Talk:Paper - The development of the adrenal glands of birds (1914): Difference between revisions

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1893 Referat fiber Fusari 1892. Mon. zool. ital., vol. 4.
1893 Referat fiber Fusari 1892. Mon. zool. ital., vol. 4.
==MAST CELLS IX THE MEXIXGES OF XECTURUS, EASILY MISTAKEX FOR XER\ E CELLS==
PAUL 8. McKIBBEX
The Anatomical Laboratory of the We-^tern Unircrsily of London, Ontario
TWO FIGrUES
In the study of the iiervus tenninalis of Xecturus maculosus, attention has already been called (IMcKibben '11 j to mast cells, the clasmatocytes of Ranvier," as thej' exist in the nasal region and in the meninges of this amphibian. The purpose of the present paper is not to attempt a description of these cells but rather to call attention to the fact that they may be easily mistaken for nerve cells when treated by some histological and neurological methods.
As is indicated in figui'e 1, these mast cells occur in great numbers in the dm*a mater. They are found also in the other meninges, along the olfactory nerve and about the nasal sac. as well as in the mesenteries and in the subcutaneous tissue where they were first described.
The cells in question (fig. 2) are elongated, irregular cells, usually with several long cytoplasmic processes. The nuclei of these cells seem poor in chromatin, taking a very feeble stain with basic dyes; but the cytoj^lasm surrounding the nuclei and that forming the long JDranching processes is seen to contain sharp granules which exhibit metachromatism. These cells, the "clasmatocytes of Ranvier" (Ranvier '90, '93. '00) as described in Amphibia, have been shown by Jolly ('00) and by ^Maximow ('02, '06) to be identical with mast cells although of peculiar form. In ^Mammalia, where no similarity in form between the mast cells of Ehrlich and the clasmatocytes exists, the confusicMi is impossible.
470
PAIL S. McKIBBEN
In tigure 1, a (Irawiiij:; iiuulo from a whole inouiit of the dura mater of Xectm'us, the form, frecjuency and extent of the mast cells are shown. Their similarity to certain sympathetic nerve cells, in shai)e, size and extent, might lead one into serious error. That those are not nerve cells has been demonstrated thus: first,
Fig. 1 Drawing, made witli camera lucida, of the dura mater taken from the roof of the cranial cavity of Xccturus; a whole mount of the dura mater fixed in formaline-Zenker's fluid and stained with Wright's stain. The blood capillaries are indicated by the dotted lines. X 70.
the cytoplasmic granules have a different form and arrangement from that exhibited by the Nissl granules of nerve cells; second, they will stain intra-vitam with methylene blue and when so stained show the cliaracteristic metachromatic tint; third, when treated with sulphuric acid and aqueous hematoxylin these granules fail to show the presence of iron wliioh is characteristic of the Nissl granules of nerve cells. In these tests for iron, control
MAST CELLS IN THE MENINGES
477
sections, known to contain nerve cells with Xissl granules, received exactly the same treatment as the sections containing the mast cells; so that the failure of the granules of the mast cells to react for iron was due, probably not to faulty technique, but to their chemical composition, when the Xissl granules in the same experiment gave the typical reaction.
Fig. 2 Drawinc, made with camera liicida, of a single mast cell in the dura mater from the floor of the cranial cavity of Xeeturus; a whole mount of the dura mater fixed in Formalinc-Zenkcr's Fluid and stained with toluidine blue. X 4oO.
Under certain conditions and in certain tissues, treatment of these mast cells in amphibia by the Golgi impregnation method, by the Cajal silver motliod and its modifications and by other methods, gives a picture in whicli it is well nigh imjiossible to determine whether one is dealing with sympathetic nerve cells oi- with these branched mast colls. Consequently in a study
478 I'AII. S. M. KIBBEN
in anijiliihia of cortaiii tissues whoro syiiipathotio norvo cells and these mast cells may occur simultaneously, when methods are used by which it is impossible to differentiate between the two types of cells, the value of the observations is open to question. In ^Mammalia a similar confusion of nerve cells and certain cells of connective tissue is not altogether impossible.
The author wishes here to acknowledge his indebtedness to Professor K. R. Bensley and to the Anatomical Laboratory of the University of Chicago for assistance in this and other work.
LITERATURE CITED
Cerletti, Ugo 1911 Die MastzcUen als regoliniissiger Bofuiul im Bulbus ol factorius dos nonualcn Hundcs. Folia Ncurobiolofiica, Bd. 5, Xr. 7. Jolly 1900 Clasniatocytcs et Mastzellen. C. R. Soc. dc Biol., pp. 609-Gll.
1900. M.\xiMow, Alexander 1902 Expcriincntelle Untersuchungcn iiber die ent ziindliche Xoubildung von Bindcgewcbe. Beitriige path. Anat. u.
allge. Path. Zicglor, sup. 5.
1900 Uebcr die Zellformcn dcs lockercn Bindegewebes. Arch, niikr.
Anat. u. Entwick., Bd. 07, p. 680. McKiBBEN, Paul S. 1911 The nervus terminalis in Urodele amphibia. Jour.
Comp. Neur., vol. 21, no. 3. Phlsalix, C. 1900 Sur les clasmatocytes dc la peau de la Salaniandra terrestre
et de sa larve. Bui. Mus. Hist, nat., pj). 72-75. liANviKH. L. 19fK) Des clasmatocytes. Arch, d'anat. niicr., vol. '.i, p. 122.
A RACIAL PECULIARITY IX THE POLE OF THE TEMPORAL LOBE OF THE NEGRO BRAIN
ROBERT BENNETT BEAN
Frovi the Anatomical Laboratory, the Tulane University of Louisiana
NINETEEN FIGURES (THREE PLATES)
While at the University of ^lichigan in 1906, I examined some casts of the interior of skulls which I had made in the Anatomical Laboratory of the Johns Hopkins University. My attention was struck by the apparently small size of the pole of the temporal lobe of the negro brain as compared with that of the white; and, proceeding to apply the calipers, the difference was demonstrated to be a measurable quantity. I then measiu'ed some brains from whites in the Anatomical Laboratory of the L^niversity of ^Michigan and others from both whites and negroes in the Anatomical Laboratory of the Johns Hopkins I^niversity, and at The Wistar Institute. I wish to thank Dr. ]\IciMurrich, Dr. Mall and Dr. Greenman for permission to use the material in their charge and for assistance in the work of making measurements.
MATERIAL AND METHODS
The material studied consisted of 127 brains of negro males, 53 of negi'o females and 53 of white males (no white females) and measiu'ements were made on each temj)oral lobe in two planes. The two planes selected are called basal and ])ole. For the basal plane I selected a plane passing horizontally through the temporal lobe, beginning posteriorly on the inferior surface at a point where a shallcnv depression is found in the inferior lateral border of the lobe by the upward projection of the petrous portion of the temporal \n)iu\ and ending anteriorly at a Hne where, if the plane were extendetl. it would l<\ive th«^ temporal
THE VNATOMICM. HECORU, VOL. 8, NO. 11 NOVEMMKU. I'.'M
4S() ROBERT BEXNETT BEAN
loho to pass aloiiK the lowest part of tlie orbital surface of the frontal loI)e. A straight -edged ruler laid alongside the brain will indicate the plane, if the edge of the ruler is on a level with the lower border of the frontal lobe and the depression in the temporal loi)e made by the petrous l)one.
The other or pole plane selected was parallel to the first and through a point 5 mm. vertically above the lowest projecting jioint of the temporal lobe. The two planes were measured both in their antero-i)osterior and transverse diameters.
The planes selected are not always the same in the brains examined, but they are the be.st that could be located and the results bear out the evidences of inspection of brains, and of skull casts, as well as of photographs of these and the evidences of Hrdlicka's measurements of the skull. Therefore they are dependable if only as an approximation of the condition. The measurements cover only a small jiart of the temporal lobe, and that the mere extremity.
It may be added that in calculating the standard deviation, skewness of the curve and probable errors, Pearson's methods or Davenport's formulae have been followed. The median has been used instead of the mean because of the small number of individual measurements, the ea.se of calculation and the almost exact identity- of the two.
MKASrHKMKXTS IN TUK BASAL I'LAXK
The antero-posterior diameter of the ba.sal plane shows the white males congregated about 52 to o() mm., the negro males about 50 to 54 mm., and the negro females about 48 to 52 mm. The mean, that is to say the point midway between the most extreme cases, is 54 mm. for the whites, 52 mm. for the negro males and 48 nmi. for the negro females. The median, that is to say the point with an equal lumiber of cases on either side, is 54.3 mm. for the white males, 51.5 mm. for the negro males and 41J.25 mm. for the negi'o females, while the extremes are separated by 2() mm. in the white males and in the negro males, but by only 22 mm. in the negro females. Tli<' averages of the antero-i)osterinr diaiiu^ter of the basal plane of the three
A RACIAL PECULIARITY OF THE TEMPORAL LOBE 481
groups are 54.7 mm. for the white males. 51.8 mm. for the negro males and 49.4 nmi. for the negro females and the mode is 55 mm. for the white males, 52 mm. for the negro males and 50 mm. for the negro females.
From these figures it will be seen that the antero-posterior diameter of the basal plane of the temporal lobe is greater in the white males than in the negro males and greater in the negro males than in the negro females, in the mean, on the average and b}' the median and the mode, the difference being about 3 mm. between the white males and the negro males and about 2 mm, between the negro males and females.
Hrdlicka has measured the antero-posterior diameters of the fossae of the skull in various races, both in adult indiWduals and young, and in monkeys and other animals, and has determined that the temporal or middle fossa of the negro skull is absolutely shorter than that of the white or that of the Indian, and that it is also shorter in proportion to the total external length of the skull, this being especially noticeable in dolichocephals. His results are based on measurements of 55 negro skulls, male and female, compared with those of 90 white skulls, male and female, and those of the skulls of 20 Indian males. Although the points and planes selected are not exactly the same as those I used, yet there is no very great difference between his and mine, and the results of the two sets of measurements, the one on the skull and the other on the brain, are corroborative.
As regards the transverse diameter of the basal plane, the white males are grouped around 48 to 50 mm., the black males around 42 to 46 and the black females around 44 to 46. The mean is 49 mm. for the white male, 42 mm. for the negro male and 44 mm. for the negro female, and the median is 49 for the white male and 44 for both the male and female negro. The extremes are separated by 14 mm. in the white male. In- 22 mm. in the black male and by 18 nun. in the black female. The averages are 49.3 nun. for the white male, 44.4 mm. for the negro male and 44.5 mm. for the negro female: and the mode is 50 mm. for \ho white male, 4i') mm. for the negro male and 44 nun. for tIi(> negro female.
482 H(»KERT BEN'NKTr HKAX
Tlic transvorso diaiiioter of the temporal l()l>o in the basal plane is accordingly greater in the white male than in the negro male by about 5 mm. and it is about the same size in the two sexes of the negro, in the mean and in the average, by the median and by the mode. A comparison will show that there is a greater racial difiference between the two sets of males in this, the transverse, diameter of the basal plane than in the antero-posterior one. Taking the averages, the difference between the two diameters in the white male brain is 54.7 minus 49.3 equals 5.4 nmi., while that in the negro male brain is 51.8 minus 44.4 equals 7.4 mm., the transverse diameter of the basal plane as compared with the antero-posterior diameter being thus 2 imn. less in the negro male tlian in the white male, or, conversely, the anteroposterior diameter relatively to the transverse is 2 mm. greater in the negro male than in the white male. This difference may, perhaps, l^e better expressed by representing the relation by an antero-posterior transverse index in which the transverse diameter is taken as 100. Then the index for the male white is 110.9, while that for the male negro is 116.4. The difference between the averages of the diameters in the negro female is 4.9 mm., differing from that of the white male by 0.5 mm., while the index is 111, almost identical with that of the white male.
Hrdlicka has measured the pituitary fossa in negro and white skulls, but his measurements do not extend to the body of the sphenoid bone and hence cannot be used for comparison.
MEASUREMENTS OF THE POLE PLANE
The measurements made at 5 mm. from the lowest projecting point of the temporal lobe are necessarily less accurate than those of the other two planes on account of the greater difficulty of oi)taining the exact location of the plane, the variable shape of the tempc^ral pole, etc. There is, however, an ai)i)reciable racial difference. The modes of the white males are about 26 mm. and about 34 mm.; those of the black males about 22 nun. and about 28 mm.; and those of the black females about 16 mm., ai)out 20 nun. and about 26 mm. This multiple grouping is
A RACIAL PECULIARITY OF THE TEMPORAL LOBE 483
due to the different shapes of the temporal pole, some being long, others round, while others are oval or oblong. These various shapes occur in each race-sex group and hence do not interfere with a fair comparison.
The transverse diameter of the pole plane is more homogeneous than the antero-posterior. The white males are grouped about 24 mm. and the negro males and females about 18 mm. The numbers of about the same value are more extensive than in the other arrays, indicating a tendency to a large grouping about the mode. A curve to illustrate this would be platycurtic, or flat-topped (McDonnell). The transverse diameter of the pole plane passes below the hippocampus.
THE SIZE OF THE TEMPORAL LOBE RELATIVE TO THE HRAIX WEIGHT AND SIZE
A comparison of the size of the temporal lobes with the total brain weights was made in the brains of 34 negro males, 21 negro females and 13 white males, and the results showed that there was a slight increase in the size of the temporal lobe with increase of brain weight, and that this increase was greatest in the white males and greater in the negro female than in the male. The brain weight of the white is greater than that of the negro and this might possibly account for the difference in the size of the temporal lobes as already determined. But this indicates that the lobes of the white are larger absolutely and i-(>latively to brain weight, than those of the negro.
The same result is obtained by a comparison of the diameters of the temporal lobes with the diameters of the cerebral hemispheres to which they belong, length with length and breadth 'with breadth.
It will 1)(^ s(>(Mi that both in series and by averages the white has the advantage^ of th(^ negro, the dimeiisions of tlie temporal lobes are actually greater in the white except in the case of the antero-posterior diameter of the basal i^lan(\ where the negro female has an advantage of 1 mm. in the avi^-age over the white male and of 2.(> mm. over tlu^ negro male.
484 ROBERT BENNETT UK AN
CONCLUSIONS
Tlu' ^('Horal roiu'lusions may ho stated foncisely as follows:
1. 'I'ho size of the pole of the teiui)oral lohe is less in the negro than ill the white, and less in the negro female than in the male.
2. Tlie differences are more pronounced in measurements taken below the hijiiiocampus than in those wliich pass through that structure. Hence it is probable that
.3. The hippocampus is larger in the negro tliaii in the white •md larger in tlie negro female than in the male.
4. Tlie shaj)e of the ix)le of the temi)()ral lobe is different in the two races, being slightly more slender in tlie negro, and almost the same size in the two races antero-posteriorly
5. The differences are not only absolute but are also relative to the weight and size of the entire cerebral hemispheres.
The brains collected at Tulane I^niversity confirm the evidence in relation to the temporal lobe of the brains examined at the I'niveisity of ^Michigan, at The Wistar Institute, and at the Johns Hopkins Univek-sity. The brains examined at Tulane University were preserved in a uniform manner, but the brains examined in the other places were not, and the differences noted at Tulane University are more distinct than elsewhere.
noteconcp:rnin(; rkcknt obskhxaiioxson iiik nkoro nn.ws
The brains examined here were j)reserve(.i in the following manner: The bodies from which the brains were removed were injected with tlie usual Souchon solution as soon after death as I)ossible. usually at least twenty-four hours after, and they were allowed to remain another twenty-four hours before the brains were removed. The skull caps were sawed as low down over the forehead and occipital region as practicable to remove thecap without disturbing the brain, and after the removal of the brain it was weighed and placed in 10 per cent formalin solution, base up, fitting it into the skull cap. Tli(> brains weic found to harden readily, and to retain their shaj)e esix'cially well in the region of the temporal lobes. The skull cap IxMng the shai)e of the vertex this also retains its shape. Should the brain be soft it may spread u little over the cut sides of the skull cap,
A RACIAL PECULIARITY OF THE TEMPORAL LOBE 485
but if the brains are fitted well into the skull cap this seldom occurs.
In a test of the accuracy of my powers of observation, nine brains were selected at random without knowing their race character, and from the temporal lo})es alone I judged the race correctly in all except two, which I called white, whereas they were from light-skinned mulattoes.
The bi'ains have been measured in various dimensions, and observations as to the size of the pons, cerebellum, convolutions, etc., have been made, but these are reserved for future publication.
The temporal lobe of the brain may be described better than it can be measured. The upj)er part of the lateral side of the lobe in the negi'o brain is flat and the lateral side is also flat as it turns downward, inward and forward straight to the tip or pole of the lobe. In the white brain the upper part of the lateral side of the lobe is round, and the lateral side is also round and instead of passing downward as a flat surface it makes a graceful rounded sweep inward to the pole of the lobe.
The medial surface of the temporal lobe is almost perpendicular in the white brain, but in the negro it sloi)es outward. This makes the temporal lobe of the white brain appear to turn inward at the pole, whereas in the negro brain it is directed downward.
The pole of the temporal lobe is more slender, smaller and nari'ower in the negro than in the white brain.
The temporal pole of the brain of the negi-o female is more like that of the white than is the brain of the negro male, especially on the lateral surface, and this is due to the rounded surface of the female negro brain anil the angular surface of the male negro brain.
LiTKHATrui", ( rri:i)
Hkan, R. H. 1!H)6 Sonic racial peculiarities of the ne^ro luaiii. Am. .lour.
Anat., vol. 5. Davkm'out. C. H. 1004 Statistical iiictluHls. IIholic^ka, a. 1890 Dimensions of the normal i)itiiitary fossa or sella turcica
in the white and nejjro races. Archives Neurol, and Psychol. Path.
1907 McMsurcMUMils of tlie cranial fossae. I'roc. V. S. Natl. Museum,
vol. :vj.
McDoNNKLi., W . H. 1901 \ ariation and corn>lation of the human skull. Hiometrica, .S.
I'l-ATK 1
EXPLAN'ATIOX OF FIGURES
1 Skull casts; side view. Note the narrow pole of the temporal lobe in the negro skull cast.
W'hili' male White male While male S'egro male Xcgia male
124.5 1245 121G 1582 15S2
Dura Dura No dura Dura Dura
The numbers refer to the serial number of brains (subjects) at the Johns Hopkins .\natoniical Laboratory.
2 .Skull casts; view from below. Note the wide pole of the temporal lobe in the white skull cast; note also the great width of the space between the i)oles in the negro casts.
Nv(jrii male Xegru male While male .Wr/ro male Xegro male
1247 1330 1216 1212 1217
Dura Dura Xo dura No dura Xo dura
3 lirains; view from below. Xote the narrow i)oles of the temporal lobes of the negro brain and cast and the wide space between them.
While hraiti White brain Xegro brain While lirain Skull east
.\nn .\rbor Ann Arbor Ann Arbor Ann .Vrbor Xegro male
1212 No dura
4 Skidl casts; front view. Note the narrow temporal poles and the wide apace between them in the negro skull casts.
Negri) male Negro male While male Xegro male Xegro male
1219 1217 1216 1330 1247
Dura X'o dura No ilura Dura Dura
W6
A RACIAL PECULIARITY OF THE TENfPORAL LOBE
HOBEUT BKNN'KTT BEAN
PIV^TE 1
WftlMiMW
487
I'l.A TK 2
EXPLANATION OF KinrHES
The outlines in figures 5 to 19 inclusive were made from projections through a lens with the brains each at the same foeal distance from the lens. The gyri and sulci of the temporal lobes are given, as only these are in focus. The outlines show the temporal lobes as if viewed from above through transparent brain substance.
5 Brain 2; white male; age 25; cause of death, pulmonary tuberculosis. Total brain length, right hemisphere 16 cm.; left hemisphere 16 cm.; total brain brea<lth 14 cm.; total brain height 10.1 cm. weigh 1304 grams. Note the wide temporal lobes.
6 Brain 1; negro male, age 65; cause of death, nephritis. Total brain length, right hemisphere 17 cm.; left hemisphere 17.2 cm.; total brain breadth 14 cm. Weight 1.361 grams. Note the narrow temporal lobes.
7 Brain 6; white male; age 55; cause of death, pulniimary tuberculosis. Total brain length, right hemisphere 16.2 cm.; left hemisphere 16.5 cm.; total brain breadth 14 cm.; total brain height 10.4 cm. Weight 1.332 grams. Note the wide temjioral lobes.
S Brain S; negro male; age 48; cause of <k'ath, tuberculosis. Total brain length, right hemisi)here 16.7 cm.; left hemisphere 16.8 cm.; total brain breadth 13.6 cm. Weight 1503 grams. Note the narrow temporal lobes.
9 Brain 7; negro female; age 75; cause of death, unknown. Total brain length, right hemisphere 16.1 cm.; left hemisjjhere 16.1 cm.; total brain breadth 12.4 cm. Weight 992 grams. Note narrow tips of the temporal lobes.
10 Brain 10; white female; age 23; cause of death, lobar pneumonia. Total brain length, right hemisphere 15.5 cm.; left hemis])here 15.7 cm.; total brain breadth 12.6 cm.; total brain height 10.6 cm. Weight H.m gr;iins. Note the wide temj)oral lobes.
11 Brain 9; negro male; age 38; cause of death, ])ulmonary tuberculosis. Total brain length, right hemisphere 16.5 cm.; left hemisphere 16.4 cm.; total brain breadth 13.5 cm.; total brain height 10.6 cm. Weight 1304 grams. Note the narrow poles of the temjKjral lobes.
12 Brain 3; nudatto male; age 53; cause of death, nephritis. Total brain length, right hemisphere 16.8 cm.; left hemisphere 17 cm.; total brain breadth 13.6 cm. Weight 1.389 grams. Note the wi<le temporal lobes like those of the white.
488
A RACIAL PECLLIAHITY OF THE TEMPORAL LOBE
ROBERT BENNETT BEAN
PLATE 2
■k>y
PLATE 3
KXPLAVATION OF FIGURES
13 Brain 14; ncgrd male: age 38; cause of death, pulmonary tuberculosis. Total brain length; right hemisphere 15.8 cm.; left hemisphere 15.6 cm.; total brain breadth 12.1 cm.; total brain height 0.9 cm. Weight 1106 grams. Xote the narrow temporal lobes.
14 Hrain 4; negro male: age (w; cause of death, nephritis. Total brain length, right hemisphere 16.7 cm.; left hemisjjhere 16.7 cm.; total brain breadth 12.1 cm. Weight 1219 grams. Xote the narrow temporal lobes.
15 Brain 12; negro female, age 70; cause of death, arterio-sclerosis. Total brain length, right hemisphere 16.3 cm.; left hemisphere 16.7 cm.; total brain breadth 12.3 cm.; total brain height 10.9 cm. Weight 1169 grams. Xote the narrow points of the temjKjral lobes.
16 Brain 11 ; mulatto female; age 24; cause of death, pulmonary anfl intestinal tuberculosis. Total brain length, right hemisphere 17 cm. (distorted; left hemisphere 16.4 cm.; total brain breadth 12.8 cm. Weight 1155 grams. The temi)oral lobes are as wide as in the white.
17 Brain 15; negro male; age 28; cause of death, lobar pneumonia. Total brain length, right hemisphere 17.1 cm.; left hemisphere 17.1 cm.; total brain breadth 12.7 cm. Weight 1304 grams. Xote the narrow point of the temporal lobes an<l the large hipj)ocampus.
IS Brain 13; negro female; age 23; cause of death, jjulmonary tuberculosis. Total brain length, right hemisphere 16.6 cm.; left hemisphere 16.4 cm.; total brain breadth 12.7 cm. WCight 1219 grams. Xote the narrow point of the tem|)oraI lobes and the large hi|)pocampus.
19 Brain 5; mulatto male: age 39, cause of diath. lobar pneumonia. Total brain length, right hemisphere 16.8 cm.; left hemisphere 16.8 cm.; total brain lireaflth 12 cm. Woicht r2.'^3 grams. The temporal lobe is witle as in the white.
490
A. RACIAL PECULIARITY OF THE TEMPORAL LOBE
ROBERT BEXNTTT BEAN
PLATE 3
UM
CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF THE MUSEUM OF COMPARATIVK ZOOLOGY AT
HARVARD COLLF-GK, XO. 254.
AN ABNORMALITY IN THE INTESTINE OF NECTURUS AIACULOSUS RAF.
LESLIE H. A HEY
SIX FIGURES
Morphological abnormalities in Necturus have been described by many workers and, because of their frequency, have long since ceased to occasion astonishment. A great majority of reported cases, however, are based on skeletal variations, while variations in the soft parts either occur less frequently, or. what is more probable, become 'smoothed out' in subsequent development and thus escape attention. The following case, involving the fusion and communication of a loop of the ileum with the rectum, would seem worthy of mention if only on account of its novelty and its bizarre nature. Acknowledgment is due Dr. E. L. Mark for critical reading of the manuscript.
The spechnen was a sexualh' mature female, the vascular system of which, fortunately, had been injected for study in comparative anatomy.
The rectum (fig. 1, /7.), which lias the usual proportions, joins the cloaca in an essentially normal fashion. The ileum, traced toward the stomach, proceeds craniad from the point where it merges into the rectum 1.5 cm. and then turns sharply and runs caudad for 3.0 cm., fusing al)normally with the rectum aliout 1.5 cm. from the end of the latter.
This reflexed Hmb of the ileum (//./;/>.) is. for the most part, somewhat sniallei- tliaii \hv norm;d ileum (il.no.), l)ut its caudal third l)econies enlarged to form a ])rominent swelling which, subterminally, joins tlu^ right lateral side of the rectum in a well defined junction. Tlie rectum receives the normal ileum a little distanci* in front of the union just described, on the right \(Mitvo-lat(>ral sidr of the rectum.
493
494
LESLIE B. A KEY
il.no
par. so
of. il. rfx
.rfj
■of.il.no.
Kig. 1 Dorsal view, rectum severed just craniad to the oviducal ai)erturcs. or, transitional region, where the dorsal mesentery transfers its primary connection from the normal ileum to the rectum; il.nn., normal ileum; il.rfx., reflex ileum; rl., rectum.
Fig. 2 Ventral view into the body cavity, with the rectum opened by a median ventral incision, .\rrows with full and broken lines show the relation of the normal and reflex ileum to their respective rectal orifices, rlc, cloaca; il.no.. normal ileum; H.rfx., reflex ileum; of. il.nn., orifice of normal ileum into rectum: of. il.rfx., orifice of reflex ileum into rectum; of. n' tit., oviducal orifice into cloaca: par.Ko., cut edge of body wall; rt., rectum.
That tho ileo-rectal loop does not end blindly at the swollen region of iniion was first tested experimentally by forcing a colored lic|uid backward in the reflex portion of the ileum, whence it appeared in tlic cloara: later this was substantiated by dissection.
ABXOKMALITV IX THE IXTESTIXE 495
When the cloaca and rectum were opened by a mid ventral incision (fig. 2), the orifices of the normal ileum and of the reflexed ileum into the rectum were easily demonstrable. The former enters by an aperture only slightly smaller than its lumen, and nothing that can be called a ty])ical sphincter occurs, although sections examined under the microscope showed the circular muscles to be somewhat aggregated at this point; the latter, on the contrary, enters by an aperture of about the diameter of a pin. located at the bottom of a deep cup-shaped collar, a little dorsad and caudad to the entrance of the ileum proper. Sections
Fig. 3 Schematic longitudinal section throu^ih the region of union of the reflex ileum and the rectum, to show the relation of the section seen in figtire 4. (UiM lines) to the adjacent parts (broken lines), il.rfx.. reflex ileum: In., lumen of rectum; of.il.rix.. orifice of reflex ileum into rectum; pnr.rt.. wall of rectum.
of this region (fig. 4) show a conspicuous band of circular muscles surrounding the constricted opening: this presiunably constitutes a sphincter. Xonnally no sphincter occurs at the junction of the ileum and rectum in Xecturus.
The large, essentially nonnal sized ai>orture of the ileum proper is easy to understand from the stantljioint of functional necessity. Init the occasion of the establishment and perpetuation of a sphincter in an apparently useless loop is not so evident.
The whole ileo-rectal \o^^p was found full of faeces a pertinent fact.
THE AX.VTOMIC.VL KECORD. VOL. S, NO. II
490 LESLIE B. ARKV
Tlio nioinhranes suj^porting this region iiro not without interest. The rectum, ami the ileum as far as the anterior bend of the ileo-rectal loop, are supported in the normal manner by the mesentery. Craniad to the loop the mesentery is attached to the ileum pro])er. wliile caudad to this transition point (fig. l,a) the ileum is not j)rimarily sui)i)orted to the l)ody wall. A narrow membraneous sheet, however, (fig. 6, ms'enr.i'il.) connects the normal ilemn with the reflex ileum; the reflex ileum and the ileorectum (fig. 6, ms'efir.rt-il.) likewise are similarly connected.
All these intestinal parts appeared to be in a well nourished condition. Blood vessels from the mesenteric vein and posterior mesenteric arteries follow their usual courses in themesentery, and smaller branches ramify through the walls of both the normal and the reflex ileum.
The time of the establishment of this abnonnality was, presumably, early in the development of the anhnal — ^an assumption to which the condition of the supporting membranes points. The narrow membranous sheets between the intestinal limbs are evidentl}^ conthmations of the ]:>rimary mesentery; this is well shown at the transition i^oint (fig. 1, a) where the mesentery ceases to support the ileo-rectal loop and directly supports the nonnal ileum.
The origin of this condition can be explained by assuming (fig. 5) a loop of the embryonic intestine to have been reflexed inside the mesenteric fold which contamed the gut loosely embedded in a mesenchymatous matrix. When, later, this common suj)i)orting fold became closely applied to the three intestinal members (fig. 6), the condition of the membranes, as described above, was effected. To complete the process, the caudal end of the loop had only to fuse with tlie rectum and to establish conn nun icatory oj)enings with it.
The finding of the ileo-rectal loo]) full of faecal matter stimulates speculation concennng the role which the loop played Avith regard to its contents. It is ])ossible that material entering the rectum from the normal ileum merely !)acked up from the rectum into the loop until the latter became filled. If, however, the intestinal movements proceeded in tli(> nonnal direction,
ABNORMALITY IN THE INTESTINE
497
par.il. rfx,
Fig. 4 LonRitvidinal section thr()\iKli the region of tlu> spliim-ter of the reflex ileum (X 13). coll., collar exteudinj!; into lumen of reetvim; niu.crc, circular muscles; mu.lg., longitiuliniil muscles; of.il.rfx.. orifice of reflex ilevun into rectum: par.il.rfx., wall of reflex ileum; par.rt., wall of rectum; .sp/i/., sphincter.
Figs. 5 and 6 Diagrammatic cross sections to show how the embryonic ileum, if reflexed inside the mesenteric fold (fig. 5). could produce the conditions of the supporting membranes found in the adult specimen (fig. 5). i7.no., normal ileum; il.rfx., reflex ileiun; ni.t'chy., mesenchyme; m.<<'cnr.d., dorsal mesentery; ms'cnr. i'i7., interilcal mesentery; ma'cnr. rt-il., recto-ileal mesentery; rt., rectum.
498 LESLIE B. AREY
such hackiiifi u]) could l)c effected only in o]ij)osition to ])(Tistalsis, whicli would tend continually to eni})ty the loop of its contents. That a certain amount of substance might enter through the sphincter and ]iroceed around the loop is possible, though hardly ]>robable. A third possibility is that the reflex ilemn had its l)erislaltic jiolarity reversed. Since the flexure ])robably occurred before the muscles were functional, tliis view is entirely tenable. Part of the faeces collected in the rectimi, where peristalsis is poorly developed, would thus be captured by the abnormal ileal loop, would be passed in an abnormal direction through the loop and out through the sphincter; the normal activity of a sjihincter would favor this view. That any of these hy]:)othetical processes involved more than a small fraction of the total faecal matter is highly improbable, and speculation as to what might have happened can easily be carried too far.
It is interesting to note that here, in nature, we find the essential condition effected by the modern surgical operation, originated by Sir A\'. Ail)Utlii!ot Lane, whereby the ileum is connected to the rectun), and the colon is thus short circuited in the conduction of food.
THK de\t:lop.mkxt of the hypophysis of
A:ML\ (ALVA
p. E. SMITH From the Hearst Anatomical Laboratory, University of California
TKN kk;ikf.>; HYPOPHYSIS or AN[IA
The origin of the hypophysis in the various fomis studied has })een a source of disagi'eement, both in observation and in interpretation. The majority of those who have worked upon this question consider that the hypophysis arises from ectoderm; however, a few well known observers. Kupffer ('94), \'alenti (in a series of papers), Xusbaum ('96j, and Gregviry ('02) state that it has also an entodermal contribution. The only author who describes the hypophysis as entirely entodermal in origin is Prather COO) in Amia. That such an interesting ]>hylogenetic anomaly is descril)ed seemed to the writer to warrant a further examination of this form, especially as Dean ('96) described this structure in this form, as of epiblastic origin.
The various specimens studied range in age from soon after the closure of the neural tube up to an IS nun. stage. In fixation and staining especial care was taken to preserve the yolk granules and cell boundaries so that these most valuable structural features would be retained. The ages could be tletenninetl only by comparison with the excellent figures of Dean ('96).
Figure 1 is from a median sagittal section of an embryo surrounding about 225° of the yolk. It corresponds to the stage figiuod l)y Dean (fig. 2) and so is about 142 hours old. or the same age as the specimen figured l)y Prallicr (fig. 1). Beneath the hypotluilnmic region of the l>rain is the foregut and the stomo
499
500 p. E. SMITH
(Jaeuiii scjjaratt'cl l)y an iiui)erfec'tly formed oral plate. The ectoderm fonning the floor of the stomodaeum differs somewhat from that of the roof. Tliat of the floor is two layers in thickness having a more acidojihilic cuticular layer and a more basophilic basal layer. The ectoderm of the roof has an imperfectly fonned cuticular layer, and a definite, cytoi)lasmic-rich basal layer, while between the two is an irregular single or double layer of cells rich in yolk and not easilj' distinguished from the entoderm cells at the juncture of the stomodaeum with the foregut.
A growth of this basal layer c^udad extends from both the floor and the roof of the stomodaeum. That from the floor contributes to the dental ledges while that from the roof is more extensive and is the hypophysial rudiment. The cells composing this mass are more protoplasmic than the entoderm cells which have many large yolk granules. Their cell boundaries are also more distinct than those of the entoderm cells. There is no limiting membrane between the entoderm and this hypophysial rudiment, at this or later stages, but in specimens properly stained and differentiated the two varieties of cells can easily be distinguished from each other. A strand of cells connecting the hjTDophysis to the basal layer of the ectoderm is present. This connecting strand was evidently overlooked by Prather, for he describes and figures (flg. 3) at a little later stage (160 hours) and in a position farther caudad, a nest of cells of this character. His figure also strongly suggests that his hypophy.sial rudiment is
ABBREVIATIOXS
b.v., blood vessel l.t., lamina tcriniualis
eel., ectoderm iiies., mesenchyme
ect.m., basal layer of ectoderm w.r., mamillary recess
end., entoderm up.r., optic commissure complex
end.d., entoderm, deep layer op., optic chiasma
eud.y., entoderm, siipcrficial layer pr.s., premandibular somite
f.g., fore gut r.p.op., recessus post opticus
hy]>., hypophysis r.pr.op., recessus preopticus
inf., infundibulum st., stomodaeum
/., limit between ectoderm and ento- .t.v., saccus vasculosus
derm r.l., vestigeal lumen
DEVELOPMENT OF THE HYPOPHYSIS
501
Fig. 1 A median sagittal section of a larva surrounding 220° of the yolk: estimated age, 142 hours. X 200.
Fig. 2 .\ median sagittal section of an embryo surrounding 290° of the yolk; estimated age, 160 hours. X '200.
Fig. 3 A median sagittal section of an embryo at the time of hatching. X 200.
502 1'. K. SMITH
i'oinu'ctcd to tlio octoclonii. In cross-sect ioii this cell mass appears as a single ovoid iiest composed of both flattened and oval shaped cells.
In a later stage (fig. 2) c()rresj)ondiiig to Dean's figure '), larva surrounding 290° of yolk, this cell mass can he still more easily distinguished from the entoderm. It has extended farther caudad and is sejmrated from the cuticular laj'er of the entoderm by an irregular double layer of yolk laden cells. The connecting strand is still very evident.
Still older specimens (figs. 3, 4, 5) shortly after hatching, show that further growth of this structure has taken place but the relations remain unaltered. In figure 4 the deeper, yolk rich, layer of entoderm shows particularly well. Directly beneath the hypophysis, to an extent, but particularly at the sides the entodermal cells have become flattened, and to them especial attention will be called later. In figure 5, two sections cephalad to figure 4, these entodermal cells are still more flattened.
In a () nmi. specimen (figs. 6, 7) the hypophysis has assumed nearly its adult position. In the dorsal and lateral portions the cells are either oval or round, and show a radial arrangement towards a minute cavity, the vestigeal lumen. Ventral to the lumen the cells are few in number, flattened, and do not radiate towards the cavity. It is to the juncture of these flattened, ectodermal, hypophysial cells w4th the entoderm, that particular attention is directed. In the early stages of the hypophysis they were easily distinguished from the entoderm of the foregut. During development, however, the entoderm has been losing more and more of its yolk granules until its appearance is practii-ally like that of the hy])ophysis, and so from this stage on these
I'"ig. 4 ( 'ross-scctioii through the ccplKilic poitioii (tf t lie liypophysis of an
embryo at the lime of hatching. X 2(K).
Fig. 5 Same scries as figure 4; two sections ciiiKlatl. X -00.
Fig. (i .\ median sagittal section of a 6 mm. specimen. X 200.
Fig. 7 ('r()ss-.scction of a slightly older specimen. X 200.
Fig. S A median sagittal section f>f an S mm. specimen. X 200.
Fig. n A median sagittal section of an .S.J mm. specimen. X 200.
Fig. 10 .\ median sagittal section of a 10 mm. specimen. X 200.
DEVELOP.MK.V'J OF THE HYPOPHYSIS
503
hyp 4
^^.
end. y.l.
504 P. E. SMITH
entodeniial cells must be identified largely by their position In a cross-section of this age (fig. 7) the same condition is evident.
Later stages (fig. 8. 8 mm. ; fig. 9, 87} mm.) show the separation of the h^pojihysis from the pharynx. This separation takes place by or becomes aiijiarent with a mesodermal ingrowth into the intercellidar clefts at the sides and base of the hypophysis. Examination of sections at this critical stage shows convincingly that part of the flattened cells of the deeper layer of the entoderm become separated from the pharynx and enter into the formation of the hj'pophysis. Tracing these entoderaial cells which border the ectodennal hA'pophysial rudiment, through the successive stages, has been the most interesting and difiicult part of the study. At the time of the separation of the hj^Dophysis from the mouth they can not be determined, structurally, from the cells of ectodemial origin. It is only by identifying them at the latest possible stage by their staining reaction and then by their position and relation that it can be said with considerable probabihty that they do enter into the formation of the adult h^^pophysis. The process is much like that described by Gregory ('02). In his figures (figs. 29, 30, 31) he indicates a flattening of the entodermal cells and their inclusion into the ectodermal hj-jiophysial rudiment. However, he carries the process much further than here described and includes all the thickened entodeniial mass caudad of the ectodermal hypophysial anlage in the formation of this structure. The difficulty of determining the limit between ectodenu and entoderm in Aniia was also mentioned by Dean.
The vestigeal lumen has been well described by Prather and needs little additional attention. A Hmiting membrane as definite as he indicated was not noted. Jvxtending away from the lumen are many intercellular spaces. It appears as if by secretion the cells force themselves apart. This is even more apparent later with the increase in the lol)ulation of the gland and the connnunication of the cavities of the various lobes with each other l)y intercellular spaces.
I
DEVELOPMENT OF THE HYPOPHYSIS 505
SUMMARY
The development of the hj^iophysis in the ganoids has been worked out with rather uncertain results. Haller ('98) has cast doubt upon the work of von. KupfTer; Balfour and Parker ('82) were in doubt as to their own results; while Dean differs from Prather in the work upon Amia. This confusion is partially due, perhaps, to the developing adhesive organ, but primarily to the difficulty of distinguishing between the ectoderm and the entodeiTii. Their union is intimate from the first appearance of the hypophysis, and it is only by notirg from the first the caudal growth of the basal layer of the ectoderm to form the hypophysial rudmient, that the origin of this gland can be given. The process in Amia differs in no essentials from that in the other teleosts and the amphibia. The relation of the entoderm of the foregut to the gland is of interest in showing the plasticity of the tissues. This adaptability of tissue or germ layers is especially well exemplified in the formation of the hjiDophysis in this form where the union of two germ layers is particularly close. As observed by the author in some other foims as well, the contiguity of the entodemi to the gland leads to the modification of the fonner and a change from its nonnal function to that of another germ layer. Whether this is due to the influence of the nervous system, the inherent tendency of the tissue, or some other factor or factors, cannot be stated at this time.
LITERATURE CITED
Balfotr, F. M. ami Pahkkh. W. X. 1SS2 On the structure and development of I.epidosteus. Trans Roy. Soc, Part II.
Dean, B. 1896 On the larval development of Amia calva. Zool. Jahrb., Bd. 9.
Gregory, E. II. 1902 Beitriige zur Ent\vickelungSKe.schichto dor Knochenfisrhe. Anat. Hefte, Bd. 20.
Hauler, B 1S98 Untersuchunjien iihcr die Hypophysc und die Infundibularorgane. Morph. Jahrb., Bd. 25.
KiNGSLEY, J. S., and Thyng, V. \\ . 19(V5 The hypophysis in Amblystoma. Tufts CnlloRo Studios. No. S.
.')()() p. K. SMITH
VON KiPKKKK, ('. lS«t3 Kntwickelungsgeschichtc (ics Knpfos. ICifieh. Anat. u. Kntwick.. Bd. J.
1S94 ni«> n«Mitunn dos Hirn Anhanpes. Sitzber. Ciesellsch. f. M<)ri)li., Miinchen.
NrsHAiM, J. 1896 Kinige neue Thatsachen zur Kntwickelungsgeschichte der Hypophysis cerebri bei Saugetieren. Anat. Anz., Bd. 12.
Pkathkk, J. M. 1000 The early stages in the development of the hypophysis of Amia, calva. Biol. Bull., vol. 1.
TiLNEY, F. 1911 Contribution to the study of the hypophysis cerebri with, especial reference to its comparative histology. Wistar Inst. .\nat. and Hinl.. Memoir no. 2.
A BRAIN MACR0T0:\1E
RICHARD W. HARVEY
HcdrsL Auaturnical Luboralary, Universily of California
TWO FIOI'UES
In recent work on the asymmetry of the basal jjangha it liecame necessary to obtam sections of the l)rain of unifonn thickness which were traced on wax phites of simihir tliickness. The sections were 3.5 mm. thick. In order to facihtatc the work and render it accurate, a macrotome was devised, which has since been mocHfied from suggestion })y Dr. G. Y. Rusk of the Department of Pathology.
The base and standard of the instrument are cast separately and screwed together. The base is Y-shaped, similar to that of a compound microscope, measuring 29 x 19 cm. and 2 cm. thick, of cast-iron, affording a firm support to the instrument. The standard measures 2x5 cm. and 32 cm. long, and is jirovided at the back with two flanges for additional strength.
Near the top of the standard is fixed a I'-shapeil i)iece enclosing the movable stage. This U-shaped piece measures 23 x 23 cm. and is 1 cm. thick. On the upper surface of each arm are laid two strips of plate-glass, separated from each other In' bits of steel from the blade of the knife which is used for cutting, and heUl to the arm by lead washers ajul round-headed screws. Tiu> m()val)le stage runs in a vertical groove fastened separately to the standard, and measures 19 x IS cm. and 1 cm. thick. Wiien raised to the level of the I'-shaiied )>iece. it fits accurately witliin the arms. To prevent drainage of litjuids into the groove a flange is placed near the edge. The stage is adjusted by a screw with a millimeter thread jiressing up agaiu.st the bottom of the stage and givhig to it a play of 10 cm. A milled head operates the screw, and by it an adjustment to a fraction of a millimeter may be made.
The knif(> is made from a clock spring, 30 cm. long, ground to a razor edge, mounted in a iiack-saw l)ack. Hoth edg(>s are ground to permit the knife to be u.sed (Mther erect or inverted. The interval l^etween the stage and the base gives amjile space for the back of the inverted Icnife, the stage not aiijiroaching nearer the base than 12 cm. To use the knife, the upjier strips of plate ghuss are removed, the blade inserted, and the glass screwed into place again.
In using the macrotome the brain is placinl on the niovalile stage and the \rvv\ to be sectioned ;idjustcd to th(> level of the lowiM" gl:i-i>
M^7
508 RICHARD W. HARVEY
strips. The knife cuts with a liack-aiid-forth motion. The section is removed and the sta^f readjustetl l)V raising; it the required lieight.
The advantages of the instrument are: (1) SimpHcity; there are no jjart-s l)ut wliat may be constructed by an ordinary technician. (2) Accuracy; the knife-l>hule being hold tigiitly lietween the plate-glass strij)s, ajid the stage suppttrted Hrmly from beneath, there is insured an accuracy' in the thickness of the sections which for microscopic work is all that can be desired. (3) Convenience; the instrument occupies about the same room as a compound microscope, and can be carried very convoniontl> from place to place in the laboratory. (4) Cheajniess.
BRAIN MACROTOME
509
Z1
^
lU
I'iy,. 1 Side viow of inaorotonu': measurements in centimeters.
<--/:>
Fig. J 'I'd]) view of macrotome; measurements in centimeters.
BOOKS RECEIVED
Tlie receipt of publicalions thai iniiy be sent to niiy of the five biDlogical journals published by The Wistar Institute will be ncknowIe<lKed under this headine. Short reviews of books that ore of special interest to a large number of biologists will be pulilislie<l in this journal from time to time.
LABORATORY APPARATUS AND REAGENTS selected for laboratories of ohoniistry and biology in their application to education, the industries, medicine and the public health including some equiimient for metallurgy, mineralogy, the testing of materials, and optical projection. oSO pages. Philadelphia. 1914, Arthur H. Thomas Comijany. A very comi)lete illustrated catalogue .showing that great care has been exerci.sed to give accurate descriptions of apparatus.
The Reagent list with analyses of the important makes is the only one of this kind i)ul)lishcd either in the United States or Europe, so far as we know, and it seems to us to afford the scientist a means of selecting his Reagents upon both the basis of purity and price, which has not been heretofore provided in any price list.
The following statement in the Preface to the volume is honest, clear, explicit and rather unicjue. "Our business is confined to the buying and selling of Apjjaratus and Reagents, mostly within the iinuts mentioned on the title page of this catalogue. We are not scientists, inventors or maTuifacturersand we are noteciuipped to <lesign and experimentally develop scientific aj^jjaratus. We believe such work is j)roperly done by the scientist in his laboratory, the manufacturer in his shop, or by the two in co()i)erati(m and that the function of the dealer advantageously begins only after such work is completed. We are ready whenever pos.sible to facilitate cooperation between the scientist with iileas for development and .selected manufacturers with facilities api)lying thereto. We own no patents, have part in no monoimlies and all of the merchandise offered herein is obtainable either directly from the makers or througli other dealers whenever our .services fail in their operation toward the convenience, (■(•(momy and general satisfaction of the i)urchaser."
This credit.'ible piece of book-nuikijig bears tiicimitrint of 'ilie \\ averly Press li.'iitiiuore.
olO
^1/
ON THE WEIGHT OF SOME OF THE DUCTLESS
GLA>ES OF THE NORWAY AND OF THE ALBINO
RAT ACCORDING TO SEX AND VARIETY
SHIXKISHI HATAI The Wisiar Institute of Anatomy and Biology
FIVE CHARTS
INTRODUCTION
In connection with another investigation, it was found that in the albii o rat some of the ductless glands show a distinct sex difTerence in weight (Hatai '13). It was found later that a similar sex difTerei ce occurs in the Norway rat also. When, however, these two form.s of rats are compared, the weights of the ductless glands are again in most instances characteristic for each form. In view of the fact that the albino rat is the domesticated variety of the Norway rat, the differences thus presented appear highly interestii g aid suggest a somewhat new line of investigation. It therefore seems vvorth while to note briefly the weight relations of these ductless glands in the two forms of rats, using the data which are available at the present moment.
The ductless gland j with which we deal here are the suprarenals, hypophysis, thymus, thyroid, testes and ovaries. A part of the Norway records here used was obtained by Dr. C. ^I. Jackson while he was at the Ljiiversity of Missouri. He has kindly placed his entire data at my disposal and I take this opportunity to thank him for his courtesy in this matter. For the weights of the ductless glands in the albino rat. the reader is referred to my recerit papers (Hatai '13, '14). The original individual data are deposited in The Wistar Institute of Anatomy in Philadelphia, where they may be consulted by anyone interested.
oil
THE ANATOMICAL RECORD. VOL. 8, SO. 12 DECEMBER. 1914
512
S. HATAI
MATERIAL AND METHODS
1. The suprarenal glatjd.s
The weiglit relations Ijctween the body and the glands in both the Norway and albino rats are shown in table 1 and their graphic representation in chart 1.
a. Albino rat. As is sho\Aii in chart 1, for a given body weight the weight of the suprarenal glands of the male albino rat is less
.15
.13
.09
.07
.05
.03
.01
SUPRARENAL GLANDS
WEIGHT GRAMS ^.o
1 " '^
^5"
y
Jf
^
_^'
^'^ '^
^ ^^<^^"
->-^ ^-^^.'^--^
^^ ^^^^-^ - *
—l> ■•^ ^"^
^ ^"^
t ^'^
t ^•
-.if ^- --—
^4 ^ '" --^■'"
s. f ^- ^^-^"
-4 ^ ■^ ^ ^-^
50 100 150 200 250 300 350 400
Chart 1 .ShowinK tlio wciglit of the sviprarcniil Rhinds in the two sexes of the Norway compared with those in the corrcspondinK sexes of the albino rat.
Males • • Norway, observed O — O Females
Males Albino, calculated Females
than that of the female. This sex difference becomes greater as the rat grows in weight. Furthennore, the difference apjiears at an early i)eriod of life; indeed it is already obvious at about 35 days of age, while sexual maturity is seldom attained in these rats before (iO to 90 days.
The sex difference in the weight of tlie .suprarenals in the albino rat is thus not primarily connected with pregnancy in which con
WEIGHT OF DUCTLESS GLAXDS
513
dition the female suprarenals are considered by some investigators (Biedl '13, and Vincent '12) to undergo hypertrophy.
b. Norway rat. As is shown in chart 1, the suprarenal glands of the Norvvay rat exhibit similar sex differences. Furthermore, the glands of the XorvNaj- rat are considerably heavier than those of the albino. We have not yet determined in the Xor^\-ay rat the exact time of the appearance of the sex diiTerence of this gland.
In table 1 we notice that the sex difference in the weight of the suprarenal glands is on the average 35 per cent in the Norway
TABLE 1
Showing the weights (grams) of the suprarenal glands in the two sexes of the Norway corn-pared with those in the corresponding sexes of the albino rat
SUPRARENAL GLANDS
Body weight j No.
Norway observed
Albino calc. : Albino calc.
Nonray observed
»T„ Body '*°- weight
69
1
0.026
0.018
0.021 '
0.037
4
67
117
4
0.065
025
035
069
3
126
175
5
0S3
031
0.049
093
6
183
226
17
075
037
0.059
0.109
15
224
278
15
0.081
042
070
0.128
10
272
319
10
088
017
0.0^6
137
5
340
375
1
0.079
0.052 I
1 1
Avg. 223
53
071
036
053
096
43
202
and 47 per cent in the albino rat, both in favor of the females. However, owing to the deficiency of 21 grams in body weight of the female as compared with the male, some correction for the percentage differences just obtained, should be made.
By gi-aphic interpolation from chart 1, we find that the weight of the female suprarenals in the Nonvay corresponding to 223 grams of body weight is nearly 0.109 gram. AMien this interpolated value for the female is compared with that observed for the male, we find a difference of 54 per cent in favor of the female rat. Similarly, we find a difference of 61 per cent in the albino rat in favor of the female.
514
S. H.\T.\I
TABLE 2
Shotcing the weights (grams) of the hypophysis in the two sexes of the Norway com' pared with thane in the corresponding sexes of the albino rat
HYPOPHYSIS
MALBS
PBHALBI
Body weight
No.
Norway observed
Albino calc.
Albino oalc.
Norway oboerved
No.
Body weight
186 226 281 315
1
14 15
1
0065
0.0071 0.0085 0.0100
0.0071 0082 0.0097 0.0107
0123 0157 0.0195
0.0071
0086 0.0095
4 9 4
182
225 273
Avg. 252
31
0.0080
0.0089
0.0158
0.0084
17
227
Concerning the differences between the Norway and albino rats in regard to the weight of the suprarenals, we find the following relations:
The suprarenals of the male Norway rat are hea\'ier than those of the male albino rat by 97 per cent.
The suprarenals of the female Norway rat are heavier than those of the female albino rat by 80 per cent.
On the average, we obtain 89 per cent in favor of the Norway rat. We conclude therefore that the Norway rat, both sexes combined, possesses suprarenal glands which are nearly twice as hea\y as tho.se of its domesticated albino variety.
This difference in the weight of the suprarenals between the Norway rat and its albino variety has ah-eady been noted by Watson ('07) but he did not distinguish the sexes. Watson's observations were made on suprarenals which had been preserved in f orin alin .
The sex difference in the suprarenals is sho\vn not only by their weight, but also often by their colors. For instance, in the albino rat the suprarenals of the male are a deep olive in color, wliiU' tho.se of the female are mucli lighter. In the Norway rat, on the other hand, the color of the glands is ashy white in both sexes.
WEIGHT OF DUCTLESS GLANDS
515
2. The hypophysis
The weight relation between the hypophysis and the body in both the Norway and albino rats is showTi in table 2, and its graphic representation i.i chart 2.
.020
.018
.016
.014
.012
.010
.008
.006
.004
.002
50 100 150 200 250 300 350 400
Chart 2 Slunviu^ tlic weight of the liypophysis in the two sexes of the Nonvay compareii with those in the eorrespondinp sexes of the albino rat.
Males • • Norway, observed O O Females
Males Albino, calculated Females
a. Albino rut. The sex difference in the weight of the hypophysis is more striking than in the case of the suprarenal glands, and indeed the difference, after a proper correction for the difference in body weight in tlie two sexes has been made, amounts to 97 per cent in favor of tlie female rat. The tlifference api^ears at about 30 to 40 days of age and thus is not inhnarily associated
HYPOPHYSIS 1 '
WEIGHT GHAMS "•^
/
'
/
_'
.,1 , / !._.
r
/
J , .,. . . , . i
/
/
- ^^
it ^ ^^
it^^ IT
^^ ,^
Z ^'^^m
-T^ ^^ ^
^ ^^tt 4
/ ^^■'^' V
-^ ^z^ ^^^
' ^^ -,^
f- ^^ ^^^ it
^'^--^^
t y*^ *
/
X ^^
-^\^ it
' ^^ T T
y
1 1
nrM~>v \A/F'I/^MT rsRAH/lcj
510 S. HATAI
witli pregnancy in the female, during which condition the liyl)o])liy8is is assumed to undergo liypertroi)hy.
b. Xorumy rat. Curiously, the sex difference in tlie weight of the h^-jiophysis in the Norway rat is considera))ly smaller, and furthennore, the weight of the hyjiophysis in both sexes is smaller than in the corresponding albinos. The difference in the weight of the hypophysis in the Norway rat is found in the following way: From the graph for the female hypophysis in chart 2 we obtain a weight of about 0.0092 gram, corresponding to 252 grams of observed male body weight. When this value of the female hyi")ophysis is contrasted with 0.008 gi-am for the observed male hyi^ophysis (see table 2, average for male), the difference is 15 i3er cent in favor of the female rat.
Although the difference of 15 per cent is quite small when comjiared with that* of 97 per cent, shown by the albino variety, nevertheless its reality is evident from the regularity and unifonnity of the results shown in chart 2. It is interesting to note that the hypophysis of the Norway shows not only a small sex difference, but its absolute weight is considerably less than in the corresponding sexes of the albino rat. AVe obtain from table 2 the following relations:
The weight of the hypophysis of the male Norway is less than that of the male albino rat by 11 per cent.
The weight of the hypophysis of the female Norway is less than that of the female albino rat by 46 per cent.
We may note from the above relations that the smaller sex difference shown by the h>i3ophysis in tlie Norway as contrasted with the albino, is especially due to the relatively smaller hypophysis of the Norway female. The sex difference is shown also in the general appearance of the hj^pophysis.
In both the Norway and alliino rats the hypophysis of the female is much swollen, the upper surface is more convex and the color is a deeper pink than in that of the male. However, we do not find any characteristic appearance distinguishing this gland in the Norway from that in its albino variety.
WEIGHT OF DUCTLESS GLANDS
517
3. The thyroid gland
The weight relation between the thyroid and the body is given in table 3, and its graphic representation in chart 3.
a. Albino rat. Unlike the suprarenals and hypophysis, the thyroid gland of the albino rat does not exhibit any difference distinguishmg the sexes either in weight or in appearance. It must be admitted, however, that this failure to reveal a sex difference may be due either to its absence, or to the fact that the sex difference msiy be masked by the great variability of the thjToid. With our present data the variation in the weight of the thjToid in the albino rat according to sex is not ascertainable (Hatai '13j.
TABLE 3
Showing the weights {grants) of the thyroid gland in the two sexes of the Norway compared with those in the corresponding sexes of the albino rat
THYROID GLAND
MALES
PEBIALES
Body weight
No.
Norway 1 observed
! Albino caic.
1
Albino calc.
Norway observed
No.
Body weight
69
1
' 015
014
015
014
3
73
117
4
0.022
0.021
0.O22
0.025
2
122
174
4
0.029
029
030
0.034
6
183
226
17
0.033
0.035
0.035
028
15
224
278
15
031
042
041
042
10
272
319
10
0.050
0.046
0.O49
0.07S
3
342
375
1
1 0.046
0.053
Avg. 223
52
1 0.032
0.034
032
037
39
203
b. Xorway rat. In the XorAvay rat also the variation in the weight of the thjToid is considerable. Thus the slight excess shown in the weight of the female thjToid (table 3) is difficult to interpret. However, from the general trend of the graph, the difference here noted may be an incidental one. Further, it is an interesting fact that the weight of the Norway thjToid is practically identical with the weight of the albino th\Toid.
Although I am unable to trace the authority for the statement, the thyroid gland in man is the only ductless gland which is
518
S. HATAl
usually stated in tho anatomical text books to cxliibit a sex difference in weight. As we see, however, the thyroid gland of the rat not only fails to exhibit a sex difference, but fails also to respond to the changes of environment represe;ited ))y domestication. If, therefore, our infoniiation concerni: g the human thjToid be correct, we have here an interesting difference in the comparative anatomy and physiologj^ of this gland.
THYROID
t\\ AKin
n
r
WEIGHT GRAMS
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50
100
150
200
250
300
350 400
Chart 3 Showing'the weight of the thyroid in the two sexes of the Norway compared with those in the ablino rat.
Males % — — # Norway, observed o O Females
Albino, ralcuhited Both sexeg.
/f. The thymus gland
The weiglit of the thymus gland is correlatod with the age of the animal and is not evidently different according to sex (Hatai '14) . Since our data for the Norway rat lack age records, no legitimate comparison between the Noi'way and albino tli\nnus can be made. (>on.sequently, the data on the weight of the thj7nus are excluded from the present paper.
WEIGHT OF DUCTLESS GLANDS
519
5. The sex glands
The weight relation between the body and sex glands in both the Norway and albino rats is given in table 4, and its graphic representation in charts 4 and 5.
a. Testes of the Norway rat as compared with those of the albino ral. The weight of the testes of the Norway rat is considerably greater
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
TCCT
^,.
1 bo 1 c^
v\
/EIGHT GRAMS
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,— T^
---T^
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^1
50
too
150
200
250
300
350
400
450
Chart 4 Sliowin}^ the weight of the testes of the Norway rat (Oiupareil wiih that of the albino rat.
Norway, observed • • Albino, caU-ulated
foi- tlie same given body weight, than in the albino rat. The ditToK'iice annnints to 21 per cent in favor <^f the Norway. I am unable to state at present whether this exces.-^ of 21 per cent is due to a uniform enlargement of all the structures of the testes, or whether it is due to the enlargement of some particular constituent. The histological investigation of this point will be of interest.
520
S. HATAI
1
.K)
WEIGHT GRAMS
-U ^5
7*^ >
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ROnV WFiriHT nRAM<5
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50 100 150 200 250 300 350 400
Chart 5 Showing the weight of the ovaries of the Norway compared with that of the albino rat.
Norway, observed o O Albino, calculated
6. Ovaries of the Norway rat as compared with those of the albino. For the same body weight, the ovaries in the Norway rat are considerably heavier than those in the albino. The difference amounts to 26 per cent in favor of the Norway. For the ovaries also we have no histological data as to the structures that are responsible for this excess in weight.
TABLE 4
Showing the weights (grams) of the sex glands — testes and ovaries — in the two sexes of the Norway compared with those in the corresponding sexes of the albino rat
SEX GLANDS
MALES — TESTES
Body weight i No.
1.3.3 172 220 2S() .317 42()
.\vg. 2m
s 10
07
rSUALES — OVARIES
Norway observed
No.
Body wclgbt
n 007
4
67
030
5
126
073
7
180
075
21
221
0.098
12
272
003
6
337
0.0.50
55
201
WEIGHT OF DUCTLESS GLANDS 521
DISCUSSION'
The preceding analysis shows that with the exception of the thyroid and the thymus, the weight of the ductless glands in the two forms of rats exhibits (1) a difference according to sex and (2) a difference according to zoological variety.
1 . Difference according to sex
Although there are scattered statements concerning some of the ductless glands for man, I am not aware that the sex relations of these glands has been previously thus clearh' showTi. At the same time, even in recent studies of the glands, both in man and animals, the sexes are sometimes either combined or not given. Consequently, in the majority of cases, information with regard to the sex relations cannot be obtained. "\ATiether or not the sex difference in these ductless glands is as marked in other animals as in the rat, remains to be determined.
Elliott and Tuckett's work ("06) suggests strongly the existence of a sex difference in the weiglit of the suprarenals in guinea-pigs, rabbits and cats. The amount of data given by these authors, however, is not sufficient for a critical test on this point. Recently Kohner T'lO) noted the structural difference in the suprarenals of guinea-pigs according to sex. It thus appears that so-called "hypertrophy of some of the ductless glands" in the females diu'ing pregnancy or diu-ing other special physiological conditions, must be received with reservation until data on the possible sex difference of the normal individuals have been obtained.
2. Difference according to zoological variety
This is another interesting relation quite worthy of further careful investigation. We have no data for animals other than rats showing the weight of the ductless glands in zoological varieties. Watson ('07) first noted that the suprarenals of tlu^ Norway rat are always heavier than those of the albino rat. The present investigation fully supjiorts Watson's finding. Watson ('08) further noted that Norway rats under captivity lose in the
522 S. HATAI
weiglit of the supraroiials as much as 28 per cent (computed from the absolute weiglit ) withm the first ten weeks. Unfortunately Watson did not record the sexes and consequently, since the weight of the adrenals show nearly 54 ])er cent nonnal difference according to sex, the reported reduction of 28 percent camiotbe acce})ted without reservation until it has been confirmed on rats of the same sex.
Elliott and Tuckett ('06) notice the weight variation in the suprarer.als of difTerent strains of guii.ea-pigs. It seems highly probable that investigations alorg this line might throw some light on the physiologj' of these interesting members of the endocrer.e system.
I shall not attempt at this time to interpret any of the differences observed according to either sex or variety; nevertheless, it may be stated in regard to the difference found between the two forms of rats that such differeiices have appeared to be the result of a response to the complex conditions represented by domestication. If it should appear that similar changes took l^lace in other species under domestication, we would have an important instance of adaptation withui the organism to the char.ges in the environment.
CONCLUSIONS
1. In both the Norway and albino rats the suprarenal glands of the males are considerably smaller than those of the females. Wlien, however, these two forms of rats are compared, both sexes of the Norway rats have suprarenals considerably heavier than those of the like sexes of the albino.
2. A sex difference is noted in the weight of the hypophysis in both the Norway and albino rats. The male hy])ophysis is lighter than that of the female. However, when these two fonns of rats are compared, the hji^ophysis of the Norway is found to be gmaller than that of the aloino rat; the greater difference l)ein.g in the case of the female.
3. Neither in the Norway nor the albino rat is a sex difference found in the weight of the tliyroid. Moreover, there is no weight
WEIGHT OF DUCTLESS GLANDS 523
difference in the thjToid according to variety in these two forms of rats.
4. The sex glands (testes and ovaries), of the Norway rats, are heavier th^n those of the albino rats.
5. The differences found between the Norway and albino rats with respect to the weight of the ductlesss glands seem to be the result of a response to the complex conditions represented by domestication.
LITERATURE CITED
BiEDL, A. 1913 Innere Sekretion. Second ed. Urban and Schwarzenberg. Berlin.
Elliott, T. R., and Tuckett, I. 1906 Cortex and medulla m the suprarenal glands. Jour. Physiol., vol. 34.
Hatai, S. 1913 On the weight of the abdominal and thoracic viscera, the se.x glands, ductless glands and eyeballs of the albino rat (Mus norvegicus albinus) according to body weight. Am. Jour. Anat., vol. 15, no. 1.
1914 On the weight of the thj-mus gland of the albino rat (Mus norvegicus albinus) according to age. Am. Jour. Anat., vol. 16, no. 2.
1915 The growth of organs in the albino rat as affected by gonadectomy. Jour. Exp. Zool., vol. IS, no. 1.
KoL.MER, W. 1910 Beziehungen von Xebennieren und Geschlechtsfunktion. Pfiuger's Archiv f. d. ges. Physiol., Bd. 144.
Vincent, S. 1912 Internal secretion and ductless glands. Edward Arnold, London.
Watson, C. 1907 A note on the adrenal gland in the rat. Jour. Physiol., vol. 35.
1908 The effect of captivity on the adrenal glands in wild rats. Jour. Phvsiol.. vol. 36.
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524

Latest revision as of 12:31, 19 June 2020

The Development Of The Adrenal Glands Of Birds

Victor J. Hays From Ihe Laboratories of Animal Biology of the Stale University of Iowa

EIGHT FIGURES

COXTIONTS

Introduction -lol

Observations -45^

Early development of cortical substance 456

Early development of chromaffin substance 461

Development after 216 hours 464

Development of the venous system 46.5

Development of the arterial system 460

The glands of the adult bird 471

Summary 472

Biblio>£rai)liy 473

IN'IKODUCTION

Although the development of the adrenal glands has been studied for the various classes of vertebrates for a number of years ajid by manj- investigators of recognized ability, there seems to be no very general agi'eement in their conclusions; aiul several o])]iosing theories have been develojiod as a result. This is especially true of the observations on the develojiment of tlu^ adrenals of birds. Here the field is in a most chaotic condition and a review of the literature shows, tliat while one theory may have th(> weight of evidence in its favor, eacli of them is supported by a number of investigators whose ability is of the liighest order. No minute description of the development of the vascular system of the adrenal glands of birds has as yet appeared. The development of the vascular system of the adrenal glands of mammals has been reported; but this cannot be taken iis a

THK ANATOMICAL RKCOnil. VOI . S, NO. 10

OCTOIIKH, I',) 14


4o'J VICTOR J. HAYS

criterion for the dcvolopniont in l)ir(ls, since in birds there can l)e no sharp division of the glands into cortex and medulhi.

The object of this investigation is to determine the source and manner of development of the various systems of the adrenal glantls of birds, and to make clear the relationship existing l)et\veen these different systems in the birds.

It is safe to say that there is no longer any doubt as to the nature of the adrenal glands, since the fact is well established that in the higher vertebrates they represent the more or less c(implete union of the interrenals and suprarenals of the lower vertebrates. The adrenal glands of the higher vertebrates are then a pair of organs, each representing an interrenal and a f^uprarenal gland of the lower classes of vertebrates. In the adrenals of mammals, the cortical substance represents the interrenals, while the medullary substance corresponds to the suprarenal glands of the lower vertebrates. Since in the case of birds there is no true medulla, the term 'chromaffin substance' will be used in place of the term 'medullary substance.' -^

According to the different investigators, the cortical substance has been derived from several possi})le sources; the mesenchyme, the mesonephros, the germinal epithehum, the peritoneal epethelium, and the sympathetic ganglia.

(iottschau ('83) and ]\Iinot ('97) took the view that the cortical sul)stance develops from the mesenchyme, the former working with mammalian embryos and the latter with human embryos. Tiic theory of mesonephric origin was suj)p()rted by 8emon ('87) and ('. K. Hoffmann ('92), both working with the embryos of birds. \'on ]\Iihalcovics ('85) working with reptiles, and Janosik ('83. '90). Fusari ('93), and Loisel ('04), working with bird eml)rvos. found a very iiitimate relationship between the adrenals and the genital glands and took the view that the adrenals <l('\('l(»j) from the germinal epithelium, so far as the cortical substance is concerned. O. Schultze ('97), from his obvserations made on embryos of Vespertillio murinus, concluded that the cortical substance of the adrenal gland arises from the sympathetic ganglia. The following observers suppf)rt the theory that the cortical substance of the adrenal glands develops from the


ADRENAL GLANDS OF BIRDS 453

peritoneal epithelium. Valenti ('93) and Souli COS), working with bird embryos, and Kuntz C\2), working with embryos of Thalassochelys caretta. This view is also supported by Poll f'06). The above citations do not cover the entire field but are given onl}^ to show the various theories which have been proposed to account for the cortical substance of the adrenal glands. Several theories have also been proposed to account for the development of the chromafl^n substance of the glands. Here again there is a lack of agreement in the conclusions of the various investigators, as was the case, in the observations on the development of the cortical substance. Gottschau f'83) and ^linot ('97) derived the chromaffin substance from the mesenchyme, the former from observations made on mammalian embryos and the latter, from human embryos. \'on ^Nlihalcovics ('85), from obser\'ations made on reptilian embryos, came to the conclusion that the chromaffin substance of the glands is derived from the germinal epithelimn. This theorj' was upheld by Janosik ('83, '90) and Valenti ('89, '93), both working with embryos of birds. Leydig ('53) described the interrenals and suprarenals of fishes and came to the conclusion that the suprarenals are derived from the sympathetic nervous system. Balfour ('78) in his classical work on the elasmol)ranch fishes, shows conclusively that the suprarenals are derived from the sympathetic ganglia along the abdominal aorta. Since that time many investigations have verified these conclusions and it is hard to account for the fact that many of the earlier investigators refused to accept the results of the work of Leydig and Balfour. Among the later investigators to hold the theory- of sjinpathetic origin of the chromafl^n substance are: Fusari ('90, '93), H. Rabl ('91), Minervini ('04), and Loisel ('04). These investigators all worked witli bird embryos. Souli ( '03) and C. K. Hoffmann, i89. 92), working witii the embryos of birds and reptiles, came to the theory of symi)athetic origin. This theory was also sup})orted by the work of Poll ( Oti) in which he used the embryos of manmials, reptiles, and birds. Kuntz ('12), from observations made on the embryos of Thalassochelys caretta. concludes that the clu'omafiin sulistance develops from the analgen of the


4")4 VICTOR .1. HAYS

prevertcl)ral sympatliotic plexuses. The above citations, while they do not cover the entire field, serve to show the confusion which exists concerning the development of the adrenal glands. A complete bibliogi'aphy will be found in the work of Poll ('06).

There are two general theories to account for the origin of the cortical and chromaffin substances of the adrenal glands; the theory of homogeneous origin and that of heterogeneous origin. The su]iporters of the theory of homogeneous origin have in turn derived the adrenal glands from the sympathetic ner\'ous system, from the mesenchj^me, and from the germinal epithelium. There is the same lack of agreement among the supporters of the theory of heterogeneous origin. These investigators have in tui'n deri\'ed the glands from the mesonephros and the peripheral part of the sjiiipathetic nervous system, the germinal epithelium and the sjanpathetic nervous system, and from the peritoneal epithelium and the s\inpathetic nervous system. Poll, from extensive observations and from a thorough review of the literature, shows that the w^eight of evidence favors the theory that the cortical substance of the adrenal glands of all vertebrates is derived from the peritoneal epithelium and that the chromaffin substance develops from the cells which break away from the anlagen of the peripheral part of the sympathetic nervous system.

\'ery little work has been done on the development of the blood vessels of the adrenal glands. Flint ('00) has worked out the blood vessels of the adrenals of mammals and reports a very interesting condition existing in this class of animals, especially as regards the venous circulation. According to this investigator the venous system may be compared to a tree, the terminal twigs uniting to form larger branches and as a natural result of this process a large central vein is fonned. He found that in most cases this central vein opens into the postcava as a single vein. In the dog, however, the central veins of the posterior and anterior lobes of the gland do nf)t unite, but open into the postcava sei)arately. This descrij)tion refers only to the venou^ system of the medullary part of the gland. The venous system of the cf)rtical part of the gland is of no great importance, being


ADREXAL GLANDS OF BIRDS 455

composed of the terminal twigs of the medullary venous tree. The arteries of the gland, according to Flint, are derived from five sources: A. phrenica. A. phrenica accessorius, A. lumbalis, A. renalis, and the abdominal aorta. These arteries branch out on the capsule of the gland fonning a network of blood vessels over the entire gland. These branches finallj- enter the cortex at various points and break up into capillaries, the terminal branches penetrating the medulla for a .'^hort distance.

Miller ('03j, working on the development of the postcaval vein in birds, did not make any attempt to work out the development of the veins in the adrenal glands other than to detennine their origin. He concluded that the veins of the left adrenal develop from the subcardinal vein and probably tho.se of the right gland are of the same origin.

Minot ('00) distinguishes between capillaries and the venous blood vessels found in several organs of the vertebrates, among these being the adrenal gland. He finds these blood vessels differing from capillaries in size, shape, relation to other tissues, and in their method of development. According to this author, these blood vessels which he calls sinusoids are larger than capillaries and are irregular in section. The walls of sinusoids are composed of a single layer of endothelial cells resting upon the parench\^na of the organ, while a capillary always has a connective tissue wall upon which the endothelial layer rests. The manner of development also differs, the capillaries developing from a chain of vasofonnative cells which becomes hollowed out and connected with a vessel already fonned, while sinusoids develop by the outpushing of the endothelium of the wall of a l)re-existing blood vessel.

The vascular spaces observetl and described b>' Kuntz ('12) in the adrenals of Thala.s.^^ochyles caretta are undoul^tedly identical with the sinusoids of Minot. Flint ('GO) finds no sinusoids in the adrenals of mannnals and is of the opuiion that the investigators who have re])orted them used sections which were too thin to show the true structure of the walls of the blood vessels.

The following observations are based exclusively on embr>os and adult of the domestic fowl (Oallus domesticus). All speci


45() VICTOR J. HAYS

mens wore fixed Avitli cliroin-aceto-fonnaklcliydo and stained hy the iron lieniatoxylin method. Embryos were injected with india hik after the method of Knower ('08). The adults were uijected with a gelatin mass. Sections used for the study of the develojmient of the vascular system were cut to a thickness of 20 micra. All other sections were 10 micra thick.

It gives me great pleasure to express my indebtedness to Prof. F. A. Stromsten for many helpful suggestions durhig my investigation of this subject and also for readhig the manuscript. I take the greatest pleasure in acknowledging my indebtedness to Prof. G. L. Houser for suggesting the subject of this investigation and for many helpful suggestions during its progress.

OBSERVATIONS

The early development of the cortical substance

The cells which are later to form the cortical substance of the adrenal glands of birds are first seen in the 96th hour of incubation. They ajipear as a thickening of the peritoneal epithelium, ventral and mesial to the mesonephros, ventral to the al)dominal aorta, and dorsal to the hind gut which is o]:)en at this time (fig. 1, ad.). The developing cells push in dorsally from the epithelium upon which they rest and become larger and more nearly circular in outline than those cells from which they arose, that is, the cells of the peritoneal epithelium. The nuclei are corrcs])()ndingly enlarged and mitotic figures may be seen in nearly all of them. The nuclei also differ from those of the parent cells in their staining properties, these nuclei all being less deeply stained and less granular than those of the peritoneal epithelium. It is probably due to the fact that the anlagen of the cortical substance appear so early in the development of the chick, that earlier investigators, using embryos which had passed this stage of development, derived the cortical substance from other sources.

During this early period of incubation the development of the cortical substance goes on with astonishing rapidity, and nine hours later, during the 105th hour of incubation, the cortical


ADRENAL GLANDS OF BIRDS


457


cells have piled up on the peritoneal epithelium so that a solid body is formed on each side of the base of the mesentery. In the meantime, folds have appeared in the peritoneal epithelium which throw these cell groups further from the base of the mesentei-y.



.^






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Fifl. 1 TransvcM-sc section through the adrenal region of a 90-hour chick vmbryo; ad., anlagcn of the cortical substance; no , aorta. X 130.

Fig. 2 Transverse section through the adrenal region of a lOo-hour chick embryo; ad., anlagcn of the cortical substance; ao., aorta; sij., anlagen of the prevertebral sympathetic plexuses; v. sc, subcardinal vein. X 130.

laterally. At this jicriod they lie just mesial to tlie ventral side of the mesonephros. This is possible because the mesonephros lies closer to the median line than in the preceding stage, due chiefly to the fact that it has been gi-owing rapidly during this period. The character of the cortical cells has not changed


loS \I('T()H .1. MAYS

during; tliis jK'riod. hut tluMr iiuji;i-a(i<)ii lias gone on rajjidly until a chain of cells can he traced from the gi'ouj) resting on the ])eritoneal ejiit helium, to a point just slightly dorsal to the ventral level o{ the aorta (fig. 2, ad.). These cells then lie hetween the aorta anil the mesonephros, in the mesench>nne. In this migration most of the cells ])ass laterally to the sul)cardhial veins hut this does not liold true for all of them, since a few of them take a j^ath median to these veins. The shape of these cells and their nuclei, together with their stainhig ])roperties, make them easily identified and the course of their migration can be followed without difficulty.

Duruig the next fifteen hours, or after 120 hours of incuhation, the cortical cells have hecome detached from the peritoneal e])ithelium and all of thorn have migrated dorsally. At this stage of development they appear as scattered cell groups reaching from the dorsal level of the suhcardinal veins to the middle level of the aorta. They have reached ahout the same level on hoth the right and left sides of the aorta, though those on the right side may he slightlj' in advance of those on the left. These cell groui)s are scattered through the mesenchyme hetween the mesonephros and the aorta and have practically invaded the entire region. The nuclei are still circular in section and show well developed mitotic figures. Occasionally cells may he seen undergoing division. Isolated cells are still circular in outHne hut tliose which are found in groups have become more or less flattened by contact with the other cells of the grou]) and ])resent an oval outline. They may still he idcntihed from anything which has yet appeared by their nuclei and staining proi)erties (fig. 3, ad.). The relative position of th(^ cortical cells at this jx'riod is shown by figure (5. It is seen that they lie on the dorsal side of the suhcai'dinal veins, lateral and ventral to the aorta, and uK'sial and ventral 1o llic i)ostcardinal veins. The region which they occupy extends ])()steriorly to a point about level with the anastomosis of the suhcardinal veins in the median line, ventral to the dorsal aorta.

From the 12()th 1o the 13()th hours of incubation there is a j^reat increase in tlx' mass of llx- cortical substance. This is


ADJ{K.\AL (;LA.\D.S of BIRDS


459



sy.


ch. a,




Kig. 3 TransviMse section through tho adrenal region of a IJO-hour i-hick rnibryo; ml., anhigen of the cortical substance; no., aorta; sy., anlagen of the prevertebral syni|>athetic plexuses; r. sc, subcardinal vein. X 90.

Kig. 4 Transverse section through the adrenal region of a 130-hour chick embryo; nd., anlagen of the cortical substance; oo.. aorta: ch. a., anlagen of th«> chromaffin substance; vies., mesonephros; ,<//., anlagen <if the prevertebral sympathetic i)lexuses: v. .sr., subcardinal vein. X 90.


4<)() \I(T()U J. HAYS

duo. j)artly to the fact that the cells are no longer scattered through tlie inesench}ine, but have collected in large groups, and jiartly to the fact that the number of these cells has been increased by the division of the older cells present in this region. At this stage the cells are arranged in large solid groups hing dorso-niesial to the subcardinal veins and ventral to the mesonephric arteries which run over the anterior ends of these cell groups. These cells then occujiy the region l)etween the aorta and the mesonephros in the region outlhied above. Owing to the close arrangement of the cells, they are losing their regular shape, but the nuclei remain circular in outline and continued development is shown by the presence of mitotic figures (fig. 4, ad.).

After 144 hours incubation the cells have become more closely grouped than in the preceding stages and are found in large oval masses on each side of the aorta. The nuclei have become more granular but still contain mitotic figures. The cells are becoming more in-egular in outline and, on account of the proximity of these cells to the mesonephros, and on account of the close resemblance between them at this time, it is difficult to distinguish one from the other. Such conditions, doubtless, are responsible for the conclusions of some of the earlier investigators that the cortical substance of the adrenals is derived from the mesonephros. Careful investigation reveals a thin layer of flattened mesenchyme cells between these two bodies.

Twenty-four hours later, during the 168th hour of inculcation, the mass of the cortical substance has greatly increased. The cells have arranged themselves m irregular chains and have taken a roughly hexagonal shape. The nuclei stain much darker than previously but they still show mitotic figures in great numl)ers, showing that the cortical substance of the gland is still hicreasing by division of its own cells. The mass of cortical substance is roughly circular in section at this time and occupies practically the .same level as the aorta and has about the same cross sectional area through the center. The mesonephros has developed ventrally until it is in contact with the adrenal only at its dorsomesial angle. The subcardinal veins still lie on the ventral


ADREXAL GLAXDS OF BIRDS 461

border of the glands. At this period of development, connective tissue fibers are collecting around the gland, giving promise of a connective tissue capsule later. A few of the fibers are seen within the body of the gland, between the cords of cells.

The cortical substance continues to grow rapidly during the next twenty-four hours and after 192 hours of incubation its cross sectional area is fully twice as great through the center as that of the aorta. The gland is about 2 mm. long at this period. The cell mass is becoming less dense than it has been for some time. A large number of the nuclei still show mitotic figures but in many of the cells these figures are no longer present. At this time, blood cells may be seen in the relatively large openings between the cords of cortical cells.

Little change in the form and size of the gland is seen durmg the next twenty-four hours. The greatest changes are seen in the internal arrangement of the cells. The gland has become much more vascular during this period and many more spaces have appeared between the cords. The cell cords have become very dense and compact, making it difficult to see the outline of the individual cell.

The above observations lead to but one conclusion, namely, that the anlagen of the cortical substance of the adrenal glands arise as groups of cells which proliferate from the peritoneal epithelium.

Early development of the chromaffin substance

The observations on the development of the adrenal gland show that the anlagen of the cortical substance arise from the peritoneal epithelium. Observations on the origin of the chromailin substance seem to show that it arises, not from the same source as the cortical substance, but from the anlagen of the prevertebral sympathetic jilexuses. It is evident then that the adrenal glands arise from two so})arate genu layers, namely, the mesodenn and the ectodenu.

After 120 hours of incubation, large oval cells are seen migrating ventrally from the sMupathetic trunks on each side of the aorta. These cells migrate shigly in most cases and most of


4()2 \I<T()H J. HAYS

them pass around to tlio ventral siile of tlie aorta and later fonn the prevertebral sj'inpathetic ])lexuses (fig. 3, sy.). At this stage of development the anlagen of the cortical substance are a loose group of cells on each side of the aorta. The cells of sympathetic origin migrate in a jiath which causes them to j^ass between the aorta and the groups of cortical cells. At this time there is no connection between these two kinds of cells. The two kinds of cells, cortical and sjmjiathetic, are easily distinguished from one another by their size and affinity for stains, the latter being the larger and taking the deeper stain.

The first evidence of any connection between the anlagen of the prevertebral s\inpathetic plexuses and the chromaffin substance is seen after 180 hours of incubation. The cortical cells have arranged themselves in large, compact masses by this time and have taken a definite outline. At this time, some of the cells migi-ating from the sjTnpathetic trunks turn off ventrally in the region of the adrenals and either enter them, or become attached to the surface of the cell groups. Figure 4 (sy.) shows several of these cells on the inner edges of the groups of cortical cells, and on the right, one cell may be seen which has penetrated to the center of the cortical substance. This development continues for some time and these new elements, the cells of s>nnpathetic origin, do not seem to differ in any way from those which pass on to form the prevertebral s\inpathetic plexuses. These cells, then , are indifferent in nature. As the growth of the embryo goes on, more of these cells are found entering the cortical substance of the gland and collecting, in most cases, in groups of two or three. Single cells, however, are found scattered throughout the cortical substance. During this period they may be found almost anywliere within the cortical substance and a great many are found around the surface of tlie glands.

After 168 hours of incubation, the ('(>]ls which are to fonn the chromaffin part of the gland are l)eginning to show some difTercntiation. Those which liave entered the cortical substance are no longer large circular cells with round, clear nuclei. The shape is becoming irregidar, as a general rule, and the cells are smaller than originjilly. The inirlei are oval and have become quite


ADRENAL GLANDS OF BIRDS 4()3

granular, in many cases, even more so than those of the cortical cells. They are most easily distinguished from the latter cells by means of their staining properties, both nucleus and cytoplasm takhig a deeper blue color with the iron hematoxylin method. These invading cells, at this stage of development, show a tendency to arrange themselves in cords throughout the cortical substance, though many solitary cells are also found. This seems to be the height of the migration of the cells from the sympathetic trunks and at this time the mesenchyme around the glands is shot full of them, and they can be seen entering the glands from all sides.

During the next twenty-four hours, the chromaffin cells within the glands have increased greatly in number and most of the sympathetic cells have disappeared from the mesench>Tne around the glands. At this time the chromaffin cells are arranged in cords, many of which have pushed in close to the venous blood vessels. This location with regard to the venous circulation cannot be taken as a general rule at this period of development, since a great number of these cords do not seem to bear any relation to the blood vessels.

The arrangement of the chromaffin cells undergoes a marked change during the next twenty-four hours, 216 hours' incubation. The cells were first found scattered, either singly, or in small groups, throughout the cortical substance. Later they became arranged in cords or columns. At this period the cells cords break down, but do not return to the original condition of solitary cells scattered throughout the cortical substance. Instead of this scattered arrangement, the cells are found in small groups arranged around the venous blood vessels. Of course, not all of th(^ grcnips are so situated, since the cords from which they originated were not all in contact with the blood vessels.

These observations bear out th(> contention that the chromaffin substance of tlie glands does not arise from the mesench^nne or germinal ei)itheliuni. Init from the anlagen of the prevertebral synijKithetic plexuses. These cells enter the cortical sui^stance as indifferent cells and later become differentiated to form the chromaffin substance^ of tlie glands.


MA


\I(T()H ,1. MAYS


Development after 210 hours' ineufyntinn

Aftor 21() lioiirs' incuhation the charactoristic features of tlie adrenal glands are firmly establislied and the development of tlie glands from that thne up to hatching is chiefly one of growth so far as the cortical and chromaffin cells are concerned. The glands increas(> in volmne slowly and become more vascular until, at the end of the period of incubation, they have the


■^^■j^\


^ ^..^^.^^^^ /•■










' 5> '


/ / 4»- ■ . •■ «J* .' ■ 0- ft , ® «■

-^ ' ' CO- SI. <*

ch.

I- in. o 'rransvcrsf section llirniigh tho adrenal ^land of a 2f)4-liour chick rnibryo; no., aorta; r//.. chromaffin substance; co., cortical substance; .s/.. sinusoids; .v//., anlatfeii of tlic j)revcrtebral synijiathctic plexuses. X 90.





appearance, in section, of a large numl)er of groups of cells almost surromided l)y blood vessels.

An idea of tlie struetinv of the gland may be had by referring to figure 5. Here the gland is seen lying betw(M'n the kidney and the aorta, practically filling this region. The substance of the gland is cut up in-egularly by venous simisoids which form a network throughout the entire gland. The cortical cells are arranged in irregular cohnnns which pass around these blood vessels and seem to form \\w foundation for all oilier elements


ADRENAL GLANDS OF BIRDS 465

of the gland. The chromaffin cells have no regular arrangement, but are found in groups varying from two or three, up to thirty or forty cells each. The only regularity to be seen in the chromaffin groups is in their relation to the venous blood vessels. Except in exceptional cases, at least a part of each group is in direct contact wdth at least one of these blood vessels.

The connective tissue, which was first seen forming around the glands at the 168th hour of incubation, develops very slowly, but after about seventeen days of incubation a dense capsule has been formed around each gland. The connective tissue is confined almost entirely to the surface of the gland but in several places rather large masses of it may be seen entering the substance of the gland. This connective tissue breaks up at once and within the gland only very small fibers are found. These fibers are found only between the cords of cortical cells.

The development of the venous system

Owing to the structure of the adrenal glands of bii'ds, the development of the blood vessels cannot be taken up separately for the cortical and chromaffin parts, as has been done for mammals.

The blood vessels of the adrenal gland develop so slowly that for specimens taken twelve hours apart, very little difference can be seen. For this reason it is very difficult to determine at exactly what age they first appear. The process is a gradual one and each condition blends perfectly into those immediately preceding, and those immediately following it.

As early as the 120-hour stage of development a few scattered blood cells are found throughout the anlagen of the glands, but no more are found than are jiresent in the suiTounding mesenclnnue tissue. Xo direct connection with any blood vessels can be seen at this stage of development but in several ]ilaces the wall of the sulx'ardinal vein pushes out dorsally into the anlagen of the gland for a \ery short distance. Xo break or division of the wall of \\\v \(Mn cati br seen at this time. I-'iffiu'e (i shows the


400


\I(T()]{ .1. HAV.S


ad.


V. a. -■-'—


V. pc. ._



. pc.


V. sc ao. V. sc


V. pc



-V. pc.


I'ig. G Reconstruction of the vascular system in the adrenal region of a 120hour chick enibrj-o; dorsal aspect; ad., anlagen of the cortical substance; (m., aorta; r. a., adrenal vein; r .pc, post cardinal vein; r. .sc, subcardinal vein.

Fig. 7 Scnii-diagraniniatic drawing of the connection between the subcardinal an<l the postcardinal veins through the adrenal in a 168-hour chick embryo; ventral .aspect; adr., adren:d gland; v. pc, postcardinal vein; r. .sr., subcardinal vein.


relation of the subcardinal veins to tlie glands and in several

places tlic outpushinp; of the Ncins into llic glands may l)e seen.

Sections of the glands at tli(> l.'^O-liour staf2;e of development

sliow that tlio subcardinal veins have pushed further into the


ADRENAL GLANDS OF BIRDS 467

gland tissue than in the previous stage. No great modification of the gland can he seen and there is no apparent increase in the number of blood cells found in the gland. The evaginations of the subcardinal veins are very small at this time, but can be traced by the structure of their walls, which at this time are composed of only a single layer of endothelial cells. Their walls are of the same structure as those of the subcardinal veins at this period of development.

This development continues during the following fourteen hours so that at this period, 144 hours' incubation, these newly formed blood vessels have reached almost to the dorsal side of the gland. In several places, lateral branches are fomiing but these extend for only a very short distance. In no case was less than two of these venous trees found and in most cases three or four of them were present. This means that the venous blood vessels of the gland are formed, not bj^ the division of one larger vein, but from several which push in from the subcardinal veins.

The development of the venous system continues by the branching of the vessels present in the gland until, after 168 hours of incubation, the gland has the api:)earance in section of having many irregular pieces cut out of its interior. At this period of development a new venous connection a])iiears in the glands of birds (fig. 7). By the gi'owth of the glands they come to lie ventro-median to the ])ostcardinal veins. At this thne, these vems tm-n ventrally to form the renal jiortal system, and in the regic^n of the adrenals a In-anch is given off to the glands. Each postcardinal gives off a In'anch to the gland on its side of the body cavity. These veins push into the glands but instead of branching after the manner of the subcardinals and fonning a system within the glands, they open directly into the blood vessels already present in the glands. In other words, they oj>en into the venous tree already fonned from the subcardinal veins. This condition naturally leads to the conclusion that there is a portal system formed in the adrenal glands of birds which might be called the adrenal jKirtal system.

At this tinu> the aorta and the postcardinal and subcardinal veins show coniuM'tix c tissiu^ in their walls, ujion which the

TIIK AXATOMICM. HKCOHl>, VOL. S. NO. 10


468 VICTOR .1. HAYS

eiulotliolial lining rests. Tliis is not true of tlio vonous blood vessels in the glands. These show no connective tissue in their walls and are larger than any capillaries found at this time. Owing to the difTerence in size and structure of these vessels I shall not call them cajiillaries, but shall adopt the tenn 'sinusoids,' jH'oposed by ]\Iinot for this type of blood vessel.

The development of the sinusoids goes on steadily, but after 216 hoiu's of incubation there does not appear to have been any appreciable increase in their number. The most noticeable change in the appearance of the gland is in the great increase in the size of the shuisoids. This growth, however, has in no way affected the nature of their walls, and they are still made up of a single layer of endothelial cells (fig. 5, si.). The adrenal portal system has broken down at this time. It is a transitory condition, persisting through the eighth and iiinth daj^s of incubation only. It is significant that this connection with the post-cardinal vein should disappear as soon as the sinusoids have increased greatly in size. It should also be remembered that the greatest activity in the development of the chromaffin substance took place during the existence of this system.

Until after 240 hours of incubation, the sinusoids are found to open into the subcardinal veins in many places and by means of no very definite vessels. At this stage, 240 hours, the sinusoids seem to join into two groups near the posterior end of each gland and enter the subcardinal veins by means of four well defined veins, two for each gland. There is no evidence of a central vein running longitudinally through the gland, but this is to be expected since the sinusoids do not arise from the branching of a single xcin, l)ut from four or five veins which push in from the .sul)cardinal vein. Each one of these veins then forms a system of sinusoids b}' re])eated branching in the gland. This later development is then the combination of several of these systems at their bases to fonn a larger sj'stem. Since there are two veins found opening into the subcardinal vein, it follows tliat these numorous systems have combined to form two distinct systems of sinusoids in each gland. These systems are distinct only in ])oiiit of origin, since there arc numerous anasto


ADRENAL GLANDS OF BIRDS 469

inoses formed between the sinusoids of the different systems and between the sinusoids of the same system.

The later development of the venous system is in no way remarkable. The terminal sinusoids continue to branch slowly up to the end of the period of incubation. At this period the gland is filled with sinusoids, so much so that in section they appear to occupy nearly one-half of the entire volume of the gland.

There can be no doubt as to the origin of the venous system of the adrenal glands of birds. It develops from inpushings of the subcardinal veins and penetrates the glands by means of numerous branches which in almost ever\' case are directly in contact with the chromaffin substance.

The development of the arterial system

Observations on the development of the arteries of the adrenal glands reveal no conditions which are in any way out of the ordinary, and the condition is the same as that of any organ of this type.

The earliest connection found between the glands and any of the nearbj' arteries appears after 120 hours of incubation. At this time a small blood vessel is .seen passing into the cortical substance of each gland from the anterior pair of mesonephric arteries. At this ]Deriod the walls of these vessels are not very distinct, and within the gland no capillaries can be seen. For some time very little progress can be seen in the development of the arteries. After 144 hoiu's of incubation the only increase in the complexity of the arterial system is the apiiearance of a very few indistinct capillaries within the cortical substance.

During the next twenty-fom* hours the arterial system of the glands develops rapidlj' and several new vessels appear during this period. .Vn artery is given off by each of the anterior mesonephric arteries just before they enter the mesonephric glands. These arteri(»s run anteriorly, one along the lateral border of each adrenal gland and two l)ranches are given off to each gland by its respective arter>', one near the posterior

ui(l the other near the anterior end of the gland, and each sends


47n


VK TOU ,1. HAYS


hranchos into tlio cortical part of tlic {!;laii(l. Tliis docs not «)ccur, liowever, until after several l)ranclies ha\e been fonned on the surface of the gland antl instead of a large artery penetrating the gland, directly, it is broken up and the branches are very small Avhcn they enter the substance of the gland. Still another arterial connection a])i:)ears at this time. This is a small artery Avliicli runs directly from tlic aorta to the post<M-ior


adr.



ventral


Kiji. 8 A, The arteries of tlie adult fowl in llie region of the adrenal jilaiids: ventral aspect; adr., adrenal gland; au., aorta; n. r., renal artery. B, The veins of the adult fowl in the region of the adrenal gland; ventral aspect; adr., adrenal gland; v. n., adrenal vein; r.p., postrava. X 2.

end of the left gland. This artery also branches on the surface of the gland before entering the cortical substance. Within the glands all tliese arteries divide still further and the terminal branches are so small that in section they a]i]iear to be smaller than the blofxl cells. It is jirobable that in the li\ing gland these capillari(>s are somewhat larger than in the sections observed. None of the capillaries within the gland were foimd in the chromaffin substance but there can be no doubt that at least the tcriiiiiial braiiclics soiiict inics ])enetra1(' this ])avt of the gland.


ADRENAL GLANDS OP^ BIRDS 471

Here again, the greatest growth of the chromaffin substance is accompanied by a correspondingly- rapid development of the vascular system.

This practically completes the development of the arterial system of the glands. At a later period, about 192 hours, the connection between the mesonephric artery and the left adrenal disappears. This artery which disappears is not the one which arises from the branch of the mesonephric artery which runs anteriorly along the lateral edge of the gland. This artery runs directly from the mesonephric artery to the gland. The corresponding artery to the right gland remains (fig. 8). Aside from this modification there is no further change in the external arrangement of the arteries, ^^'ithin the glands there is a slight increase in the number of capillaries and the nature of their walls undergoes a marked change. When first formed, the walls of the capillaries contain no connective tissue, but as the period of incubation draws to a close, a small amount of it may be seen in the walls of the larger ones. If any connective tissue is present in the walls of the smaller branches, the amount is so small that it cannot be seen in sections prepared b}' iu\y of the ordinary methods.

The glands of the (idult bird

In the adult biiil, the adrenal glands lie just anterior to the l)ifurcation of the postcava, one on each side of the median Hue. They are about 1.5 cm. long and 0.5 cm. wide at the widest part. The right gland is roughh' triangular, while the left is oval in outline (fig. 8, ad.). The internal arrangement of the cortical and chromaffin substances shows no change from the condition found in the embryo at the close of the jieriod of incuiiation. In the natural increase in size of the glands it is the cortical substance, chiefly, which has increased in mass so that there is much more of this in proportion to the chromaffin substance than was jiresent in the embryo. The same relation between the blood vessels and the tis.^^ue of the gland is found here as was described in the well advanced embryos. The sinusoids jiass between the grcnips of chromaffin cells, while the capillaries lie in the cortical substance but each encroaches to a certain extent upon the territory of the other.


472 VICTOR .1. HAYS

The trunks of the venous trees have increased f2;reatly in size and form large central vessels which may be C()mi)ared to the central vein of the adrenal gland of maimnals. The sinusoidal character of the venous blood vessels persists in the adult and even in the largest vessels very little connective tissue is found in the walls. Near the close of the period of incubation, the venous blood was found entering the postcava by means of two sejxirate veins from each gland. This condition is not found in the adult. Tlie two veins anastomose on the ventral surface of the gland and the blood from both venous trees enters the postcava through a common vein (fig. 8).

The arterial system of the glands is essentially the same as that described for the embryo. Since this is true, it is evident that the mesonephric arteries from which they derived part of their blood supph' have persisted as the renal arteries.

In the adult, the blood enters the gland by means of several arteries (fig. 8). It may enter the left gland directly from the aorta or through the anterior or posterior branches of that artery which arises from the renal artery and runs along the lateral border of the gland. The supply of the riglit gland differs from that of the left in that there is no direct connection with the aorta and in that there is a direct connection with the renal artery. The blood leaves both glands in the same way, entering the postcava at the bifurcation by means of a single vein from each gland.

SUMMARY

1. The aiilagen which give rise to the cortical substance of tlu! adrenal glands of birds appear as groujjs of cells which migrate dorsally from the peritoneal epithelium.

2. The chromaffin substance is derived from indifferent cells which wander in from the anlagen of the prevertebral sympatlietic plexuses.

3. The chromaffin substance of the glands lies in contact with the venous blood vessels. The vessels of the arterial system are found almost entirely in the cortical substance. In general, this is the same condition as was found by Flint in the adrenal glands of nianiniuls.


ADRENAL GLANDS OF BIRDS 4/3

4. The entire venous system is derived from the subcardinal veins. Within the glands, the vessels of this system are sinusoidal in character.

5. During the period that there is the greatest influx of cells from the anlagen of the prevertebral sympathetic plexuses there is also the greatest activity in the development of the vascular systems. Is it possible that the relationship of cause and effect exists between the simultaneous activity in the development of these distinct systems of the adrenal glands.

BIBLIOGRAPHY

Balfour, F. ]\r. 1878 Development of elasmobranch fishes. London, pp. 237 247. Flint, J. M. 1900 The blood-vessels, angiogenesis, organogenesis, reticulum,

and histology of the adrenal. The Johns Hopkins Hospital Reports,

vol. 9, pp. 153-230. FusARi, R. 1893 SuUo sviluppo dclle capsule surrenali. Lette alia R. Acad.

di sc. med. e nat. di Ferrara, nella sed. d. 25 giugno. GoTTSCHAU, M. 1889 Structur und embryonale Entwickelung der Xebennieren

bei Saugetieren. Arch. Anat. u. Phys. Anat Abt., Jahrg., pp. 412— iSS. Hoffmann, C. K. 1889 Zur Entwickelungsgeschichte der Urogenitalorgane bei

den Reptilicn. Zeitschr. f. wiss Zool., pp. 261-300.

1892 Etude sur le dcveloppment de I'appariel uro-genital des oisseaux.

Verhandl. d. Konink. Akad. van Wetenschapen te Amsterdam. Deel

1, no. 4, pp. 1-54. Jano§ik, J. 1883 Bemerkungen liber die Entwickelung der Nebenniere. Arch.

mikr. Anat., Bd., 22, pp. 738-745.

1890 Bemerkungen iiber die Entwickelung des Genitalsystems. Sitz.

Ber. Akad. Wiss. Wien. Matli. nat. Ki., Bd. 99, abt. 3, pp. 260-288. Knower, II. McE. 1908 A new and sensitive method of injecting the vessels

of small embryos, etc., under the microscope. Anat. Rec, vol. 2, n<i.

5, pp. 297-214. KuNTZ, A. 1912 The development of the adrenals in the turtle. Am. Jour.

Anat., vol. 13, no. 1, pp. 71-88. Leydig, F. 1853 Anatomisch-histologischc Untersuchungen i'lbcr Fische un<i

Reptilien. Berlin. LoiSEL, G. 1904 Les phenom^nesdes(5cr<5tion dans lesplandesR^nitales. Revue

gcncralc et faits nouveaux. Journ. <le IWnat. et de la Phys. .\nnrc

15, pp. 536-562. Miller, A. .M. 1903 The development of the postcaval veins in birds. Am.

Jour. Anat., vol. 2, pp. 2v83-29S. MiNERViNi, R. 1904 Des capsules surrenales. D(!*veloppment, structure, fonc tions. Journ. de IWnat. et de la Phys., Ann(^e 40.


MiNOT, C. S. 1S97 Human ciiilnyolopy. New York.

1900 On a hitherto unrecognized form of bir)o<l circulation without

capillaries in the organs of Vertchrala. I'roc. Uoston Soc. Nat. Hist.,

vol. 29. pp. l.S,V21."). VON MiHALCOVics, 188o Untersuchungen iiber die Kntwickelung des Harn und CJeschlcchts-apparates dcr Amniotcn. Internat. .Monatschr. Anat.

Hist., Bd. 2, pp. 387-414. Poll, H. 1906 Die vergleichendc Entwichelungsgeschichte dcr Nebennicren system der Wirbeltiere. Hertwig's Handbuch d. vergl. u. exper. Entwg.

d". W irbeltiere, Bd.. 3. pp. 443-GU;. Raul, II. 1S91 Die Entwickelung und Structur der Xcbenniercn bei den Vfigeln.

Arch. mikr. Anat., Bd. 38, pj). 492-523. ScHULTZE, O. 1897 Grundriss der Entwickelungsgeschichte des .Menschen und

dcr Saugetiere. Leipzig. Semon, R. 1887 Die indififerentc Anlage der Keimdriisen beini lluhnchcn und

ihre Differenzierung zum Hoden. Ilabilitationsschriit. Jena. SouLiE, A. 1903 Recherches sur Ic devcloppment des capsules surrenales chez

les vert(br(s sup(rieurs. Jour, de I'Anat. ct Phys. Par Annee 39

pp. 197-293. ^'ALE^"TI. G. 1889 Sullo svilupjuj dellc capsule surrenali nel polio ed in alcuni

Mammiferi. Atti d. Soc. Toscana di Sc. Xat. Pisa, vol. 10.

1893 Referat fiber Fusari 1892. Mon. zool. ital., vol. 4.

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