape, but narrows markedly mill liends vontrally in its posterior third. The oval portion is not marked by any iine\eness, but the narrow posterior third is traversed longitudinally by a shallow primitive groove. At the ]i(Miphery of the shield the ectoderm is continuous, becoming thin and folding over dorsally to fonn the anmion.

B. Amnion and amniotic cavilij

The hne of demarkation between the embryo and the amnion is difficult to distinguish in nianj- of the sections, but the amniotic ectodenn is very thin and is overlaid by mesodenn which binds it loosely to the overlying chorion. Owing to the oblique plane of sectioning, an exaggerated impression of the depth of the amniotic cavity is gained from figure 16. The cavity appears in the reconstruction as a mere cleft except at the extreme posterior end where it comes into contact with the body stalk.

C. Body stalk and allantois

The body stalk, occurring at the posterior end of the yolk sac, is a fairly comixict mass of mesoderm attaching the entire vesicle to the chorion (fig. 22, BD.S.). A few loose strands of mesoderm extend from the body stalk to the chorion, and at one point near the chorion the body stalk is interrupted by a large cavity. Some primitive blood-ves.sels are found also in the body stalk, but no attempt has been made to represent them in the drawings.

The allantois at its proxhnal end appears as an evagination of the yolk entodenn and within the next few sections become? a compact round column of cells. The proximal portion of the allantois tenninates abruptly and no trace of it can be found for a few sections after which it reappears as a detached segment. In the reconstruction this detached segment shows a marked constriction.

A WAX MODEL OF A PRESOMITE HUMAN EMBRYO 375

D. Yolk sac

The yolk sac is much flattened dorsoventrallj' although its probable nonnal shape was nearly spherical. As the chorionic vesicle is also flattened in the same direction, it seems likely that both chorion and j'olk sac were flattened by their own weight prior to fixing. On the ventral and posterior surfaces of the yolk sac are numerous blood-islands.

E. Chorion

There are two layers present in the chorion, an inner mesodermal layer, which is loose m texture but distinct, and an outer and more compact ectodermal layer. Chorionic villi are attached to the chorionic membrane at intervals. The same laj^ers appear m the villi that'are present in the chorionic membrane, the \-entral mass consisting of the mesodermal element and the outer layer a covering of ectoderm. A syncytial and an epithelial layer may be distinguished in the ectoderm, but thej^ have not been shown in the figures.

F. Twin vesicle

In figure 30 there occur between the large embryo and the chorionic membrane two smaller vesicles which pro\-e to be parts of a second smaller embrj^o evidently undergoing degeneration. In the larger of these two smaller A'^esicles a sphere of ectoderm surrounded by mesoderm can be distinguished. The ectodermal sphere enclosing an amniotic cavitj- is thickened on one side to form the embryonic ectoderm, while the remainder forms an amnion. The second and smaller vesicle is apparently the degenerating yolk sac of the small twin embryo. Both vesicles are loosely bound to the body stalk and to the chorion by strands of mesoderm.

CONSTRUCTION OF MODEL

The plane of sectioning is represented by the line AB. The sections were made 10 ^ thick. A few sections were irregular in thickness or were lost, a nmnber hdve been twisted and a few

376 CLARENCE L. TURNER

broken into fragments. However, by taking the perfect sections as guides, the imperfect sections may be made to confonn to the shape as indicated in the perfect sections. With these few exceptions, the sections are in good condition. All the drawings in this series were made with a camera lucida and all the imperfections are figured as they occur in the sections.

.1 . Irregularities

The more outstanding irregularities are Hsted here with the expectation that they will prove useful for corrections during the construction of a model. The irregularities were checked by making a dupUcate set of drawings with carbon paper, usmg one set for the construction of the model and carefully marking the necessary alterations on the other set of drawings.

Section 2 to section 9. The amnion on the right side has collapsed or has been pushed in.

Section 3 to section 1 5. There is a shrinkage of the mesoderm on the left side of the embryo between the embryonic disk and the jolk sac.

Section 5 to section 17. An indentation hi the right side of the yolk sac and the overlying mesodenn is evidently an artifact.

Section 3 to section 20. The embryonic disk is cracked in most of these sections and in a few the parts have suffered a slight displacement.

Section 14 and section 15. Two sections have apparently been lost between these two.

Section 17. This one is 40 n thick instead of 10 p thick.

Section 16 and section 17. The left half of the emljryonic disk is bent vent rally so as to be out of adjustment.

Section 23. There is a lateral compression m this section which distorts it somewhat. The foregoing section may be taken as a guide.

Section 24. As in section 23.

Section 30. The yolk sac membrane and the overlying mesodenn are .shrunken and distorted.

Section 32 and section 33. These are somewhat broken and

A WAX MODEL OF A PRESOMITE HUMAN EMBRYO 377

the pieces displaced, but the general boundaries of the sections are still evident.

Section 34. The ventral half of the yolk sac has been dislocated toward the left.

Section 35. There are two slight breaks in the walls of the yolk sac.

Section 37. This section is 20 m thick.

Section 40. The walls of the A'olk sac are broken at the ventral point and are shifted toward the left in the ventral half.

Section 42. The sides of this section are somewhat compressed.

Section 46. This section is bent toward the left in its ventral half.

Section 47. The sides of this section are slightly compressed and the lower half is dislocated toward the left.

Section 48 and section 49. Several sections are missing between these two.

Section 50 to section 81. There are many slight irregularities in the shape of the yolk sac, but the shape may be made out by using the following sections as of normal shape: sections 58, 61, 63, 68, and 73.

B. Magnification

The sections have been cut 10 // in thickness so that a magnification of 100 would make the wax sheets 1 nmi. in thickness. In the illustrations in this article a magnification of 100 has been used, but the drawings have been reduced one-half for publication. It is suggested that they be stepped up to their original size (twice as large as represented here) when wax sheets of a thickness of 1 mm. may be used.

C. Modeling

A model such as the one illustrated in plate 1 may be constructed by the usual Boms' wax-plate method. A more substantial model which may be handled by students may be constructed by substituting blotting-paper soaked in equal parts of beeswax- and soft paraffin for wax sheets.

378 CLARENCE L. TURNER

The structures which sen-e best as guide lines in building the model are the bod\- stalk and tlio allantois. The posterior margin of tlie anuiiotic ca\ity can also l)e used to ad\antagc.

BIBLIOGRAPHY

Strekter, CiEO. L. 1019 A humun embryo (Matcer) of the prpsomitc perinrl. Contributions to embryology, vol. 9, Carnegie Inst. Wash. Pub. No. 272.

1919 Formation of single ovum twins. Johns Hopkins Hospital Bulletin, vol. 30, no. 342.

A WAX MODEL OF A PRESOMITE HUMAN EMBRYO

379

EXPLANATION OF PLATE AND FIGURES

Plate 1. Model, X 50, representing the amnion cut away on the right side exposing the embryonic shield and the amniotic cavity. The body stalk is represented as bisected to show the allantois. The mesoderm overlj-ing the yolk sac is represented as cut away on the right side to expose the yolk sac.

Figs. 1 to 81 This is a series representing all the sections of the ovum in the plane of A B (pi. 1).

ABBREVI.iTlONS

.\LL., allantois .\M.C-'., amniotic cavity AM., amnion BD.S., body stalk CH.MES., chorionic mesoderm CH.ECT., chorionic ectoderm PR.GR., primitive groove PR. ST., primitive streak PR.KT., primitive knot MES., mesoderm EMB.D., embryonic disk

Y.S., yolk sac

BL.IS., blood-island

CH.V., chorionic villus

TW.V., twin vesicle

EMB., posterior portion of embryo

Y'.S', yolk sac of twin

AM.C.TW'.V., amniotic cavity of twin

vesicle EMB.ECT., embryonic ectoderm of

twin vesicle

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THE

ANATOMICAL RECORD

EDITORIAL BOARD Irving Hardestv Warren H. Lewis

Tulane University Johns Hopkins University

Clarence M. Jackson Charles F. W. McClure

University of Minnesota Princeton University

Thomas G. Leb Wiluam S. Miller

University of Minnesota University of Wisconsin

Frederic T. Lewis Florence R. Sarin

Harvard University Johns Hopkins University

George L. Streeter

University of Michigan

G. Carl Huber, Managing Editor

1.130 Hill Street, Ann Arbor, Michigan

VOLUME 20 DECEMBER, 1920— MARCH, 1921

PHILADELPHIA THE WISTAR INSTITUTE OF ANATOMY AND BIOLOGY

CONTENTS

NO. 1. DECEMBER, 1920

George S. Huntixgtox and Charles F. W. McClure. The development of the veins in the domestic cat (Felis domestica), with especial reference, 1) to the share taken by the supracardinal veins in the development of the postcava and azygos veins and, 2) to the interpretation of the variant conditions of the postcava and its tributaries, as found in the adult. Twelve figures (in colors) 1

E. V. CowDRY. Anatomy in China. One illustration 31

Eugene L. Settles. The effect of high fat diet upon the growth of lymphoid tissue. Sixteen figures (three plates) and one chart 61

Ivan E. Wallin. A case of persistent left supracardinal vein with two left spermatic veins. One figure 95

NO. 2. JANUARY, 1921

E. T. HsiEH. A review of ancient Chinese anatomy. Thirty-one figures 97

Oliver H. Gaebler. Bladder epithelium in contraction and distention. Xine figures. 129 Walter N. He.ss. Tracheation of the light-organs of some common Lampyridae.

Ten figures 155

Proceedings of the American Society of Zoologists. Eighteenth .Annual Meeting 163

Proceedings of the .\merican Society of Zoologists, .\bstracts 181

Proceedings of the American Society of Zoologists. Constitution, etc 233

Proceedings of the .\merican Society of Zoologists. List of Officer.s and Members 237

NO. 3. FEBRUARY

Juan C. NaSagas. Two cases of monoventricular heart with atresia and transposition of some of the roots of the great vessels. Eight figures (two plates) 255

H. E. Jordan. Further evidence concerning the function of osteoclasts. Five figures. 2S1

Paul K. Webb and J.\mes Barrett Brown. A case of independent costal bars of the epistropheus in man. Two figures 297

Vincent Vbrmooten. A study of the fracture of the epistroi)heus due to hanging with a note on the possible causes of death. Twelve figures 305

P. E. LiNEBACK. A case of unilateral Polydactyly in a 22-nini, embryo. One figure 313

iii

IV CONTENTS

NO. 4. MARCH

llELF.y Dean Kino. A comparative study of the birth mortality in the albino rat and in man 321

D.wiD M. Sii'KH.sTF.iN. The efTccts of acute and chronic inanition upon the development and .structure of the testis in the albino rat. Five plates (fourteen figures). . . . 355

Bk.\dley M. Patten and Rees Philpott. The shrinkage of embryos in the processes preparatory to sectioning. Eight figures 393

Charles H. Miller. Demonstration of the cartilaginous skeleton in mammalian fetuses 415

Alexander Gibson. Note on a persistent left duct of Cuvier. One figure •. . . 421

4

THE ANATOMICAL RECORD, VOL. 20, NO. 1, DECEMBER. 1920

Resunien por los autores, George S. Hiintiiigtnn y

Charles F. W. McClure,

Columbia University y Princeton University-.

El desarrollo cle las venas en el gato dom^stico (Fells doniestica), con especial nienci6n de: 1) la participaci6n de las venas suiiracardinales en el desarrollo de la postcava }■ vena azigos, y 2) la interpretaci6n de las condiciones de variaci6n de la postcava y sus tributarios encontradas en el adulto.

Esta investigaci6n fu^ comenzada en 1905 con el prop6sito de fleterininar el plan \enoso outog^nieo normal que servirfa como base ])ara cxiilicar las vanaciones observadas en el gato adulto como resultatlo de un tlesarroUo atipico de las venas. Kl trabajo vii ilustrado con doce figuras en colores, basadas en reconstnicciones en cera. y dichas figuras serviran tanibien para explicar las condiciones observadas por los autores en el hombre. Algunos de los puntos mas importantes tratailos por los autores son los siguientes: 1. l.a divisi6n postrenal de la vena postcava se deriva exclusivamcnte de una parte de las venas subcardinales. partir endo del lado derecho de lo cjuc los autores han llaniado el cuello renal, y de las venas supracardinales. Ninguna parte se deriva principalmente de las venas postcardinales. 2. Las venas azigos se tlerivan de las supracardinales. 3. Una nueva interpretaci^n sobre el desarrollo de las venas sexuales. 4. Un esfjuenia compuesto (jue presenta combinados todos los trayectos venosos (pie jjueden aparecer tlurante la ontogenia. Pi>r medio de este esipiema se pueden interpretar los diecisiete tipos en los cuales pueden clasificar.se las variaciones de la postcava encontradas en el gato y en el hombre.

Translation liyJcK^ K. \oni<l(-s Carnrll .Mrdiml Collrse. Npw Voric

AirnORS ABSTRACT OF THIS PAPER ISSUED BY THE BIBLIOGRAPHIC SERVICE, NOVEMBER 15

THE DEVELOP.MEXT OF THE VEINS IN THE DO.AIESTIC CAT (FELIS DOIMESTICA) WITH ESPECIAL REFERENCE, 1) TO THE SHARE TAKEN BY THE SUPRACARDINAL VEINS IN THE DEVELOPMENT OF THE POSTCAVA AND AZYGOS VEINS AND 2) TO THE INTERPRETATION OF THE VARIANT CONDITIONS OF THE POSTCAVA AND ITS TRIBUTARIES, AS FOUND IN THE ADULT

GEORGE S. HUNTINGTON Columhia University

AND

CHARLES F. W. McCLURE Princeton University

TWELVE riGUHES (iN COLORS)

This investigation was begun in 1905. In the preceding years we had found that the variations or atypical conditions of the venous system observed by Darrach,' McClure^ and others in the adult cat could not all be explained on the basis of the existing knowledge of the development of the veins. We therefore determhied to study in detail the normal ontogenetic plan of the veins in the cat, with the hope that we might be able to interpret correctly the variant conditions of the venous sj^stem which arose as the result of atypical development of the veins.'

We have recently extended our observations to a study of the development of the veins in man, the pig and the rat, and while

' Darrach, W. 1907. Variations in the postcava and its tributaries as observed in 605 examples of the domestic cat. Proc. Amcr. .\ss. Anat., .■^mer. Jour. .\nat., Vol. 6.

- McClure, C. F. W. 1900. On the frequency of abnormalities in connection with the postcaval vein and its tributaries in the domestic cat (Felis doraestica). Anier. Xat., Vol. 34.

^ Huntington, G. S., and McClure, C. F. W. 1907 The Development of the Postcava and Tributaries in the Domestic Cat. Proc. .\mer. .\ss. .\nat., .Amer. Jour. Anat., Vol. 6.

1

2 GEORGE S. HUNTINGTON AND CHARLES F. W. MrCLURE

it has been observed that important generic differences exist in the pig and the rat, the development of the veins in man has been fi)und to resemble more closely that observed in the cat.^

Although our investigation has been completed, it may be some time before the detailed publication is ready for the press. We have therefore deemed it advisable to publish a preliminarj'^ summary of our work in the form of a series of diagrams which illustrate the nonnal ontogenetic plan followed by the veins, with especial reference, however, to the shaie taken by the supracardinal system of veins in the development of the azygos vein and of the postrenal division of the posteava in the cat. A brief summary is also given of the potential postcaval variants in the adult cat and man. An explanation of these variant conditions is based on a composite diagram (fig. 12) combining all of the \'enous pathways which may arise during ontogeny and which are potentially capable of being retained in the adult in atypical individuals.

The diagrams which we present are based on a large series of wax reconstructions made after the method of Bom, of cat embryos ranging between 5 and 45 millimeters in length. They represent a series of critical ontogenetic stages leading from the early primitive \'enous groimdjilan common to all vertebrates (fig. 1). up to the conditions obtaining in the adult cat.

In constructing these diagrams it was deemed desirable to include all of the main axial venous channels of the body other than those investigated by us, and we fully appreciate and acknowledge that the previous contributions of other investigators, esjx'cialiy those of Hathke," Ilochstetter^ and F. T. Lewis,' have made this possible.

' Huntington, G. S. and McClure. C. F. \V. 1920. A scries of diagrams explanatory of the development of the posteava in the cat, with especial reference to the .share taken by the siipracarilinal system of veins. I'roc. Amer. .\ss. Anat., Anat. Kec, V<il. 18.

» Kathkc, H. 1838. Uebcr den Bau und Entwicklung dcs Venensystcms der Wirbeltiere. Dritte Bericht iiber das Xatur»vissensrhaftlichc Seminar zii Kcinigsberg. Idem. 1832. Abhandlungen zur Uildnngs-und ICiitwickliing.igesi'hichtc des -Menschen und der Thiere. Leipzig, T. I.

Hochatctter, F. 1893 Heitnige zur Entwickelungsgcschichte ilea .\mnioten, III, Siiuger, Morph. .lahrb., Ud. 20.

' I>ewis, F. T. 1902 The development of the vena cava infcrinr. Amer. Jour. Anat., VoL I.

DEVELOPMENT OF POSTCAVA IN THE CAT 6

The uniform color scheme shown in the figures makes it easy to follow the transformations of the embryonic venous system through the different stages of its development. Only a brief account of each critical stage will be given in the present paper, while a more detailed description will be reserved for a later publication in which the actual reconstructions will be demonstrated on which our observations have been based.

Fig. 1. Cardino-Subcardinal Stage.

This stage of development may be regarded as representing a common groundplan of the vertebrate embryonic venous system. It forms the starting point which is succeeded by a series of modifications gradually leading up to the conditions observed in the adult. In some cases these modifications are brought about by the persistence or atrophy of certain of its component vessels, while in others, modifications arise by the addition of newlyformed vessels to the primary groundplan. The diagrams we present illustrate these modifications of the embryonic groundplan as observed in the embryo of the cat.

The principal vessels of the embryonic venous groundplan consist of three pairs of essentiallj' bilateral symmetrical veins, viz. : the precardinal {Pre.) and postcardinal {Pc.) veins which open in conmion into the sinus venosus through the ducts of Cuvier (D.C.) and the subcardinal (Subc.) vehis. The postcardinal veins lie dorsal to the mesonephroi, while the subcardinals lie ventro-medial to the same. Anastomoses between the postcardinal and subcardinal veins are present and intersubcardinal anastomoses are met with caudal to the origin from the aorta of the omphalomesenteric artery.

The sex veins from the gonads (G) open into the subcardinal \-eins at this stage. The veins of the liver drain for the most part directly into the sinus venosus through the V. hepatica comnmnis (V.H.C.) and no connection between the liver circulation and the right subcardinal vein has as yet been formed.

The blood collected from the body-walls and mesonephroi by the postcardinals, as well as that carried by the subcardinal veins, is returned to the heart through the ducts of Cuvier (D.C.) in conmion with that brought from the head region and anterior limb-buds by the precardhial veins.

4 oeorge s. huntington and charles v. w. mcclure

Fig. 2. Establishment of the Pars Hepatica and Pars subcardinalis of the postcava, constituting the prerenal Division ok the Postcava in the Adult.

The significant features of this stage of development, are the estabUshment of the prerenal division of the adult postcava, and the beginning replacement of an originally bilaterally s}^nmetrical by a subsequent asymmetrical plan of axial venous organization.

As shown by F. T. Lewis, the prerenal division of the jwstcava is formed by the establishment of a communication between the veins of the liver and the right subcardinal vein. The point at which this communication is established with the right subcardinal has been previously designated by one of the writers' as the hepato-subcardinal junction (Hep.SubcJcl.).

The portion of the prerenal division of the postcava whicli lies cranial to the hepato-subcardinal junction may be termed the pars hepatica (P. Hep.). It is formed in situ by a rearrangement and transformation of vascular channels already formed, viz., by the V. hepatica communis, the hepatic sinusoids and by the vascular area formed within the caval mesentery.

The portion of the prerenal division of the postcava which lies caudal to the hepato-subcardinal junction is known as the pars subcardinalis (P.Subc.), as it is formed largely bj' a portion of the right subcardinal vein. Slightly caudal to the origin of the omjjhalomesenteric artery from the aorta, the pars subcardinalis establishes a wide communication with the left subcardinal, through an intersubcardinal anastomosis (Int.Snbc.Aiiast.) and also one with each postcardinal, by the enlargement of one of the anastomoses that exist at this level between the intersubcardinal anastomosis and the postcardinal veins (subcardino-post cardinal anastomoses, Subc.Pc.Aiiast. (fig. 12)).

As the result of these modifications of the early embrj'onic groundplan, the blood from the region of the body which lies caudal to the intersubcardinal anastomosis (body-walls and mesonephroi) is now, for the most part, directed from the postcardinal {Pc.2), on both sides of the body, through the subcardino-post • McClurc, C. F. W. 1!K)0 A contribution to tho anatomy and development of the venous system of Didclphys marsupials (L.;. Amer. Jour. Anat., Vol. 5, p. 171. 1

DEVELOPMENT OF POSTCAVA IX THE CAT 6

cardinal anastomosis to the prerenal division of the postcava. Also, correlated with these changes, the post cardinals (Pc.2), caudal to the intersubcardinal anastomosis, become greatly enlarged, while the segments cranial {Pc. 1) to this anastomosis become reduced and return blood from the bodj'-walls of the thoracic region and from the cranial end of the mesonephroi directly to the heart bj^ the ducts of Cuvier (D.C).

The sex veins still open into the subcardinal veins. Anastomoses are also still present between the subcardinal and post cardinal veins, caudal to the intersubcardinal anastomosis, which form part of the mesonephroic circulation. In the region cranial to the intersubcardinal anastomosis, however, the subcardinals soon become associated with the anlagen of the adrenal bodies forming the main venous drainage line of these organs which is retained throughout subsequent stages of development.

Fig. 3. Further Transformations of the Postcardinal AND Subcardinal ^'eins Which are Associated Largely with the Growth of the Mesonephros.

Separation of the Postcardinal Veins into a Thoracic AND Lumbar Division.

The originally continuous postcardinals have now become di\ided into a cranial or thoracic (Pel), and into a caudal or lumbar (Pc.2) pair of veins. The former collect the blood chieflj' from the body-walls of the thorax and from the anterior portion of the mesonephroi, while the latter drain the more caudal regions of the body.

The lumbar division of the postcardinal (Pc.2), on each side of the body, now encircles the relatively large mesonephros, both dorsally and medially, so that in reconstructions of the veins at this stage each mesonephros appears to be arched over by or to lie within a great venous basket or trough formed by the postcardinal vein and its subcardinal anastomoses.

The peiTnanent kidneys (K) have migrated craniad from their earlier position ventral to the umbilical arteries and now occupy a position dorsal to the lumbar postcardinals (Pc.2).

Cranial to the intersubcardinal anastomosis (Int.Subc.Ancisi.) the subcardinal veins, except that portion of the vein of the right

6 r.EORGE S. HUNTINGTON AND CHAKLES V. W. McCLURE

side which forms tho pars suhcardinalis of tho iiostcava (P.Subc), have become still more closely associated with the adrenal organs so that from now on, we may speak of these veins as the adrenal veins (Adr.). Caudal to tlie intersubcardinal anastomosis the subeardinal veins have lost their original continuity so that the sex veins, of subeardinal origin, now drain directly into the postcardinals {Pc.2), as well as into the intersubcardinal anastomosis. The significance of this observation lies in the circumstance that the sex veins at this time are exclusively of subeardinal origin, a condition which is retained in the adult of lower vertebrates, up to and including birds.

Fig. 4. The Establishment of the Supracardinal System OF Veins and the Renal Collar.

.\ bilateral and originally symmetrical venous channel deAelops dorso-medial to the jmmitive post cardinal and dorso-lateral to the aorta, into which the somatic post cardinal tributaries secondaiily drain. This secondary venous channel forms what we have termed the Snpracardiual Syste7n of Veins (Sprc). It extends, from the level at which the posterior limb veins unite with the postcardinals, to a point craniad where it joins that portion of the postcardinals (Pel) which alone persists to form the cranial end of the adult azygos (-42.) veins. Between these levels the su]nacardinal veins come to enter into the definite organization of both the adult postcava in its postrenal division and of the azygos in its lumbar and part of its thoracic segments, entirely replacing in these districts the primitive postcardinal veins.

"It is important to note that the supracardinal veins are not in any sense merely sjiionyms for the dorsal limb of the periureteric ring described by Ilochstetter and others, but comprise a continuous morphologically uniform system of longitudinal venous channels which contribute to the establishment of the adult condition in both the postcaval and azygos areas."'

The beginning of the establishment of the supracardinal sj-stem of veins takes i)laco at a rclati\ely early stage of development, and its cranial extension into the thoracic region is evidence that its appearance is not primarily associated with the cranial migration of the pennanent kidneys. Frcfiucnt anastomoses occur

' Loc. cit., footnote .^.

DEVELOPMENT OF POSTCAVA IN THE CAT 7

between the postcardinals and supracardinals at an early stage of development and, at this time, the anastomoses between the right and left supracardinal veins fintersupracardinal anastomoses), as shown in figure 4, have not yet been formed.

The early anastomoses between the supracardinal and postcardinal veins soon undergo atrophy and disappear. A large single anastomosis (fig. 4, R.CoI.), at about the level of the intersubcardinal anastomosis, is retained, however, on each side of the body, which permits blood collected by the supracardinals in the lumbar region to reach the heart by way of the prerenal division of the postcava. Tliis anastomosis we have designated as the subcardino-supracardinal anastomosis (R.CoL, fig. 4), since, in the later stages, it appears to connect the subcardino-postcardinal anastomosis with the supracardinal vein.

The blood collected by the supracardinal veins which is not directed to the prerenal segment of the postcava through the subcardino-supracardinal anastomosis, reaches the heart by way of the ducts of Cuvier (D.C.).

The formation of this subcardino-supracardinal anastomosis, at about the level of the intersubcardinal anastomosis, establishes the presence of a circum-aortic venous ring at this point which we have designated as the Renal Collar.

In order to appreciate the topographical relations of the renal collar to the main venous channels and the aorta, the reader is referred to fig. 12, a diagram based largety on the reconstruction of a 1() millimeter embryo of the cat. As clearly shown here, the renal collar is formed by the pars subcardinalis of the postca\-a (P.Subc), the intersubcardinal anastomosis (Lnt.Subc. Anast.), the right and left subcardino-post cardinal anastomoses {SiibcPcAnast.), the right and left subcardino-supracardinal anastomoses (SitbcSprcAnast.) , the right and left supracardinals (B and C) and the anastomoses between the supracardinals dorsal to the aorta at this point, at which level the renal veins (R.V.) enter the collar.

The sex veins (fig. 4) still join the postcardinals and, in some cases, as shown in fig. 3, thej^ may also open into the intersubcardinal anastomosis, a condition which is occasionally retained in the adult when multiple sex veins are present.

8 geokge s. huntington and charles f. w. mcclure

Figure 5. Progressive Development of the Bilateral, Symmetrical System of Supracardixal Veins.

Separation of the Supracardinals into an Azygos and Lumbar Division.

Completion of the Cranial ^Iigration of the Permanent Kidneys, the Development of the Renal Veins and the Establishment of the Periureteric Venous Rings.

The supracardinal veins (Sprc.) at first undergo a progressive development during which their bilateral symmetry is retained for a considerable period of time. They soon separate, however, into a cranial or azygos and into a caudal or lumbar pair of veins, from which the azygos veins and a segment of the postrenal division of the adult postcava are, rcsj)ecti\ely, derived.

The bilateral symmetrical pair of supracardinals in the lumbar region anastomose freely with each other dorsal to the aorta and become greatly increased in size. Blood which they receive from the bod}--walls through four pairs of dorsal tributaries, and that received by them from the external (£?./?.) and internal iliac (/./Z) veins, now roaches the prerenal segment of the postcava exclusivelj' through the right and left subcardino-supracardinal anastomoses (lateral portion of renal collar, R.Col. fig. 5), which have become correspondingly enlarged.

Blood collected by the supracardinals in the thoracic region (azygos veins), chiefly from the bodj'-walls, is returned to the heart through the right and left ducts of Cuvier {D.C.), in common with that collected from the head region and anterior limbs by the precardinal veins.

The permanent kidneys (K) have completed their migration craniad, and the hilus of each kidnej' now lies at about the level of the renal collar (fig. 12). After the migration of the kidneys has been comiilcted, the permanent renal veins (R.V.) are formed. These consist at first of a right and left pair of renal veins which extend between the hilus of each kidney and the lateral portion of the renal collar (li.W, fig. 12).

The relation of the renal veins to the lateral portion of the renal collar (subcardino-supracardinal anastomosis) is shown in figs. 8 and n which arc lateral views of the right side of actual recon

DEVELOPMENT OF POSTCAVA IN THE CAT 9

structions of the veins of cat embryos measuring, respective!}', 16 and 25 mm. in length. Near the hihis of the kidney, each renal vein divides into two branches (fig. 5) and, in some cases, the bifurcation may even extend back to the renal collar.

The primitive postcardinal veins {Pc.3, fig. 5) still retain their bilateral sjnnmetry. They unite caudally with the supracardinals in the lumbar region and, in addition to blood received from the mesonephroi and gonads, they also receive, in part, that collected by the external (E.Il.) and internal iliac (I.Il.) veins. Craniad, the postcardinals (Pc.2) also unite with the supracardinals (Sprc.) through the subcardino-supracardmal anastomosis (lateral portion of renal collar, R.Col., fig. 5) so that the blood collected bj' the supracardinals and postcardinals in the liimbar region is then conveyed to the prerenal division of the postcava, on each side of the body, through the original subcardino-postcardinal anastomoses {Subc.Pc.Anast., fig. 12) which constitute the ventral portions of the renal collar. (Compare figs. 5 and 12.)

As the result of tliis cranial and caudal union in the lumbar region between the postcardinal and supracardinal veins, a venous ring has been established on each side of the body, through which the ureter (Ur.) passes. This periureteric venous ring is bounded cranially by the caudal border of the subcardino-supracardinal anastomosis (R.Col.. figs. 5 and Sand Subc.Sprc.AnasL, fig. 12), dorsally by the supracardinal and ventrally by the postcardinal vein. In the region of the renal collar the ureter (fV.) lies dorsal to the postcardinal (Pc.2) and sex vein, while further caudad it passes \-entral to the postcardinal vein.

Final Transformations of the Veins (Figure 6) Which Lead Up to the Conditions Found in the Adult Cat (Figure 7).

The primary bilaterally symmetrical plan of the supracardinal veins in the lumbar region (fig. 5, Sprc.) is soon replaced by an asymmetrical one (fig. 6) . This change is initiated by a reduction of the left side of the circum-aortic venous ring, involving its supracardinal component and of the portion labelled R.Col., fig. 6, while the corresponding channels of the right side enlarge. This

10 GEORGE S. HUNTINGTON AND CIIAHLES 1\ \V. McCLrRE

rhange is finally followed by the conipletp atrophy of the loft side of the reiuil collar, or strictly speaking, of the suhcanlinosupracardinal anastomosis of the left side.

In Cf)nsequence of this change, the blood collected by the left supra cardinal vein is therefore directed toward the right supracardinal through the intersupracardinal anastomcses and, together with the blood collected by the right supracardinal, now reaches the prerenal tlivision of the postcava by way of the right side of the renal collar. P'ig. (i rejjrescnts a stage in which the left side of the renal collar is undergoing atrophy, while in fig. 7, the left side of the collar has completely disappeared.

While it may be said that the right supracardinal veui is chiefly' concerned in the formation of a portion of the postrenal division of the postca^•a, the supracardinal vein of the left side is also involved. The left supracaidinal (fig. (i) does not, as one might suppose, undergo complete atrophy in niUi, but rather is drawn into or fuses with the vein of the right side, at least in the cadual half of its extent. This portion of the postcava derived from the supracardinals (pars supracardinalis, fig. 7) may therefore be regarded as being formed largely through a fusion of both supracardinal veins, and not from a single vein on the right side, as is usually described to be the ca.se, although the latter furnishes the major contribution.

It has been stated abo\e that after the complete atrophj' of the left side of the renal collar, all of the blood collected by the suj«acardinals in the lumbar region leaches the jirerenal division of the |)ostcava through the right side of the renal collar. One of the most interesting observations we may have made regarding the development of the veins in the cat, is that the right side of the renal collar typically enters directly into the formation of a definite portion of the po.strenal division of the postcava, which we have designated the pars renalis (P. Ren.) of the postcava, on account of its relation to the ejitrance of the renal veins (R.V., fig. 7). The maimer in which this is brouglil about can best be illu.strated by a series of actual recon.structions of the veins which show the relations that the right side of the renal collar bears to

DEVELOPMENT OF POSTCAVA IN THE CAT 11

the prerenal division of the postcava and to the supracardinal and postcardinal veins. The reconstructions referred to are represented by figs. 8, 9, 10 and 11 which are lateral views of the veins of the right side of cat embryos measuring 16, 25, 29 and 45 mm., respectively, in length.

In the 1 6 mm . embryo ffig. 8) it is seen that the right periureteric venous ring is still complete and that blood from the caudal region of the body can reach the prerenal division of the postcava by two routes, viz., by way of the right postcardinal vein (Pc. 3), into which the sex veins open, and by way of the right supracardinal vein and right side of the renal collar. This latter route is the permanent one typically retained in the adult and constitutes the postrenal division of the postcava. In the 16 mm. embryo, from which this figure was drawn, the left side of the renal collar is also intact, so that blood from the left side of the body can also reach the prerenal segment of the postcava through a corresponding set of veins (fig. 5).

In the 25 mm. embryo (fig. 9) both postcardinal veins {Pc.2) have given up their caudal connection with the external and internal iliac veins and the left side of the renal collar has also completely disappeared, so that blood from the hind limbs and lumbar region of the body, now reaches the prerenal division of the postcava solely through the fused supracardinals and the right side of the renal collar. The right postcardinal vein opens into the ventro-caudal border of the renal collar (figs. 9 and 12) and returns blood to the prerenal segment of the postcava, which it receives exclusively from the right mesonephros and from the right gonad through the sex vein.

The venous arch formed by the fused supracardinals and right side of the renal collar, in figs. 8 and 9, is a marked and constant chai-acter of these veins in the earlier stages, a condition, however, which is later changed. This change consists of a straightening out of the arch formed by the supracardinals, and of an actual elongation, in a cranio-caudal direction, of the right side of the renal collar. Fig. 10, of a 29 mm. embryo, shows the renal collar in the process of elongation, while in fig. 11, of a 45 mm. embryo, the elongation has been completed and the collar assumed the

12 GEORGE S. HUNTINGTON AND CHARLES F. W. McCLURE

(■(inditioii ])eiinaiioiitIy rotainod in tho adult. As a result of this elongation, the point at uhieli the right j)ostcardinal (Pc.2) opens into the renal collar becomes gradually shifted caudad, so that the right post cardinal finally opens into the postcava f renal collar) somewhat caudal to the points of orighi of the right renal veins (/?.]•.. fig. 11).

The blood from the right gonad reaches the right postcartiinal through the sex vein of subcardinal derivation. After the complete degeneration of the right mesonephros, the original drainage line of the right postcardinal is occupied exclusively by that of the right sex vein (figs. 8, 0,10, 11 and 7). The original point of connection of the right postcardinal with the renal collar, although shifted caudad, is therefore retained in the adult as the point at which the postcava is joined by the right sex vein. This point, as we have seen, is the ventro-caudal border of the right embryonic renal collar. In figs. and 7, the elongation of the right side of the renal collar is represented as having taken place.

Considerable variation has been found to exist in the adult cat, as regards the relation of the points at which the right sex and the right renal veins oj^en into the postcava. This variation can undoubtedly be explained, in some cases, at least, on the ground that the extent to which the right side of the renal collar elongates in a cranio-caudal direction may diflfer in individual cases. The opening of the right sex vein into the postcava, caudal to that of the right renal vein is, however, now easily exi)lained, on the basis of an elongation of the right side of the renal collar. Furthermore, it is plainly evident that the right postcardinal vein does not, in the slightest degree, as hitherto supposed, enter into the formation of the postrenal division of the postcava which, as tve have seen, is formed hrj the supracardinal veins (P. Sprc.) and by the right side of the renal collar (P. Ren., fig. 7).

As far as the postcava and its tributaries are concerned, there still remain to lie considered further changes regarding the right and left renal veins and the sex \ein of the left side.

It has been stated above that after the migration of the kidneys has been completed, the permanent renal veins are fonned. The.se consi.st at first of a right and left pair of renal veins which

DEVELOPMENT OF POSTCAVA IN THE CAT 13

extend between the hilus of each kidney and the lateral portion of the renal collar (Subc. Sprc. Anast., fig. 12).

The condition which obtains on the right side of the body in the adult, appears to be brought aljout by the persistance of the more ventral of the two embryonic renal veins and the complete atrophy of the other (fig. 7). This single right renal vein then retains its connection with the pars renalis of the postcava which is formed from the right side of the renal collar (fig. 7) .

The relations of the postcardinal vein, into which the sex vein opens, and of the two embryonic renal veins to the renal collar are originally the same on both sides of the body (figs. 5 and 12). When the left side of the renal collar (subcardinosupracardinal anastomosis) atrophies, however, the more ventral of the two embryonic renal veins and the left postcardinal vein continue to retain their connection with the left subcardino-postcardinal anastomosis. The result is that the latter, together with the more ventral of the two embryonic renal veins, then forms the left renal vein of the adult, while the left postcardinal vein, after the complete degeneration of the mesonephros, serves as the pathway through which the left sex vein opens into the left renal vein (compare figs. 6 and 7).

On the basis of their development, the presence in the adult cat of two, three or even four renal veins on the same side of the body is now not difficult to explain. When more than two renal veins are present this condition is undoubtedly related to the extent to which the bifurcation of the original embryonic renal veins is involved.

It has long been erroneously stated in text-books of embryology that the postcardinal veins in the thoracic region give rise to the azygos veins. The history of the development of the azygos veins in the cat is illustrated in figures 3 to 7, inclusive, in which it is shown that they are derived chiefly from the supracardinals and that in the adult cat only the proximal end of the right azygos near the duct of Cuvier, is derived from the postcardinal vein (Pel).

As stated at the beginnhig of this paper the chief object of our investigation was to establish the normal ontogenetic plan

14 GEORGE S. HUNTINGTON AND CHARLES F. W. McCLURE

of thp veins in tho cat, with the hope that we might ho able to interpret correctly the valiant conditions of the venous system which arose as the result of at>'pical development of the veins." On the basis of this investigation we have therefore constructed a composite diagram (fig. 12) of the embiyonic veins of the cat which make their appearance, at one time or another, during the course of ontogeny.

^^'e have already shown in the preceding jiages how some of these embryonic veins function only temporarily and then disappear, while others persist and are carried into the adult stage. A\'hen we meet AVith a venous variant in the adult it is therefore due, in the majority of cases, to the occurrence and persi.stence of some modification of the ontogenetic plan ordinarily followed by the veins, which is carried into the adult. It is also evident when sucli atypical conditions arise, that their explanation lies in the determination of the normal potential enibrj'onic pathways which may have been concerned. Also, if our composite diagram of the embryonic veins is correct, we should not only be able to interpret the atypical conditions already found, but should also be able to predict those which are potentially capable of occurring in the adult cat.

On the basis of this composite ontogenetic plan of the veins we have been able to classify under 17 main Types the variant conditions of the postcava which may occur in the adult cat. We have also found that all of the postcaval variations thus far observed in man by other investigators, as well as by ourselves, can bo classed under these same types.

If we return to the composite diagram (fig. 12) we see that the embryonic veins which typically enter into the formation of the adult postcava are the right supracardinal (B), the right subcardino-supracardinal ana.stomosis [Subc.Sprc.Anasl.), the right subcardino-postcardinal anastomosis {Subc.Pc.Anast.}, the intersubcardinal ana.stomosis I Inl.Siihc.Annst.), the pars subcardinalis il'.Sulic.) and tho i)ars hopatica [P. Hep.) of the postcava.

'• Huntington, O. S. and McClurc. C. F. \V. 1907 The interpretation of variations of the postcava and tributaries of the adult cat, based on their development. Proc. Amcr. Ass. Anat., Amcr. Jour. Anat., Vol. 6.

DEVELOPMENT OF POSTCAVA IN THE CAT 15

Oil the other hand, it is plain that the persistence in the adult of the left siipracardinal (C), or of the right postcardinal (A), or left postcardinal (D), either singly, in combination with one another, or with the right supracardinal vein {B) to form the postrenal division of the postcava, would constitute an atypical condition of the veins. In addition to the tj'pical condition of the postcava, mentioned above, which we may speak of as Type B, there are therefore 14 other combinations potentially possible between the right and left postcardinals and the right and left supracardinals in the lumbar region, any one of which may persist in the adult and constitute a variant condition of the postrenal division of the postcava.

These Types are as follows (fig. 12) :

1. Type A, persistence of right postcardinal {A) vein.

2. Tjrpe AB, persistence of right postcardinal (A) and right supracardinal (5) veins. Right periureteric venous ring.

3. Type ABC, persistence of right postcardinal (A), right supracardinal {B) and left supracardinal (C) veins. Right periureteric venous ring.

4. Type ABCD, persistence of right postcardinal (A), right supracardinal (B), left supracardinal (C) and left postcardinal (D) veins. Right and left periureteric venous rings.

5. Type ABD, persistence of right postcardinal (A), right supracardinal (B) and left postcardinal (D) veins. Right periureteric A'enous ring.

6. Type AC, persistence of right postcardinal (A) and left supracardinal (C) veins.

7. Type ACD, persistence of right postcardinal (A), left supracardinal (C) and left postcardinal (D) veins. Left periureteric venous ring.

8. Type AD, persistence of right (.4) and left postcardinal (D) veins.

9. Type BC, persistence of right {B) and left supracardinal [C) veins.

IG GEORGE S. HIXTIXGTOX AXD ClIAULES F. W. McCLURE

10. Tiipc BCD. porsistonoc of right (B) and left supracardinal (C) and left jiostcardinal (,D) veins. Left iK'riureteric venous ring.

11. Type BD, persistence of right supracardinal (B) and left postoardinal (D) veins.

12. Type C, persistence of left supracardinal (C) vein.

13. Type CD, persistence of left supracardinal (C) and left postcardinal (D) veins. Left periureteric venous ring.

14. Ti/pe D, persistence of left postcardinal (D) vein.

^^'ith the exception of Types ABD, ABCD and BCD, all of the above-mentioned Types have been observed by us or by others, either in the adult cat or man. Tj-pe ABCD, however, has been figured by Hochstetter" as occurring in Erinaceus europaeus.

It is interesting to note in Types A, D and AD (fig. 12), that the lateral portion of the renal collar (subcardino-supracardinal anatomosis. ,Suhc. Sprc.Anast.) does not enter into the formation of the postrenal division of the postcava, and, furthermore that an atypical condition invariably results whenever the postcardinal veins persist in the adult. This further emphasizes the fact, already mentioned, that the right postcardinal vein does not, in the slightest degi'ee, typically enter into tiic formation of the postcava in the adult cat.

Three other types of variations of the postcava are met with which maj' lesuit from atypical development of the embryonic veins. These are as follows (fig. 12) :

15. Absence of the Prerenal Dii'ision of the Postcava and Substitution for the Latter in the Thoracic Region, of the Right or Left or of Both of the Supracardinal (azygos) Veins, as the Direct Cranial Continuation of the Postrenal Division of the Postcava.

The iK)strenal division of the postcava, in such cases, is usuall}- formed b}' the right (Type B), the left {Type C) or by both of the supracardinal veins {Type BC). It would be quite pos.sible, however, for the post cardinals (.4 and D) in the lumbar region also to persist in place of, or in combination with the supracardinal veins (B and C) but, as far as we are aware, such a condition has not been observed,

" Loc cit.. Taf. 23, fin. 24.

DEVELOPMENT OF POSTCAVA IN THE CAT 17

• Cases in which the prerenal division of the postcava (pars hepatica and pars subeardinalis) is wanting, are undoubtedly due to the circumstance that, for some reason or other, the embryonic liver circulation has not been tapped by the right subcardinal vein (figs. 1 and 2). Blood from the liver therefore continues to reach the heart throughout all subsequent stages of development, as in fig. 1, through the V. hepatic communis (V.H.C.) which serves as the hepatic revehent vein in the adult. In variants of this character in which the postrenal di\'ision of the postcava is formed by the supracardinal veins, the renal veins open into the latter and also, on each side of the body, the sex vein opens into the renal vein. This is due to the persistence of the lateral portion of the renal collar on each side of the body, into which the renal and sex veins open, the latter through the postcardinals, and the retention of its connection only with the supracardinal vein. In such cases the lateral portion of the renal collar does not enter into the formation of the postcava and, as the pars subeardinalis of the postcava is wanting, the ventral portion of the renal collar (subcardino-postcardinal anastomosis, Subc.Pc. Anast.), has not been formed, or, at least, has not been carried into the adult stage.

The occurrence of variants of this character in the adult cat and man, serves as a complete confirmation of its presence in the embryo and of the morphological imitj' of the supracarduial system of veins.

10. Persistence of the Cardinal Collateral Veins {The Marsupial Type of Postcava).

With very few exceptions among marsupials, the postrenal division of the postcava lies ventral to the aorta and its iliac tributaries which is the reverse of the conditions usually observed in placental forms. This has been found by one of the writers'- to be due to the circumstance that the postcava in the hnnbar region is formed in marsiii)ials by a fusion of two veins which takes place ventral to the aorta, and which have been termed the Cardinal Collateral Veins.

" MoClure, C. F. W., toe. ciL, 1906.

IS OEORGE S. HUNTINGTON AND CHARLES F. W. McCLURE

Veins occupying a similar position to the cardinal coUatoral veins of marsupials are present in the embryo of the cat. They may form an extensive plexus of vessels which connect with the siipracanlinals dorsally. and encircle the aorta ventrally between the renal lc\el and the origin from the aorta of the umbilical arteries. In the diagram (fig. 12) only the more caudally situated portion of the cardinal collateral system of veins [('(') is shown, where thej' form a venous ring with contiguous venous channels, on each side of the body, through which the umbilical artery passes. These rings are very constant in character in this location and the ivutnil or cardinal collateral i)ortion of the ring has been fountl to persist both in the adult cat and man, as the sole pathway through which blood can reach the postcardinals or supracardinals, as the case may be, from the external iE.Il.) and internal iliac (I. II.) veins. Cases in which the cardinal collateral veins have persisted in the adult are very rare and we know of only thre(> instances, two in the cat and one in man, in which this condition has been observed. In the marsupials, on the other hand, it is the ventral or cardinal collateral iC.C.) element of this circum-umbilical venous ring which normally enters into the formation of the post cava in this region, while the dorsal elenient of the ring disappears.'-^

.\s far as we have observed, the cardinal collateral veins are very evanescent in character and do not i)lay any especially signilicant role in the normal transformations of the embryonic veins in the cat. For this reason we have omitted them, for the most part, from our diagrams in order to avoid complications and too much detail.

17. Persistence of the Renal Collar in the Adult.

AVe know of three cases in man and none in the cat, in which a complete circum-aortic venous ring, the embryonic renal collar, has persisted in the adult. Now that we know the potential |K).ssibilities of the veins in this region, however, other cases of this type of \ariant will undoubtedly be found, not only in man, but also in the cat.

In.-<tances in the adult in which the left renal vein passes dorsal to the aorta before joining the postcaval vein are also easily ex " .VIcClure, C. F. W., loc. cit., 1906, p. L'03.

DEVELOPMENT OF POSTCWA IN THE CAT 19

plained. This is liroiight about by the retention of a connection between the hiteral portion of the renal collar on the left side and the supracardinal veins, and the atrophy of the anastomosis between the pars subcardinalis of the postcava and the left postcardinal vein (subcardino-postcardinal anastomosis).

The presence of multiple sex veins on one or both sides of the body, or of an anastomosis between the sex veins of opposite sides in tlie adult, has not proved a difficult matter to interpret, but may best be considered in detail at anotlier time. \'ariants of this character are largely related, though not always, to atypical conditions of the embryonic subcardinal veins. No instance has yet been found, however, in which the continuous subcardinal channels in the lumbar region, as met with in the embryo (fig. 2), have been carrietl into tlie adult stage.

While for convenience of description we may classify' the potential variant or atypical conditions of the adult postcava into 17 distinct types, we fully appreciate that combinations of these types may also occur. The circumstance, however, that we now possess a classification based upon a definite ontogenetic plan of the veins, seems to be a distinct advance over our former knowledge, as it not only permits us to interpret the atypical conditions of the postcava thus far observed, but also enables us to predict others which are potentially capable of occurring, and which .still remain to be found.

THE ANATOMICAL RECORD. VOL. 20, NO. I

COLOR WIIKMK OT rKllHES

Blue: Cardinal System of Veins and tlieir Derivatives.

Hed: Subeardinal System of Veins and tlieir Derivatives.

Hrown; Sui)raear(linal System of Veins and their Derivatives.

(ireen: V. liepatir communis and Diietiis \'eniisus .Arantii.

Yellow: Sul>cardino-Sui)racardinal .\nastomosis (lateral jiortion of l!enal

Collar) and Uenal Veins. Lavender: Cardinal ('(dlaleral \'eins.

I'lClHKS

Kigs. 1 to 7, inelusivo, diagrams illustrating the <leveloi)ment of the veins in the eat (Ventral N'iews).

Figs. S to II, inclusive, lateral views of reconstructions of the right side of the renal collar and of the right postcardinal, right supracardinal and right sex veins in cat embryos measuring, respectively, 16, 25, 29 and 45 millimeters in length.

rig. 12. Composite diagram of the endiryonic veins of the cat.

OXTOCiKNETIC Dl\ ISIONS ol ADILT I'OSTC.W.V (KIC. 7)

Pars Hepatica, P. Hep. 1 ,, i i^- • •

„ c. I 1- 1- I. ^. 1 f I rt'renal Divismn

Pars Subcardmalis, P. Siibe. J

Pars Kenalis, P. Hen. 1 ^ , i •-.• • •

,, .. ,. ,. ,, .. ( Postrenal Division

Pars Supracardinahs. 1 . hprc.

20

FATLANATION OF FIGURES

ABBREVIATIONS

.1., Right Postcardinal Vein (Lumbar

Division) Adr., Adrenal Vein (Adrenal Organ in

fig. 7) Ao., Aorta Az., Azygos Vein B., Right Supracardinal Win (I.iniibar

Division) C, Left Supracardinal ^'ein (Lumbar

Division) C.C., Cardinal Collateral Veins (fig. 12) C.IL, Common Iliac Vein C.J., Common Jugular Vein C.S., Coronary Sinus D., Left Pdstrardinal Vein (Lumbar

Division) D.C., Duct of Cuvier /).V., Ductus Venosus Arantii E.Il., External Iliac \e\n E.J ., External Jugular \'ein 6'., Gonad Hep.SubcJit., Hejiato-Subcardinal

Junction. /.//., Internal Iliac ^'ein. /../., Internal Jugular ^'oin Int.Subr.Atiaal., Intersubcardinal Anastomosis. A'., Kidney (Metanephn s) L.In., Left Innominate Vein

P. Hep., Pars Hepatica of Postcava

P.Ben., Pars Renalis of Postcava

P.Sulie., Pars Subcardinalis of Postcava

P.Spic, Pars Supracardina is of Postcava

Pe., Pustcardinal Win

Pel., Postcardinal Vein (Thoracic Division)

Pc.2., Postcardinal Vein (Lumbar Division)

Pre., Precardinal Vein

Prcvi., Precava

R.Col., Subcardino-Supracardinal Anastomosis or lateral port ion of Renal Collar in figs. 4 and 5 and on left side in figs. (5 and 7

R.In., Right Innominate Vein

R.V., Renal Vein

Sel., Subclavian Vein

Sj.rc, Supracardinal Vein

Svhc, Subcardinal Vein

.S'j/b. Pc.Anast., Suboardino-Pcst cardinal Anastomosis

S iihc .S pre .A no.st ., Subcardino-Suiiracardinal Anastomosis

S.V., Sex Vein

Vr.. Ureter

V.H.C., Vena Hepatica Communis

21

22

Hep.SM-bt.Jcl.

P. Sulc:

-Ihit.S-ubc.Anasl. I-nt.S

23

24

25

26

AJr.

!e>ial Collar

SoxV.

enal Collar

SexV.

FromMeionepliros

27

SexV.

MesonepKroic drai«4ge

10

28

Aar.Cr^ fUep.Sutc.

Jet.

SexV.

RcTHTiaTiiof nesOTiepliroic drainage (Pc.2.)

29

ftsleirj-."

Resumen por cl alitor, E. V. Cowdry,

Peking Union ^Medical College, Peking, China.

La Anatoniia en China.

El presente trabajo es una breve relacion de un estudio sisteniatico sobre la.s condiciones presentes y necesidades futuras dc la ciencia de la Anatomi'a en China. Despucs de mencionar los factores principales en la introduccion de la jNIedicina moderna en dicho pais, el autoi' publira una lista de todas las Escuelas inedieas que funcionan actuahnente en China, asi conio lo nonibres de los anatomicos que ensefian en ellas, llamando la atencion sobre la falta de anatomicos que puedan dedicar todo su tiempo a la ensehanza y la dificultad para obtener material para la diseccion.

Tambien incluye en su traliajo la lista de socios, constitucion y programa de la primera sesion de la Asociacion Anatomica y Antropologica de China y discute la influencia de esta Asociacion sobre el desari-ollo de la Anatomi'a en el pais mencionado.

Translation by Jos^; I*'. Xonicicit Cornell ,Mctiii;al College, New York

THE ANAIOMICAL RECORD, VOL. 20, NO. 1

TrTTTTTTTT

T^

1 S 7 1

TTT

^^^^5^

vV^vv

First photograph of the Anatomical and Anthropological Association of China taken at the entrance to the Anatomical Laboratory of the Peking Union Medical College of the Uockefelli-r Koundatinn on Fehniary 27. 19i0.

{2

AUTHOR S ABSTRACT OF THIS PAPER ISSUED BT THE BIBLIOGRArHIC SERVICE, DECEMBER 6

ANATO.MY IN CHINA

E. V. COWDRY

Anatomical Laboratory of the Peking Union Medical College of the Rockefeller

Foundation

ONE FIGURE

INTRODUCTION

The following agencies are concerned in the development of modern medicine in China:

1. Foreign Missionaries: Most of the pioneer work has undoubtedly been accomplished through the energj' and devotion of foreign missionaries who have labored faithfully in the face of prejudice and superstition. In 1913 the China Medical Missionary Association passed the following resolutions which make their purpose quite clear :

1). That in establishing medical colleges and hospitals our sole object is to bring the blessings of healing to the souls and bodies of the people of China, and to give a thorough training in medicine and surgery to young men and women of education and intelligence, enabling them as fully qualified doctors to be of the highest service to their country.

2.) That we have no desire to create permanently foreign institutions, and that our aim and hope is that these medical colleges will, graduallj' and ultimately, be staffed, financed, and controlled by the Chinese themselves.

3). That we desire to bring our teaching work into line with the regulations of the Ministry of Education, and in all ways to co-operate with and assist the Government of the Republic in medical education, so that a strong and thoroughly equipped medical profession may be established in tliis great land.

2. Foreign Agencies of Non-Missionary Character: The British Government has materially aided in the development of medicine in South China. It has been particularly successful in secm-mg the support of wealthy Chinese in founding the Medical Depart 33

34 K. V. COWDRY

nient of the University of Hongkong. Even the President of China sliowcd his interest in the enterprise by estabhshing the "Ta Tsung T'ung C'h'uan Hsueh Fei" feUowshij) for univcrsitj' students. Unfortunately the war has depleted the Colonial Treasury, and, I have been told, the Chinese have shown less interest in the ontciprise following the award of the German rights hi Shantung tn the .Japanese. The school buildings, which are up-to-date in every particular, are situated on the side of the mountain and command a fine view of the harbor. The equipment is excellent, the surroundings the finest and most healthful along the South China coast, the facilities for preliminary education good: all that is needed to make the medical department one of the best and most attractive in China is an adequate full time staff. The Professor of Anatomy teaches also clinical surgerjand the Professor of Physiology acts as Dean and teaches, in addition, microscopic anatomy. Members of the faculty are allowed to practise as consultants. To keep abreast of recent atlvances in medical education arrangements nmst be made for the maintenance of at least three full time men in each of the departments of Anatomy, Physiology and Pathology. The future of this institution is very bright in view of the broad minded attitude of the authorities, that it is the purpose of the Medical School to .serve the whole of South China, not merely the Colony and Chinese of British nationality.

The Ciennans made good begirmings in Slianghai and Tsmgtau which were interrupted by the war. The Shanghai School was located in the French Concession and was maintained ui close affiliation with a strong engineering department which was financed largely by Krupp interests, .\fter the seizure of the buildings, with part of the general equipment and library, bj' the French authorities, (he teaching was transferred to the Tung Chi and Pauhun Hospitals in the International Settlement. Most of the German instructors were deported and the remainder forbidden to enter either of these hospitals, so that at present most of the actual instruction is given to the students by two German doctors in private houses just across the street at Nos. 24 and 25 Burkill Road. There are 120 students and about 40 women

ANATOMY IN CHINA 35

in the Nurses Traiiiing School. The institution is now called the Tung Chi Medical School and is apparently being maintained by the Chinese Government. Provision has been made for premedical and engineering work at Woosung and I have been told that the Peking Government has granted a simi of $300,000 for the construction of new buildings for these departments. Most of the information which I obtained at the office of the Commissioner of Foreign Affairs in Shanghai regarding Tung Chi proved to be unreliable and misleading. The other school, in Tsingtau, has been taken over by the Japanese authorities but is not being operated by them.

The Japanese Medical School in JNIukden is unquestionably one of the best medical institutions in China. Its strength Ues in its full time staff. It publishes a volume of researches each year which will bear careful study, ^^'hile it is actually owned by the South Manchuria Railwaj' it is nevertheless under strict governmental control. Hospitals are also maintained m nearly all of the large cities l)y an influential Japanese philanthropic society under the presidency of the distinguished statesman, Count Okuma. In view of the further consideration that a large number of Chmese physicians have received their trainmg in Japan, it is not surprising that the Japanese exercise considerable influence in medical education.

Several .\merican Universities have undertaken medical work in China. In the Yale-Hunan Medical School at Changsha a special attempt has been made to cooperate with the Chmese. This school has made headwaj' in spite of its inaccessibility and the chronically unsettled condition of the province. The land and equipment of the Harvard Medical School in Shanghai was taken over in 191(3 by the Rockefeller Foundation.

The China ^Medical Board of the Rockefeller Foundation is responsible for the most recent developments in medical education. Its purposes are clearlj^ set forth in a letter, under date of March 15, 1915, from Mr. John D. Rockefeller, Jr., to the various missionary societies in Great Britain and the United States as follows :

36 K. V. COWDRY

1. To assist Missionary Societies to strenp;then their medical schools and hospitals hy providing oquipnipnt and other facilities, and by making annual urimt**. ii-** 'K-'iy e found cxpctlient, for the support of pliysicians and nurses, selected by the respective Missionar\' Boards, subject only to the P'oundation's approval of the professional qualifications of the appointees.

2. With the consent of the Missionary Boards, to reorganize and expand existing medical schools, with their hospitals, and to support these, wholly or in part, from its own funds.

3. To aid other medical schools that are not strictly missionary.

4. To establish, equip and .support new medical schools and hospitals. In choosing its agents, pliysicians and nur.ses for independent schools or hospitals, the Foundation will select only persons of sound sense and liigh character, who arc sympathetic with the missionan,spirit and motive, who are thoroughly qualified for their work professionally, and who will dedicate themselves to medical ministration in China. Beyond these qualifications, the Foundation cannot properly impo.se tests of a denominational or doctrinal nature, such as are deemed desirable by ^lissionary Boards for their own medical missionaries or agents.

The Board originally planned to establish two new medical schools, one in Peking and the other in Shanghai, but has recently decided to devote all its energies to the foundation and mainteance of one really first class school in Peking. To this end $7,000,000 have already been exjiended on l)uildings and equipment. The 3'early Inulget is a large one owing to tlie fact that the entire staff is on a full time basis. It already amounts to about .S750,000 per annum and will probably reach a million in the near future. The China Medical Board has also contributed generously toward the assistance of other medical schools and hospitals. Up to the end of 1918 pajanents totalling .S676,889.70 were made to thirty-one institutions.'

3. The Chinese themselves.- The work of the Chinese Government should be given careful attention. The Army Medical

' Roger S. Greene, The Rockefeller Foundation in China, "Asia," November, 1919.

"The Chinese government has discovered that it has a saving's account with a credit balance of five million dollars in the Russo-Asiatic Bank. The amount was placed there hy the old Ini[H'riul Board of Education in .\Iiinchu days, when the department of education wa.s one of the wealthiest in the government. Owing to the confu.sion incident to the change of regime, and the disappearance of the official.s who deposited the money, the account was entirely lost sight of." (North China Star, .May 13, 1920.)

ANATOMY IN CHINA 37

School, the Naval Medical School, the National Medical College and the five Provincial Medical Schools constitute a creditable foundation on which to build. They represent a conscientious attempt on the part of the Chinese to assume responsibiUty for their own needs m the waj' of medical education. The late President, Yuan Shih-Kai, declared, that "For a country to be strong and prosperous it is essential that its citizens be healthy."

It is important that these medical schools should grow rapidly and become the back bone of the nation. Up to the present they have received very little foreign support and it is doubtful whether they will accept any. The Director of one of them told me that open cooperation with a foreign institution might have a bad effect upon his annual budget (owing to antiforeign feeling). Some medical missionaries, on the other hand, take but little interest in Chinese schools because they see in them no opportunity for evangelistic work. One doctor dismissed the question by saying that "it is difficult to cooperate with them because they are only heathens anj- way."

The case of the Kung Yee ^Medical College is instructive. This school belongs to a group of Chinese in Canton. It has excellent buildings in a fine location, and, until recently, had a fairly complete staff. The instruction given is of a relatively high grade. The educational policj^ of the institution was under the control of an executive committee in which foreign influence predominated. A proposal was made to become affiliated with the Canton Hospital (Missionary) which was apparently acceptable to all parties. At the last moment, unexpectedly and in an unconstitutional way, the Chinese members of the Kung Yee Society refused to ratify the agreement. The missionary element in Canton is almost unanimous in declaring that thej* can have no more confidence in the Kung Yee Society and that further negotiations are impossible. Affiliation has now been effected between the Canton Hospital and the Canton Christian College.

The Chinese schools have been unable to keep pace with the rapid advances in the foreign controlled institutions, which tend to attract the best students. With a depleted treasurj- the Chi

38 E. V. COWDRY

nese may prove reluctant to make large expenditures to accomplish something which the foreigners will do for them gratis. Ver}- skillful and diplomatic assistance is called for. As a rule the liuildings and oquijimcnt arc adequate for the present needs. It miglit be possilile, however, to improve the lilirarj- accommodations and to strengthen the teaching staff. The addition of one or two realh* well trained Chinese, who have travelled abroad, with a liberal salarj- guaranteed, to one of these colleges would soon react beneficially upon the whole institution. It is also desirable that members of the staff, already under appointment, should be given an opportunity to travel, .\bove all, research work should be encoiuaged. It might be a good idea to try the European policy of offering prizes and medals for the best work done. Perhaps the President of China would himself consent to make the awards.

The underlying difficult}-, however, is the deeph' rooted conviction, handed down for forty centuries, that the medical profession is but a fourth or fifth rate occupation. The sentiment of a nation like China cannot be changed over night nor j-et in fifty years' time, but a beginning has been made in Peking, for example, where the splendid Iniildings of the Rockefeller Foundation will surely lead people to doubt whether, after all, the medical profession is so very degiadiiig. The raising of a despised trade to the level of a dignified profession requires long and sustained effort throughout the country, but until it has been accomplished, we cannot hope for any real development of modern medicine in China.

The people generally look upon disea.se and sickness in an apathetic and fatalistic way, believing that it is a visitation of providence in jiunishment for their transgressions, or at any rate that it is the will of God, as our forefathers thought in Europe several hundred years ago and some continue to think. While such views prevail there can be no real progress. This tendency to shift the responsibility from their own shoulders is characteristic of the Chinese in all their dealings, and will be very difficult to correct. They are handicapped also by certain customs like foot l)inding, and the l)in(iiiig of the breasts in young women

ANATOMY IN CHINA 39

before marriage, which they still practice blindly, having forgotten their origin and not troubling to ask the why or the wherefore.

Efforts to introduce modern medicine in China will be unavailing unless a nation-wide campaign is carried on by Chinese and foreigners alike for the education of public opinion. At present the graduates of the schools which have been established are regarded with indifference or active distrust by the vast majority of their countrymen. It is particularly difficult for those of them who have to go into the interior, awaj^ from the thin film of foreign influence, to live up to their new ideals, in the face of universal incredulity and without sympathy or assistance of any kind. A beginning is being made from several angles without proper coSrdination and on a very small scale. Professor John Dewey of Colmnbia University is perhaps doing more than any one man to divert the funds squandered by the millitarists into educational channels and to lead the mass of the people to see themselves as others see them and to assume full responsibility for the orderly development of their own lives. Dining vacations some of our students make a practise of giving public lectures on hygiene and preventive medicine; but what are one or two among so many? I am thoroughly Ib sympathy with Doctor Peter's puljlic health campaign but I should Hke to see it on a much larger scale like the world-wide demonstrations of the International Health- Board. The Chinese people are not devoid of business instinct and I am inclined to think if it were demonstrated to them repeatedly how much may be actually gained by improA-ed sanitation and through an intelligent appieciation of the piinciples of hygiene, that thej' would not be um'esponsive. Every means of publicity should be utiUzed and the vernacular press pushed to the lunit In a concerted attempt to educate the general masses of the population to a realization and appreciation of the good work which is being done in the medical schools and hospitals throughout China, emphasis being placed upon those under Chinese control.

At the same time wealthy merchants and business men should face their duty to their country. It would not be at all a difficult matter to select a group of five or six Chinese in each of the great

40 E. V, COWDRY

cities of Kaiiknw, Shanghai and Canton who could, with hut little personal sacritice, establish and maintain a medical school on an equallj" efficient and elaborate scale to that founded through the generosit}' of an American citizen in Peking. The example has been set and I think that we can count on its being followed.'

A list of the medical schools with the names of the anatomists follows. Those marked with * were personally visited.

Canton

1. *KwanKtunK Provincial Medical College.

2. *IIackctt Medical College for Women.

Harriett M. Allyn (part time) S. \\'. Kwan (part time)

3. *Kung Yee Medical School

D. J. Todd (part time) J. A. Hofmann (part time) John Kirk (part time) Wong Tak Kwong (part time) Wong King Yip (part time) Ch'ui Kam Cli'i (part time)

4. *Kwang Wha Medical School

5. *i;cole de Medicine Franco-Ciiinoise de Canton

Gilbert Desrallons (part time) P. Tsoi (part time)

6. Liang Yiieli Medical College

Chee Sek-chong

Leung Kin-Cho (part time)

Changsha

7. Hunan- Yale Medical School

T. C. Lieu

A. S. Crawford (part time) .1. W. Williams (part time) P. C. Chu (part time)

Chengtu

8. West China Union l'nivei"sity

H. L. Canrinht (part time) W. H. Morse (part time)

•"In c'lnnccfinn with the proposed organization of a University in Amoy, for which >t.O0O.(K)0 has been donated by Mr. Chen Kia-Kcng, a wealthy retired merchant in the Straits, it is now reported that another rich Straits merchant, Mr. Wang Vig-Chu, has given a further sum of $.3,000,(XX) for the estalilishmcnt of a medical college in the ITniversity." (China Medical Jr)urnal, 1920, vol. xxiv. p. 216.)

ANATOMY IN CHINA 41

Foochow 9. Union Medical College

Jesse Gossard (part time)

Hangchow

10. Hangchow Provincial Medical College

Li Ding

11. Hangchow Hospital and ^ledical Training CoUege

Tsu Peh Long

Dzen Ven Dah (part time)

Hongkong

12. *Hongkong University

H. T Earle (part time) Kenelm H. Digby (part time) C. C. Wang (part time)

Mukden

13. *South Manchuria Railway Medical School

K. Sliiino K. Kudo T Mikami

14. *Union Medical College

R. H. Mole (part time)

Nanchang

15. Nanchang Pro\incial Medical College

Paotingfu IG. *Cliihli Provincial Special Medical School Chang Peh Ching Tien Yuen Chin (part time)

Peking

17. *Army Medical School

C. P. Ch'ang

W. S. Kuei (part, time)

C. Y. Hei (part time)

18. *Government Medical School

K. Ikegami Dr. Futamura

19. *North China Union Medical School for Women

Ethel Leonard (part time) Li Pau Chen (part time)

20. *Peking Union Aledical College of the Rockefeller Foundation

E. V. Cowdry Davidson Black S. R. Dotwilcr R. S. Stone Paul H. Stevenson

42 E. V. COWDRY

Shanghai

21. *8t. Johns University (Pennsylvania Medical School)

E. M. Merrins Dr. Lincoln (part time) Dr. Yin (part time) W. S. Now (part time)

22. *L'Auroro University' Medical School

Dr. Florence R. P. Hernaiilt

23. *Tung Chi ^Medical College (being a continuation of the former

German Medical School)

Soochow

24. *Soocho\v (Kiangsii) Provincial Government Medical College

Sah Fou-Zicn Tsu Ho Yung

Tientsin

25. *Xaval Medical School

Tsinanfu

26. *Shantung Christian University (1918-19)

R. T. Shields L. M. Infile Wu Djao Hsiang Wang Hwei Wen

BUILDINGS AND EQUIPMENT

The anatomical laboratories in China varj- from a single bare room to costly buildings fitted with every convenience. The anatotnical laboratory of the Peking I'liion Medical College, lioro illustrated is certainly llio most elaborate. The anatomical laboratories of the Japanese Medical School in Mukden are housed in a plain l)ut .substantial building and are fidly equipped with everj'thing neccssajy ff)r teaching and research. The University of Hongkong has good reason to be proud of the School of Anatomy erected in a .splendid location, high up on the mountain side largely through the generosity of the late Mr. Ng Ui Hing, one of the leadiiig merchants of the colonj". Mention should also be made of the new anatomical lalioratory of L'Aurore University, the au.stere simplicity of which is quite pleasing. Some of the Chinese institutions are a strange mixture of the old and the new. Occasionally one may see minors placed at the top of a flight of

ANATOMY IN CHINA 43

stairs, and in other strategic positions, in order to turn back the evil spirits and in this way make the place more healthy.

I shall not take space to describe the smaller laboratories, some of which are very unprepossessing, except to say that good work may be done with vei'y meagre equipment if it is gone about in the right way. One becomes ^■ery tolerant in China. From modest beginnings great developments may be expected. The mere rudiments of anatomy properly or evenindifferentlj^ taught will serve to indicate the fallacj- and the danger of native Chinese medicine. Our policj' is to encourage and stimulate, not to go away with the feeling that the conditions are hopeless.

Both large and small institutious suffer from lack of library facilities. At present there is no library in the whole of China to which one can refer for back numbers of standard European journals. Some are to be found in Peking (where the library of the Peking Union Medical College is being rapidh' enlarged) one or two in Shanghai and a few more in Hongkong. Tung Chi has a few valuable sets of German journals. Under these conditions teaching is hampered and research work is set aside because it is not altogether satisfactory to have to devote time and energy to a problem which may already have been solved by some one else. Dr. Greenman's poUcy of the wide distribution of the Wistar journals in China is most helpful and constitutes an miportant step in the right ilirection. The relatives of the late ^Ir. Andrew Carnegie could make no more fitting memorial to him than the estabUshment of a real library in China, free to millions of people.

. STAFF

The twenty-six medical schools of China nmnber onlj^ about two dozen teachers who are able to devote all their time to anatom}'. These teachers are certainly overworked but their pUght is not so bad as those who have to teach a whole variety of subjects and sometimes have to attend to hospital and, more rarely, to private practice in addition. Often the instructors are so busy that the}' have neither the tmie nor the energy to settle down and do one thmg well, with the result that makeshifts and time saving devices are resorted to. Chinese medical schools are

44 E. V. COWDRY

inferior to those of Japan in this respect. It is not that those in authority fail to appreciate the gravity of the situation: they are sunply unable to remedy it through lack of funds. In several schools, however, one cannot help feeling that some of the money invested in buildings could more profitably have l)een spent on the staff. The teachers suffer with the students. They leave promising, perhaps remunerative, careers behind them and come out to China young and enthusia.stic. They have Lmuunerable demands upon their time and energy, they do reallj' pioneer work in isolated stations, and become, to some extent, 'Jacks of all trade.' Middle age finds them often with large families, but without that moilern prereiiuisite — a specialt}' — so that they are just a little out of the running for positions in the modern and up-to-date medical schools which are boimd to spring u]). It is essential that anatomists and others shall have a certain amount of leisure time to plan their teaching, to keep up with world progress and to engage in research. Unfortunately it is always easier to secure funds for buildings and equii)ment, which .repre.sent something tangil>le and permanent, than for the salaries of teachers and in\estigators. With patience, however, the condition in China will slowly improve.

TEACHING

With foreigners of so many nationalities it is not surprising that the methods of teaching anatomy should be varied. Perhaps the most pernicious system is as follows: The foreign instructor, who speaks not a word of Chinese, comes in and makes anatomical drawings on the blackboard and labels the parts. A Chinese interpreter then makes his appearance and tran.slates the terms into Chinese. When the students return next day they are required to repeat the drawings from memory. They have no practice in dissecting, even on animals, and accordingly have to learn how to u.se their instruments upon the li\ing subject, sometimes with disa.strous results. One of my questionnaires was answered as follows:

"We don't teach histology, embr3-ology, comparative anatomy, as our scope is to form jjractitioncrs onl\'. Besides, the intel

ANATOMY IN CHINA 45

lectual standard and scientific previous education of our scholars are not high enough to allow us to emphasize pure science."

The greatest stumbling block in the teaching of anatomy, next to inadequacj' of staff, is the difficulty of obtaining human material for dissection. To the best of my knowledge only the Japanese Medical School at Mukden and the University of Hongkong have a sufficient and regular supply of bodies on which they can relj'. Onlj' tweh'e of the twenty-six medical schools offer regular courses in human dissection. In Peking we have only been able to secure four bodies in the last year and a half. T\Tien the first entered the building all our servants left us immediately and we had some difficulty in replacing them. The police and the authorities generally are not sympathetic, and there seems to be but little hope of obtaining sufficient material in Peking for sometime to come. In the provinces some of the schools obtain material from executions but this source is sporadic and unsatisfactory. It is interesting that in Japan, where the worship of ancestors is also prevalent, bodies may l)e obtained more easih' than perhaps anywhere else in the world (Cowdry '20, p. 72).

The regulations regarding dissection of the Chinese Government are as follows, quoting the translation given in the China ^ledical Journal :

Order of the Board of Interior No. 51, November 22, 1913:

Article I. A physician, in case of death from disease, may dissect the body and inspect the diseased part to determine (examine) the origin of the disease, but he must first obtain the consent of the relatives of the dead person and clearly inform the local magistrate before proceeding to dissection.

Article II. The police and inspectors, in case of mysterious death, the cause and origin of wliich cannot be accurateh' ascertained without dissection, may appoint a physician to dissect said corpse.

Article III. The bodies of all those meeting death bj- punislmicnt or dying in prison from disease, without relatives and friends to claim their bodies, may be given by the local magistrate to a physician for dissection, to be used for the purpose of experimentation in medical science, but after dissection the body nuist be sewed up and buried.

Article IV. If any are willing for the benefit of science to offer their bodies for dissection and leave word to that effect before death, they may do so, but the whole bod>- must be sewed up and returned to his or her familv after dissection.

46 E. V. COWDRY

Article N'. Tliese regulations arc in force from the day of their proclamation.

Supplementary order of the Board of Interior, No. 86, April 22. 191J,.

Article 1. All medical colleges and hospitals, which are proved to l)p in good condition by the local authorities and recognized beforehand by the Board of Education or estaiilished by the pubhc, shall be allowed to perform dissections.

.\rticle 2. According to Acts No. 1 and 4 of the General Laws this may be enforced and the medical men allowed to perform postmortems as soon as the consent of the family is obtained. (During summer this may be done immediately after reporting to the local authorities.)

Article 3. When the colleges and hospitals mentioned in Art. 1 of By-laws apply for any dead body from the local authorities the following rules must be observed: —

('. Proper lettei-s with official seal.s are needed on both sides — local authorities and the college when dealing with any deceased criminal or decea.sed prisoner. .\ny private medical college recognized by the Board of Education may also apjily in similar manner.

a. Special certificates shall be made by the judicial authorities of the local government, and the same shall be given at the time when dead bodies are issued to the medical colleges, .\fter examination the certificates shall be kept in the college until the end of the month when they shall be returned to the local authorities so as to enable them to preser\'e records. There shall be no need to send these to the prisons.

Hi. The name, age. district, and number of the dead jierson shall be noted in the certificate, which shall be properly dated with official seals by the local government before the same is sent. The college receiving the corpse .shall keep a copy of the name, age, date, etc., so as to faciUtate examination when required.

Article 4. A certificate of death by a qualified medical man shall first be sent to the local authorities before a post-mortem examination is allowed on certain |)erst)ns. who have not died in a hospital as mentioned in Art. 4 of (ieneral Laws, .\fter examination a report shall be submitted to the local authorities for reference.

.\rticle ,5. With the (■xceptif)n of .\rts. 1 and 4 of (Jeneral Laws any or many parts of a dead bodj' dissected may be retained, if such are necessary- for medical demon.stration. This may be done according to Art. 3 of General Laws.

Article G. When any or many parts have been removed from a dead body for medical demon.st rations, the rest of the corpse shall, if possible, be sewed up according to Arts. 3 and 4 of General Laws. (Dead bodies mentioned in .\rt. 3 of (ieneral Laws which are supplied to medical colleges shall be treated in the same way.)

,\rticle 7. .\ di.s-sected body after being sewed up shall be returned to the family if po.ssible. If unclaimed it shall be buried by the college which has difwected the body. After the funeral, a sign .shall be shown

ANATOMY IN CHINA 47

on llio tomb where the deceased has been buried. (Any deceased person having no family as mentioned in Art. 3 of General Laws may be taken to a crematorium by the medical college and cremated if necessary. After burning, the ashes of the deceased shall be gathered and buried, and proper signs shown on the tomb. Tliis shall be duly reported to the local authorities.)

Article 8. .All medical colleges shall report yearly the number of dead bodies dissected, to the police court if at Peking, and to the local authorities at other places, in order to facilitate reporting to the Board of Inteiior for the preservation of the records.

Article 9. These By-laws may be revised at any time with a view to improvement.

Article 10. These By-laws shall be enforced on date of [iromulgation.

The chief difficulty is that these regulations are interpreted to mean that the written consent of the individual before death must be supplemented by the sanction of the relative, which it is almost impossible to obtain.

Owing to the pressure of other duties, the teachers are often unable to properly adapt their methods of teaching to the lack of himian material. They soon come to rely upon the use of anatomical models made in Europe or Japan and give up theii' efforts to obtain bodies for dissection; for it takes a lot of time and energy to cultivate the authorities, to drink endless cups of tea, to make petitions for favorable legislation and arrangements for executions. Yet it is possible, with a little care, to give the students an idea of the science of anatomj' without the aid of himian dissectioii. It is usually quite a sunple matter to obtain a skeleton from abroad or even in China. For instance, the students at Paotingfu have, through their own initiative, amassed quite an interesting and useful collection of bones from the graves in the vicinity. Living models should be used extensivelj'. The students should be obhged to make a careful and complete dissection of some mammal comparing the structure carefully with that of man. In the south of China advantage maj* be taken of the monkeys which are sold as pets, for from two to fi\'e dollars a piece.

Lack of time and insufficient laboratory equipment are responsible, in some cases, for a rather low standard of work in histology, embryology and neurology.

48

E. V. COWDRY

\Miile the teaching in the better schools is worthy of the highest I)i:iiso, there is a general tendency, which 1 have already noted in the case of the Japanese medical schools, to give too many lectures and too little laboratory work. It is true that the cost of laboratory furnishings may be a certain deterrent; but, on the other hand there is the time factor. It is more wearing on the teacher to gi\e one hundreil lectures than to teach in the lal)oratory for the same length of time. The proportion of lectures to laboratorj- work in some of the principal colleges is given in table 1.

TABLE 1 Proportion of lectures to laboratory work in anatomy*

.\rray Medical School

Chekiang Provincial Medical College

Chilili Provincial Medical College

ficole de Medicine Franco-Chinoise

Hackett Medical College

Hangcliow Hospital and Medical Training College.

Hunan Yale Medical College

Japanese Medical School, Mukden

Kiangsu Provincial Medical College

Kung Yee Medical College

Liang-Yueh Medical College

Peking Governmental Medical College

Peking Union Medical College

West China Union University

LECrrRES

LABORATOBT

per cent

83.0

17.0

86.6

13.4

91.3

8.7

100.0

•

35.8

54.2

80.0

20.0

32.7

67.3

50.0

71.4

28.6

36.9

63.1

80.0

20.0

70.4

29.6

10.0

90.0

40.5

59.5

This high percentage of lectures is very bad for the students. It means that most of their information comes to them second hand, predigested in the mind of the lecturer, and that they are, to a large extent. roi)bed of the incentive and privilege of making obser\ati()ns for them.selves and of learning how to make logical deductions therefrom. This method of training does not teach the student self reliance, which is particularly necessary in China, where, after gratluation, he is often placed entirelj' on his own resources without sympathetic and stimulating help from those around him.

Unfortunately information has not yet been received from St. John's University.

ANATOMY IX CHIXA 49

In some colleges the time devoted to anatomy is altogether too long. I learn for example, from the Kung Yee Medical College, in answer to mj- questionnaire, that the students suffer 1178 hours of instruction in anatomy. Long hours with lack of time to think and of opportunity to pursue work along special lines, chosen by the students themselves, is deadening. It usually fails to create in the student a thirst for knowledge and a desire to help himself.

There is one more consideration in the training of the student which should, in my opinion, receive attention in view of the fact that it is the purpose of the medical schools to turn out men of strong character, not merely physicians skilled in their professions. Reading through the ])iinted announcements of the various colleges we meet with catagorical prohibitions relating to the conduct of the students. A merely negative attitude of this kind does not itself tend to strengthen character, ^^llen all restraint is removed and the student leaves the college a reaction is in dangei- of setting in. It is surely through education, teaching that what is right is also expedient, that the best results are to be obtained.

The standard of instruction has unquestionably been raised by the action of the Council on Medical Education (1915) in urging the various medical schools to meet the following requirements necessary for admission to "Grade A:"

1. Course of Instruction. That the course of instruction shall extend over a period of five j'ears of, at least, 32 weeks each.

That the text books used and the instruction given shall be equivalent to that in European and American schools.

That human dissection, and complete courses in lal^oratory work, shall be included in the curriculum.

2. Entrance Requirements. That the standard of admission shall be graduation from a Middle School as defined by the Educational Association of China, and, in addition, at least one year of preliminary work including laboratory courses in physics, chemistry and biologj^; this preliminary or "pre-medical" year being arranged to supplement the ]ireparatory instruction already given in ^litldle Schools.

50 E. V. COAVDRY

5. Hofiiiitn} Yciir. That Ijoforo loi'civiiin a nirdical ilegree, students who ha\(> (■()inj)letO(l the fivo years of regular instruction, shall spend one year as interne in an ajjproved hospital, or in some other line of sjiecial medical work, at the conclusion of which the applicant for a degree shall present a thesis acceptable to the faculty of the medical school.

./. D('(jrccs. That onh' students who ha\"e met the entrance requirements, have completed the regular course of instruction in an approved school, and at the termination of the hos))ital year have ]iresented an acceptable thesis shall be entitled to receive a medical degree.

0. Sta;tf. That the minhnum staff shall be ten men on the field giving full teaching time. To ])rovide for furloughs, language study, etc., this re(|uiroment means a stalT of at least fifteen fully qualified teachers either foreign or Chinese.

6. Equip/ucnl. The school must be adequatelj- eciuipped with modern appliances for instruction, projierly 0(iui])petl laboratories in Chemistry, Pathology, Bacteriology. Anatomy, and Clinical Microscopy, and must be maintained on an efficient basis. The scientific instiuments and apparatus shall be sufficient to i)ermit students to do iiulividual work.

7. Hospital Facililics In connection with each medical school and under control of the facultj-, there shall be one or more hospitals suitable for teaching iimjioses, each hospital to have at least 100 beils. One or more daily dispensaries should be connected with the college hospital.

S. Curriciihnn. Tlie schools approved by the C. M. M. A. shall meet the curriculum requirements which the Council on Medical Education will prejjare in il(>tail upon the lines alreadj' suggested.

While travelling from college to college one is impressed with the relati\ely small attendance. N'ery few of the colleges are filled to (•apa<'ity. This is to be attributed to the fact that the science of medicine does not ajiitear to lie very attractive to Chinese students, rather than to the lack of premedical training which may easilj- be secured in Peking. Shanghai, Hongkong and the larger cities. It is difficult to ascertain tlic maximum mnnber

ANATOMY IN CHINA 51

of students which maj^ enter the medical schools of China each year, because in the poorer schools, where but httle attention is given to laboratory work, almost any number may attend the lectures. The Chinese Ciovernment Schools are certainly much better attended than the missionarj' establishments, perhaps because their entrance requirements are less exacting. Table 2 will show how meagre is the supplj' of doctors which is being trained to supph^ the needs of 400 milhon people. The entering classes of 16 colleges combined only contain 355 students. Contrast this with the conditions following the war in the United States and Canada. The Universit j' of Toronto, for instance, has an entering class in the medical school of 416 students to supply the needs of a country with a population of about 8 millions, alread}^ quite well stocked with doctors.

During the last few years the following medical schools have been closed, partly through a desu-e to concentrate activities and thus increase the standard of work:

Harvard IMedical School, Shanghai.

Women's Medical School, Soochow.

Universitj of Nanking Medical School, Nankmg.

Union Medical College, Hankow.

German Medical School, Tsingtau.

Provincial ^ledical School, Wuchang (?). The following resolution of the Council on Medical Education (1920) seems to forecast the closure of other schools through lack of adequate su})port :

That in \-ie\v of the difficulties hitherto experienced in securing adequate staff and support for the medical schools at Changsha, Chengtu, Mukden and Foochow, the Association would commend to the incoming Council the careful consideration of the following question, in consultation with the missions interested in the development of those schools:

a. \Miether steps can be taken to meet the urgent need of a broadened basis of support for the Aledical Scliool at Changsha, by the provisioji of an adequate endowment, or b>' the full co-operation of missions working in that area, in view of the fact tliat should this not be obtained, the continued existence of the school will prove impracticable.

h. Whether the Missions at work in Southwest China can set aside a sufficiently large staff of efficient teachers to enable the \\'est China

THE ANATOMICAL RECORD, VOL. 20, NO. 1

52

E. V. COWDRY

Union University Medical Department to approximate to the C. M. M. A. niinimuin rcciuironipnts.

c. W lu'tlicr sonio inca.surc of co-operation between the Union Medical College, Mukdon, and the School of Medicine, Tsinan, could not be satisfactorily arranK(>d.

d. Seeing tliat the I'ukien Christian University is not intending to develop a medical department, as the Council is informed, should not the authorities of the Uukien Medical College be urged to reconsider the continuance of that school?

TABLE 2 Actual allendance and teaching capacity

COLLEGE

ACTUAL NtrUBER IN

rinaTTEAR

MAXIMUM NDUBER

51

42

25

14

21

30

7

57

20

25

14

S

7

10 14 10

85

C'hihli Provincial Medical Colleee

45

ficole de Medicine Franco-Chinoise de Canton

Hackett Medical College

Hangchow Hospital and Medical Training College

Hangchow Provincial Medical School

50 80

Hunan Yale College of Medicine

Japanese Medical School, Mukden

60

40

50

K\vang-\Vha Medical College ,

25

Liang-Yueh Medical College

25

Shjintung Christian Vniversitv ('10-20)

30

Soochow Provincial Medical School

60

West China Inion I'nivesrity

Women of the better class are gradually becoming interested in medical education and the outlook for the future is good. At least six medical schools welcome them in Chijui, whereas in .Ia])an they are permitted to enter only one, and that of distinctly inferior grade. Notwithstanding the fact that a beginning has been made in coeducation; and the initial prejudices of a very conservative race partly overcome, there is a strong movement for the strengthening and maintenance of at least two medical schools exclusively for women, one in the North or Central China and the other in the South, which shall be in large mea.sure stafTed and controlled bv women. The wisdom of introducing

ANATOMY IN CHINA 53

a system of education into China which has not proved eminentlj^ satisfactory in Europe or ^\merica is doubtful. It is fair, I think, to say that in the United States the best students seek to enter Hopkins, Chicago and other coeducational institutions in preference to the women's medical colleges, in which it has never been possible to establish an equally high grade of instruction. If China is to keep abreast of the times, it is essential that her women shall be encouraged to come out and exercise their influence, not to retii'e into the seclusion of feminine institutions.

RESEARCH

It is not an easy matter to carry on research work in China. One of the greatest obstacles is geographical isolation enhanced by insufficient libraiy facilities. The country is so vast and the number of anatomists so small that each must rely ahnost entirely upon his own resources. In order to bring together men and women of like interest and to create a stimulating intellectual atmosphere an "Anatomical and Anthropological Association of China" was formed at a meeting held on Thursday afternoon, February 26th, 1920, in the anatomical laboratory of the Peking Union Medical College, as follows:

HONORARY MEMBERS Ales Hhdlicka, U. S. National Museum, Washington, D. C.

ACTIVE MEMBERS

AxDERSsoN, J. G., Peking, (Councillor)

Black, Davidson, Department of Anatomy, Peking Union Medical

College, {Councillor) Boring, Alice M., Department of Biology, Peking Union Medical

College. Britland, A. J. D., Peking Union Medical College Hospital. Brubacker, a. F., Lia Chow, Shansi. Chang, P. C, Department of Anatomy, Chihli Provincial Medical

School, Paotingfu. Chen, S. P., Tsiing Pu Hutung, Peking. (Councillor) CowDRY, E. v.. Department of Anatomy, Peking Union Medical College,

(President) CowDRY, X. H., Department of Anatomy, Peking Union Medical College.

54 K. V. COWT)RY

Chxjan, S. H., Director, Army Medical Colkge, Peking, {Councillor).

Daxtox, G. H., Tffing Ilita College, Peking.

DiGHY, Kknklm, H., Diparlmeitt of Anatomy, University of Hongkong,

Hongkong. DiTTMER, E. G., Tsing Hua College, Peking. DoBsoN, R. J., Peking Union University, Peking. Earlk, H. T., Dean of the Medical Faculty, Victoria University,

Hongkong, {Councillor). Favst, F. C, Department of Pathology, Peking Union Medical College. Gr.\y, Douglas, Physician to the British Legation, Peking. Hahding, B. M., I Chow Fu.

Hodges, P. C, Peking Union Medical College Hospital. Howard, H. J., Department of Ophthalmology, Peking Union Medical

College. Hsieh, E. T., Department of Anatomy, Peking Union Medical College,

{Councillor) . Ingle, L. JNI., Department of Anatomy, Shantung Christian University,

Tsinanfu, Shantung. Ingram, .). H., American Board Mission, Peking. IxotYE, M., Department of Anatomy, Tokyo Imperial University,

Tokyo, Japan. Li Ding, Department of Anatofny, Hangchow Provincial Medical School,

Hangchow. Li Pau Chen, Department of Anatomy, North China Union Medical

School for Women, Peking. Lieu, T. C, Hunan-Yale Medical School, Changsha, Hunan. Main, D. Duncan, Hangchow. Maxwell, J. P., Peking Union Medical College. Mediiurst, C. Spitigeon, Peking. Morse, W. R., Changtu, \\'est Cliina.

Merrins, E. M., St. Johns University, Shanghai, {Councillor). Neal, J. B., Shantung Christian University, Tsinan, Shantung. Ono, ShunIchi Koishik-vwa, Kobinatadai II, No. 35, Tokj'o. Packard, Charles, Department of Biology, Peking Union Medical

College, {Secretary-Treasurer). Phillips, E. Marg.\ret, 13 Nan Wan Tzu Hutung, Peking. Porter, L. C, Peking University, Peking. PoRTKRFiELD, W. W., St. .lohns University, Shanghai. Ridge, W. S., Peking. Read, Bernard I>., Department of Physiological Chemistry, Peking

Union Medical College. RosENius, Elsa, Peking.

ScHUMAKER, ARTHUR, Tsuug Pu Hutung, Peking. Shields, R. T., Department of Histology and Embryology, Shantung

Christian University, Tsinanfu, Shantung, {Councillor). Snell, Hohn a., Soochow. Steven.son, p. H., Lu Chow Fu, .\nhui. Stone, R. S., Department of Anatomy, Peking Union Medical College.

ANATOMY IN CHINA 55

Taxg, E. H., Director, National Medical College, Peking. {Councillor).

Taylor, H. B., Anking.

TixG, V. K., Director, Geological Survey, Peking, {Councillor).

Van Buskirk, J. D., Severance Union Medical CoUege, Seoul, Korea.

Wilder, J. W. D., Peking.

Williams, J. D., Department of Anatomy, Hunan-Yale Medical School,

Changsha. Wv Lien Teh, Peking,

CONSTITUTION

1. The Association shall be called the Anatomical and Anthropological Association of China.

2. The object of the Association shall be to advance the sciences of Anatomy and Anthropology' in the Far East, in the broadest sense, especially in the coordination and centralization of activities, in the improvement of conditions for teaching and research and in the financing of special investigations and expeditions.

3. .All persons who are interested in the objects of the Association shall be eligible for membersliip.

4. The names of candidates for membership shall be submitted to the Secretar>'-Treasurer at least one month before the meeting at which they come up for election.

5. Each member shall paj' an initiation fee of $2.00 to the SecretaryTreasurer.

6. Annual dues shall be determined at the first annual meeting.

7. ^Members duly elected shall be able to assiune hfe membership by the payment of •'^50.00, it being understood that the Association does not assume any obligations with respect to pubhcations.

8. Upon the recommendation of the Council persons who further the interests of the Association either financially or in other w5ys shall be elected patrons of the Association.

9. The officers of the Association shall consist of a President, elected annually; and a Secretary-Treasurer, and twelve councillors, elected to serve for a period of two years.

10. The Council shall meet at the call of the President, in the interval between annual meetings for the consideration of expenditures, of recommendations for membership, and for the arrangement of programmes for meetings. The Council shall also deal with all other matters of concern to the Association and make recommendations to it for deci.sion.

11. Annual meetings of the Association shall be held in close affiliation with the China Medical Missionary A.ssociation.

12. Special Meetings shall be held at the discretion of the President and at least throe members of the council.

13. For the election of members, changes in constitution, extraordinary expenditures, and dropping of members, a three-fourths vote of those present will be required; for all mattei-s of minor import, a simple majority vote will be sufficient.

66 E. V. COWDUY

PAPKI{.S PRESENTED AT THE MEETING

1. Relations of Aiiihropology to Medicine. Ales Hrdlicka, V. 8.

National Musouni, WasiiinKton, D. C.

2. The Altitiulc of the CItincsc Gorernment towards Dissection. S. 1'.

Chen, Official Representative of the Board of Interior.

3. The Jewish Colony at Keifengfu. Dr. C. D. Tonney, American

Legation, Peking.

4. Stone Implements of Neolithic Type tn China. J. G. Andersson,

Peking.

5. Head Flattening. E. T. C. Werner, Peking.

6. Anthropologisches Sludium I'ebcr L'nterextremitaten der Chinesen.

Kotaro Sliiino, Department of Anatomy, South Manchuria Railway Medical School, Mukden. (Read by title.)

7. Observations made at the Second Chinese Government Animal Experi mental Station. Chou Wei-lien, Director.

8. Methods of Anthropometry. .\les Hrdlicka, U. S. National Museuni,

Wasliiiigton, D. C.

9. i'ebcr die Panethschen Zellen des Duodenums von Schwernen. E. H.

Tang, Director, Government Medical School, Peking.

10. A Review of Chinese Anatomy from the Period of Huangti (Yellow

Emperor 2697 B. C). \\. T. Hsieh, Department of Anatomy, Peking Union Medical College.

11. Seal Characters with Special Reference to Anatomical Terms. .]. H.

Ingram, Peking.

12. The Skull .Measurements of Three Hundred Chinese. S. H. Chuan.

Director, .\rmy Medical College, Peking. 1.3. Height, Weight and Chest .^feasurements of 860 Chinese Sttidenls. S. H. Cluian, Director, Army Medical College, Peking.

14. Height, Weight and Chest .Measurements of Healthy Chinese. A. C.

Hutcheson, Nanking.

15. .1 Comparative Study of Physiail .Measurements of Chinese Students.

Arthur Schumaker, Peking. (Read by title.)

16. The Origin of the Vitreous. Hars'ey J. Howard, Peking Union

Medical College, Peking.

17. The Secretion of I'rine in the Camel. B. K. Read, Peking Union

Medical College, Peking.

18. The .Application iif X-Rny Study to Certain Anatomical Problems.

Paul f '. Hodges, Peking Union Medical College. (Read l)y title.) I '.I. .1 Report on the ir('.s.'(/r In.stitu'.e of .[natoniy and Biology and its Relation to Biology in China. Chi Ping, The Wistar In.stitute, Phil.idelpiiia, Pa., U. S. A. (Read by title.)

20. The Comparative Anatomy of the .Mastoid Region. Jui Hua Liu,

Peking L'nion Medical College.

21. The Endocranial Anatomy of Oreodon (preliminary report), David son Black, Department of ,\natomy, Peking l'nion Medical College.

22. The Birds of North China. G. W. D. Wilder, Peking.

ANATOMY IN CHINA 57

23. The Innervation of the Soft Palate.' !M. Inouye, Department of

Anatomy, Tokyo Imperial University, Tokyo, Japan.

24. The Relation of the Interstitial Cells of the Reproductive Organs to

Secondary Sex Characters in the Domestic Chicken. Alice M. Boring, Pckinf>; Union Medical College.

25. A Study of the Differentiation of Blood Cells in the Bone Marrow

with the Aid of Janus Green and Other Supravital Dyes. E. V. Cowdrj-, Department of Anatomy, Peking Union Medical College. (Read by title.)

26. Some Growth Chances in the Walls of the Thorax in the Fetus. C. K.

Roys, Department of Anatomv, Shantung Chi-istian Universitj', Tsinanfu. (Read by title.)

27. The Surgical Anatomy of the Ovary with Special Reference to the

Blood Supply. S. J. Kirkby-Gomes, Peking. (Read bj- title.)

28. Cytological Reinvestigations on the Somatic Cells of Ascaris with

Special Reference to Mitochondria. Scunlchi Ono, Tokyo.

29. The Effect of Starvation and Refeeding upon the Mitochoridria, the

Golgi Apparatus, and other Cytoplasmic Constituents. Shunlchi Ono, Tokyo.

30. The Effect of Radium on Cell Division. Charles Packard, Peking

Union Medical College.

31. The Present State of the Schistosome Problem. E. C. Faust, Peking

Union Medical College.

32. Problems under Investigation in Connection with the Collection of

Human Embryos. E. V. Cowdry, Department of Anatomj-, Peking" Union ^ledical College. (Read by title.)

DEMONSTRATIONS

1. The Innervation of the Muscles of the Soft Palate. Michio Inouye,

Department of Anatomj^, Tokj'o Imperial I'niversity.

2. Preparations of Mitochondria in the Somatic Cells of Ascaris.

Shunlchi Ono, Tokj^o.

3. Preparations Illustrating the Effect of Starvation and Refeeding upon

the Mitochondria, the Golgi Apparatus and Other Cytoplasmic Constituents. Shunlchi Ono.

4. Experimental Alterations on the Mitochomlria of Plant Cells. N. H.

Cowdr>-, Department of Anatomy, Peking Union Medical College.

5. Microscopial Preparations of the Interstitial Cells of Sebright Testes.

Alice M. Boring, Peking Union Alodical College.

6. A Demonstration of the Behavior of Mitochondria in Bone Marrow

Cells by Supravital Staining with .lanus Green. E. \. Cowdry, Department of Anatomy, Peking Union Medical College.

7. Schistosome Larvae in Man and Other Animals. E. C. Faust,

Peking Union Medical College.

8. Methods of Anthropometry. Ales Hrdlicka, U. S. National Museum,

Washington, D. C.

58 E. V. COWDRY

9. .4 Demonstrnlion of Some of Professor Dogtel's Original Preparations

of Nerve Endin^/s. Sliunlchi Oiio, Tokyo. 10. Preparations Illuslralimj the Effect of Feeding Meat and Fat upon the Mitochondria in the Acinus Cells of the Pancreas of the Guinea Pig. Ma Wen Chao, Dopartment of Anatomy, Peking Union Medical College.

It is hoped that this A.ssociation will open up lines of investigation which were formerlj' closed to anatomists as individuals, and that it will be successful in enlisting the active cociperation of many workers who are not professional anatomists.

China is a veritable terra incognita which offers unique opportunities for pioneer work along certain lines. The establishment of the U. S. National Research Council, alone, is sure indication that science is passing from an indi\'idualistic to a cooperative basis. As Dr. Livingston aptly remarks: "It has been occasionally suggested that one of the reasons for the slow advance of science lies in the fact that scientific research problems are still generally attacked by indi\'iduals or by small, local groups of workers influenced bj' a single individual, rather than by plamied coojieration among a juunber of workers in different institutions. Individualistic research has been characterized, by the late Professor C. E. Bessey, as a kind of guerilla warfare upon the unknown." The wonderful discoveries which were made during the wai' are due to the fact that in a national emergency individual plans and aspirations are abandoned and coordination becomes the order of the day.

In the Orient, racial prol)lcm.s are uppermost, several of which have been indicated in a recent address by Hrdlicka (1920). Anatomists are certainly in a position to contribute valuable informatif)n relating to the phy.sical standards and potentialities of the Chinese race, which, in the last analysis, nuist fonn the basis for the adjustment which is Ijound to take place between the East and the West. If an ariangement can be made whereby careful records are kei)t of all the dissections carried on in the l)rincipal medical schools for a period of five or six years, a number of interesting facts are sure to be brought to light. A tabulation of the freciuoiicy of tlie chief progressive and regressive variations will be iielpful in forming an r)pinion as to whether the

ANATOMY IN CHINA 59

Chinese are a progressive or regressive type, and will, perhaps, indicate what evolutionary tendencies thej^ exhibit along certain lines. Realizing that a thorough knowledge of physical standards is also prerequisite to any concentrated programme for public health work in China the members of the China jMedical Missionary Association, through their Research Committee, have made a special study of the height, weight and chest measurements of healthy Chinese, and further investigations along similar lines are contemplated.

Friendly cooperation is also necessary for the successful study of vertebrate palaeontologj^ and in order to collect data bearing upon the ancestrj- of man. We are told (Matthew, 1915) that mankind differentiated in Central Asia and migrated from this region to all parts of the world, and there seems to be a strong probability that in the course of time "missing links" of great miportance will be discovered in China. The Du-ector of the Geological Survey of China appreciates the importance of this type of investigation and has indicated his willingness to cooperate, so that a well organized attempt is now bemg made to collect specmiens and data. A movement has also been set on foot in Peking largely through the initiative of Dr. Hrdhcka, for the establishment of a Natural History Museimi. At present research work along several lines is greatly handicapped through lack of museum facilities. A few isolated collections occm- here and there, made chiefly by private individuals. Those of Ai-thur Stanley and of Kurz in Shanghai, and of Gee in Soochow, are of special interest. Through the generosity of the Rockefeller Foundation our own laboratory is well equipped for comparative work.

An attempt is being made to stimulate research work in embryology through the collection of Chinese embryos and fetuses, and by offering facilities for their study. In less than a year 83 specimens have been collected and \\-e have managed to arrange for the shipment of specunens from different parts of the country to Peking. While most of them come at present from hospitals under foreign control we are unremitting in our efforts, with the help of om- students and graduates, to obtain them directly

60 K. A". CO\\T)RY

from native phj'sicians because this source, if it can he made available, should prove to be almost inexhaustible.

Thus far I ha\e referred to the desirabilitj- of cooperation in tlie collection of specimens and data; the more difficult type of co()peration, in actual laboratorj' experimentation directed toward the solution of definite anatomical and biological problems, though very desirable, will pr()l)abl\- not be realized in China for many years to come on account of the dearth of jiersons trained in experimental work.

BIBLIOGRAPHY

China Medical Board of the Rockefeller Foundation, First, Second. Third and Fourth .Annual Reports. 1915, 1916, 1917 and 1918.

Council on Medical Kdueation Reports. China Medical Journal, 1913, 191.5, 1917, W-'O.

CowDRY, E. V. 1919 Pica for the Formation of an .Anatomical .Association in China. China Medical Journal, Vol. 33, pp. 517.

CowDKY, K. V. 1919 .\n Ai>pi'al for Human Endiryos. Privately printed in Peking.

CowDRY, E. v. 1920 .Anatomy in Ja|)an, .Anatomical Record, Vol. IS, p. 07.

Fischer, W. 1915 Die deutsche .Mcdizinschulc fiir Chincsen in .'shanghai. Miinch. mcdiz. Wochenschr.

Hri>i.£ik.\, .Ales 1020 The .Anthropology of .Asiatic Peoples. China Medical Journal, vol. 34.

HsiEH, E. T. 1921 .A Review of .Ancient Chinese .Anatomy. Anatomical Record, vol. 2;'. This paper will appear in Jan., 1921, p. 97.

Kleinweg de Zwaan, J. P. 1917 Volkerkundliches und Cieschlichtlichcs iibcr die Heilkunde der Chincsen und Japaner. Xat. verh. van d. Hollandsche .Maiitschappij d. Wetenschapjien te Haarlem, Derdc Verzameling, Zevende Teel, Haarlem, De lOrven Loosjes, 65(5 pp.

I.ivi.Nr.sTON, Burton E. 1920 Constructive Scientific Research by Cooperation. Science, vol. 51, p. 277.

.Matthew, VV. D. 1915 Climate and Evolution. .Annals of the New York .Academy of Sciences, vol. 24, p. 171.

Report on .Medicine in China by the China Medical Commission of the Rockefeller Foundation, 1914, University of Chicago Press.

Co

Hesiunen por el autor, Eugene L. Settles, University of Missouri.

Los efectos de una dieta grasa abundante sobre el crecimiento del

tejido linfoide.

Dos gatos j6venes procedentes de la misma cria fueron alinientados durante cuatro meses y medio, uno con leche que contenfa 6 por ciento de grasa, el otro con la misina cantidad de leche con 3 y medio por ciento de grasa, suplcmentada en el caso del primero por carne grasa y en el ultimo por carne magra. Desjiues del primer mes ambos presentaban excelente salud. El gato que recibia alimento rico en grasa prescntaba un exceso en el peso del cuerpo y 6rganos, como indican las ^siguientes cifras : Peso total (despues de deducir el exceso de grasa), 30%; timo, 84.8%; glandula linfatica mesenterica, 52.7%; bazo, 23.8%; hfgado, 93.7^0 ; pancreas, 80.6%; tibia izquierda, 44.1%; f6mur izquierdo, 34.0%; corazon, 21.1% y rinones, 27 por ciento.

De estas cifras se deduce que el timo y la glandula linfdtica mesentdrica, junto CQn el hfgado y pancreas, presentan un exceso de peso relativamente mucho mayor que el exceso del total. El estudio microsc6pico demostr6 un exceso aim mayor en la cantidad de tejido Unfoide a lo largo del canal alimenticio (t6nsilas palatinas y faringeas, placas de Peyer y foliculos solitarios). I^s placas de Peyer eran tres veces mas grandes que lo normal y se hallaron numerosos folfculos solitaries y acumulaciones linfoides mas pequenas en el gato alimentado con la dieta mas rica en grasa, mientras que en el otro no se i)udo hallar ningun foli'culo solitario. De estos datos el autor concluj'e que el tejido linfoide responde con marcadas diferencias en su cantidad a las diferencias en la dieta, consistentes en diferencias en el contenido de grasa y valor en calorias. Estos dos factores no han podido separarsc aun.

Traiulntion by loti F. Nonidei Cornell Medical Collece, New York ,

ADTH0R8 ABSTRACT OF THIS PAPER ISSUED BY THE BTBLIOGRAPHIC SERVICE, NOVEMBER 1

THE EFFECT OF HIGH FAT DIET UPON THE GROWTH OF LYjVIPHOID TISSUE

EUGENE L. SETTLES Anatomical Laboratory of the University of Missouri

SIXTEEN FIGURES (3 PLATES)

In spite of the universal interest in and the innumerable studies which have been made upon lymphoid tissue, very little has been learned regarding the factors which regulate its nonnal growth. It is known that lymphoid tissue is relatively much larger in amount durmg infancy and childhood and that it dmiinishes during adult life. It is also knowTi that enlargement of lymphoid tissue may result from the effects of acute or chronic inflammation. However, the great variations in the Ijaiiphoid tissue, which are well known to occur, especially during childhood, form an unsolved problem.

Since the most miportant differences m the factors to which young annuals are subjected are those associated with differences m diet, it seemed worth while to investigate the effect of vaiying diets on the amount of lymphoid tissue. The food element which seemed most likely to have a specific effect was thought to be fat, and for the following reasons.

Schiifer ('85, '12), who has made numerous studies on the relation between leucocytes and fat absorption, concludes from his own work and that of others that leucocytes, some varieties of which are formed in lymphoid organs, are known to take up fat in the villi and transport it to the lacteals.

Kischensky ('02), in studying the intestinal epithelium of young kittens during fat absorption, found leucocytes containing fat. From his description we may conclude that these small round cells with large nuclei" are Ijanphocytes. He also found fat droplets in the macrophages of the lymph glands four to six hours after a meal.

61

62 EUGENE L. SETTLES

E. R. and E. L. Clark ('17) observed that leucocytes are attracted to and actively ingest injected fat in the transparent tails of livinp anijihibian larwac. Again. l,\7nphoc>'tes contain lipolytic ferment, while ii()lynK)rphomiclear.s contain proteolytic ferment (Fiessinger and Marie, '09).

Czcniy ("07) says that, with hypertrojihy of fat in children, he finds enlargement of the tonsils, thpnus, adenoids, and of the deep and superficial hnnph glands, and that with regulation of diet in adiposity, he finds a diminution in size of Ijnnphatic organs.

Hutinel (according to Stcchman, '10) says that in acute intestinal inflammation after heaUng of the intestinal processes themselves there is a persistent emaciation of the child due to the disturbance of function of the mesenteric lpn])h glands. He also .studied mesenteric l>nnph glands of dogs hi diflerent stages of digestion, and concluded that during digestion fat is emulsified in the mesenteric lymph glands and further worked over, and that here there nnist bo a real chemical change. He says that the colorless content found in hnnph vessels is soap. He also says that all the Ijnnph glands play a similar role in inanition.

Poulain ('02) states that Ijnnph glands play a double role in digestion, in that there occurs in lymph glands both splitting and synthesis of fat. He also says that during infection there is a lessened lipase activity of l3Tnph glands and concludes that this may be the explanation of the general disturbance of nutrition which is found in intesthial infection.

Steehman ('10) investigated the question of relationship of l\-mph glands to fat digestion, and his conclusion is that the lymph glands are definitely concerned in the digestion of fat, and he states that they are assimilative organs for the fat derived from the tissues.

Bartel and Stein ("00) (luote Paltauf, who holds that the enlargement of the thymus in status lymjjhaticus is not the cause of death, but merely a symptom of the general disturbance of metabolism further characterized by enlargement of the tonsils, l>inph glands, and other lymphoid organs. He also describes fatt}' livers hi man}' of these cases.

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE 63

According to Kanthack and Hardj^ ('94), a meal causes a considerable rise in the niunber of lymphocytes in the blood. In rabbits, after a meal, they may form from 70 to 80 per cent of leucocytes, while in man two hours after a full meal they form about 30 per cent of the white blood-cells. These authors conclude that active digestion produces lymphocytosis, while starvation decreases the number of Ijanphocytes.

Thus, through the literature runs the strain of e\'idence that the lymphoid tissue plays an important part in the metaboUsm of fat.

It is well known that increase in the specific functions of tissues results in an increase in size. Hence, if lymphoid cells are concerned with absorption, transportation, and possibly with digestion of fat, one might expect the organs producing them to increase in size with an increase in the amount of fat handled by them.

As noted in the review of literature, the immediate effect of fat feeding has been investigated, and it has been found that the number of Ijnnphocytes in the blood stream increases markedly during digestion, but shows a decided decrease in number during inanition. No definite reference, however, was found in the literature to any studies on the effect of a long-continued high fat diet on the size of lymphoid organs. It was therefore decided to plan experiments to test this question.

In addition to the general ph3^siological and anatomical interest of this question, there are possible clinical applications of great importance. If lJ^nphoid tissue is regulated to any considerable extent by the amount of fat given in the food, it follows that some of the enlargement of tonsils and adenoids in children may be due to a too high fat diet, particularh' in those predisposed to this trouble by heredity.

The experunents reported here were begun with the idea of discovering the effect of an abnormal increase or decrease in the amount of fat in the diet upon the growth of Ij-mphoid tissue. Milk was selected as the basis of the diet because of the ease of handling its fat content as well as for its general nutritional qualities. Ivittens were chosen as suitable animals for the experi

64 EUGENE L. SETTLES

ment because of the possibilitj- of feeding them at regular intervals and of controlliiig accurately the amount of food consumed at each meal. A litter of four kittens was obtained for the experunent. They were healthy animals, alK)ut three weeks old, and had not yet been weaned.

It was realized from the start that, if dependable results were to be secured, the animals would have to be attended to with greatest care, particularh' as regards cleanliness of food, dishes, and cages, regularity' of feeding, and mental condition. On accoimt of the uncertainty of delegating such matters to a changing janitor force, it was decided from the start to feed and care for the animals personaUy. This was carried out from the beginning to the end of the expermient, except for short intervals when dependable substitutes were secured. The milk used was secured on alternate days from a reliable dairy and kept in clean bottles. During the wann weather the milk was kept on ice. The dishes were washed in liot water after each feeding. The floor of the cages consisted of wooden slats, the sides of finemeshed wiie. Water and a pan of sand were kept in each cage continuously, the sand being changed two or three tunes a week and the cages kept clean. Particular care was taken to keep the kittens free from all infections, parasites, or uncleanl}- conditions because of the possible effect of such agents upon lymph glands.

The kittens were fed the full ajuount of milk j)lamied for them every day. At first they were fed three times a day, later twice a day, with an occasional daj' on which the total day's feeding was given at one time. The four kittens were kept in separate cages, with ample room for moving about. Throughout the entire experiment they were turned out of their cages frequently and allowed to play and exercise for an hour or more. They were treated kindly; in fact, thej' grew to be leal jx-ts.

Since no data were available as to the proper caloric requirement of young kittens, it was first necessary to determine the nonnal amount of milk consumed daily. A four-day test showed that the kittens consumed approximately 1)4 cc. of 3i per cent milk per 510 gram bod\- weight or al)out 100 calories per kilo of body weight.

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE

65

It was decided to feed the cats milk varying in fat content, as follows: no. 1, low fat, low calorie; no. 2, noniial fat, normal calorie; no. 3, high fat, high calorie; no. 4, high fat, nonnal calorie. Based on the rough estimate mentioned above of 100 calories per kilo, the normal nmnber of calories, and using 3| per cent fat as normal, the four cats were started on the diet shown in chart 1 The calorie contents, not shown in the chart, were: no. 1, 37.08 cal.; no. 2, 58 cal.; no. 3, 78.83 cal.; no. 4, 58 cal. The weights of the cats were, respectively, 510, 510, 538, and 510 grams.

J« % Fat CCMilk

, 1 1

n.

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\

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J '

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i

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nso

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nso

1000 7S0 500 250

Cat No/

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/

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This general plan was followed with increase in quantitj' once, until the death of cats no. 1 and no. 3. Thereafter, cat no. 4 was shifted to a high calorie diet, that is, it was given a dailj^ amount of 6 per cent milk equal to the amount of 3§ per cent milk given to cat no. 2. This was done m order to have a decided difference in the amount of fat given to the surviving cats.

The data concerning weight changes, amounts of milk given, with dates at wliich changes in amounts were made, are shown so fully in chart 1, that it is unnecessarj' to repeat them in detail. However, certain supplementary comments should be made.

THE ANATOM'CAL RECORD, VOL. 20, NO. 1

66 EUGENE L. SETTLES

On account of the dilficulty of koejiinn the cats healthy on a pure milk diet, it was decided at the end of a week to give each cat a small amount of meat in order to keep them in good condition. Cat no. 2 received lean meat exclusively, while cat no. 4 was given meat containhig small amounts of fat. The feeding of meat was continued throughout the remainder of the experiment, at two- or three-day intervals. This has been omitted from the chart. Changes in quantity were made whenever a stationary weight or increased greediness of the eats made it advisable.

A glance at the chart shows that none of the cats responded well to the change hicident to weaning and confinement in separate cages. Instead of the rapid increase in weight which all animals of this age should .show, there was a three-weeks period durmg which the weight remained stationary, as in cat no. 2, or declined, as in cats no, 1, no. 3, and no. 4. At the end of this period cats 1 and ',i, which had been respectively on the low and high calorie diet, died, while cat no. 4 was in a very weakened condition. Although cat no. 2 appeared to be healthier than cat no. 4, still it maintained practically the same weight as at the start.

It is probable that the death of cats 1 and 3 and the poor condition of cats 2 and 4 toward the second of the third week were due to the change from mother's to cow's milk, accentuated in cats 1 and '.i bj- the markedly abnonnal fat percentages.

After this, however, the condition of both cats no. 2 and no. 4 imj)roved and continued excellent throughout the remainder of the experiment. From the third to the seventh week cat no. 2 increased slowly in weight. From the seventh to the twelfth week its weight remained practically stationary, even though the quantity of milk was increased at two different times. From the twelfth week to the end of the experiment its weight increased steadily, though slowly.

After the end of the third week when cat no. 4 almost died, it apparently adjusted itself to the high fat diet and began to gain weight, until, at the eighth week, its weight exceeded that of cat no. 2. From this time on imtil the end of the experiment the rate of gain of cat no. 4 was much more rapid than of cat no. 2.

I

EFFECT OF HIGH FAT DIET ON L\-AIPHOID TISSUE 67

During the last two weeks of the experiment, an attempt was made to increase still further the amount of fat consumed by cat no. 4, consequently 9 per cent milk was given during this period. However, during the first few days following this final change in diet, the cat did not drink the full quantity of milk. During the last week it accustomed itself to this extremely high fat percentage and at the time when the animals were killed it was consuming the entire amount of milk offered.

Cat no. 4 was killed on February 11th, nineteen weeks and three days after the begimiing of the experiment. Cat no. 2 was killed two days later, at the same time of day as no. 4 and at exactly the same interval of time after the last feeding. The autopsies will be given later.

The history of the expermient, as represented graphically ia the chart, shows that the original experiment of feeding four kittens of the same litter had be to modified owing to the death of two of the cats at a period before any of the four had become adjusted to cow's milk and confinement. Cat no. 2 received the same diet throughout, as regards fat percentage, and the amount of diet was determined by the natural appetite of the animal. AMiile its growth was much slower than normal so that the total weight and size of organs cannot be considered normal, nevertheless it serves as a satisfactory control as regards the effect of differences in fat content of the diet. Cat no. 4, starting out with a diet of 6 per cent milk containing the same number of calories as the control animal, after the death of cat no. 3, was given the same quantity of 6 per cent milk as that of the 3| per cent milk fed to cat no. 2, hence it received a greater number of calories. Diu'ing the latter half of the experiment this cat received some fat meat while cat no. 2 received nothing but lean meat. During the last few days of life, cat no. 4 was consuming the amount of 9 per cent milk equivalent to the quantity of 3§ per cent milk taken by the control. Hence cat no. 4 was fed a high fat diet throughout the experiment, and after the fifth week it received a high calorie as well as a high fat diet.

The cats, as has been stated, were kept clean and free from parasites throughout the experiment, with the exception of a

68 EUGENE L. SETTLES

small luiiiibcr of fleas which appeared at times and were treated with insect powder. The general condition of both was excellent during the last fifteen weeks.

AUTOPSIES Cats no. 1 and no. 3

Owing to the fact that cats nos. 1 and 3 had failed to adapt themselves to cow's milk and had lieen in an increasingly weakened condition for several daj's before they died, it was thought that Uttle would be gained from extensive study of the lymphoid organs. Careful autopsies showed nothing markedly abnormal in the thoracic and abdominal organs. The large mesenteric lymph gland from each cat was weighed and examined microscopically. The weight of the gland from cat no. 3, 1.470 grams, exceeded that from cat no. 1, 1.42:^ grams. ])y 0.047 gram. ]\Iicroscopic examination, however, showed a definitely larger number of l}^nphoid cells making up the cortex and medullary cords and filling the sinuses in cat no. 3 as compared with cat no. 1.

Cats no. 2 and no. 4

As previously mentioned, both these cats were in perfect health at the end of the experunent; their coats of fur were smooth and silky and they were active and playful. Cat no. 4, which had been fed the high fat diet, was larger and heavier and conspicuously fatter than cat no. 2, which had received a normal percentage of fat. The two cats were killed at exactly the same hour of the day and at the same length of time after the last feeding.

Autopsy of cat no. 4 (male). Cat was killed with chloroform I'ebruary 11th at 9:50 a.m. The last feeding was given at 2:30 P.M., February 10th. There is a layer of subcutaneous fat over the abdomen, about one-ciuarter of an inch thick. .Much fat is j)resent in the omentum. The peritoneal, pleural, and pericardial surfaces are smooth and shiny, with no increase in fluids in these cavities. The lacteals are well injected with fat. The

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE G9

chief mesenteric lymph gland is homogeneous in appearance and seems large and swollen. It weighs 3.040 grams. The other small, scattered mesenteric lymph glands were not noticeably increased in number. The stomach and intestines show nothing abnormal from the outside. On opening, the stomach is found to contain a considerable amoimt of partly digested material and the small intestine much yellowish semisolid material. No worms or other parasites were visible to the naked eye in stomach or intestine. The mucous membranes showed no especial reddening or other abnormality.

In the lower part of the ileum, the Peyer's patches (folliculi agminati) stand out with exceptional clearness. They form mottled raised areas projecting into the lumen of the bowel clearly marked out from the surrounding mucosa. The largest patch is the one in the terminal ileum, just above the ileocecal valve, which measures 3 cm. in length. In the 12 cm. of intestine anterior to this there are four round j^atches, each about 1 cm. in diameter, all conspicuously raised over the surrounding surface. The pancreas is large and normal in appearance, weighing 9.055 grams. The spleen is dark red with numerous white spots, and has rounded edges. It weighs 3.060 grams. The liver is very large with rounded edges, and has a yellowish color. It weighs 118 grams. The right and left kidneys are dark red in color, showmg nothing abnormal. Their weights are 6.5 and 6.7 gi-ams, respectively. The lungs are air containing and normal, save for one small atelectatic area in the upper right lobe. The heart is surrounded by a considerable amount of fat. It shows nothing abnormal. Its weight is 7.9 grams. One each of the right bronchial and right inferior cervical Ijanph glands were examined and preserved. They show nothing unusual macroscopically. The thymus is homogeneous in appearance and seems unusually large. It weighs 5.495 grauTS. The right and left tonsils are -covered with hemorrhagic spots. In order to preserve them without injury for histological study, some of the surroundmg tissue was dissected out with them, therefore it was not possible to estunate their weight accurately. The pharyngeal tonsil which is located at the top and posterior wall of the pharjmx, is

70 EUGENE L. SETTLES

easily seen as a definitely raised area containing many raised whitish translucent spots. The left fcnun- was preserved. It weighs I). 557 grams, while its greatest length is 7.8 mm. The left tibia was also preserved. Its weight is 5.200 grams and the greatest length is 83 nnn. ]\Iost of the subcutaneous fat was dissected out. It weighs 10V).4 gi'anis. Either all or parts of the various organs were preserved in Zenker's fluid for microscopic study.

Autopsy of cat no. 2 (yyjale). Cat was killed with chloroform, February 13th at 9:20 a.m. The last feeding was given at 2:30 P.M., February 12th. There is little fat present over the abdomen. The omentum likewise contains little fat. There is no increase in the fluid in the pleural, pericardial, or peritoneal cavities. Linings of all these cavities are smooth and shiny. The lymphatics are filled with chyle. The chief mesenteric lymph gland is homogenous in appearance. Its weight is 1.900 grams. The stomach and intestine show nothing abnonnal externally. On opening, the stomach is found to contain a small amount of nearty digested food and the small intestine contains very little except some brown mucus. No worms or parasites were visible to the naked eyes in the stomach or intestine. The mucous membranes are ajjparently normal. On opening the lower end of the ileum, it is found to be practically empty. A long Peyer's patch is found here. It is scarcely raised above the general epithelial surface and its extent is difficult to determine. The remainder of the small intestine was searched carefully for other Peyer's patches, but none could be seen in the gross specimen. The presence of the brown mucus here possibly prevented us from discovering the smaller patches at the time; however, the entire small intestine was presersed for further examination. The pancreas shows nothing abnormal. It weighs 5.540 grams. ^Ihe spleen has sharp, definite edges and its surface is mottled with small round nodules. It weighs 2.470 grams. The liver is normal apparently; it is dark red in color and has sharp edges. Its weiglit is 00.9 grams. The right and left kidneys are nonnal in appearance, weighing 5.1 and 5.3 grams, respectively. The right lung shows a small atelectatic area, otherwise both hmgs are

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE 71

normal. The heart is normal, weighing 6.5 gi-ams. The thymus is very pale. It weighs 2.973 grams. The largest right inferior cervical lymph gland shows nothing abnormal macroscopically. It is veiy pale in color. At the roof of the pharynx in the place where the pharjmgeal tonsil was easily seen m cat no. 4, only a faint mottling can be seen. On dissectmg this tissue loose from the bone and examining it carefully, definite small nodules may be seen. The left femur was preserved. It weighed 4.870 grams and its greatest length was 67.5 mm. The left tibia was also preserved. Its weight is 3.607 grams and its greatest length 73 mm.

DISCUSSION OF AUTOPSY FINDINGS OF CATS NO. 2 AND NO. 4

The postmortem examination confirmed the observations of the living animals that the two animals were entirely free from disease. It is noteworthy that no parasites were found.

The difference in the weight of these two anmials at the time of death has already been referred to. It was ob\-ious merely from the superficial inspection at the time of autopsy that the subcutaneous fat, the fat in the omentum and around the heart was noticeably greater m the cat which had received the high fat diet. Moreover, the macroscopic appearance of the liver, with its rounded edges and yellow color, made it appear highly probable that the difference in the weight of this organ in the two cats was due to an extra fat content in cat no. 4. (This was later confiiTQed by histological findings.) Aside from these differences in stored fat, the most noticeable difference in the two cats was found m the lJ^nphoid tissue. Even without the compaxison of the weights of the different lymphoid organs, the greater size of those in the fatter cat was very apparent. This was epecially noticeable m the case of the Peyer's patches. In the cat fed on high fat diet, the Peyer's patches were large, discrete, conspicuous, and prommently raised above the intestinal wall, while those of the cat fed on normal fat percentages were scarcely raised above the epithelial surface and so inconspicuous as to make their detection very difficult from macroscopic examination. The same contrast, in somewhat less degree, was noticeable in the case of the pharyngeal tonsils. The lymphoid tissue

/- EUGENE L. SETTLES

in the pharynx of cat no. 4 was fairly thick and well raised above the surface, while in this same region in cat no. 2 the hnnphoid tissue was represented merely by a faint mottling of the roof of the pharjnx.

The comparison of a number of the organs of the two cats is best brought out by a chart showhig the weights. These weights were all obtained in the fresh state.

Chart 2 gives the weights of the larger lymphoid organs (such as mesenteric l>^nph glands, thymus, spleen, etc.) of the two cats and also the weight of other organs (such as the heart, kidney, liver, etc.) for the sake of comparison. The smaller Ijinphoid organs, such as the Peyer's patches, the palatine tonsils, cervical l>nnph glands, and pharjTigeal tonsils, could not be accurately weighed on account of the necessity of leaving some of the surrounding tissue attached to them, hence the comparison of these was based upon microscopic studj'.

In chart 2, the weights of the two cats, and the absolute and relative weights of their various organs are first given. The excess body weight of cat no. 4 over cat no. 2 is next shown, together with the excess weight of its various organs.

For several reasons the body weight of cat no. 4 should be corrected, in order to obtain a fair comparison of the various organs. It has been mentioned that 109.5 grams of subcutaneous fat was found in cat no. 4, while cat no. 2 had very little subcutaneous fat. Again, the liver of cat no. 4 proved to contain an enormous amoimt of stored up fat. Beside these two factors, the gastro-intestinal contents were much greater in cat no. 4 than in cat no. 2. Now it would seem that the organs which would give the best relative comparison between animals such as these two cats at the end of the experiment would be the heart, kidneys, and perhajis the skeleton. On obtaining the average of the percentages by which cat no. 4 exceeds cat no. 2 with respect to heart, kitlneys, tibia, and fenuu-, the result arrived at is approximately 30 per cent. This same figure is obtained approximately if the excess subcutaneous fat (100. o grams) jilus a ]wttion of the liver weight (37..") grams), which accounts for only part of the stored-up fat, be subtracted from the gross body weight

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of cat no. 4. Thus, subtracting 147 from 1729, the resultant figure 1582 is obtained as the corrected weight of cat no. 4, which is 3G3 grams, or 30 per cent in excess of the weight of cat no. 2. Were the excess gastric and hitestinal contents also subtracted, the figure would probably be lowered to about 25 per cent, which is about the average by which the heart and kidneys of no. 4 exceed no. 2. However, for safety, the figure 30 per cent is chosen for the table.

^^'ith this new percentage excess as a basis, the percentage excess of the varioiis organs of cat no. 4 over cat no. 2 are calculated. By this means a tnier esthnate is arrived at of the actual effect of the difference in diet on the individual organs.

It is seen from the corrected percentage table at the bottom of chart 2 that the organs may be divided into three groups:-l) those api)arently affected by the difference in diet, i.e., the liver, the thymus, pancreas, and mesenteric lymph gland; 2) those which may have been affected by the difference in diet, i.e., femur and tibia, and, 3) those which were apparently not affected by the difference in diet, i.e., the kidneys, spleen, and heart. Discussion is reserved until the microscopic findings have been given.

MICROSCOPIC STUDY OF ORGANS FROM CATS NO. 2 AND NO. 4

The various organs were fixed in Zenker's fluid for the most part. They were dehydrated hi graded alcohols and aniline oil, cleared in xylol, imbedded in paraffin, and sectioned at 10 m or 15 IS. Since this technique proved to be unsatisfactory- hi the case of the thjnnus, portions of this organ were imbedded in celloidon. Bouin's fixative anil the method of dehydration described by Allen ('lU) were also tried, but the tissues treated in this way proved to be too hard to section well. The sections were stained with J\ layer's haematoxylin and eosin. The attempt was made, in each case, to secure specimens and sections from the two cats which corresponded as exactly as possible, as regards the part of the organ from which they were taken, the plane of sections, and the technique employed.

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE 75

The chief object of the microscopic study was to find out the difference in the amount of lymphoid tissue in the IjTiiphoid organs of the two cats. ;Measurements with the micrometer eyepiece w-ere made of the sections of the different lymphoid organs of the two cats. However, the wide variation in the shape of these organs in the two cats and the uneven distribution of the lymph follicles and cords as well as the varying sizes and distribution of vessels, connective tissue, and spaces in the organs of the two cats make this method rather unreliable. The most satisfactory comparisons were derived from observation of the sections and from microphotographs taken at the same magnification.

Liver. The liver of cat no. 2 (control) is apparently normal histologically. In contrast to this, the liver of cat no. 4 (fed on the high fat diet) is packed with fat globules of various sizes to such an extent that the whole liver structure is altered and its regularity destroyed. The cell structure is also changed by reason of the stored fat. The liver cells present a spongy appearance due to the presence in them of fat globules of various sizes. In manj^ places the fat globules are so large that it is difficult to determine whether they are inside the liver cells or whether they are intercellular.

The microscopic fuidings in the liver of cat no. 4 adequately explain the differences noted in the gross specunens of the two cats, especiaUj^ the unmense difTerence in the weight of the two organs.

Pancreas. No significant histological difference was found in the case of this gland from the two cats.

The microscopic study of the lymphoid organs will now be considered.

Cervical lymph gland. The variability hi shape and size of lymph glands makes comparison of the smaller glands unsatisfactory. Fortunately, the cat possesses an enormous mesenteric lymph gland, on which comparisons of size are feasible. The cervical glands, one from each cat, are selected as samples of smaller glands and are to be compared merely as regards relative distribution of lymphoid tissue, as seen with the microscope.

70 EUGENE L. SETTLES

While the cortex of the glaml from cat no. 2 is wider at one point than the cortex of that of cat no. 4 at its widest point, a fllancc at the figures of the two glands (figs. 1 and 2) shows that this gives an erroneous idea of the comparative amount of cortical substance present in the two glands. In cat no. 4 the cortex maintains a fairly even thickness throughout the entire circumference — a thickness which in no place falls far below the maximum. In cat no. 2 the cortical substance is either missing entirely or very narrow o\er approximately two-thirds of the circumference, benig present only as two separated masses at the two ends of the section. Recognizable follicles are present in both glands. They are more numerous in the gland from cat no. 4, in which they are arranged fairly regularly around the circmiiference of the gland, with an occasional follicle more deejily placed. In the medulla of cat no. 2 the cords are narrow and somew'hat irregular, but in cat no. 4 they are much wider and more continuous. The sinuses contain many more Ij-niphocytes in the gland from cat no. 4 than in that from cat no. 2.

It is clear, from the comparison of the glands, that there is a definitelj' greater amount of lymphoid tissue in the gland of cat no. 4 than in that of cat no. 2.

Plianjtujcitl tonsils. As may be seen in figure 4, a cross-section of the pharyngeal tonsil of cat no. 2, the lymphoid cells are .somewhat sparsely distributed in the reticulum. Two definite large solitary' follicles are present. The Ij-mphoid cells are more closely packed around the eilges of these follicles than at any other place in the section. In the centers of the follicles the hinjihoid cells are somewhat grouped together, leaving definite clear spaces between.

In the pharyngeal tonsil from cat no. 4, figure 3, the lymphoid cells are much more closely packed together. The solitary follicles are crowded with lymphoid cells. There is a much larger amount of lymphoid ti.s.sue outside the follicles than in the gland of cat no. 2, and the lymphoid cells here are more closely packed together.

The measurements of the lymj)hoid ti.ssue of a typical crosssection of the pharyngeal tonsils are as follows:

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE 77

Cat no. 2, greatest length, 3.5 mm.; greatest width, 0.52 mm.

Cat no. 4, greatest length, 5 mm.; greatest width, 1 nam.

The approximate areas of the cross-sections are: Cat no. 2, 1.82 sq.mm., and cat no. 4, 5 sq.mm. Since the sections are through comparable parts of the glands and since care was taken to secure exact cross-sections, these figures give a rough estimate of the relative volumes of the two glands, namely, a proportion of 1 to 2.7. In view of the relatively greater density of the lymphoid cells in the gland from cat no. 4, it is probable that the pharyngeal tonsil from cat no. 4 contains in the neighborhood of three times as much lymphoid tissue as that from cat no. 2.

Palatine tonsils. A comparison of these is somewhat unsatisfactory, owing to the difficulty of orienting them for obtaining corresponding sections. However, smce then' oval shape makes possible a cross-section perpendicular to the long axis, and by selecting the sections through the largest part of each gland, a fair comparison is secured. Two such sections, pictured in figures 5 and 6, show the following.

The section from cat no. 2 (fig. 6), is oval in shape. There is a narrow open space in the middle, which represents the crypt which extends deep into the gland.

Twelve solitary follicles may be counted arranged in a single marginal laj'er. The periphery of the follicles as well as the spaces betw^een follicles are densely packed with l>Tnphoid cells. Bordering the crypt, Ij-mphoid cells are more densely packed than in the surrounding area.

In the section from cat no. 4 (fig. 5) the crj^jt is shown extending to the surface. There are twice as many follicles — twentyfour — as in the gland from cat no. 2, and thej^ occur in two and three layers. The epithelium Iming the crypt is invaded and, in many instances, largely replaced by Ij^mphoid cells, which form a dense area near the limien. The distribution of lymphoid cells is about the same as in cat no. 2.

Measurements of sections of the two glands are as follow's:

Cat no. 2, greatest length, 3.4 mm.; greatest thickness, 1.8 mm.

Cat no. 4, greatest length, 5.4 mm., greatest thickness, 2.5 mm.

The areas of the two sections are in approximately the ratio of one to two for the sections from cats no. 2 and no. 4, respectively.

78 • EUGENE L. SETTLES

Although these are only rough approximations of the size of the gland, all the data point to the gland from cat no. 4 as being very decidedly — prol)ably at least 100 per cent — larger than the gland from cat no. 2, wliich, with a sunilar relative distribution of lymphoid cells, means a decidedly greater total amount of lymphoid cells in the cat receiving the higher fat diet.

Spleeti. The sections shown in figures 9 and 10 are taken from the widest portions of each gland. In the section from cat no. 2 (fig. 8) a considerable number of red blood-cells may be seen scattered among the lymphocytes and other cells. The lymphoid cells are numerous and evenlj- distributed. The malpighian corpuscles are rather small and contain definite germinal centers. The section from cat no. 4, figure 7, contains a greater nimiber of red blood-cells. The malpighian corpuscles are more nimierous than in cat no. 2 and definitely larger. The genninal centers have about the same appearance as in cat no. 2, possibly not as distinct.

It will be remembered that there was very little difference in the weight of the two spleens, considering the difference in the size and weight of the two animals. The microscopic study, however, shows a slight difference in the lymjihoid tissue in the two cats. The spleen of cat no. 4 contains perhaps sUghtly more lymphoid tissue than that of cat no. 2, due to the increased number and definitely larger size of the malpighian coipuscles. However, the difference is hardlj' enough to justify the conclusion that the spleen has been modified by the difference in diet.

Thymus. Figures 9 and 10 show the thymus gland of cat no. 4, and no. 2, respectively. These typical sections are very difficult to compare microscopicallj-, owing to the great difference in the shape and arrangement of the lobules. Moreover, a comparison of the relative size of the medulla and cortex in the lobules is inaccurate as the section goes through the different lobules at different levels.

In the section shown from cat no. 2 some of the lobules show a definite demarcation between cortex and medulla, while others show none, according to the part of the lobule cut through in the

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE 79

section. The cortex of the lobules is densely packed with lymphoid cells, the medulla being comparatively free from them.

WIn the section of thymus from cat no. 4 there are clearly more large lobules present than in cat no. 2. "Whether the total number is greater is very difficult to say, owing to the it-regularities in size and shape. There is little difference in the relation of cortex to medulla in cat no. 4 as compared wi^h cat no. 2. The place in the lobule through which one section passes affects this relationship, as in cat no. 2.

Apparently, then, the most important point in the microscopic comparison of the thymus of cat no. 2 and the thymus of cat no. 4 is the larger size of lobules found in the latter. Since the total weight shows a percentage excess for the thymus from cat no. 4 of 54.8, as sho-^\Ti in chart 2, and since the microscopic study shows l>anphoid tissue to fonn at least an equal percentage of the entire gland, there is an excess percentage of lymphoid tissue of at least 50.

Mesenteric lymph glands. The sections were taken through the enlarged part of the glands, at which place they were of about the same diameter. Both glands at this point contain two definite lobes, separated by connective tissue.

Figures 11 and 12 show sections of the two larger lobes of cat no. 4 and no. 2, respectively. These two lobes are about the same size. In the section from cat no. 4 we notice a decidedly great number of solitary follicles which are also larger and show a thicker and denser rim of lymphoid cells, as compared with the gland from cat no. 2. In cat no. 4 these foUicles are found in the medulla as well as in the cortex. Few are seen in the medulla of the gland of cat no. 2. The cortex of cat no. 4 apparently contains more lymphoid tissue than that of cat no. 2, but the difference is not great. However, the most striking thing about the sections is the comparison of the medulla. There is m cat no. 4 a greater area of medulla than in cat no. 2. The cords in the medulla are greater in number and decidedly larger and more continuous. Like^ase, the sinuses cover a greater area and contain a great many more lymphocytes in the gland from cat no. 4 than are found in cat no. 2, where the sinuses are comparatively

80 EUGENE L. SETTLES

free from Ijinj^hocytes. The two smaller lobes of cat no. 2 and oat no. 4 coiniwre in practically the same way as the larger lobes.

The comparison of these two tyi)ical sections, then, shows but little difference in the comparative area occupied by lymphoid cells in the two glands. The medullar^' cords are larger and the follicles are larger and more densely packed with cells at the periphery' in cat no. 4 than in cat no. 2. However, the extrafoUicular acciunulations of Ijiiiphoid tissue are perhaps greater in cat no. 2. Other sections of these glands were studied and showed similar conditions. Since, however, the gland from cat no. 4 showed a percentage weight which was 22.7 per cent higher than that from cat no. 2, it is obvious that the percentage amount of lymphoid tissue present in the mesenteric hnnph gland of cat no. 4 exceeds that of cat no. 2 b}' at least 22.7 per cent.

Peyer's patches {agminated follicles). By far the most striking difference found in any of the h^l1phoid organs was that found in the comparison of the Peyer's patches, as seen through the microscope. Cross-sections of the long patch located in the tenninal portion of the ileum are shown in figures 13 and 14 and parts of them shown again at a higher magnification in figures 15 and llj.

A comparison of the dimensions of the cross-sections is as follows :

Width of jiatch, cat no. 4, 7.5 mm.; cat no. 2, 5.2 mm. Average thickness of j)atch, cat no. 4, 2.2 mm.; cat no. 2, 1.04 nmi.

Since this patch has been found in several cats to be of approximately the same length and of fairly uniform width, it is possible to estimate, from the two ilimensions given, the relative volumes of the Peyer's patches in cats no. 2 and no. 4. The areas of the cross-section are found to be: for cat no. 4, Ki.o s(i.nuii.; for cat no. 2, 5.4 sq. mm. It follows that the volume of the gland from cat no. 4 is three times the volume of the gland from cat no. 2. This is a far greater difference than has been found in any of the organs in which comparison by weight was jiossible. Moreover, a study of the sections shows an etiually striking difference in the histological picture. The section from cat no. 2 shows a row of nine follicles, lying mainly between the muscularis mucosae

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE 81

and the circular muscle layer, with a fairly wide stretch of submucosa intervening between the follicles and the latter. Toward the lumen, these follicles have projections, most of which end at the muscularis mucosae. A few of them break through this layer and extend out into the base of the villi, forming wedgeshaped structures. Between the follicles there is some Ijnnphoid tissue in the half of the patch toward the lumen, while in the other half there is loose tissue. The villi over the patch are, in the main, normal appearing, save for the few whose bases are invaded by the wedge-shaped lymphoid projections, though perhaps they are slightly shorter than over the remainder of the mucosa.

The section from cat no. 4 shows extraordhiaiy differences. There is about an equal number of follicles, but the individual follicles are enormously larger — in fact, as seen in figures 15 and 1(3, they may well be called gigantic — as compared with those from cat no. 2. The space at the subinucosa between the follicles and the circular muscle layer is somewhat less than in no. 2. The follicles are packed with lymphoid cells. Toward the lumen, the muscularis mucosae is broken through at many more places than in no. 2, and the wedge-shaped projections into the villi are much larger and more numerous. The \illi o\er the patch are very short and wide, many containing a central mass of lymphoid tissue. The spaces between adjacent follicles are smaller than in no. 2, and are filled with lymphoid tissue in the half tow-ard the lumen, as in cat no. 2.

It is obvious that the proportion 1 to 3, found for the volumes of the patches, jn-obably underestimates the relative amounts of lymphoid tissue, since the follicles are equally packed, while in no. 4, the projections through the submucosa are much greater and the spaces between the foUicles much less.

A very suggesti^•e finding, also, was that of the presence on cat no. 4 of isolated follicles, separated from the Peyer's patch, usually one or two in each section. None were found in cat no. 2. This suggested that new follicles may have developed in cat no. 4 and led to a study of the lower ile\un to determine how extensive this difi'erence might be.

THE ANATOMICAL UKCORD, VOL. 20, NO. 1

82

EUGENE L. SETTLES

Soli lory foil icUs and ly/iiplioid (iccuinulaliDim in the lower ileum. In order to obtain an estimate of the relative number and size of solitary follicles in the lower ileum, five blocks of intestinal tissue from cat no. 4 and six from cal no. 2 wore examined. The jiieces, .', to 1 cm. loiijz;, were taken at various corresponding levels, from the lower third of the small intestine. The blocks were embedded in jiaraHin and cut transversely into sections 25 ^ thick. Every fifth section was sa\Td. The results are as follows:

Cat no. 4: block (1) 385 cm. above caecum in 35 sections 6 solitary follicles

Cat no. 4: block (2) 25J cm. above caecum in 29 sections 19 or lymphoid

Cat no. 4: block (3) 205 "n. above caecum in 25 sections 17 accumulations

Cat no. 4: block (4) 10 cm. above caecum in 45 sections 35

Cat no. 4: block (5) 11 cm. above caecum in 42 sections 01

Total 176 sections 138

Cat no. 2: No. (1) 39 cm. above caecum in 03 sections

Cat no. 2: No. (la) 32 cm. above caecum in 46 sections

Cat no. 2: No. (2) 25 cm. above caecum in 56 sections

Cat no. 2: No. (3) 20} cm. above caecum in 55 sections

Cat no. 2: No. (4) 15 cm. above caecum in .50 sections

Cat no. 2: No. (5) 10 cm. above caecum in .54 sections

solitary follicles

or lymphoid

accumulations

Total 324 sections

In estimating the number of follicles in cat no. 4, follicles aj)pearing in more than once section were counted once onlj'. Peyer's patches seen in some of th(> l)locks from I)o1h specimens were disregarded.

The follicles' seen in cat no. 4 vary from small accumulations of lymphoid cells, located outside the muscularis mucosae, to fidl-sized follicles, many of which project through the muscularis nuico.sae into liie base of the villi.

The result of this estimation is mo.st striking. In the intestine of cat no. 2, 324 .sections were examined, and no trace was found of lymphoid accumulations or solitary follicles, apart from Peyer's jKitchcs. In cat no. 4, in only a little more than half as many sections, 138 separate lymphoid accumulations or solitarj- follicles were seen, in additi<m to Peyer's jiatches. This result is the most .striking one which has been obtained and harmonizes with the study of the two Pe3er's patches. There can be no question

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE 83

but that the difference in diet is an exceedingly important factor ill the regulation of the amoimt of lymphoid tissue in the intestinal wall.

DISCUSSION AND CONCLUSION

In reviewing the results of the experunents, it should be emphasized that whatever effect may have been produced by the difference in diet cannot be attributed unequivocally to the mere difference in the fat content of the diet, since there was also a difference in the amount of calories. The experiment, therefore, shows the effect of a high calorie diet, in which the excess calories are pro^•ided by the fat of cow's milk. \Mth this definitely understood, let us group together the results which have been obtained.

A comparison of the weights of organs has shown that there has been produced, in the animal recei\ing the richer diet, an enlargement of ])ancreas, liver, th3'nms, and mesenteric Ijanph gland out of proportion to the enlargement of other organs, such as heart and kidneys. Gross appearance and the study of microscopic sections have also shown a striking enlargement of the Ijanphoid tissue along the digestive tract — of the palatme and pharyngeal tonsils — and especially of the Peyer's patches and solitary follicles. Microscopic stud\' and comparison of the elements making up the lymphoid organs showed the hanphoid tissue to be either equallj' extensive or more extensive, relati\-eh-, in the cat fed the high calorie, high fat diet as compared with the control. The excess weight and size were found to be due not to stored-up fat (except in the liver), but to increase in Ij^mphoid tissue proper. Therefore, it is obvious that, in lymph gland and thymus, with a decided excess in weight, and at least an equal distrilnition of h'mphoid tissue, the high calorie, liigh fat diet has resulted in a \-ery substantial increase in the amount of lymphoid tissue proper. In the two tonsils and particular!}' in tlie Peyer's patches, all of which are made up of practically solid lymi)hoid tissue, the difference in size as seen hi corresponding sections — and which amounts, in the case of the Peyer's

84 EUGENE L, SETTLES

patches, to a 200 j)er cent excess — indicates a decidedly larger relative amount of lymphoid tissue as a result of the higher diet.

An exception is furnished by the sjiloon, which though a Ivmphoiil organ, shows no excess weigiit nor any marked increase in lymphoid tissue proper. It might be urged, in ex])lanation, that the spleen is extremely variable in size in nonnal anunals, as has been pointed out by .Mivart ('98) and Ilatai flo), among others, and that a larger number of experiments might yield a result different from the present single experiment. However, this would be unjustifiable, considering the similaiityof treatment of the two animals. It is only fair to conclude that the size of the spleen and the amount of lymphoid tissue contained in it have not been affected by the difference in diet.

The very great excess increase in the thynnis is of extreme interest. It has been found by many observers that the thj'nms is remarkabl}' .sensitive to undernourishment. Its response is so striking that Hammar (05) has given the name 'accidental hunger in\'olution' to the great reduction in size which occurs. Jonson ( '09) founil in rabbits, after four weeks of underfeeding, a reduction in weight of thjmus to one-thirtieth the weight of the control. .Jackson {'15) observed a loss of 90 per coMit relative weight in the thj-nms of rats given a maintenance diet between the ages of three and ten weeks. Stewart ('18) obtained, in rats held at maintenance diet from birth to ten weeks, an SO per cent loss in relative weight of the thymus. .Jonson ('09) found an extremely ra])id recovery rate on resumption of normal feeding, nonnal weight being reached after three weeks of normal diet following a period of und(>rnourishment.

The i)re.sent study indicates that the thjnius responds to a surplus diet, in which the surplus calories are suj)plied bj' fat, bj' a decided increase in size. It thus sujiplements and sujiports previous studies which .shows the thymus to l)e jjarticularly sensitive to differences in diet.

The sunilarity in respon.se of the thymus and of the l}'m])h glands and lymphoid tissue along the intestinal tract affords evidence in support of the theory that the thjinus .should be grouped with lymj)hatic glands as a lynjphoid organ.

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE 85

The results furnish new e^•idence in support of the view, suggested at the beginning of the paper in the review of Hterature, that the lymphoid organs are concerned with metabolism — probably with fat metabolism — for they sli()\\- a marked response to the high fat diet, along with the li\-er and pancreas, which are known to be specifically concerned with the storage and digestion of fat. In responding to an increased function, or demand, for Ijnnphoid cells, or lymphocytes, by an increase in size, the hTnphoid organs would be merely following the wellproved law of functional adaptation, according to which increase in the function of an organ is accompanied by increase in size.

Further studies should be made in order to analyze the two factors of high calorie and high fat, which have been combined in the present expermient, and also to test the effect on lymphoid organs of other dietary factors. However, whether the results have been caused by one or the other, or both, they are of value, for they show that these organs respond very decidetlh- to differences in diet, by differences in size, which are far out of proportion to the relative differences in the size of the entire anunals.

SUMMARY

Four kittens of the same litter and practically the same weight were fed on diets differing in fat content, with the purpose of discovering the effect of a high fat diet on lymphoid tissue.

Two of the anunals, one of which had been fed on a low fat percentage (0.7 per cent) and the other a high fat percentage (6 per cent), died at the end of three weeks. No appreciable difference was found in the gross appearance or weight of the h'mphoid tissue of these two cats. However, microscopic examination showed a noticealjly greater amomit of l>anphoid tissue in the mesenteric lymph gland of the cat which had received the high fat diet.

The other two kittens were kept for a jjeriod of four and onehalf months, one on a normal fat percentage diet (3?, per cent) and the other on a high fal jierciMitage diet ((> per cent). Thej both remaincil in perfect health throughout the last three and a half months of this time.

80 EUGENE L. SETTLES

Although the two cats starte<l witli the same size and body weight, at the end of the four and a half months the cat fed on higluM' fat diet weighed 'AO grams more than the control, and was practically '.iO per cent larger, excluding the amount of stored fat present.

In the cat fed on a high fat percentage diet, the organs known to he concerned with fat metabolism and storage (the pancreas and liver) were noticeably larger, both by actual weight aiul percentage than in the control specimen.

In addition, the lymjihoid tissue, with the exception of the spleen, was noticeably heavier in the cat receiving the high fat diet, the excess aniomiting to a difference of 85.8 per cent hi the case of the thjTiuis ami .■)'_'. 7 per cent in the case of the mesenteric l>nnph gland.

In contrast to this, the heart and kidneys were only about 25 per cent larger in the larger animal.

Microscopic examination of similar cross-sections from all the l}^nphoid organs of the two animals showed either an equal or a greater amount of lymphoid tissue per unit area in the cat which had been fed on the high fat diet. The difference was most strikingly shown in the case of the Peyer's patch and the solitary follicles in the intestine.

It is pointed out that the results obtained indicate that a combined high fat. high calorie diet iiroduces a general enlargement of the lymi)lioi(i tissue of the body, which is most strikingly seen in the lyniphoiil tissue of the gastro-intestinal tract, but that they do not differentiate between the two factors — high calorie and high fat. An analysis of these two factors as well as the efTcct of other food elements should form the subject of further investigations.

My sincerest thanks are due Dr. K. K. Clark for his invaluable advice and interest in the prol)lem here presented.

J

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE 87

BIBLIOGRAPHY

Allen, Ezra 1919 A tfclmiqvie which jireserves the normal cytological conditions in germinal and interstitial tissue in the testis of the Albino rat.

Anat Rec, vol. 16, no. 1, p. 25. Bartel .\nd Steix 1906 Uber abnormale Lymphdrusen befunde und deren

Bezichung zuni Status thymico-lymphaticus. Archiv. f. Anat. und

Physiol., Anat. .\bt., S. 231. Cl.\rk, E. R. .\nd E. L. 1917 A study of the reaction of Ij-mphatic endothelium

and of leucocj'tes in the tadpole's tail, toward injected fat. .\m.

Jour. Anat., vol. 21, p. 421. CzEB.N'EY 1907 Zur Kentniss der exudativen Diathese. iNIonatschr. f. Kin derh., Bd.6, S. 1. FiESSiNGER .4XD Marie 1909 Lbs ferments des leucocytes dans les e.xudats

des s(5reuses. C. R. de 1. See. de Biol., p, 1062; also, Jour, de Physiol.,

T. 11, p. 746. Hammar 1905 Zur Histogenese und Involution der Thymusdriise. Anat.

Anz., Bd. 27, S. 41. H,\TAi 1915 The growth of the body and organs in Albino rats fed with a

lipoid free ration. Anat. Rec, vol. 9, p. 5. Jack.son, C, M. 1915 Changes in the relative weights of the various parts,

systems and organs of young .\lbino rats held at constant body weight

by underfeeding for various periods. Jour. Exp. Zool., vol. 19, p. 135. jENSO>f, Avid 1909 Studien liber die Thymusinvolution: Die Akzidentelle

Involution bei Hunger. .\rch. f. Mikr. Anat., Bd. 73, S. 390. Kanthack and Hardy 1,S94 The morphology and distribution of the wandering cells of mammals. Jour. Physiol., vol. 7, p. SI. KiscHENSKY, D. 1902 Zur Frage iiber die Fettresorption im Darmrohr und

den Transport des Fettes in andere Organe. Ziegler's Beitr., Bd. 32,

S. 197. MiVART, St. George. 189S The cat, p. 181. New York: Chas. Scribner's

Sons. Newton, R. C. 1919 A case of enlarged thymus gland and some remarks on

status lymphaticus.' .\mer. Jour, of Med. Sciences, vol. 167, p. 354. PouLAiN 1902 De Taction des ganglions lymphatiques sur I'absorption et la

resorption des graisses. Revue mens, des Maladies de I'enfance, T.

20, p. 289. Sch.\fer, E. a. 1SS5 On the part played by amoeboid cells in the process of

intestinal absorption. Int. Monat. fiir .\nat. und Physiol., Bd. 2, S. 1.

1912 Textbook of microscopic anatomy, pp. 396, 405, 521, 548, 551,

676, 681. New York: Longmans, Green & Co. Sthbeman, H. a. 1910 Histologische Untersuehung iiber die Beziehungen des

Fettes zu den Lymphdriiscn. Beitr. z. Path. Anat. U. Z. allg. Path.

Jena, Bd. 48, S. 170-20'J. Stewart, C. A. 1918 Changes in the relative weights of the various parts,

systems and organs of young albino rats under-fed for various periods.

Jour, of Exp. Zool., vol. 25, p. 333.

EXPLANATION OF FIGURES

Figures 1 to 16 are microphotographs of histological sections of organs from cats no. 2 and no. 4. Tlipy are arranged in pairs- in each case the even numbers (2, 4, 6. etc.) placed at the riglit, being taken from the organ.s of cat no. 2, the o<ld numbcr.s (1. 3, 5. etc.) at the left, from cat no. 4. The two pictures shown in each pair were taken at exactly the same magnification. The enlargement varies for tlie dilTercnt pair.<!. The two pairs shown in figures 15 and 16 show, at a higher magnification, parts of the same sections as are shown in figures 13 and 14, respectively.

I'LATi: 1

EXPL.\N.\T10N OF FIGURES

1 and 2 Cross-sections of inferior cervical lymph glands. 10 /i thick. Figure 1, eat no. 4; figure 2, cat no. 2.

3 and 4 Cro.ss-scctions of jiharyngeal tonsils, 10 /i thick. Figure 3, cat no. 4; figure 4, cat no. 2.

5 and 6 Cross-sections of right palatine tonsils. 10 im thick. Figure .5, eat no. 4; figure 6, cat no. 2.

7 and 8 Cross-sections of spleen, taken at the widest parts of the organs, 10 M thick. Figure 7, cat no. 4; figure 8, cat no. 2.

88

EFFECT OF HIGH FAT DIET ON LYMPIKUD TISSUE

EL'GEXK L. SETTLES

PLATE 1

^5.j^^^^^ "^i

J

1

8

PLATE 2

EXI'LAXATION OF FIGURES

9 and 10 Cross-sections of corresponding parts of thymus; embedded in cellnidin. and eut 15 n thick. Figure 9, cat no. 4; figure 10. cat no. 2.

11 and 12 Crciss-sectii)ns of mesenteric lymph glands, 10 /i thick. Figure 11, cat no. 4; figure 12, cat no. 2.

Vi and 14 Cross-sections of the long Peyer's patch in the terminal ileum, 20 ti thick; magnified 4.25 (approx.). Figure 13, cat no. 4; figure 14, cat no. 2.

00

EFFECT OF HIGH FAT DIET ON LYMPHOID TISSUE

KfGEXE L. SETTLES

PLATE 2

91

I'l.ATI'; 3

EXPLANATION OK FIGURES

15 and 10 Iliglicr-power magnification of parts of same sections as shown in figures 13 and 14.; magnified 18 times (approx.), Figure 15, cat, no. 4; figure 16, cat no. 2.

92

EFFKCT OF llKUl FAT DIET ON LVMI'lIOln TISSUE ki:gkn-e l. settles

I'l.ATE 3

93

Resumen por el autor, Ivan K. \\'alliii, University of Colorado.

Vn caso de pLUsistencia de la vtMia suiiracardinal izciuicrda con dos venas esperniaticas izc[uierdas.

La doscripf'i6n do oste caso consiste principalniontc en una ilust radon de las variaciones venosas del sujoto estudiado. I^ porci6n intViidr de la vona cava inferior consta de dos troncos. La vena es])('rniatioa iz(iuienla esta rejiresontada por dos vasos distintos: uno de ellos coniunifa con la vena renal y el otro con la vena supracardinal iztiuiorda, ([ue persists en este caso.

Translation by JiW- F. Xonidpa Cornell MctlirnI CoIIcrc. New York

AUTHOR S AnSTRACT OF THIS PAPER ISSfED BY THE BIBLIOGRAPHIC SERVICE, NOVEMBER 15

A CASE OF PERSISTENT LEFT SUPRACARDINAL VEIN WITH TWO LEFT SPERMATIC VEINS

IVAN E. WALLIX

Dc/xirlinenl of Anatomy and the Henry S. Dennison Research Laboratories,

University of Colorado

OXE FIGURE

The occurrence of duplication of the inferior vena cava is not an ahogether rare condition. In recent j-ears Givens' has described two cases observed in the dissecting room of Cornell LTniversity Aledical College, Ithaca. He also reviewed the literature of some fourteen cases.

The venous ^•ariant here recorded was found in a male cada^-er in the dissecting room at the University of Colorado School of ^ledicine. There were no records of the age or the cause of death. The approximate age was sLxty-five years.

Figure 1 illustrates the lower part of the caval system in this subject. In character it is quite similar to the veins found in subject no. 466 described by Givens. The left persistent supracardinal is larger than in Givens' subject. In his specmien the size ratio between the right and left supracardinals was 3 to 1.6. In my subject the ratio is about 2 to 1.5.

An unusual feature in this subject are the two left spoiinatic veins. So far as I can learn this is the first recorded instance of such a condition. The figure shows the nature of the two veins. The one emptying into the renal vein was about one-third the size of the one emptying into the left supracardinal. The two veins were dissected out for some distance in the conl. With the exception of their i:)roxunal ]iarts where \\\ey separate to empty into the above-named veins they lie close together in all of their course.

' Givens, M. II., 1012. Duplicjition of tlie inferior vena cava in man. .\nat. Record, 6:475HIS6.

95

96

IVAN E. WAI.MN

'I'lu' coiKiiliKii I'diiiHl l)y Hiiiitiiintoii and McCluic-' in a luinian subject may lidp to (>xj)Iaiii llic ilupliratiiui nt' the loft spciniatic '.•oiii. Tlioy found fonostia*- in tlic H'lial rollar whicli cstal)lislicd connections Ix'twcon the ligiit s])('iniatic \'ein and the right renal vein. Hy a further extension of the fenestrae along the vein a condition might he jiroduced wliich would he like the character of the veins in this subject.

citiiuiV Vtin

Lfjl SpcTssW Vt'inJ

• Personal communication from Professor McCliire.

THE ANATOMICAL RECORD. VOL. 20. NO. ?, JANUARV, 1921

98 E. T. HSIEH

Chinese writing, however, reallj' dates from the time of the 'Yellow Emperor,' Huang-ti (3), 2(597 B.C., who ordered his servant Tsang Ch\h (4) to iiiako. words in the fnnn of imitative sjnnbols. These wore done in laciiuer ajjon strij^s of bamboo or palm leaves. Paper and pens came much later. It is said that the vertical arrangement of characters was adopted because it is much easier to write up and ilown a bamboo than around it. Many characters were elaborated iluring this jieriod. We are told that Shen-Nung saw a good crop and made a character representing crop ears; that Huang-ti wrote a 'cloud;' Yao (5) a 'turtle;' Yii (6) the 'bell and the kettle,' and so on. The symbols devised represented pieces of string of different lengths with knots at various places in their course. Those consisting of a single knot with a small piece of string attached have suggested the name of 'tadjiole characters' for this writing. These characters soon became profoundly modified.

Figures 1 and 2 illustrate the pictorial type of the writing of the Hsia dynasty, 2205 B.C.

A considerable change was also made about the beginning of the Chin djniasty (7), 255 B.C., when Li Si (8) greatly improved the terms and divided them into Ta Chiian (9) and Hsiao Chuan (lOj. Hsiao Chuan was changed to Chin Chuan (11) during this period. A little later Cheng Aliao (12) devised a script called Li Shu (13), or plain square writing, which the first Chin emperor observed and ordered to be used throughout his empire. Paper was first manufactured at this time by Wang Lun (14).

In the Han dynasty (15), 206 B.C., writing was further improved by Chia Fang (Ki), San Tsang (17), Tsai I (18), and Shih Ching (19), who wrote the word, Han Li (,20), as may be seen by reference to figure 3. In the Chin (21) dynasty, 265 A.D., Chung Yin (22) anil Wong Hsi Chih (23) changed the writing into a style more nearly approaching that of the present day. Typical Chi-dynasty (479 A.D.) wTiting is well illustrated in figure 4, and this may be compared with the modern Chinese on pages 125 127.

The works of Huang-ti (3), written over four thousand years ago, '2697 B.C., are the most interesting and original of the great

A REVIEW OF ANCIENT CHINESE ANATOMY

99

It

— A

ffl ^1^ ^T

I^^'

l|g

i

^ i^ i ^3

t il f II '^

-v/^

2

Fig. 1 Old style of writing, Hsia dynasty, 2205 B.C.

Fig. 2 Old style of writing, Hsia dynasty, 2205 B.C.

Fig. 3 Old style of writing, Han dynasty, 206 B.C.

Fig. i Old style of writing, Chi dynasty, 479 A.D.

100 E. T. HSIEH

C'liiiiosc iiiodiral classics. They stand at the basis of native Chinese medicine. Thej" were written on bamboo strips in words of the tadpole style as a record of questions which Huang-ti asked his servant Chi Pe (24). I^ater, in the I Ian dynasty (206 H.C.), they were gathered together into book form and were eddied Xeiching (25) Inlernal Chussics, Su Wen (20), Inquiries and Ling Shu Ching (27), The Classics of (he Living Srpirit. Unfortunateh', they were composed in such gemiine literarj' style that they were ditHcult to understand until the thne of Tang (28), in 020 A.D., when Wang Ping (29) wrote explanatory notes for each book.

In the Chow djTiasty (30), 1122 B.C.. there lived an anatomist called Chin Yuoh .len (31), who wrote a treatise about the \'iscera and arteries and called it Xanching (32), or Hard Classics. This vohnne contains, among other tilings, a number of interesting measurements of the weights of the difTcrent organs of the men of that time.

In the Han dynasty, 20(5 B.C., Chang Chi (33) wrote two hocjks (34 and 3.5) on The Essentials of the Gold Medicine Case and on Fevers, which are very popular to this day. The Prescription for Emergency (36), by Ke Hung (37), appeared in the Chin period (38), 205 A.D. and, about two hundred years later, we meet with Chu Cheng's (30) copy of the Testament (40).

Many other authors follow, of whom we may mention Tsao Yuen Fang (41) in the .Suei dynasty (42), 689 A.D.; Sun Si ^liao (43) and Wang Show (44). in the Tang dynasty (45), 020 A.D.; and Wang Kun, Shen Kue, Chen Chi, Tang Chi, Liu Wen, Han Ti, Pang An Shih, Cheng Ho Chung, Tang Shen, Wang Chu, Hsu Su, Chen Ssu Wen, Hsia Tc Chang Kuo. Chen Tze Ming, Chen Yen, Li Hsun, Yen Yung Ho. and Yang Chih Ying (46-64) —all in Sung dynasty (05), 900 A.D.

Liu Wen Su, Chang Yuan Su, (hang Chung Cheng, and Li Hao (()6-69) were prominent medical writers in the Chin (70) (lyna.sty (1200 .\.I).), and Wang Hao Ku, Sha-Tu-Ma-Su, Wei Ye IJn, Chu Chen Ting, Wang Kue Juei, Chi Te Chi, Tai Chi Tsung, and Wang Lii (71-78) in the Yuan dyna.sty (79), 1280 A.D.

A REVIEW OF ANCIENT CHINESE ANATOMY 101

Thv iiuiiK! of ( 'hang ( 'lii I'iiig (80j is famed as a great anatomist in the -Ming dynasty (81), 1368 A.D. Chang wrote a mmiber of books. His most famous one he called Leiching (82). It dealt intensi\ely with the visceral and vascular systems.

Important ad\ances were made in the C'hing dynasty (83), 1(344 A.D., when the Emperor Chien Lung (84) edited an Enqjdopedia of Chinese Medicine (85) and the go\'ernment encouraged research. Sheng Teng's (86) book on osteologj' (87) is replete with interesting observations. In the days of ("hia Ching (88), 1796 A.D., a terrible epidemic raged among the children in the town of Chang Li Hsien (89) and many died. A certain magistrate, named A\'ang Chui Jen (90), visited the jjublic cemeteiy and found that, since the children were buried in very shallow graves, the hungry dogs were able to uncover the bodies and devour them. AVang's cvn-iosity was so stinuilated that he went daily to the cemetery and observed over thirty complete bodies dismembered by the dogs. He was thus enabled to test out the old theories and to make important new observations which formed the basis for his book which he called ^l Correction of Fnults in Medicine (91).

At present anatomy is out of date in native Chinese medicine because the doctors only prescribe herbs for the patients and make no attempt at surgical oi)erations.

As it is impossible for me to attempt to review, in the space at my disposal, the whole of the ancient science of anatomy, I shall confine myself to a discussion of splanchnology', angiology, and anthropology.

IIISTOUV Ul I'lllNESK SPLAXCIINOLOGY

Splanchnology and angiology may be traced back to the time of Huang-ti. 2697 B.C. The two subjects were then more or less philosophically treated, and the theories advanced at that time have l)een luindtMl down to us almost without change and constitute the foundation of native Chinese medicine to-day.

Life is said to depend upon the action of a female principle which embraces a male principle. These principles are ojiposite powers of vigor or strength which are equal in weight. When

102 E. T. HSIEU

they are properly balanced there will lie lu) disease of any kind and the pei-son will be productive and healthy. These principles are distributed (niite differently in the body. The exterior is male and the interior female; the back male and the abdomen female; the viscera male and the parenchjiiiatoiis organs are female. Each principle has three degrees in quality, namely, great female principle, female principle proper, and yoimg female principle; great male i)rinciple, male i)rincii)lc j)r()per, and young male principle (92-97). These three degrees of principle are evenly distributed in their respective organs and viscera.

There are twelve tract.s for the transmission of these principles in the general circulation. Translating literally we read that: The hand receives the great female principle of the lung; the foot receives the great female princijile of the spleen; the hand recei\'es the female principle proper of the pericardivnn ; the foot receives the female principle proper of the liver; the hand receives the young female jirinciple of the heart; the foot receives the young female principle of the kidney. The hand receives the great male principle of the large intestine; the foot receives the great male principle of the bladder; the hand receives the male i)rinciple proper of the small intestine: the foot receives the male principle proper of the stomach; the haiul receives the yoimg male principle of the three burning spaces; the foot receives the young male principle of the gall-bladder.

The three bin-ning spaces referred to are situated in the thorax, abdomen, and ]5elvis and are illustrated in figme 13. They are supposed to be filled with fatty tissue.

We read further, that, since the exterior is male and the interior female, then the male and female principles are as the coat and the lining (98). (Literally, gieat male and young female are the coat and the lining; male proper and young female are the coat and the lining; young male and great female are the coat and the lining.)

The quality of the principles varies in different organs and we have corresponding differences in the amount of air and of blood. The great male prin(ii)le usually has much blood and very little air; the male j)rinciple proper has both blood and air

A REVIEW OF ANCIENT CHINESE ANATOMY 103

in good quantity; and the young male prinfiiilc has verj' little blood but much air. The great female principle has much air and little blood ; the female principle proper has much blood but little air; and the young female principle has very little blood but much air.

The liver (fig. 7), heart (fig. 5), spleen (fig. 8), lungs (fig. 9), and kidneys (fig. 10) are commonly called the five parenchj'matous organs, while the gall-bladder (fig. 15), stomach ffig. 14), large intestine (fig. 16), small intestine (fig. 11), bladder (fig. 12), and the three burning spaces (fig. 13) are regarded as the six viscera. The pericardium (fig. 6) and brain maj' also be refeiTcd to as organs. There are some differences of opinion about this, however, because Chi Pe, the servant of Iluangti, 2()97 B.C., claimed that the brain, bone-marrow, gall-bladder, and uterus arc prenianont singular bodies, which would indicate that the brain and bone-marrow may also be classified as true organs. The meaning of the term organ (99) is to store up, but not to eliminate, while the word viscera (100) means to eliminate, but not to store up.

Huangti, 2697 B.C., describes hi his book on Neiching, or Internal Organs, what the different organs store. We read that the liver (fig. 7) stores the blood, which contains the soul; that the heart (fig. 5) stores the pulse, which contains the spirit; that the spleen (fig. 8) stores the nutrition, which contains the thoughts; that the lungs (fig. 9) store the breath, which contains the energy, and, finally, that the kidneys (fig. 16) store the germinating i)rinciple, which contains the will. He explains also his idea of their action. The liver has a rancid odor, a sour taste, a brown color, makes the sound chiich (101), a note in Chinese music, and at will is the seat of anger. The heart has an odor of toast, a bitter taste, a brownish-red color, makes the sound chih (102), and at will is the seat of happiness. The spleen has a fragrant odor, a sweet taste, a yellow color, makes the sound kitng (lOii), and at will is the seat of thought. The lung has a fishy smell, a hot taste, a white color, makes the sound slieng (104), and is the seat of sorrow. The kidneys (fig. 16) have a putrid smell, a salty taste, a black color, make the sound yu (105), and at will are the seat of fright.

104

E. T. USIEH

Jirif^?k

^^J^

.7 8

Fig. 5 Heart with three cords, as kidney, liver, and spleen (Huang-ti period, 2697 B.C.).

Fig. 6 Pericardium. Fig. 7 Liver. Fig. 8 Spleen.

A REVIEW OF ANCIENT CHINESE ANATOMY 105

Those five organs are siijjposed to work lianiK)iiiously together and serve in the (knelopnient of the bodj' as follows: The liver produces the ligaments, forms the heart, and controls the lungs. The heart produces the blood, forms the spleen, and controls the kidneys. The spleen produces the flesh, forms the lungs, and controls the liver. The lungs produce the skin and hair, form the kidneys, and control the heart. The kidneys produce the bone-marrow, form the liver, and control the spleen.

The five organs control the five senses and all parts of the bod}-. The liver has an eye at its opening, converts the fluid into tears, supplies the Hgaments, and nourishes the nails. The heart has the tongue at its opening, converts the fluid into perspiration, supplies the pulse, and nourishes the complexion. The spleen has the mouth at its opening, converts the fluid into saliva, supplies the flesh, and nourishes the lips. The lungs have the nose at their opening, convert the fluid into snivel, supply the skin, and nourish the fine hairs. The kidneys have the ears as their openings and also the genito-urinary region, they convert the fluid into spittle, supply the bone, and nourish the hairs.

The five organs arc related to the six viscera which answer each other in their action (p. 103). The lungs relate to the large intestine, which answers the skin; the heart relates to the small intestine, which answers the arteries: the liver relates to the gall-bladder, whicli answers the ligaments; the si)leen relates to the stomach, which answers the muscle, and, la.stly, the kidneys relate to the three burning spaces and the bladder, which answer the skin and the hairs.

The functions of the organs and viscera are described as follows: The heart" is the king who directs the bod}', the lungs are the pronnilgators who carry out his orders. The liver is the general whose iluty it is to meditate carefully. The gall-l)ladder is the central legal officer, who makes judgments. The pericardium is the minister to bring happiness. The spleen is the officer of granaries who creates the five tastes. The large intestine is the ofHcer of conununications who .starts all sorts of changes. The small intestine is the receiving office in which digestion is carried on. The kidney is the officer of vigor or strength who

106

E. T. HSIEH

9

in

pjtnn pxB'h

Wj T

//r iiii

11 12

Fig. 9 Lung with trachea (2697 B.C.) Fig. 10 Lnrgc intestine with the upper opening for the small intestine and the lower part for the rectum.

Fig. 11 Small intestine with the upper and lower openings. Fig. 12 Uiadilcr and urethra.

A REVIEW OF ANCIENT CHINESE ANATOMY 107

serves through his intellect. The three burning spaces constitute the sewage system from which all the canals drain into the bladder where the fluid is stored; after having been acted upon by the air, it is finally passed out.

The surrounding walls of the organs and \'iscera are also described: The thorax and abdomen constitute the city wall and the pericardium (fig. 6) is the palace of the king; the stomach is the granary and the throat and small intestine the post-office. The five openings of the stomach are called the doors, entrances and outlets (of the granary). Water and grain enter the body by the esophagus and air by the trachea. The food enters the stomach where essence soaks into it and it becomes air, which, if of nourishing nature, passes into the lower burning space. The air, entering at the trachea, passes through the epiglottis, which is the door of the voice. The mouth and lips are the fan for the voice, the tongue the machine for the voice, and the u\'ula the pass for the voice. The larjTix divides the air. The breath, coming from the lungs, is thought to act upon the transverse bone (hyoid) and the tongue (in speaking).

In the same book Huangti gives some measurements of the alimentary tract which will be of interest to anthropologists (see also p. 121).'

Distance from lip to teeth J inch

Width of mouth 2J inches

Distance from teeth to epiglottis 3} inches

Capacity of mouth and pharynx 5 Ko (1C6)

Weight of tongue 10 oz.

Length of tongue 7 inches

Width of tongue 2J inches

Weight of esophagus 10 oz.

Width of esophagus 1} inches

Length of esophagus 1 ft. 6 inches

Length of stomach stretched out 2 ft. 6 inches

Circumference of stomach 1 ft. 5 inches

Diameter of stomach 5 inches

Capacity of stomach (dry measurement) 3 tou (107) 5

sheng (108)

' L'nfortunately, we cannot ascertain their equivalents in present-day standards.

lOS

E. '1. HSfEH

/

iS ji P

13

14

15 16

Fig. 13 The tlirec burning spaces (2697 B.C.).

Fig. 14 Stomach.

Fig. 15 Gali-bla<l.lcr.

Fig. 16 Kidney.

A REVIEW OF ANCIENT CHINESE ANATOMY 109

('irriuiifcrfncc of sm:ill intestine 2J inches

Diameter of small intestine ,*j inch

Length of small intestine 33 ft.

Capacity of small intestine (dry measurement; '2 ton, 5 sheng

Circumference of large intestine i inches

Diameter of large intestine 1} inches

Length of large intestine 20 ft.

Capacity of large intestine (dry measurement) 1 tou

Circumference of rectum 8 inches

Diameter of rectum 2} inches

Length of rectum 2 ft. 8 inches

Capacity of rectum . -\ Ko

The small intestine is attached to the spine posteriorily, and anteriorily to the navel. It exhibits sixteen loops. The large intestine lies on the left side of the navel and has also sixteen curves.

In the book called Nanching, or Hard Classics, written by Chin Yiirli Jen in the Chow djniasty, 1122 B.C., we find the niorpholofrj- anil weights of the different organs and viscera described. It difl'ers from Neichiiuj in the following jiarticulars:

Liver, three left lobes and three right lobes. . . 4 catties, 4 oz.

Heart, seven holes and three pillars contains 3 Ko of

vigorous principle 12 oz.

Sjjlcen, flat, 3 inches thick, 5 nches long, contains }

catty of loosening extract 3 catties, 3 oz.

Length, eiglit lobes 3 catties, 3 oz.

Kidneys, two in number • 1 catty, 1 oz.

Ciall-bladdcr rests on the short lobe of the liver, contains 3 Ko of essential fluid 3 oz. 3 drams

Stomach •. 2 catties, 2 oz.

Small intestine . 2 catties, 14 oz.

Large intestine 2 catties, 12 oz.

Hladder when stretched 9 inches long, contains 9 sheng,

9 Ko of urine 9 oz. 2 drams

Trachea, 2 inches wide, 1 ft. 2 inches long, in 9 sections 12 oz.

Rectum 12 oz.

In the Tang dynasty, 020 A.D., Sun Ssu Miao wrote two books in whicli he followetl the descriptions given in the Xatiching over 1700 years earlier with but slight modifications. However, the weights of the intestine and stomach and the length of the intestine difi'er somewhat from tho.se given by Huangti in his

110

E. T. HSIEll

r^

17

4: -& m S fi

19

Fig. 17 Surfnnc anatomy, letters indicate the l)one.s, front view (2097 B.C.).

FIr. is Ditto, back view.

Fig. 19 Ditto, aide view.

Fig. 20 Uo<ly measurements, front view.

A REVIEW OF ANCIENT CHINESE ANATOMY 111

Neichinc/, 2007 B.C. Sun Ssu Miao described two bladders, one receiving the 'essential fluid,' and the other, fluid and urine. In his books each organ or viscus had attached to it the name of a protecting god. This indication of theocratism is not, however, found in later writings on Chinese medicine. Controversy has been active regarding the three burning spaces (fig. 13j for upward of four thousand years. In the Nanching we read that the three burning spaces have no form, that they control the air (vigor), and that the two kidneys should be classed as two separate and distinct organs, the left being the real one and the right the 'gate of life.' The 'gate of life' is said, in the male, to contain the semen and, in the female, the uterus. This conception is entii'ely different from that advanced in the Xcicliing. Huangti, 2697 B.C., Wang Shu Ho (109), Huei Tstmg (110) and Sun I Kuei (111), all contend that the burning spaces exist only in name, but not in form (lOS and 109).

The second theory assumes that the burning spaces exhibit definite structure. This view is actively supported by Hsu Tun (112) and Chen Wu Tse (113) in the Sung dynasty. The former observed a piece of fatty membrane, about the size of a man's hand, near the bladder and two whitish cords emerging from it and running to the brain. He concluded that the membrane constituted the burning spaces (114). In the Ming dynasty, 1308 A.D., Yii Po (lloj writes that the fatty membrane in the thorax also belongs to the three burning spaces. Chang Chi Pin holds the view that the thorax and abdomen are constructed Hke a large sac (110), that the inner lining is very red and that these linings are in triith the burning spaces. He debates the subject at length.

.Vccording to a third theory, the three bm-ning spaces are capal)le of suixlivision into upper and lower parts governing corresponding regions of the bod}'. This idea is due to Li Kao (117) writing in the Yuan dj'nasty, 1280 .V.D. (118-119). Later in the -Ming dynasty, Ma Shih (120) described the three bm-ning spaces as hcing a compound of two sets, one without form and the other with fonn. He says in his book (121) that the upper, middle, and lower burning spaces, described in Ranching, are

11:

E. T. IISIEU

a ^ oL .a a m A t

^ «

71'

n=MMi!m

22

Kig. 21 Ho<ly meusiircments, back view (2697 B.C.).

Fig. 22 Traveling vessels with their needling points, front view.

Fig. 23 Ditto, buck view.

A REVIEW OK ANCIENT CHINESE ANATOMY 113

without form and filled with air, whilo the three burning spaces of the hand, foot, and young male have fonii.

A few words may here be said about the tenii '^lingmen,' or 'gate of life' (122), which is first used in the Manchiiig, 1122 B.f. The still older book T-C"hing (123), originally written by Fuhsi (124) in 28.")2 B.C. and revised by Wen A\'ung (125) in 1122 B.C., says that "Keep in the learning of water, to which the kidney belongs, and you will be strong" (12()). Hoa-show (127) claims, in the Yuan period, 12S0 A.D., that the air of the 'gate of life' connects with the kidnej'. We find that later, in the Ming period (1368 A.D.), ("hao Hsia Ke (128) advanced evidence that the 'gate of life' is located at the needling point in the lumbar region, and further that female water belongs to the right kidney and male water to the left, between which there is a space of IJ inches. This area he believed to be the 'palace of life' from which the true fire, which is without form, is sent (129). But Sun I Kuei ( 130j expressed a different view, according to which the 'gate of life' is the original or mobile air of the body which i)lays lictween the two kidnejs (131). Chang Chi Pin is a little more specific in his theory that the 'gate of life' corresponds to the orifice of the uterus where the kidney stores its essence. In Taoism this location is called 'Tautien' (132). According to still another view, the 'gate of life' is at the back opposite to and at the same level as the navel (,133). All these conceptions indicate that the men of the time were tiying to i-everse the error of the Xancliitui which described the 'gate of life' as resident in the right kidney.

Between the Sung and Yuan dynasties. 960-1280 A.D.. there is but little improvement in the science of splanchnology, '^fhe publication of Chao Ilsien Ke's (134) MnrphoUnjicnl Atlas (13o) and of Sun 1 Kcui's book on Huiiuui Itikrnal Organs (136), mark, however, a certain advance. Subsequently, in the Ching period, 1644 A.D., Feng Chiao Chang (137) reversed the teachings of (liao and improved his descriptions. In Feng's hook we read that the lung is attached to the third vertebra and hangs down in four lobes which nvo gray in color, that it possesses twenty-four lobes in order to provide for the circulation of air

in

E. T. HSIEH

S Nit

ft

-F /4 R iu -:; y 5 r. !") T. S ;^

24

2 5

-t: fp) -^

0, njj n^

2

'fulfil mnf

9

^ S"- aE -^ ^^- *^

I

))f

Ttf

^^ ]i?: -(?> ^ }jf 27

Fig. 24 Fig. 25 Fig. 26 Fig. -27

Heart and trachea, Wang-ching-jen's personal drawings (1796 A.D.). Stomach, panorca.s, and esophagus. Trachea, lung, and esophagus. Liver with gall-bladder.

A REVIEW OF ANCIENT CHINESE ANATOMY 115

from the various organs, that it is empty as a beehive with no opcniiip; below, ami that it fills on inhalation and empties on exhalation. The spleen is attached at its upper left end a little below the eleventh vertebra, it is sickle-shaped, and is enveloped by the same membrane as the stomach, and moves when a voice is heard, grinding on the stomach, and aiding in transportation and digestion. The pericardium is situated above the transverse membrane (diaphragm), with which it is connected, and below the vertical membrane, it has yellow fat and encloses the heart, to which it is connected by a thin fibrous membrane-like silk. The heart is attached to the fifth vertebra lying below the tube of the lung and above the diaphragm; it is conical in shape like a lotus bud, with openings at the side, but none below; it shows some indi\-idaal variation, being connected with the tongiie above and by means of four cords with the lung, spleen, liver, and kidneys. The diaphragm is attached to the ribs and to the spine and prevents the impure air from coming up from below. The bladder lies at the level of the nineteenth vertebra below the kidneys and in front of the large intestine; it possesses an opening below, but none above. Feng remarks that according to some books the bladder has an upper opening only and that others say that it has no opening at all, opinions which he considers to be quite erroneous. He believes that the urine is produced through a process of air change in the body. The kidneys are two in number, each the shape of a bean, one on either side of the spine, and separated by about 1 ' inches. They are enveloped in yellow fat and each is supplied with two cords which run uji and down. The upper pair are attached to the heart and the lower pair run down along the spine, pass over the coccj-x, where they enter a space about half the size of a man's hand: they leave this space through two holes and pass upward along with the spinal cord to the brain (l.'^S).

In the Ching dynasty (1()44 .V.D.), during the days of Chia Ching and Tao Kung (179(1 1821 A.D.), there lived a Chihli medical man, A\'ang Ching Jen, who spent forty years ui the study of splanchnology- and wrote a book entitled Corrections of Faults in Medicine in order to overthrow the teaching in the

ik;

E. T. HSIEH

^^

1"; U ^> ^^

29

28

'■%<tm>^'?\^^^*'^

iWt

rm%

30

31

P'ig. 2S Bladder, urethra, ami vns deferens. WanR-ching-jen's drawing (1796 A.D.).

Fig. 29 Tongue and epiglottis. Fig. 30 Omentum. , Fig. 31 Vena cava and aortn.

A REVIKW OK ANCIENT CHINESE ANATOMY 117

Nancliiiin. W'aiin made use of his except ionallj' good opportunities for study. His book is based upon twenty-four corrected pictures of the organs and N-iscera, of which figures 25 to 31 will serve as examples, and foiitains the following five essays :

1. The Epu/loltis, Right and Left Air Gates: the Main Protective Tube, the Main Nourishing Tube; and Air and Blood Centers.

2. The Route of Digestion and the Excretory System.

3. The Brain.

4. The Air, the Blood, and the Pulse.

5. The Ah-^ence of Blood in the Heart.

We may mention in conclusion Peng Tsung Ilai (139), from the pro\'ince of Ssuchuan, who wrote during the Kwang Hsu period, 1875 A.D. He was a follower of Wang and was fortunate in being able to secure an atlas of western medicine for comparison in testing out tlu> theories in Meiching. Nevertheless, he holds to the old view.s and describes the 'gate of life' as corresponding to the cords of the kidney and the fat lying below the cords as the lower burning spaces. The fat in the region of the omentum corresponds in his mind to the middle burning space and that above the diaphragm to the upper burning space. He describes that ])art of the bladder which connects with the fat as the place where the water enters. .\nd finallj' he seems convinced that the brain carries out the action of the heart, which is in direct opposition to the theories of Chin Cheng Hsi (140) and Li Chih Chen (141), the former being of the opinion that the brain is the seat of memory and the latter that it is the 'palace of (iod' (142, 143).

HISTORY OF CHINE.<<E .WGIOLOGV

.\ngiology and osteology are the only sciences in which the arts of acuinmcture, cautery, and osteopathy are used therapeutically. During the time of Huangti. 2()97 B.C., acupuncture was used extensively as a method for the treatment of tlisea.se {Neiching, vol. 14), but just how the practice originated we cannot tell. We have read al)out the relations of the five organs to the different parts of the body, how the skin relates to the

118 E. T. HSIEH

lung, muscle to spleen, vessel to heart, ligament to liver, and bone to kidney; now, when the needle punctures the different tissues at \arious depths, there will be a reaction on the organ to which the tissue is related.

The vascular system makes connections between the organs and \'iscera which <are placed inside the body and all the other parts.

I'he traveling vessels circulate the blood and the air to nourish the male and female principles, to moisten the bones and ligaments, and to lubricate the joints. Twelve pairs are recognized with their respective branches (figs. 22 to 23).

1 . The hand great female hmg vessels from the middle burning space to the tip of the thimib.

2. The hand male i)roper large intestine vessels from the tip of the thumb and of tiie small finger to the large intestine.

3. The foot male proper stomach vessels from the middle of the nose to the middle toe of the foot.

4. The foot great female spleen \-essels from the great toe to the lower part of the tongue.

5. The hand young female heart vessels from the heart to the inside of the little finger.

t). The hand great male small intestine vessels from the little finger to the small intestine.

7. The foot great male bladder vessels from the inner corner of the eye to the little toe of the foot.

8. The foot young female kidney vessels from the little toe to the root of the tongue.

9. The hand female proper pericaniiiiiii vessels fi-oni the middle of the stomach to the tip of the middle finger.

10. The hand young male three burning space vessels from the tip of the little finger to the three burning spaces.

11. The foot young male bladder- vessels from the outer angles of the eyes to the little toes.

12. The foot female proper vessels from the hairy spots on the big toes to the vertex of the head connecting with the central vessels (144).

There are also eight singular traveUng vessels as follows:

A REVIEW OF ANCIENT CHINESE ANATOMY 119

1. Tho CliuiiK Moa (14oj, or 'ventral rising vessel.'

2. The Jen Moa (14(i), or 'responsible vessel.' '•i. The Tu Moa (147), or 'governor vessel.'

4. The Tai .Moa ri4S), or 'girdle vessel.'

5. The Yin C'hiao Moa. (14ilj, or 'outer heel vessel.' G. The Yang Chiao Moa (150), or 'inner heel vessel.'

7. The Yang AVei Moa (151), or 'external longus ves.«el.'

8. The Yin \\'ei ^loa (152), or 'internal longus vessel.' Though the twelve pairs of traveling vessels are separated in

their course, six regular anatomoses occurring in the extremities are recognized:

1 . The foot great male ^\-ith foot j'oung female.

2. The foot young male with foot female proper. '^. The foot male proper with foot great female.

4. The hand great male with hand yoimg female.

5. The hand young male with the heart.

(). The hand male proper with the hand great female.

The trax'eling vessels are usually deeply placed and concealed in the muscles, but one pair, as it pas.ses the external malleolus. lies superficially and can easily be seen to pulsate. Each vessel has definite places in its coui-se where the pulse air may be let out. Some of them have more than others, but the total number is 3()5. These places are called the 3(35 needling or punctme points (153).

In addition to the twelve pairs of traveling vessels, we have twelve pairs of traveling ligaments, following the same covu-se. to deal with. The ligaments are more closely associated with the limbs, muscles, and joints (154). The pulsating vessels are not able to ])ass over the larger joints, where they turn to the skin antl make their connections so that we are unable to trace their pulsations. They are fifteen in number (155).

The stomach has a large vessel for itself. The branches of the vessels are called Sun (15(5), or descendents. They serve for the overflow of the strange and malicious excess ami for the conveyance of nourishment and protection. The large junctions of the vessels with the muscles are called Hid (157) and the smaller ones Htsi (158). In the muscular fibei-s and the muscular

r_>() K. T. IISIEH

junotioiiri lliL'ie arc routes tor nourishment and protection, where the air meets. To correspond with the needHng points 365 small branches of vessels and 30.5 mnscular junctions are recognized (15i)). Each of the five organs has five traveling vessels, making in all twenty-five small traveling vessel spots; and each of the six viscera six traveling vessels, making thirty-sLx more small traveling vessel spots.

Counting the twelve traveling vessels and the fifteen i)ulsating vessels, we have altogether twenty-seven air routes which go up and down. The site where each starts is called the spring, the cvn-rent carries nutrition wiiich flows toward the termination or needling spot.

There are likewise 3C5 articulations which receive air in the following manner. The fi\e organs have six viscera, and the six viscera twelve springs wlienee the air circulates through the four passes (at shoulders and hips) and is distributed directly to the joints.

Witli reference to the pulse, we read that in the normal condition there is one beat for each expiration and inspiration. When each expiration has three beats and each inspiration four it is said to be the pulse of death (KiO).

When we remember that this complicated system which we have outlined has been handed down to us from Huangti, over four thousand years ago, we cannot help admiring the thoroughness and ingenuity which has been displayed. The obvious inconsistencies and contrailictions are svu-ely to be expected.

In the Tang period, t)2() A.l)., Sun Ssu Miao collected the atlases used by prominent doctors and wrote an interesting l)ook on Acupuncture and CnuUrij. He made illustrations in five colois showing 050 needling points in three planes (front, back, and side views). He listed 345 special names for the different points (101). rnfortunately, the original pictures in his atlas have been lost. .\ few years later \\'ang Tao (102) revised the atlas and made twelve pictures corresponding to those in the books of Huangti, Sun, and others (103). We still have the descriptions, l)ut these illustrations have also been lo.st.

A REVIEW OK ANCIENT CHINESE ANATOMY 1 L' I

III tli(^ SuiiK dynasty (0(50 A.D.) the Eniporor Jon Tsuiig ( 1<)4) ordered \\'aiig Wei I (105) to construct a bronze figure in which all the old theories of anatomy were to be corrected and incorporated. Holes were drilled to represent the needling points, in accordance with the descriptions of Sun Ssu Miao Hfili). The interior of the figure is fitted with models of organs and viscera surrounded with water.

During this dynasty two important works were written by Hsi Fang Tzu (1(57) entitled \'eedlin(/ Cautery Classics on the Bronze Figure (l(i8) and Ming Tang Xeedling Cautery Classics (1(39). About half the needling points rnentioned differ from Sun's descrijitions. Several other papers of less importance dealing with acupuncture and cauterization appeared at this time, which it will be hardly worth while to consider here.

Yang Chi Chow (170) collected all the old records and compiled a sj'stem of acupunctvne and cauterization (171) in the Ming dynasty, 1408 .\.D., which deserves mention before concluding this section.

ANTHROPOLOGY

The measurements which 1 have already given (pp. 107, lUU) will indicate clearly the intense interest which the old Chinese anatomists took in detennining physical standards. Huangti, many years ago, made a conscientious attempt to ascertain and record the average measurements of the men of his day. He said to his servant Po-Kao (172): "I desire to know the average length of the bones if a iierson has a height of seven feet and a half." Unhappily, the standard has been lost, so that we cannot ascertain the absolute value of the feet and inches used as units by Huangti, but the figures still possess a certain relative value. In answering, Po-Kao gave the following measurements (figs. 20 and 21):

Head eirciimferoncc 2 ft. 6 inches

Thorax 1 ft. 5 inches

Hairy area of scalp 1 ft. 2 inches

Verte.\ of head to angle of mandible 1 ft. inch

Thyroid eminence to interclavicular notch 2 inches

122

E. T. HSIEH

Sternum loii(!l 1> 9 inches

Sternum to umbilicus 8 inches

I'mbilious to transverse bone (pubes) 6 inches

Width of transverse bone fij inches

Upper border of the pubes to upper border of internal

condyle 1 ft. 8 inches

I'pper border of internal condyle to its lower border. . . 3j inches

Lower border of internal condyle to internal malleolus . 1 ft. 3 inches

Internal malleolus to sole 3 inches

Back of knee-joint to foot, dorsal surface 1 ft. tl inches

From dorsal surface of foot to ground 3 inches

External angle of frontal bone to the clavicle 1 ft.

Clavicle to axillary space 4 inches

.\xillary space to twelfth rib 1 ft. 2 inches

Twelfth rib to hip-joint 6 inches

Hip to the middle of the knee -. 1 ft. 9 inches

Knee to external malleolus 1 ft. 6 inches

Kxlernal malleolus to calcaneus 3 inches

Calcaneus to ground 1 inch

Between two mastoids ... 9 inches

Between two ears 1 f t . 3 inches

Between two malar prominences 7 inches

Between two hips 6J inches

Foot length 1 ft. 2 inches

Foot width 4J inches

Shoulder to elbow 1 ft. 7 inches

KIbow to wrist 1 ft. 2J inches

Wrist to first joint of middle finger 4 inches

First joint of middle finger to tip of finger 5 inch

Border of hair of scalp to seventh vertebra 2\ inches

Seventh vertebra to sacrum 3 ft.

In the Sung period, 9G0 A.D., the emperor ordered his phy.siicians to edit a system of medicine fl73), in whirh we can find some further mcasiirement.s, but unhapi)ily the method of making them has not been described. We read that there are 365 bones in the male and five less in the female, that 190 of them are concealed so that they cannot be seen and that 256 possess bone-marrow.

The works of Huangti remain perhaps the most complete on record. He is certainly to be regarded as the father of Chinese medicine.

A REVIEW OK ANCIENT CHINESE ANATOMY 123

CONCLUSIONS

It is quito evitlent from the foroKoinp; account that in the beginning the science of anatoiny in China was based upon actual dissection of the human Ijody.

The most notable evidence in favor of this conclusion is briefly as follows: rhijK), the servant of Huangti. 2(>r)7 B.C., writes that "after death the body may be dissected and actual observations made." A little later we read that Yin Chow (174), 1122 B.C., killed Pi Kan (175) and dissected his heart to discover whether it had seven openings. In the Han period, 20(5 B.C., Wang Mang (17()) .slew Chen Hsun (177) and dissected his ann; the same gentleman also captured a revolutionaiy and ordered his physicians to dissect him.

We find, also, that executions were frequently adapted to anatomical purposes. For instance, Liang Shao Pao (178), 960 .V.D., sent his medical officer with an artist to make pictures during an execution of thieves, probably by the rather slow slicing jjrocess; and the local officer, Li I Hang (179), employed doctors and artists and labored himself to make dissections and to correct drawings during an execution at Ssu Chow. Yang Chik (180) compared these drawings with the old books, found them to be correct, and accortlingly constructed his famous Alias of Trulh.

We have already mentioned the terrible epitleniic which raged among the children in the town of Chang Li Hsieh in the days of C'hia Ching (1796 A.D.), and of how a certain magistrate, named Wang Chin Jen, happened to \isit the public cemetery where he found that hungiy dogs were uncovering the bodies, hastily buried in shallow graves, and devouring them. ANang's curiosity was so aroused that he went daily to the cemeter>' and observed over thirty complete bodies dismembered. He was thus enabled to test out the old theories and to make important new observations which formed the basis for his book called .4 Correction of Faults in Medicine.

Unfortunately, this direct method was soon replaced by a rule of authorit}' somewhat similar to that which reigned in Europe

124 E. T. HSIEU

before the Renaissance. For instance, Tlw Essentials of a Gold Medicine Case and a book on Fevers, written by Chang Chi in the Han dJ^lasty (20(5 B.C.), remain verj' popular to this day. ^^'ith the reintroduction of direct observation and a true appreciation of the vahie of experimental niethoils, we may look for great advances.

A RKVIEW OF ANCIENT CHINESE ANATOMY 125

Blbllograpbj

1. ^ *5. Huangtl (2697 B.C.)

2. ^' "J Huengtl (2697 3.0.) 3^ ^ i£. ^^L Huangtl (2697 B.C.)

4. ?fiil -^1 - Chin Ytleh Jen (1122 B.C.)

5. '7 Z-> ^-i. Huang '^i Mi (265 A.D. )

6. .^ ■? ^^ t£ Wang Su Ho (265 A.D.) T, 4' ^ ^ T Sun 33U :.!iao (620 K.D.)

8. f^ '$. ^^'-^r Wang Tao (620 A.D.)

9. "T 'l^ -f: T Sun Sau Miao (620 A.D. ^

10. 4>J X. 01^^ '/X /^ ^ ;g .<>2.Sun Ssu Miao (620 A.D.)

11. ^^. ij ^ti I '^' Suhuangmen (960 A.D.)

12. ^ /^ ^ Chen Wei Tssi (960 A.D.)

13. -5.' ^"4" .^-^ 4^ Sung period (960 A.D. )

14. tlb ^ ^ ^ Wang Hao Van (1280 A.D.)

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17. ^^ i'-fi fft ^, Chang Chi Pin (1368 A.D.)

18. 'fit ^l 1^ ^. Ma Shih (1368 A.D.)

19' ^ "^ '^hio Haie Ke (1368 A.D.)

20. '^ n f-M H^ Sun I Kuei (1368 A.D.)

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THE ANATOUICAL RECOnD, VOL. 20, NO. '.'

Kpsuiiien por el alitor, Olixcr H. < iacblcr I'liixcrsidad dc Missouri.

El opitplio (Ic la V('ji{ja duraiito la contraccioii y la dislonsi6ii.

El |)respnto trahajo tiala del prolilrma dc si durante el proceso (le distensi6n fisiologica, ol nuiiicro dc capas cclularcs del opitelio dp la vpjifja pprniaupcp conslantc o, por el coutrario, si disuiinuye, P.S dpcir, si las cc'lulas ppitpliak's siuiplciuputp sp a|)lauan o si se dispoupii pu un niinipro inenor dp capas. En los pstudios llevados a cabo, p1 autor ha pniplpado niatprial procpdpnte de ratas. coiipjillos dp indias. y conp.jos, p(>ro p1 ti'al)a.io uiiis iinporfantc fup lipcho pu pompJos.

Para rpsolvpr pi prohlpnia sp hau piuplpado dos niptodos. El prinipro ponsistp pu contar el ni'uupro do pai)as dpi pjiitplio pn vpiifias PU divprsos grados dp distpusion, poiuparando dicha.s pajias pon p1 muupro pucontrado en vejigas contraidas. El segundo niptodo pniplpado dpppndp dpi hcpho de que si no hay una (lisposiciAu dp las pplulas ppitplialps pn ini nunipro lupiior dp pa])as, la rclacion (jup rpprpspnta p1 ai)lananiir'nto dpi ppitplio en ruaUiuipr diippcion dphp spr idpntipa a la (|up ippresenta el aplananiipiito dp sus pplulas pn la inisnia diippcion. Estas iplacioiips SP dptprniinaron mediantp nipdidas dpi ppitplio y de dipz mil pplulas. pn dos spiIps dp vejigas de ponejos.

Eas pniiplusioiips ol)tpnidas ])or anihos nu'todos son: 1) I>a (listpiisiAn fisiologica niod(>rada no disniinuyc^ p1 nunicro de papas dp pplulas pj)itflial('s; 'J) I,a distpiision (isiologica niiixinia no disniinuyp las capas citadas en mas del 12.") jior ciento; 3) I^.s pplulas de las cajias mas profundas no p.stan unidas tan fntimanipiitp conio las dc las papas supprfipialps. y 4) Las pc'lulas no sufiPii una contraccion ulterior dpspups cpip ha conipnzado p1 |)lpgamipnto dpi epitclio.

Tniitrtlnlton l»y JiW^ F; Noniilf^ fornrll Mcdionl Collw \. « \ .rl.

AtTUORtt ABifTRlCT OF Tllia PAPKft IMVZD BTTIIR UIDLIOURAPIIIC SEHVICR, NOVEMBER 15

BLADDER EPITHELIU.M IN CONTRACTION AND DISTENTION

OLIVER H. GAEBLER Anatomical Laboratory, University of Missouri

NINE FIGURES

The Hiain problem with which this paper deals may be stated in the followinp; ([uestinns: Does the epithelium of a bladder in distention have the same number of layers of cells as the epithelium of a similar bladder in contraction? Does the process of distention involve onlj' a stretching of the cells, or also an arrangement into fewer layers?

This ])i()hlem has been discussed for many years. London ('81) studied the relation between thickness of the epithelium and degree of distention of the bladder, because he believed that data obtained would be of interest in connection with the problen of resorption of substances from the urine. Since the epithelium of the bladder forms a barrier between the contained urine and llie capillaries in the underlying connective tissue, the thinning out of this epithelium on distention was thought to be significant in connection with the stated problem. In regard to the number of layers of cells, London ('81) said that there was an apparent diminution during distention, but an actual diminution only in the numl)er of layers of nuclei, and not in the number of layers of cells.

Dogiel COO) studied tlie histology of bladder epithelia of mice, rats, and various other mammals, and claimed that the cells of the first two layers, counting from the surface layer, were so interlocked by protoplasmic processes that there was no possibility of a change in their relative position occurring during distention.

Eggeling ('01-'02) and many others published articles on the histology of M;i(M<T epithelium, but did not touch upon the

r-»9

I'M) OLIVER H. GABBLER

pr()l)lem uikIit (iiscussion in this paper. Harvey CO!)) described the variations in all the layers of the walls of both bladder and ureter during contraction and distention. In regard to the bladder epithelium, he says that there is a decrease of 50 per cent in the number of layers of nuclei during distention, and also a decrease in the actual number of layers of cells.

Concerning the hunuin bladder, one hisfologist (Lewis and Stiihr, '18, p. 324) .says the following: "The epithelium has been described as two-layered in the distended bladder, the outer cells having terminal bars; in the contracted condition it becomes several layered, and the bars form a net (>xtending into the epithelium. Thus it is not believed that during distention the layers merely flatten; they are thought to 'slip by each other.' The columnar cells ma}-, however, become extremely flat."

The various ob.servers, using material from many sources, and employing numerous methods, have, therefore, reached several conclusions that bear upon the particular problem here discussed. Some of them have pointed out (he decrease in the number of layers of nuclei in bladder epithelium durmg distention and have determined this decrease quantitatively. Some have stated that while there is a decrease in the number of layers of nuclei, there is no decrease in the actual number of laj'ers of cells. Others have claimed that there is an actual decrease in the number of layers of cells during distention, but have made no statements regarding the extent of this decrease. The following studies were therefore made for the purpose of finding out whether there is any diminution in the number of layers of cells during distention, and, if so, how great the diminution is.

M.\TERIALS AND METHODS

In the experiments that follow the animals used were white rats, guinea-pigs, and rabbits. The preliminary work, done on .some material from each of these three sources, suggested that the results would l)e very nuich alike, if not identical, for the three animals, and since rabbit material seemed the most favorable for the particular methods of procedure and staining required, the final work was done on rabbit material.

CHANGES IN BLADDER EPITHELUM 131

111 <)l)t:iiiiinn bladders in various dogipos of contraction and distention, it is evident that the more nearly normal, or phj-sio lofiical, the process of contraction or distention, the less open to oljjection is the result. Bladders in various defjrees of normal distention or contraction can be obtained by siin])ly taking animals from their cages, killing them at once, and relying on chance. If chance killing does not j'ield a sufficient number of contracted bladders, female rabbit bladders can be made to contract by pressure on the lower abdomen or by irritation of the urethra. With male rabbits the pressure method is less reliable. If completely contracted bladders are wanting, thej- can be produced bj- cutting the urethra or o])ening the l)la(lder in any way, in an animal that has just been killed. If greatly distended l)ladders are desired, the animals are given an abundance of water, taken from their cages and jilayed with or excited in any way for thirty minutes to an hour, and suildenl}' killed.

To fix a bladder found in partial or complete distention, the urethia and ureters are clamped with one hemostat immediately after theal)domen has been opened, and are then cut on the side of the hemostat away from the bladder, so that the urine is retained. The bladder is then immersed in saturated mercuiic chloride solution for two or three minutes. This destroys the contractilitj- of the muscle cells. In guinea-pigs a longer exposure was needed to accomplish this result. The bladder is next transferred to phj'siological salt solution, cut open, wa.shed out in several changes of salt solution if necessary, and returned to mercuric chloride solution for tweh^ hours.

In completely contracted bladders, the part used for sections is a cylindrical piece secured from the middle of the l)la(Kler by two parallel cuts, made at right angles to the long axis of the bladder antl 2 or 3 mm. apart. In parth' or completely distended bladders, a corresponding equatorial zone, about 5 mm. wide, is cut out after fixation. This zone is cut open anywhere, measured just Ix-fore imbedding, and cut into a convenient number of pieces, all of which are imbedded.

The solution of the prol)lem depends fundamentally upon an umnistakal)le staining of the cell boundaries. Such staining will

V.i'2 OLIVER H. GAEBLKR

l^rcvcnt ovorlookinp; of cells whose nuclei arc not included in the section, and will enable one not only to count the number of layers of cells, but also to measure accurately the size of the cells. \ number of staining methoils were tried, but it was found that the followintt iron heniatoxyUn methods, when used with rabbit material, were the most successful:

Fir.fl miihnd. 1. Fix in a saturated solution of mercuric chloride in physiological salt solution.

2. Stain with freshly prepared Hansen's hematoxylin to which no sulphuric acid has been added (Lee, '13, p. 159) until the sections are \'er3' black. This retiuires fifteen to thirtj- minutes. Decolorize in 2.0 per cent iron alum solution, to the point where cell boundaries show plainly, paying no attention to the la\'ers of the l)ladder wall other than the epithelium. Clear and mount without count erst aining.

Second method. Mallory's chloride of iron hematoxylin method, as described in Mallory and ^^'right's 'Pathological Technique,' page ."^10. In differentiating, again watch the epithelium only.

.Vlt hough the solution of the problem depends fundamentally upon the success of the foregoing procedures, one very important complication remains. Due to the complexity of the folding of the epithelium of comjiletcly contracted bladders, sections taken at right angles to the long axis of the bladder will be perpendicular to the epithelium at only a few points, and tangential everj-where else (fig. 9 1. This diffirulty is avoided by securing bladders that have contracted just to the point where folds begin to form, and fixing them in this condition by the method previously desciiljcd. Sections can then be obtained that run perpendicular to the surface of the epithelium, just as carefully prepared sections of distended bladders do. This simplifies the entire problem a great deal.

.\lthough important results were obtained from rat and guineapig material, tiie rc^sults obtained from six rabbits will co\er all the facts a.scertained. so it will be best to give the details of this part of the work, and j)ass by the remaimler to avoid repetition.

Six r:'.l)bits, all of the same litter, all female, and a little less than half grown, were dealt with as follows:

CHANGES IN FJLADUEU Kl'ITHELR'.M 133

liitbbit no. I. Wcii^lit, 2(i oz. Tlie rabbit was well supplied with water, Tuesday, January li, l'.l2(); taken from cage at 8:30 v.\i., played with for half an hour, and killed hy a blow at 9 P.M. The abdomen was opened. The bla<lder was found widely distended, was clamped olT, removed, and sus|)ended in bichloride solution for two minutes. Its ('([Uator measured 10.1 cm. Jt was suspended in normal saline while the base was cut olT. Xo contraction followed. The .bladder was washed out and replaced in bichloride at !): U) i-.m.

Hnlilnt no. ,i. Weifziht, 2(5 oz. This ral)bit was taken from the cage, .lanuaiy G, li)2U, 9:15 p.m. Pressure was put upon the lower abdomen at once, and resulted in passage of a small amount of urine. The animal was left for a minute, and was then killed In- a blow. The abflomen was ojiened, and the bladder found completely contracted. The bladder was removed, washed out with physiological salt solution, and jHit in bichloride at 9:20 p.m.

li'c.libit no. ,?. Weight 2() oz. This rabbit was killed Saturday, Jaiiuaiy 24, 1920. The jirocedurc and results were veiy similar to those for ral)bit no. 1, excepting that the distention was smaller. The equator of the bladder measured 8.2 cm.

Rabbit no. .',. Weight, 2(5 oz. The rabbit was killed Saturday, Januaiy 24, 192(3. Procedure and results were vciy similar to tho.se for rabbit no. 2. The bladder was not found completely contracted, but contracted completely when the base was cut.

Rabbit no. J. Weight, 24 oz. The bladder of this rabbit was partly emptied by ])ressure on the abdomen. The animal was then killed by a blow, and the bladder was found partly coptracted. It was clamped off and removeil, susiientled in bichloride three minutes, suspended in noinial saline while the base was cut off, and \va.^then washed out. The folds in the epithelium had just begun to form in one region of the bl.'ulder. The Ijladder was replaced in the fixative within ten minutes after the death of the animal, .lanuary 20, 1920.

Robbit no. II. \\'eight, 24 oz. The ral)bit was killed on February I. 1920. The procedure and results were practically identical with those for rabbit no. 5.

The .sections were all cut 10/x thick. While tliis is thicker than is usually recommendeil for the methods of staining iised, staining of cell boundaries in the epithelium is in no way interfered with, and sections of this thickness were valuable because the relations in any one focal plane could be more firmly establisheil by focusing at various depths.

RKSILTS OUTAIM:!) HV rOfNTlXC, Tin; NIMRER OV LAYERS OF

KPITnELI.\L CELL.><

After all these specimens hail been sectioned, two methods of apiiroaching the problem were used. The first, and most obvious, was simply to count the number of layers of cells in the epi

134 OLIVER II. CAKHLKH

tholia of tho various lilnddors. In tho poniplotoly contracted liladdors, witli coni])loxly folded e})itlielia, the iuiinl)er of layers varies a great deal, due to the great number of places where the section is tangent. But at frefiuent intervals the number of layers is three to four, and if the number of layers is approximately the same over the entire bladder, these places must be the points where the section is cut perpendicular to the surface of the epithelium, and hence the points giving the correct number of layers. The miiiii)er of cells in .sections from bladders that had contracted just to the point where folds began to form was also counted, and in these there were regularly three to four laj'ers. The number of layers in the distended l)ladilers was also three to four. In all cases the variation was slightlj' greater than this, for there were points at which only two layers of cells coukl l)e distinguished, and others at wliich there were no less than six layers, but three to four layers constituted the most frequent thickness.

The sections were studied under oil immersion, at a magnification of 950. With this magnification, the cell boundaries stained by the indicated methods stand out with surprising clearness, both in the contracted and in the distended specimens. Low magnifications proved very deceptive. Several of the figures illustrate the mistakes most easily made in counting the number of layers of cells.

Figure 1 is a camera-lucida drawing of a portion of one of the sections from the distended bladder no. 1. .\t lower magnifications one would readily suppose that, counting down from the large surface cell, at the point indicated bj' the arrow, there were in all three layers. Rut at higher magnifications it is clearly seen that there is a junction of the two cells lying beneath this surface cell, and that there is a cut edge of a basal layer cell just above the nearest connective-tissue nucleus; so the number of layers in this region is five. Focusing down, the slip seen at the l)ase in the focal plane of the draw ing develojis into a nucleated cell.

The method of counting nuclei was not found serviceable in determining the number of layers at any given focal plane. This is shown in figure 2. which is a camera-lucida drawing of a

( II.VNtiKS IN ULADDKU KIMTHKLH M

135

poitidii of a section of the (listcndcil bladilcr no. 3. If ono depended upon the nuclei, the number of layeis would \aiy between two and one. But here again the edges of cells cut outside of their nuclei make the variation one between three and four layers. It should also be mentioned that if a line is drawn perpendicular to the surface of the epithelium at (o), it passes through four cells,

I

V

Fig. 1 Camera-iucidii drawing of portion of cpitholiuin of ilistcnded bladder no. 1 (XH28). The arrow marks tlie point at wliich the five-layered cpitlielium is easily mistaken for a three-layered one.

Fig. 2 Camcra-lucida drawing of portion of distendeii epithelium of bladder no. 3 (XU28). The layers of nuelei vary between one and two. .\ctiial layers of cells vary between three and four.

but the number of layers is really only three, since the last two cells through which the line passes are really in the same layer, the boundary between them being diagonal.

Figure 3, a caniera-luciila ilrawing of portion of the epithelium of distended bladder no. 1, again emphasizes the fact that in this series of studies tlie method of cotmtiim luiclei had to ho aban

l.i(i

t>I,l\i:i{ H. CAKBLKH

iloiu'd, lu'cvuiso the iminhcr of layers of cells was the infoiniation desired. It also jiresents another example of the importance of counting cells whose cut eilges might easil}' escajie notice at low magnifications. In the region (A) the epithelium might easily be mistaken for a two-layeied one, because the small cut edge of a second layer cell and the surface cell aie about equally granular

4

Fig. 3 Camcra-Iuci<l;i drawing of portion of the distended epithelium of bl.iddcr no. 1 (X 705). The figure shows the importance of counting portions of cells not containing nurlri, .such as those in the region .l,\vhon estimating the number of layers.

Fig. 4 f'amcra-lucida drawing of portion of the epithelium of contracted bladder no. (i (X 7fl.5). Tlii.s figure shows two places at which. the contracted epithelium is only two layers ihli-k.

and appear about the .same shade. But a line, distinct cell boundary separates them.

When all the.se precautions are observed, there will still be some points where the distended epitheliimi appears to be only two layers thick. Hut, tinning to the bladders that have contracted to the point where folds just begin to form, we will find

THAXOES IN- HLAUDER KPITHELIUM 137

finite as many ])lacc> w licic (ho fijithcliuiii is only two layers tliick. Figure 4 shows a piece of eontraeted epithehuin, and at two places in the' figure there are only two layers of cells.

There is evidence that the cells in the epithelium are hound to their neighbors pretty firmly. If one examines (he variou.s figures of contracted and distended epitlielium shown in this paper, it is noteworthj' that in the distended bladders the cells are still bound to their lateral neighbors along a considerable distance. In the surface layer these boundaries between cells may run perpendicular to the surface or at almost any other angle, but the length of the boundarj' bears about the same relation to the greatest thickness of the distended cells as the lengths of the boundaries between surface cells in the contracted epithelium liear to the greatest thickness of the cells in contraction. The surface cells with basal processes are also interesting objects in this connection. Figures 5 and 6 show portions of two bladders, one in contraction and one in distention, in which there is a comparable, though not identical relation of such cells. The three cells in the second layer, in (he region between (A') and (B') of figure 0, bear about the same, relation to the large surface cell in this region as the three second-layer cells in the region between (A) and (B) in figure 5 bear to the contracted surface cell with the basal processes. .\nd the significant point in the figures is that the surface cell in figure (i, though distended to the great length of 05. 7m still has points along its lower border that suggest remnants of basal proces.ses. Considering the degree of distention of this surface cell, f)ne would expect its lower boundarj- to be more nearly straight, if there were not a firm attachment of the lower cells that exerted a tension at (he two points where the most marked irregularities exist.

Sections of the extensiveh' folded epithelium of completely contracted blatlders are also interesting subjects for stud\'. On the crest of a fold, a .section (hrough (he epi(helium will frequently have (he appearance shown in figure 7. The appearance of (he surface cells is that of partial distention, as (hough (hey had l)een stretched by the pushing in of the folil.

i:js

(»LlVi:i{ II. (I.VKBLER

In the l)i)lt()in of tlio j)its, or nitlicr tioufilis, hctwoeii fokls, the colls fio(|uoiitly havo a onlumnar appearam-o. This is shown in figuiv S. Ill tlic iiiidtllc nf llic i)ioco of cpitlioHuin shown, this cohininar aiipcarancc is not onl.\' apiiarcnt, Imt real, while at the hortlors the Hgure is niisloadiiig, bceausf fho c'j)itholiuni is rotated through ninety degrees from the position in which it is usually figured.

6

Fig. .5 Camera-lucida drawing of iiortion of the epithelium ofdistended bladder no. 6 (X 705). The surface and second-layer cells in the region between .4 and H bear a relation to one another similar to that of the corresponding cells in figure ti, in the region .1' to /}'.

rig. G Camera-lucida drawing of portion of the epithelium of distended bladder no. 3 (X 705). Note the i)rojections on the lower surface of the large surface cell, suggesting remnants of basal processes.

The first method of a])i)roaching the ])rol)leiii under discussion — the method of sinij)ly counting the numi)erof layers of cells in any given focal plane — therefore results in the conclusion that the range of variati(m in the number of layers in the contracted bladtler is about the same as in the distended blatlder. The usual munber of layers in l)oth is three to four, and in either

CHANGES IN BLADDER EPITHELIUM

139

contracted or distended l)ladders there may he places wlieie tliere are onlj- two hijers or where there are more than four. This method of stating results still does not give completely the information desired, for the question remains: Does the contracted bladder contain more area covered bj- four layers and the distended l)ladder more area covered by three layers? If there is

\f^'

8

l-'ig. 7 f'amera-liicida drawing of the epithelium at the crest of a fold in completely contracted bladder no. 2 (X 422). Xote the iiartially distended appearance of the surface cells.

Fig. 8 Cameru-lucida driiwiug of the epithelium in a trough between folds of completely contracted bladder no. 2 (X 422). Note the columnar appearance of the cells.

such a difference, it is not so noticeable as to be at once agreed upon after studying two comparative sections. 8o at this point the second method of incjuiry, depending upon cell measurements is brought in.

140 OLIVER H. GABBLER

MF.TIK^n OF CELL MEASUREMENTS, AND ITS RKSri/l'S

It is evident that if all of the stretching of the e]Mth('liuni is to he accounted for hy stretching; of the cells, and not by 'slipjiinp;' or rearrangement into fewer layers, the ratio that represents the stretching of the epithelium in any given direction should be identical with the ratio that represents the stretching of the cells in this direction.

The amount of stretching of the epithelia was determined as follows: After fixing, as stated before, an equatorial zone, 3 to o mm. wide, was cut from the distended bladders and from those that had contracted to the point where folds just began to form. These zones were cut open along any meridian, thus converting them into ribbons, the length of which, measured just l)efore imbedding, gave accurate results as to the length of the epithelium in the completely distended bladders. The ribbon-like strips were then cut into a convenient number of pieces, all of which were imbedded. Sections were cut perpendicular to the surface of the epithelium and jiarallel to the equator of the bladder. By projecting a section from each block of any particular zone, and measuring it with a wheel tracer, the length of the complete epitheliuni— i.e., the circumference of the circle which it forms in a complete section perpendicular to the long axis of the bladder at the equator — was calculated.

The lengths of the cells were then measured, in the direction parallel to the surface of the epithelium, in the same sections. It is evident that if there has been no slipping, the ratio of contracted to distended cells should be the same as that of contracted to distended e])ithelium. It must be borne in mind that the ({uantities here compared are linear quantities, and not areas, and that like dimensions, and not squares of like dimensions, are therefore compared.

Completely contracted bladders cannot be compared with greatly distended ones by this method, because of the impossibility of obtaining accurate information in regard to the length of the epithelium in the completely contracted bladder. When the fokls of the e])itlielium first form, they are fairly regular

CHANGES IX HLADDER EPITHKLUM

111

loiiniliidinal, nr rather lucikiioiial, folds. Hut on further conIriK^tioii the\' become very irre^uhir, proljahly (hie to the fact tlial the longitudinal muscle layer, contracting, carries with it the tunica projjria that runs into these already formed folds. Figure !) illustrates this jioint. It is a sketch of a jxtrtion of the ei)ithelium of a completely contracted bladder in surface view. The bladder was found completeh- contracted in a freshly killed adult ralihit. liase and apex were cut off, and the l)la(lder was

riu. ".t Krc'C-liaml (Iriiwinp of c|iithcli:il surface of coinplctely coiitriicteil Miiililcr (X ~.o). Tlip vertical direction of the drawing is meridional with res|iect to the liladder. The figiire shows that transverse sections may |)as3 through the same fohl three times.

cut open alotig a meridian. It was then spread out flat, with the epitiielium uppermost. The corners were juimeil down, and the specimen hardened in bichloriile solution. A small square piece was cut out ami sketched. The \ertical direction of the drawing as here shown is longitudinal with respect to the bladder. It is easily s(>en that a section iimning at right angles to the long axis of tlic lil.idder might cross the same irregular longitudinal fold three limes. ( 'ouse(iueul ly. when the sections are studied, it is impossible to decide whether a given fold has been jiroduced

1 I J oi,i\ KU II. (;.vkhm;k

l)y iiu'riilional or h}' ctiuatorial i'(iiitiactioii. lO iiit'a.suro the loiiKth of the surface of the ej)itheUuin in sections across a coml)letely contracted hhidder is tlierefore useless, 'i'his was noticed duriiifi the jiroHniinary work on this problem. Tlie length of the contracted epithcliuni, nHiltii)Hed hy the amount of stretchinj? obser\ cd in the cells, far more than accoimted for the length of the distended ejiitlielitnn. This was true even though all masses of ej)it helium within the main lumen, or all .><eparate portions of the lumen not connected with the main lumen in the section, were left nut of consideration.

The measurement of the length of the cells j)arallel to the surface of the e])ithclium was doii(» with a micrometer eyepiece. It is essential that some method lie em])loyed which will result in representing all parts of a given circumference, and prevent undue choosing of certain tjpes of cells that one comes to think of as tj'pical. For example, one may take every cell in a given layer that has a nucleus and clearh' defined boundaries, or every second or third cell of this description, according to the number ot cells desirctl. The variation from cell to cell, in the same region, and from one part of the circumference to another, is very great. The largest cells maj- be six to ten times longer than the smallest. The first hundred cells in any given layer of a section, on the other hand, may be one and one-fourth times the size of the second hundred in the same .section. But if the average of three hundred or more cells representing all ])arts of a given circumference is taken, and the measurements repeated in difi'erent .sections from the same bladder, using the same method, the results will be nearly identical. So the method of taking every cell in a given layer, having a micleus and clearly deiined boundaries, ami comi)aring the a\"ei'age size with that of cells similarly chosen from another bladder is an entiiely reliable method of comparison. In the case of cells tliat have the .><hape of a parallelogram, the length of the side i)arallel to the surface of the epithelium is taken as the length of the cell.

The results obtaineil from se\eral measurements of each epithelium, and about six thousand cell measurements, in material from the six ralibits, weie as follows (tal)le 1):

CHANGES IN BLADDER EPITHELIUM 143

TABLE 1 Bladder no. 1 (distended)

Length of epithelium S rni.

Length of cells:

Avcraue

Ist (surface) layer 470 cells 51 . 4/i

2ntl layer 38.5 cells 32. 4p

3rd layer .330 cells 18.8^

Bladder no. i (completely contracted)

Length of epithelium measurement impossible.

Length of cells:

1st layer 386 cells 27.6m

2ntl layer 275 cells 18.3m

3rd layer 220 cells lO.l/i

Bladder no. S (partially distended)

Length of epithelium 6.5 cm.

Length of cells:

1st layer 345 cells 46.2/i

2nd layer 3.85 cells 29.9/i

3rd layer 330 cells 18.9m

Bladder no. 4 (completely contracted)

Length of c[)ithclium measurement impossible.

Length of cells:

1st layer 220 cells 27.7m

2nd layer 220 cells 18. 8m

3rd layer 220 cells 9.6m

Bladder no. S (contracted to beginning folding)

Length of epithelium 3.8 cm.

Length of cells:

1st layer 393 cells 26.0m

2nd layer 440 cells 17.6m

3rd layer 330 cells 10. 5m

Bladder no. 6 (contracted to beginning folding)

Length of epithelium ; 3.7 cm.

Length of cells:

1st layer 294 cells 25.9m

2nd layer 385 cells 17. 1m

3rd layer 330 cells 10. Sm

Blnddpis no. 2 and no. 4 were completelj' contracted, so the length of cpitliehiini is not entered for reasons previously stated. If we compare the contracted bladders no. 5 and no. G with the distendeil i)ladders no. 1 and no. 3, and find the ratio between the lengths of the ejiithelia and Iietween the lengths of the cells of each lajer, we obtain the following ratios (table 2):

THE ANATOMICAL Rr.COIlD, VOL. 20, NO. 3

144

OLIVER IT. GAEBLKU

TABLE 2

KATioa or

No. t

No. 8

No. 1 No. 6

No. 3 No. 6

Tjonffths of eDithcli&

2.16

1.98 1.89 1.74

2.10

1.98 1.84 1.79

1.75

1.78 1.74 1.75

1.71

Lengths of cells:

1 st laver

1.77

2n(l liiver

1.70

1.80

The significance of these results will now be discussed.

In the first place, it is evident that no great change in the length of the cells, measured parallel to the epithelial surface, occurs after folds have begun to form. The epithelia of bladders no. 2 and no. 4 were completely contracted and complexly folded. Nos. 5 and 6 were contracted to the point of beginning folding. Comparing the sizes of the cells, there is little difference. The surface cells (first layer) of nos. 2 and 4 are even slightly larger than those of nos. 5 and G, probably because of the stretching at the crests of folds spoken of i)re\iously and illustrated in figure 7.

Secondly, the ratios between bladders no. 3 and no. 6 and between no. 3 and no. 5 show that there is no indication whatever of slipping of cells. The cells in bladder no. 3 have been stretched just as much as the epithelium. It must be borne in mind that 6.5 cm. represents the equatorial length of the epithelium of bladder no. 3 after fixing and dehydrating. In the fresh condition it measured S.2 cm., so that thediameter at this point, or transverse axis, as it is sometimes called, was 2.6 cm. At this stage in distention the transverse axis is considerably shorter than the long axis, so that this bladder was well distended.

Tiiirdly, we notice that in comparing bladder no. 1 with nos. 5 and 6, the ratios indicating the stretching of the cells all fall short of the ratio indicating the stretching of the epithelium, aiid that they fall jirogressively shorter from the surface layer io fiie third layer. If Ijladder no. 3 is regarded as partly contracted, with reference to bladtler no. 1 and the ratios determined, the same variation will again be established, so that bladder no. 1 is compared with tliree comparal)le bladders, with practically identical

CHANGES IN BLADDER EPITHELIUM 145

rosults in every case. Still, the amount that the surface cells fall short is very small, and may be accounted for by the fact that as one measures the surface cells that have' nuclei and clearly defined cell boundaries, fewer large cells than small cells conform tf) this standard. If the ratio is correct, it would mean that a piece of the surface lajer that contained 198 cells in contraction contained 216 in distention, or that every twelfth cell in the surface layer of the distended l)ladder had crept in from a lower layer. The widest divergence is obtained by comparing the third layers of bladders 1 and G. The cells of the third layer of no. 1 are 1.74 as long as those of no. 6, while epithelium no. 1 is 2.1G as long as that of no. G. This means that a piece of the third layer that in contraction contained 174 cells in distention contained 21G, or that every fifth cell, approximatel}', in the distended condition had entered the hner from another layer. If one imagines this, the greatest divergence found, occurring in each layer of five lajered epithelium, it would be just sufficient to reduce the layers from five to four. The exact amount of rearrangement of cells indicated by taking into account all the ratios tabulated in comparing bladder no. 1 with blaikiers no. 5 and no. 6 would be a change from a four-layered epithelium in contraction to a3.5-layered one in distention, or a five-layered one in contraction to a 4.4-layered one in distention. .Vnd this distention was a large one, for the circinnference of the bladder before fixing was 10.4 cm. at the equator, which compares favorably with the greatest distentions seen in rabbits of twice the weight of this one, though more than a score of autopsies of such rabbits were taken note of.

Measurements similar to those above tabulated and discussed were also made on three bladders from adult rabbits. These rabbits were of the same litter, weighed a little more than 5 pounds each, and had been used for experiments in connection with studies on tlie de\elopment of bone.

The bladder of rai)bit no. S was found contracted to the point where folding of the epithelium just begins. Rabbit no. 9 had a partly distended bladder. Rabbit no. 10 was played with for three-(iuarters of an hour, then ;inaesthetized with ether. The

14(l OLIVER 11. r.AEBLER

ahddiiicn was ojjonod, and the hladdor was found Kif'atly distended. Its shajM' aj^proaehed the sjiherical, as is the case in complete distention. Its equatorial circumference was 9.5 cm. before fixing. The technique employed was idc^ntical with that previous!}- descril)ed.

The epithelia of these l)ladders had, on an average, nearly one layer of cells more than those of the previous series. Measurements were made of cells of three layers, and also of those basal cells situated between the tapering ends of ceils which, though of the next higher level, also reach the basement membrane. The results were as follows (table 3) :

TABLE 3 Bladder no. 8 (contracted to beginning folding)

Length of epithelium 4.2 t:ni.

Length of cells:

.\verage

1st layer (surface) 477 cells 29. \ii

2nd layer 440 cells 20.0m

3r(l layer 330 cells 14.9m

Basal cells 330 cells 9.7m

Bladder no.

Anatomical Record 19 (1920)

Contents

THE ANATOMICAL RECORD

Contents

NO. 1. JUNE

NO. 2. JULY

NO. 3. AUGUST

NO. 4. SEPTEMBER

NO. 5. OCTOBER

NO. 6. NOVEMBER

A Description Of A Six-Legged Dog

The nature of the primitive Haversian system

Hermaphroditism in man

BOOK REVIEW

Anatomy Of A Fetus Of A Cyclopean Goat

The Changes Of The Systemic Venous Plan During Development And The Relation Of The Lymph Hearts To Them In Anura

Studies On Striped Muscle Structure

Symmetrical Bilateral Dystopia Of The Kidneys, In A Human Subject, With Outward Rotation Of The Hilus, Multiple Arteries And Veins, And A Persistent Posterior Cardinal Vein

Studies In The Dynamics Of Histogenesis Growth Motive Force As A Dynamic Stimullts To The Genesis Of Muscular And Skeletal Tissues

Racial And Sexual Differences In The Appendix Vermiforaiis

Studies In The Development Of The Opossum Didelpbys virginiana L.

Accessory Pancreas In The Dog

Observations In Connection With The Early Development Of The Human Suprarenal Gland

Note On The Anatomy Of The Areae Postremae

The History Of The Earliest Stages In The Human Clavicle

THE PROBLEM OF THE CORACOID

THE WEIGHTS OF THE VISCERA OF THE TURTLE

The Collateral Circulation In A Case Of Complete Closure Of The Mouth Of The Superior Vena Cava

A Wax Model Of A Presomite Human Embryo