Difference between revisions of "Anatomical Record 8 (1914)"

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THE
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ANATOMICAL RIXORD
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EDITORIAL BOARD
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Ira7xg Hakdestt
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Tulane University
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Claeence M. Jackson
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University of Minnesota
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Thomas G. Lee
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University of Minnesota
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Frederic T. Lewis
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Harvard University
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Waeren H. Lewis
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Johns Hopkins University
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Charles F. W. McClcke
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Princeton University
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WiLUAM S. Miller
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University of Wisconsin
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Florence R. Sarin
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Johns Hopkins University
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George L. Streeter
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University of Michigan
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G. Carl Huber, Managing Editor
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1330 Hill Street. Ann Arbor, Michigan
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VOLUME 8 1914
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PHILADELPHIA THE WISTAR INSTITUTE OF ANATOMY AND BIOLOGY
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SO: Ceo 2
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CONTENTS
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1914
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No. 1 JANUARY
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J. Parsons Schaeffer and Louis H. Nachamofsky. Some observations on the anatomy of the upper extremities of an infant with complete bilateral absence of the radius. Six figures 1
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James F. Cobey. An anomalous right subclavian artery. Two figures 15
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J. Douglas Perkins, Jr. An anomalous muscle of the leg: Peronaeo-calcaneus internus. Three figures •. 21
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R. M. Strong. Some ideas in laboratory equipment. Four figures 27
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Xo. 2 FEBRUARY
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Charles R. Stockard. The artificial* production of eye abnormalities in the chick embryo. Two plates 33
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R. A. McGarry. a case of patency of the pericardium and its embryological significance. One figure 43
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George G. Scott. The percentage of water in the brain of the smooth dog-fish. Mustelus canis 55
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Randolph West. A note on the presence of a musculus cleido-atlanticus m the domestic cat (Felis domestica). One figure 65
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Proceedings of the American Association of Anatomists. Thirtieth session: Abstracts: Demonstrations ^ 69
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No. 3 :\IARCH
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.\rthur William Meyer. The occurrence of supernumerary spleens in dogs .-ind cats.
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with observations on corpora libera abdominalis. IV. Studies on hemal nodes.
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Twelve figures M7
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J. Playpair McMurrich. The nomenclature of the carpal bones 173
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No. 4 APRIL
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J. B. John.ston. The nervus terminalis in man and mammals. Nine fisures IS5
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Samuel T. Orton. A note on the circulation of the cornu ammonia. Two figures 199
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Adam M. Miller and J. E. McWhurter. Expcritnents on the development of blood
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vessels in the area pelluciiia and embryonic body of the chick. Thirteen figures.. . 303
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Reproduction of models by The Wistar Institute 22S
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List of members of the American .Association of .Anatomists -JQ
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iii
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iv CONTENTS
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No. 5 MAY
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J. G. KuAMEH and T. \V. Todd. The distribution of the nerves to the arteries of the
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arm, with a discussion of the clinical values of results. Five figures 243
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Harkis K. Sa.stee. The brain of ft black monkey (Macacus maurus) : The relative prominence of <iifTerent gyri. lour figures 257
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Charle-s E. Joh.vson. An additional case of pancreatic bladder in the domestic cat.
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One figure 267
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Hahoij) L. Kearney. On the relative growth of the organs and parts of the embryonic and young dogfish (Mustelus canis) 271
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HoBEUT Hexnett Bean. The eruption and decay of the permanent teeth 299
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Arthur Wii.uam Meyer. 0.steology rcdivivus: \ criticism 303
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No. JUNE
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Barto.n G. Dcpre and T. Winoate Todd. A transitional type of cervical rib, with a
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commentary. Four figures 313
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Georoe p. Leonhart. A case of stylo-hyoid ossification. Two figures 325
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Richard W. Harvey. A case of multiple renal arteries. One figure 333
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J, R. Driver and A. B. Denison- The morphology of the long accessorius muscle.
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Four figures 341
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Franklin I'aRadise Johnson. A ca.se of atresia ani in a human embryo of 26 mm.
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One figure » 349
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F. E. Chide.ster. Cyclopia in mammals. Twelve figures 355
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F. E. Chide-ster. Twins in fish, one with a cyclopic deformity. Four figures .367
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No. 7 JULY
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E. K. liusKiNS. On the vascularization of the spinal cord of the pig. Five figures ... 371
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Edward V M alone. A course of correlational anatonjy 393
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Franklin P. Reagan. A useful modification of Mann's methyl-blue-eosin stain 401
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No. 8 AUGUST
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Hcsalind Wulzen. The morphology and histology of a certain structure connected
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with the pars intenncdia of the pituitary body of the ox. Seventeen figures 403
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J. C. Miller. Ossiculum lus 41.")
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E R. HoHKiNs. Persistent arteriac branchii suporficialis, antibranchii superficialis et mediana. One figure 421
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No. 9 SEPTKMHEH
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H. E. Jordan, 'i In- microscopic structure of mammalian cardiac muscle with si)ecial
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reference U> Bo-o:ilicd 'muscle cells.' Eight figures 423
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R. R. Hensley. The thyroid gland of the opossum. Three figures 431
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T. Winoate Todd. Covers for dissecting tables. Three figures "^^^
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T. Winoate Todd. A tank for the preservation of anatomical material. Three figures 444 A. O. Wee8E. A simple electrical heating device for incubators, etc. Fourfigures 447
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CONTENTS V
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No. 10 OCTOBER
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Victor J. Hats. The development of the adrenal glands of birds. Eight figures... 451 Paul S. McKibbex. Mast cells in the meninges of Xecturus and their differentiation from nerve cells. Two figures 475
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No. 11 NOVEMBER
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Robert Bennett Bean. A racial peculiarity in the pole of the temporal lobe of the
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negro brain. Nineteen figures (three plates) 479
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Leslie B. Aret. An abnormalitj' in the intestine of Necturus maculosus Raf.
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Six figures 493
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P. E. Smith. The development of the hypophysis of Amia calva. Ten figures 499
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Richard W. Harvey. A brain macrotome. Two figures 507
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No. 12 dece:mber
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Shinkishi Hatai. On the weight of some of the ductless glands of the Norway and of the albino rat according to sex and variety. Five charts 511
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Otto C. Glaser. On the mechanism of morphological differentiation in the nervous
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system. Three figures 525
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SOME OBSERA ATIOXS ON THE AXATO.MY OF THE UPPER EXTREMITIES OF AX IXFAXT WITH COMPLETE BILATERAL ABSEXCE OF THE RADIUS
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J. PARSOXS SCHAEFFER AND LOUIS H. XACH.AJMOFSKY
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The Anatomical Laboratory of the Yale Medical School
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SIX FIGURES
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On Februan' 20, 1913, the bod}- of a white, male infant, aged one day, of average size and weight reached the anatomical rooms of the Yale ^Medical School. On inspection the body appeared to be well developed and normal, save for an odd-appearing deformity of both upper extremities. At autopsy the pleural cavities were found to contain a considerable amount of blood, doubtless the result of a birth injury-.
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LTpon examination of the defomied upper extremities, it was found impossible to pronate or supinate the antebrachium and hand, save for a slight alteration in position allowed by turning the humerus and ulna on their vertical axes. The hands were fixed in marked adduction; the right one making a right angle and the left one considerably less than a right angle with the antebrachium. Both hands were rotated on the ulnae so that their dorsa presented \entrad, that is, they were fixed in pronation and abutted the ulnae at their medial aspects (figs. 1 and 5).
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The position of the hands indicated lack of radial support. Careful examination failed to reveal any trace of a radius in either arm. A jjrovisional diagnosis of complete absence of both radii was made. This was later confinned by Rontgen rays and bj' dissection (figs. 2 and 5).
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The ulnae seemed normal in position and size. However, due to the faulty position of the hands, the distal extremities of the ulnae formed very prominent subcutane<ius points at the wrists (figs. 1 and 2).
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1
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THE ANATOMICAL RECORD. VOL. 8, NO. 1 JAM'ARV, lOM
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2 J. PARSONS SCHAEFFER AND LOUIS H. NACHAMOFSKY
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The fact of <)l)sorving the absence of both radii and of the resultant faulty position of the hands seemed of little value. It was, therefore, deemed advisable to make a careful dissection of at least one of the extremities to ascertain to what extent other anatomical errors were present. In order to study the feasibility of tendon transplantation in such cases, in an attempt to lessen the deformity and to increase the efficienc}^ of the member, a dissection of the antebrachium and hand was deemed of especial value.
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The dissection was done by the junior author (Nachamofsky, ria>' many instances in the fonnation of tendons; the muscles arising or inserting by fleshy contacts where normally tendons are present.
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Another fact to be noted is that those muscles normally associated with the radius, but in this case only partly differentiated, were found to attach to the ventral surface and lateral border of the ulna.
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Xot only the muscles of the antebrachium and hand but many f)f the brachium and shoulder likewise were found to be abnormal.
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Mwscles of shoulder. The origin of the deltoid muscle was approximately nonnal. Its insertion was, however, markedly altered. It jjassed distally from its origin; its fii)ers converging towards the lateral intermuscular septum, to which it gained inwrtion just j)roximal to the lateral cpicondyle of the humerus.
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The deltoid had no insertion on the humerus, but l)ecame continuous with the teres major dor.sally; with the brachio
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COMPLETE BILATERAL ABSENCE OF RADIUS
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Fig. 1. Sketch of an infant witli complete bilateral absence of the radius. Especially note the abnormal position of the hands. The prominence at the wrist is caused by the distal extremity of the ulna. See text for further description of the upper extremities.
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4 J. PARSONS SCHAEFFER AND LOUIS H. XACHAMOFSKY
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Fi^. 2. Skianraii , , i ixtrcmilics of infant sketcho(i in fig. 1. Note
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the rharartpristic position of the IuukIs and tlio complete absence of both raiiii. Ab UHUal the carpal hones show no ossification at this age.
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radialis and the extensor carj)i radialis longiis and brevis muscles distally: aiul nioro or loss witli the pectoralis inajor muscle vent rally.
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The supraspinatus and tlio infraspinatus and the teres minor muscles were normal save that the latter and last were inseparably mingled.
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COMPLETE BILATERAL ABSENCE OF RADIUS 5
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The teres major muscle at its origin was undifferentiated from an abnormalh' extensive origin of the long head of the triceps brachii muscle. Contrary to the normal course of the muscle, in passing from origin to insertion, it coursed lateral to the upper extremity of the humerus and became continuous with the deltoid, the brachio-radiaUs, and the extensor carpi radialis longus and brevis muscles. At no point was the teres major muscle directly attached to the humerus.
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The latissimus dorsi muscle was inserted b}' two distinct tendinous slips. Near its insertion the lateral and somewhat larger slip terminated in a fleshy band which became incorporated with the common mass of the heads of the triceps i^rachii muscle. The faulty course of this portion of the latissimus dorsi muscle, as well as that of the teres major muscle mentioned above should here be noted. A shorter medial head of the latissimus dorsi muscle coursed cephalically and ventrally, giving a tendinous portion to insert on the humerus just distal to the subscapularis muscle and a caudal fascial expansion which gave origin to a part of the medial head of the triceps brachii muscle.
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The pectoralis major muscle in addition to its normal insertion sent fibers into the deep aspect of the deltoid muscle, thus fonning an accessory muscular band one cm. wide.
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Muscles of brachium. The biceps brachii muscle attempted an origin from the supraglenoid tubercle, and some of its tendinous fibers could be traced to it, but its long head mainly arose from the capsule of the shoulder joint which it materially strengthened. The short head of the muscle arose as usual irom the coracoid process of the scapula. The belly of the biceps brachii inserted (?) along the distal half of the medial and lateral surfaces and the medial and lateral epicondylic ridges of the humerus. The interval between the epicondylic ritlges was bridged over by stmie biceps brachii fibers which passed distally to insert onto the coronoid process of the ulna and to give origin to the extensor digitonmi comnmnis and the extensor digit i quint i proprius muscles. The canal thus fonned between the epicondyles of the humenis transmitted tlie median nerve lakrally and the brachial artery 7?iediaUy.
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6 J. PARSONS SCHAEFFER AND LOUIS H. NACHAMOFSKY
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The brachialis (iinticus) imiscle as sucli was absent. The apparent absence of this muscle together with the fact that some biceps brachii fibers inserted on the coronoid process of the ulna loads one to believe that the brachialis was incorjwrated with the bicei>s brachii fibers and that it had not differentiated from it.
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The coraco-brachialis muscle arose with the short head of the bicei)s brachii nmscle from the coracoid process. It had an abnonnally extensive insertion on the humerus and into the brachial fascia.
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An acromio-lnimoral muscle appeared as an anomalous band, arising from the inferior surface of the overhanging acromion process and the capsule of the shoulder joint. It inserted on the humenis just lateral to the major tubercular crista. It lay beneath the deltoid muscle. This may explain the absence of a bony insertion of the latter muscle and might be considered an is<^lated deep portion of it.
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The long head of the triceps l^rachii muscle arose very extensively not only from the infraglenoid tubercle ))ut from a goodly portion of the axillary border of the scapula where it was intimately blended with the teres major muscle as mentioned in the previous paragra])h. The medial head of the triceps brachii arose along the distal third of the dorsal surface of the humeiiis. The lateral head was partly incorporated with the long head and in part arose from the tendon of insertion of the latissimus dorsi muscle. As usual it gained insertion on the olecranon process of the ulna and into the antebrachial fascia in the immediate neighborhood.
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The anconaeus muscle was normal in its origin but its area of insertion was abnonnally extensive; the whole ])roximal half of the dorsal or extensor surface of the ulna was occupied by it.
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Mnficlcfi of the antebrachinm and hand. The brachio-radialis muscle took its origin from the distal fibers of the deltoid muscle and from the over-lying fascia. It inserted into the transverse carpal ligament and into the antebrachial fascia. The peculiar insertion of this muscle was probably due to the rotation of the hand about the ulna. The muscle took a rather devious course:
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COMPLETE BILATERAL ABSEN'CE OF RADIUS 7
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Turning ventrally from its origin, it occupied a position between the extensor carpi radialis loiigus and brevis muscles medially, and the extensor pollicis longus muscle (?) laterally, lying over a mass of undifferentiated muscular tissue.
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The extensor carpi radialis longus and bre\'is muscles arose by a common fleshy head of origin from the caudal portions of the deltoid and the triceps brachii muscles. They coursed distally
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Fig. 3. Diagrammatic sketches of superficial (to the left) and deep (to the right) dissections of the ventral aspect of the right antebraehiiim and hand. The details of the dissection are purposely omitted. See text for description of figure. X = flexor carpi ulnaris muscle; a = palmaris longus muscle; c = flexor carpi radialis muscle; r = extensor carpi radialis longus et brevis muscles; b = brachioradialis muscle; n = ulnar nerve; p = flexor profundus digitorium muscle; y = hypothenar muscle; s = flexor digitorum sublimis muscle; u = ulna; 2 = lunibrical muscles undifferentiated; ni = undifferentiated muscle.
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over the latero-central aspect of the antebrachium, following the course of the brachio-radialis muscle. Both muscles inserted on the transverse car])al ligamont medial to tlie Iirachio-radialis. The brevis was distinguishable from the longus only after tiiey had traversed half tlieir course (fig.3).
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An extensor muscle of the thumb was present but did not correspond to any of the normal thumb extensors. It arose partly
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8 J. PARSON'S SCHAEFFER A.VD LOlIS H. NACHAMOFSKY
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inm\ tlic inosl distal hiccps hnu-liii fibois and was intimately associated with a coninion niusole mass adherent to the ventral surface of the ulna. The muscle passed distally and became superficial at the region of the carj^us where it was lateral to the extensor digitorum comnmnis muscle. Its tendon gained the dorsum of the hand by pa.ssing through the first osteo-fibrous canal on the dorsum of the wrist and it inserted on the base of the distal i)halaiLX of the thumb. On the dorsum of the hand a small nmscular sheet arose from the thumb extensor which passed medially under the tenilons of the other extensors to insert on the hypothenar fascia over the fifth metacarjial bone (fig. 4).
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The extenst)r digitorum conununis nmscle was a round nmscle which arose in conunon with the extensor digiti (juiiiti proprius muscle from the distal fibers of the biceps brachii muscle, from the lateral epicondyle of the humerus, and from the antebrachial fascia. It passed suj)erficially and distally through the second osteo-fibrous canal onto the dorsum of the hand. It coursed l)etween the extensor digiti ([uiiiti proprius nuiscle medially and tlie extensor of the thumb laterally, lying over the ulna and an unilifTerentiated mass of muscle deeply placed. On the dorsum of the hand the extensor digitorum communis muscle gave off four tendons which inserted by broad fascial expansions on the j)halang('s of the second, third, fourth and fifth fingers. The more direct tendinous insertions were, however, to the distal segments (fig. 4).
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The extensoj- digiti (juiiiti j)roj)rius muscle arose in common with the extensor digitorum communis muscle. It was quite superficial on the antcbrachium with the extensor carpi ulnaris muscle medial to it. On the dorsum of the hand its tendon divided, one j)art going to insert with a tendon from the extensor communis digitoniiii nmscle and the otlier becoming continuous with the fascia ov(;r the fifth metacarpal bone (fig. 4).
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The extensor carpi ulnaris muscle was nonnal except for the absence of a distinct tendon of insertion. The muscle teniiinated in a broad fascial band wliicli inserted (m the medial aspect of the distal extremity of tin; ulna. Its usual insertion on t)ie fiftli metacarpal Ixoie was wanting.
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COMPLETE BILATERAL ABSE^X'E OF RAD IT'S 9
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The remaining muscles of the extensor group were either totally missing, as in the ease of the supinator fbrevis; muscle, or were not differentiated, but remained merely a muscle mass which lay between the extensor of the thumb and the flexors of the antebrachium. Since the flexor pollicis longus muscle was absent, it is likely that it had not differentiated from this mass. It should here be noted that the absent and undifferentiated muscles in the specimen are nonnally intimately associated with the radius, both with respect to their origin and their course.
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The flexor carpi ulnaris muscle was normal in size and position. It, however, lacked a clean-cut tendon and did not find an insertion on the carpus. The only point of insertion was to the capsule of the joint between the ulna and the carpus.
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The palmaris longus muscle (?) arose together with the flexor carpi ulnaris from the medial epicondyle of the humenis, and passed into the antebrachium lateral to the latter nmscle. The palmaris longus and the flexor carpi ulnaris had a common insertion on the capsule of the joint between the carpus and the ulna (fig. 3).
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The flexor carpi radialis muscle (?) took its origin from the medial epicondyle of the humerus in common with other flexors, and from the distal fibers of the biceps brachii and the intenmiscular septum. It passed lateral to the pahnaris longus i?) and was separated from it in the distal half of the antebrachium l\v the ulnar nerve. The fibers of the muscle converged to a jx)int at the junction of the middle and distal thirds of the antebrachium. From this point the muscle again spread out into a triangular muscular sheet to ultimately insert on the ventral surface of the ulna and the proximal aspect of the can:)us. It is probable that the flexor carpi radialis nmscle in its distal third is nonnally more or less supported and directed by the radius. The latter being absent, the muscle dro])])ed to a secondarv support on the ulna (fig. 3).
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The ])ronator (ratlii) teres muscle wa.< entirely wanting.
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The flexor digitonim sublimis nuiselc (?) arose by two heads: that from the medial epicondyle was extremely small, and baroIv extended to this bony ]>()int. It also gained a slight origin
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10 J. PARSONS SCHAEFFER AM) LOlIS H. XACHAMOFSKY
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from tlie medial inlcnnuscular sei)tuiii. Tlie radial head of tlie imiscle dro])ped more distally and deeply, due to the absence of the radius, and arose from the lateral border of the uhia near the car]His. The latter origin was found on a deeper level than that of the flexor digitonnn jirofundus nuiscle, and in its passage into the hand it lay ventral to the mass of thenar nmscles. The two heads joined in the liand to fonn a distinct tendon which inserted on the base of the distal phalanx of the index finger. In the palm of the hand a sheet of nmscle tissue extended from the tendon of the flexor sublimis digitonmi (?) over the flexor profundus digitonnn towards the fifth metacar]ial l)one. It was not clear what tliis muscle represented (fig. 3).
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The flexor digitorum ]irofundus muscle arose beneath the superficial muscles from the whole ventral surface of the ulna. It lay ventral to the second head of the flexor digitonmi sublimis muscle. The muscle was fan-shaped, converging to a point on the carpus and continuing into a tendon which sent three slips to the bases of the distal jihalanges of the third, fourth and fifth fingers (fig. 3). In the pahn the tendon passed beneath the flexor sublhnis digitorum. From the ventral surface of the tendon an undifferentiated sheet of muscle extended toward the fifth metacari:)al bone and lay beneath the accessory sheet of nmscle given off from the flexor digitonnn sublhnis. From this muscular mass two lumbrical muscles were given off for the fourth and fifth fingers (fig. 3).
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The thenar muscles were represented by a small mass of undifferentiated nmscular tissue. This muscular mass arose from the superficial fascia and from the undifferentiated extensor muscular mass. It extended to the base of the second phalanx of the thumb. A distinct tendon for the mass was wanting.
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The extensor pollicis longus muscle was absent as a distinct muscle. It was probably incorporated in the undifferentiated extensor mass.
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The hypothenar muscles were not differentiated into individual muscles, but together formed a triangular sheet of muscle which arose from the transverse carjial ligament. The nmscular sheet inserted on the medial border of tli(> fifth metacar])al bone.
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COMPLETE BILATERAL ABSENCE OF RADIUS
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11
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The pronator quadratus muscle was proljably represented by a mass of muscular tissue which surrounded tne distal extremity of the ulna (fig. 4) .
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The palmar interossei muscles were normal.
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The dorsal interossei muscles were absent except the one for the index finger.
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—/■ UI71Q
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Fig. 4. Diagranimatic sketch of a tlissection of the hiteral aspect of the antebrachium and of the dorsum of the hand of the right upper extremity. Only the muscles are indicated, o = flexor carpi ulnaris; h = palmaris longus and flexor carpi radialis (?) musch^s; c = extensor carpi radialis longus et brevis muscles; d = brachio-radialis muscle; c = extensor of thvuiib;/ = extensor digitorum communis muscle; g = extensor iligiti quinti proprius muscle; h = undifTerentiateii muscle; i = extensor carpi ulnaris muscle; j = pronator quadratus muscle (?); k = tendons of extensor digiti quinti projjrius muscle; / = sheet of muscle from thumb extensor.
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Fig. 5. Outline drawing of the hones of the right brachium and antebrachiuni after the muscles were removed. The hand is also shown in its fixe<l position.
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B. O.'^TKOLOGY
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 +
 +
The humeiiis was shorter than nonnal. mea.suring only o cm in length. The proximal epi]ihysis wa.^ relatively extensive. l.D cm. in length. It projected cephalically and ventraily from the shaft at an angle of about 135° (fig. 5). The shaft of the humenis was more or less rounded and not easily divisible into surfaces and borders.
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12
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 +
 +
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J. PARSONS SCHAEFFER AM) LOlIS H. NACHAMOFSKV
 +
 +
 +
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Tho rapsiilo of tlio oll)<)\v joint was vory lax and tliin. It had incorporalinl in it many iiuisclc fihors. and tho difforontiation of the various ligaments of the joint was very slight. The size of the capsular ligament i^ennittcil a rather complex elbow motion. Not only was the nonnal ginglymoid movement possible in its full extent, but a distinct trocoidal movement of the ulna on the humerus was also possible. This condition in a measure compensated for the absence of the radius and made a small degree of pronation anil supination of the antebrachimn possible.
 +
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Nerves to Coraco-bracriiaiis and Biceps Mm.
 +
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<. ^.^Suofa-scaoular N.
 +
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"- -.^ 5 rJ7C
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Median M
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Long Thoracic. N. Meo. Ant. Thorac. N.
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(Circum(lex>
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' Fig. 6. Diagram of the brachi.al jilexus of the right upper extremity. See text for description of it.
 +
 +
It should also here be noted that the medial aspect of the distal extremity of the ulna formed a diarthrodial joint w^ith the carpus.
 +
 +
The osteology of the hand and carpus appeared normal for the age of the infant.
 +
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C. NEUROLOGY
 +
 +
The distribution of the nerves was more or less normal, but the altered musculature necessarily complicated the arrangement of the nerves. However, the nerve supply was an aid in diiTercntiating the various muscles of the antebrachium and hand. The one striking thing about the nerves throughout the upper extremity was the unusually large size of the main trunks. The brachial plexus also deviated from its normal arrangement. A.s is indicated in the diagram of the plexus (fig. (>), the medial and lateral components of the median nerve remained independent to the level of the bend of the elbow. Ui'^ro. the components
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COMPLETE BILATERAL ABSENXE OF RADfUS 13
 +
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united to form the median nerve proper. Another peculiar condition of the median nerve was the origin of its medial component firmer head) from both the medial and dorsal cords of the plexus. The musculo-cutaneous nerve (?) ended in the substance of the biceps muscle and another small nerve from the lateral cord ended in the coraco-brachialis muscle. In the diagram these nerves are designated nerves to coraco-brachialis and biceps mu.scles."
 +
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The medial anterior thoracic nerve was a branch of the middle trunk. At least the nerve so designated filled the description of the medial anterior thoracic nerve in every way save its point of origin.
 +
 +
The medial brachial Clesser internal) cutaneous nerve was entireh' absent.
 +
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D. COXCLUSIONS
 +
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The agenesis of the radius in this case must have been due either to a failure of the radial portion to give ri.se to an anlage, or if the latter were established, some affection must have destroyed the skeleton anlage after it had begun to differentiate. In view of the fact that there was a complete absence of the radius the natural inference is that there was a lack of origin of the element.
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It is difficult to say to what extent the absence of the radius was responsible for the marked errors in the nuisculature of the upper extremity. Certainly the ab.sence of radial suj^port and stimulus must have to a great extent influenced the muscles that normally arise and insert on this bone (it will be recalled that the latter muscles were in many instances profoundly altered i.
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Other antebrachial nuisdes, as well as those of the hand showetl marked errors. The faulty position of the hand, doubtless primarily caused by lack of radial support, may have been responsible for some muscle alterations, especially those of the hand and those that normally in.sert on the carpus. Lack of radial guidance and stimulus may have influ(Miced others. It is. how««ver. difficult to see how the ab.sence of the radius could have had any bearing on the development of the nuisclos of the shoulder and proximal half of the brachium. Notwithstanding, many of these
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14 J. TAKSONS SCHAEFFER AND LOUIS H. XACHAMOFSKY
 +
 +
muscles were quite anomalous in thoir anatomy, as is indicated in the text.
 +
 +
It would, therefore, seem that the whole error-complex of the upper extremity was primarily due to the lack of a proper formati\e stmmlus or stimuli, and tliat the absence of the radius could merely account for secondary muscular errors due to the lack of support and stimulus normall}' supplied by this bone. The faulty position of the hand seemed purely secondary, due to lack of radial support and muscular contraction.
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AX AXO.ALILOUS RIGHT SUBCLAVIAN .AJiTERY
 +
 +
JAMES F. COBEY The Anatomical Laboratory of the Yale Medical School
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TWO FIGURES
 +
 +
Among the variations in the arrangement of the branches of the aortic arch in man, there is an unusual anomalous condition in which the right subclavian artery arises from the arch distal to the left subclavian. An example of the aforementioned anomaly was met with by the writer in the dissecting room of the Yale ^Medical School during the session of 1912-1913.
 +
 +
A description of the specimen, with an attempt to explain the embr^'ology thereof and with a suggestion of symptoms that might arise therefrom, is offered here in brief.
 +
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DESCRIPTION
 +
 +
The anomaly to be considered was noted in the dissection of a male, negro cadaver, aged approximately forty-five years. The right subclavian artery, instead of arising normally in conjunction with the right conuiion carotid from the innominate artery, came off as an entirely separate artery from the descending limb of the aortic arch on the left side of the body after the left subclavian artery was given off (fig. 1). The anomalous vessel reached the right arm by passing dorsal to the trachea and the esophagus across the vertebral column.
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The right subclavian took its origin from a point on tiie dorsal aspect of the descending limb of the aortic arch 5 inch distal and to the right of the normally placed left subclavian artery (fig. 1). Leaving the aorta, it passed at an angle of 45 degrees to the right and cephala(i between the esophagus and the bony vertebral column. Tills direction was maintained in its further course through the neck with l)ut a slight lateral curve to the point where the first branches arose from it.
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15
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16 JAMES F. COBEY
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As is indicated (fig. 1 ), the riglit vertebral artery was the first branch of the anomalous right subehi\ian and it came off at a distance of 4§ inches from the origin of its parent from the aorta. It therefore corresponded to tlie normal position ior the vertebral artery - a fact worthy of note on account of differences in the position of the vertebral artery in cases of anomalous subclavian arteries like this. The right subclavian artery was crossed in the root of the neck by the right pneumogastric (vagus) nerve, but the inferior (recurrent) laryngeal l)ranch of the vagus did not hook around the subclavian artery as usual. — that is, it was not recurrent, as shown in figure 1.
 +
 +
There was no innominate artery j)re8ent in the subject, both common carotid arteries arising separately from the arch of the aorta. The relations of the second and third parts of the right subclavian artery and the origin and distribution of its branches were perfectly normal.
 +
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EMBRYOLOGIC EXPLANATION
 +
 +
Embryology readily explains the anomaly described above by assuming a defect in the absorption of the primitive right aortic arch in the embryo. Absorption occurs ordinarih' distal to the point of origin of the right subclavian artery (a to b, fig. 2 B). In the case in cjuestion the position of absorption was along the fourth branchial arch (« to c, fig. 2 C). The embrj^onic right aorta became the right subclavian artery (a to x, fig. 2 C).
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The position of the right subclavian so far cephalad on the left arch (arch ]iroper) of the aorta may be explained in two ways: Either there was a positi\e migration of the artery from point A' in figure 2 C to point .r in figure 2 I), or the migration is onh' apj)arent and the real change was a dragging down of the aortic arch in the mid-line by a downward movement of the heart and pulmonary system. Probably both processes progressed para passu and had a .share in bringing about adult conditions found in this case. The second \ iew gives a reason for the position of the right subclavian artery dorsal to the trachea. The pulmonary system descends ventrally with the heart through
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ANOMALOUS RIGHT SUBCLAVIAN ARTERY
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17
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Fig. 1 Drawing from a dissection of the ventral aspect of the nwk anil thorax showing origin, course, and relations of the anomalous right subclavian artorj-. A window is cut into the aorta to show point of origin of anomalous vessel.
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a, recurrent (inferior) laryngeal nerve
 +
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b, vagus nerve r, phrenic nerve
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(/, inferior thyroid artery
 +
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c, sympathetic cord
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/, anterior scalene muscle
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(J, vertebral artery
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h, transverse cervical artery
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i, suprascapular artery
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j, internal mammary artery
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A', anomalous right subclavian artery
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/, right common carotid artery
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tn, trachea
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H, left connnon carofi<l artery
 +
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o, left subclavian artery
 +
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p, superior vena cava
 +
 +
7, aorta
 +
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r, origin of anomalous right subclavian
 +
 +
artery .V, left bronchus /, pulmonary artery M, descentling th«»racic aorta c. heart
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THE ANATOMUAl. RECORP, VOL. 8. NO. I
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18
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JAMES F. COBEY
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the lieart-shapt'il space {tigs. 2 C and '2 D) wliioh is surrounded by the two embryonic aortae, so that the trachea comes to lie ventral to the anomalous subclavian artery when this is formed. The esophagus necessarily occupies the same position because, since tlie large blood vessels in the region develop around the fore-gut, the latter lies from the first in the loop ventral to the
 +
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A B c D
 +
 +
Fig. 2 Series of diagrams of the embryonic arterial arches for comparison of the normal with the abnormal development of the right subclavian artery. Dotted lines indicate points of absorption.
 +
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A Diagram representing primitive conditions.
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B Diagram representing the usual development.
 +
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C Diagram showing the anomalous right subclavian artery (diagrams A, B, and C were modified from Piersol's Anatomy).
 +
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D An original diagram to illustrate subsequent change in position of anomalous right subclavian artery to condition described in text. The formation of the right vertebral artery should be noted also.
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rs and /.s, right and left subclavian ar
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te, internal carotid artery ec. external carotid artery cc, common carotid artery ma and Inn, right and left aortic arches
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respectively i, iiuiominate arterj'
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teries respectively ao, aorta
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p, pulmonary artery r, vertebral artery X, |)()int of origin of anomalous right
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subclavian arterv
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dorsal aortae, and will therefore be ventral to an anomalous right subcla\ian artery as found in this cadaver, since the artery represents in part the original right dorsal aortic arch.
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The exact extent and position of the absorption would appear to determine the point of origin of the right vertebral artery. That is, if the absorption of the right arch were not complete
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ANOMALOUS RIGHT SUBCLAVIAN ARTERY 19
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 +
medially, as in figure 2 C, the unabsorbed portion would persist as the right vertebral artery which might thus arise from the aorta or even from the right common carotid artery. In my specimen the absorption was apparently complete, however, and the vertebral artery arose directly from the right .subclavian (fig. 2D).
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 +
The frequency with which such anomalies of the subcla\ian artery occur is represented in a report published by Arthur Thomson. This report is the result of the efforts of a committee of collective investigation for the Anatomical Society of Cireat Britain and Ireland. Five hundred cases in all were examined and, of these, five (1 per cent) presented the anomalous condition in which the right aortic arch persisted distally.
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APPLICATION
 +
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It is within the range of possibility that the pressure exerted upon the right subclavian artery in its position dorsal to the trachea and esophagus, as reported above, might pnjduce symptoms resembling those of cervical rib. The natural inference would be that owing to pressure on the artery there would result a strong pulsation of the vessel and maybe trophic changes in the arm, forearm, and hand. Other symptoms and conditions associated with pressure on large blood vessels might be expected.
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Anatomically the right arm appeared perfectly normal and further dissection of the body showed no other anomalies.
 +
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I am indebted to Prof. J. Parsons Schaeffer for suggestions and for reading the manuscript.
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AN ANOMALOUS MUSCLE OF THE LEG: PEROXAEOCALCANEUS IXTERNUS.^
 +
 +
J. DOUGLAS PERKINS, Jr. University of Pennsylvania Medical School
 +
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THREE FIGURES
 +
 +
The cadaver presenting this anomal}' was that of a muscular negro of unknown age, and was one being used for ordinary dissection purposes in the Laboratory of Anatomy of the Uni\'ersity of Pennsylvania. The condition was found to be bilateral, the muscle being present in both the right and left legs.
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It is a flat muscle arising partly by digitations from the flexor hallucis longus and partly from the lower half of the mesial surface of the fibula. Its fibers pass downward and inward into a tendon at its internal border. The tendon courses dowTiward and forward under the ligamentum laciniatum and over the sustentaculum tali to be inserted into the periosteum, and also into a tubercle at the distal internal surface of the calcaneus, just superior and lateral to the tendon of the flexor hallucis longus. At its origin it overlies the flexor hallucis longus; lower down the tendon enters the same compartment with that of the flexor hallucis longus, occupying a position superior and lateral to the latter.
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The nerve supply could not be worked out as it had I urn destroyed before the writer took up the dis.section. but it probably came from the same muscular branch as that which supplied the flexor hallucis longus, that is, from the nen'us tibialis.
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The blood supply is eff"ectod by means of a branch of the artoria peronaea.
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The action is to assist in extension of the caqnis and ver>slightly to aid in supination.
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' From the Laboratory of .\n;itoiuy of tlu« University of Pennsylvania.
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21
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22 J. DOUGLAS PEKKINS
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Associated witli tliis muscle, there were found several other anomalies in the plantar rep;ion.
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The tendon of the flexor hallucis longus broke up into two slij)s. the extra one later dixidiiifj; into two. which went to the second and third digits. At the lateral side of the distal forking, the lumbrical of the fifth digit took origin.
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The insertion of the quadrat us plant ae divided and surrounded the branch of the flexor digitorum longus to the fifth digit.
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 +
A very slender slip of tendon connected the tendons of the fiexor digitorum brevis and the flexor digitorum longus of the fifth digit.
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 +
As far as the writer has been able to determine, this anomaly was first reported by Alexander ]\Iacalister,- who gave the muscle its name. He describes it as follows:
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 +
Peroneo-calcaneus ihternus is a .small muscle which .... seems to resemble the tensor oi the synovial membrane of the ankle of Henle and Linhart, .... it arises below the flexor hallucis longus from an oljlicjue line on the back of the fibula behind the external malleolus, passes over the back of the sustentaculum tali, in the groove with the flexor hallucis to be inserted into a tubercle of the os calsis. This muscle. I have elsewhere referred to ^s the probable homotype.of the pronator quadratus.
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M. Auvray reports later, in 1896 r-^
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Muscle surnumeraire de la region profomle posterieure de In jambe. Faisceau p^roneo calca^en interne. Macalister a d^crit sous ce nom im 'petit faisfcau' se detachant audessous du flechis.seur propre du gros orteil de la face posterieure du penjiie et venant se terminer sur le tubercle du calcaneum. Jc reporte un fait double de cette anomalie musculaire, rencontre sur Ic meme sujet. Dans mon cas, il ne s'agit pas d'un petit 'faisceau' conune le dit I'autcHir precedent, mais de deux veritables muscles nettement distincts des muscles voisins.
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Sur la jambe gauche le muscle est represents dans ses deux tiers supSrieurs par un corps charnu situS au-de.ssous et en dehors du long flSchisseur propre du gros orteil. Les fibres viennent converger obli
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 +
 +
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Transactions of the Royal Irish Academy (1872); vol. 25, Science, part 1. p.
 +
12.5. A<l<iitional observations on muscular anomalies in human anatomy, Alexan<ier .Macalister.
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 +
'Bulletins «le le Socic^'tt Anatomique de Paris, TT Annee, (189G), 5me Serie, Tome 10., F. 7, p. 22.3-224. Anomalies musculaires et nerveuses. M. .\uvray.
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AN AXOMALOrS MUSCLE OF THE LEG
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23
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^ ^
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Kiij. 1. .Superficial dissection. F.L.D., M. rt«'x«)r »Iigitoruin longus; /'.L., M. peron.'ieiis longus; F.L.H.. M. flexor halhuis lonpiis; T.A.. M. tibialis antirus; P.H., M. poronaeus brevis; P.C.I., M. peronaeo-caleanous internus: P.I.T.F.L.. Lig. Malleoli lateralis postcrius; I.A.L., Lig. lariniatum.
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Fig. 2 Deep <lissection. Sm., insertion of M. semimembranosus: P.T.A., A. tibialis i)osterior; r..l...\. jxTonaea; P.T.\., branch of N. tibialis.^., origin of the M. flexor halluois Umgus cut away from the fibula; F.L.P., M. flexor digitorum longus; F.L.H., M. flexor hallucis longus; I., intenligitation brtwwn M. flexor halluois longus an«l the M. peronaeo-<'aleaneus internus; P.C.I., M. |>eronacoealcaneus internus; 7.1., M. tibialis antirus; In., insertion of M. pfronaeo-calcaneus internus; /'./,.. M. peroneaus longtis; IS., septum musrulare p«tstrriu.<".
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IM
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J. DOUGL.\S PERKINS
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Fig. 3 Plantar rogion. F.L.I)., M. Hoxor difiitoruiii longiis; P.C.I. , M. peronaco-calcanoous intcrnus; F.L.H ., M. flexor halliicis longus; Ah.H ., M. Abductor halluois; L^'., M. lutnhricalis of oth digit; F.A., M. (luadratvis plantac; F.B.H., M. flexor hallucis brevis; F.P J., first plantar intcrosseus muscle; P.L., M. peronaeus longus; L.P, Lig't., long plantar ligament; F.B.D., M. flexor digitorum brevis.
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quement vers un tendon (lui s'otcnd sur toutc la longueur tlu muscle. Co tendon passe sur la face interne du calcaneinn dans la memc goutticire fjue le long flechisseur projjre, et vient s'inserer dans le fond de la gouttiere ealcaiK'-ene interne sous la chair carr<'>e.
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 +
Sur la jamlx' droite, il s'agit d'un muscle qui est le plus volumineux des muscles de la couche profonde de ce cotd. II s'ins6re par son corps charnu sur la face post(rieure du peron^' dans toute son etendue, entrc Ics in
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AN ANOMALOUS MUSCLE OF THE LEG 25
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 +
sertions des peroniers lateraux en dehors et du long fl^chisseur propre en dedans. Les fibres charnues convergent obliqu(ment vers un tendon qui occupe la face posterieore du muscle, s'en detache en arriere de la tibio-tarsienne pour passer dans la meme coulisse tendineuse que le long flechisseur propre, et s'inserer comme du cote oppos^ au fond de la gouttiere calcaneenne sous la chair carree.
 +
 +
A. F. Le Double^ speaks of it as follows :
 +
 +
Par deux faisceaux fixes, I'un au tibia, I'autre a I'aponevrose qui recouvre le flechisseur tibial et aboutissant a un tendon commun qui se divise, a la plante du pied, en deux branches dont la plus interne va sf perdre sur le tendon du flechisseur du gros orteil. Ces faisceaux ont ete decrits sous le nom de M. peroneo calcaneus internus par M. Macalister qui les a decouverts. M. Auvray en signale receniinent un nouveau cas 1896.
 +
 +
The following mention is made of it by L. Testut:^
 +
 +
Faisceau peroneo-calcaneeus interne (Peroneo-oalcaneus internus de Macalister). C'est un petit faisceau, decrit par Macalister, se detachant, au-dessous du flechisseur propre du gros orteil. de la face jxjsterieure du perone et venant se terminer sur le tulxTcule de calcaneuni. Macalister, qui I'a decrit le ])remier, le rapproche du fai.-^ceau tenseur de la synoviale du cou-de-pied. Xe pourrait-on pas le rapprocher. avec autant de raison, du long accessoire des flechisseurs.
 +
 +
The specimen was examined by Dr. Cleorge A. Piersol. who stated that he regarded the peroneo-calcaneus internus as an accessor^' long flexor.
 +
 +
With the idea in view that a pr()t()tyj)c might exist among the mammalia, the writer made a search of the literature concerning the myology of extremities, and was unable to find mention of a similar muscle represented in any group.
 +
 +
The author wishes to express his gratitude to Dr. CJeorge A. Piersol, Professor of Anatomy, and to Dr. (Jeorge Fetterojf. Assistant Professor of Anatomy, untier whose direction the work has been done; also to J. Percy Moore. Ph.D.. and Merkel H. Jacobs, Ph.D., for their assistance.
 +
 +
Trjiiti^ dvn variations <iu .syst«^mr tmisrtilairo
 +
I'hominc (1897), Tome "J,
 +
p. 404, Le Doublf.
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' Trait i" dos variations du syst»Mm> niusculairc <lo Ihoinino ot »lo lour signification au point <lr vut* (le I'.anthropoloKio zooloni(|ui\ I'aris. IS'.)7, L. Ti^stut.
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26 BOOKS RECEIVED
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 +
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BOOKS RECEIVED
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ANATOMY AXD DISSECTOR IX ABSTRACT, Stewart L. McCurdy, A.M., M.D., professor of anatomy and surgery. University of Pittsburgh; orthopedic surgeon Presbyterian an<l Columbia Hosjjitals; SI illustrations, 372 pages, fourth edition, $1.00. Mediral Abstract Publishing Company, Pittsburgh, Pa.
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DISEASE AXD ITS CAUSES, W. T. Councilman, A.M., M.D., LL.D.. professor of pathology, Harvard University; 254 pages including index, $.50 net. Henry Holt and Company, Xew York, and Williams and Xorgate, London.
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A -M.VXU.AL FOR WRITERS; covering the needs of authors for information on rules of writing and i)ractices in printing, John Matthews Manly, Head of the Department of English, The University of Chicago, and John .\rthur Powell, of the University of Chicago Press; 225 pages including index, 1913, SI. 25. The University of Chicago Press, Chicago, 111.
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MODERX PROBLEMS OF BIOLOGY, lectures delivered at the University of Jena, December, 1012, Charles Sedgwick Minot. LL.D., D. SC; fifty-three illustrations, 124 pages, 1913, $1.25 net. P. Blakiston's Son and Company. Philadelphia, Pa.
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CUXXIXGHAM'S TEXT-BOOK OF AXATOMY, edited by Arthur Robinson, M.D., F.R.C.S., professor of anatomy, Universitj^ of Edinburgh; 1124 figures from original drawings, ()37 of which are printed in colors, and two plates, 1596 pages including index, 1913, .?(!.. ")0 net. cloth, .$7.50 one-half Morocco. William Wood and Company, Xew York.
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 +
DIE AXATO.MIE DES MEXSCHEX. mit Hinweisen auf die iirztliche Praxis. Erste Abteilung: Einleitung, Allgcmeine CJewebelehre, (Jrundziige der Entwickelungslehre. Friedrich Merkel, professor in Gottingen. 251 .\bbildungen im Text. 255 pages including index, 1913, S marks. V'erlag von J. F. Bcrgmann, Wiesbaden.
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SOME IDEAS IX LABORATORY EQUIPMENT
 +
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R. -M. STRONG Hull Zoological Laboratory, The University of Chicago
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FOUR FIGURES
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 +
In a previous paper' I described some electrical heating apparatus for paraffin baths in use at the University of Chicago. Recently, some improvements have been made, and I discuss these and some other laboratory apparatus, in this article.
 +
 +
In the paper just mentioned, I described a new form of thermostat designed for the Lillie type of paraffin bath. Though this thermostat runs for a number of weeks ^^^thout attention, it occasionally becomes necessary to clean it, and one improvement consi-sts in making the mounting more simple for the needle which makes and breaks the current to the 'cut out.' In the new form, the tube ])ranch to be cleaned may be made accessible by removing only one screw which has a milled head as may be seen in figure 1. The tulx' branch is cleaned by a swab of cotton wrapped around the roughened end of a slender rod and dipjied in nitric acid. In case the cotton slips off the rod and becomes ])ack<Ml in tin- tuln*. another rod \nth a barbetl point is used to remove it.
 +
 +
Another improvement consists inomittingthe flanges at the t()j)s of the two branches of the glass tube. It was found that the preparation of these flanges often involves, even in the hands of a skilled workman, a slight contraction of the inside (hameter of the tube branch at its top which prevents a perfect fitting for the adjusting-screw plug. If the latter does not completely close the tube branch at all points, mercury slips up above it and interferes seriously with tlu^ accuracy of tinthermostat.
 +
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The moimting of a ]>araffin ])ath recently installcMl in the z(M>logical laboratories of The Tniversity of Chicago is shown in figure 2. It is constructed of angle iron 39 mm. wide on the side: ami it is KKS cm. high at the bottom of the }>araffin bath. A trough for dripping paraffin will l)e noticed in the shelf. It increases in depth from lo mm. at the left end to 'M) mm. at tlu> right, and it is 1.5 mm. \\\(U\ This paraffin bath was obtained from tiie Spencer I^>ns (\)mi)any. and it is .">0 cm. wide. 64 cm. high, and ;^9 cm. dee]). It will be noticed that the cross section
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' H. M. Strong. Electrical heating of par.affin hnth.<. Anat. H<x'., vol. 7, no. 1, January, VM'.i, pp. O-IO; (> toxt figures.
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28
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It. M. STRONG
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Needle screw head
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Binding post
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Adjusting screw
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-Lock-nul
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Binding post
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Fig. 1 From ])h()t()f!;rapli of iniprov('<l vippor portion of thormostat
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area of the mounting is a few iiichos wntlor and (Iccjicr tliaii tliat of the bath, for the sjikc of stal)ility. The sHdinj? door was made as hirge as possible to furnish easy access to tlic electrical st(n'e inside.
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'I'he i)ositions of the thermostat ;uid of the automatic switch, described in my j^revious i)ai)er, are indicated in figure 2. The switch box should ordinarily be at the opposite end of the bath from that shown in figure 2.
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LABORATORY EQUIPMENT
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29
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— Tne'rrioilcii
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^-"e^
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Fig. 2 From photograph showing mounting of paraffin l);ith with parts of electrical heating ai)paratus in view.
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A box for wasliiiiji; niiero.'^<,-{)])t' slidc."^ !.•< shown in Hpiirc 3. While writing this paper, I wa.s informed that .^imihir hoxes have been used elsewhere, but the idea may not l)e familiar to many workers. I have used this box with satisfaction for .several years. It is eonstrueted of eorrugated. galvanized iron, and its dimensions are as follows: greater diameter 7;} inches, inner i-hamber ")J inclu's. This leaves a space just wide enough for a 1 by :\ inch slide. The outsid(« wall is two inches high, and that of the inner chamber is Ij inches liigh. The Im^x is placed
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30
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R. M. STFtONG
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FIk- 3 From photograph of box for washing microscope slides. Fig. 4 From photograph of apparatus for washing material in bottles or dishes and also for the bo.\ shown in figure 3.
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uiidcr ;i tap as in fi^;ur(' 4, and water flows out over the top of the inner clianihcr into the slide chaml)er and from there out over the outer edge. A gentle circulation of water is thus i)rovided in all parts of the slide chamber, which I testetl by making the water densely turbid with a few drops of fuchsin. In the course of a very few minutes, all traces of the
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LABORATORY EQUIPMENT 31
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stain disappeared from the slide chamber even witli a rather gentle fall of water into the inner chamber. It is important to have the box in a horizontal position. It will be noticerl in fig. '4 that labels at the upper end of the slide are not touched by the water.
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Apparatus for washing histologically fixed tissues is shown in figure 4. This stands on a shelf above a sink, and the box is 82 cm. long, 5 cm. high, and 30 cm. wide. A .series of small taps are provided, and all may be kept running by water at very moderate pressure, which enters at the right. Reducing T's lead to brass pet cocks and branched taps. At the left is seen the wash box which appears in figure 2. The pipe is plugged at the left of the tube which stands over the wasli box. It is at once apparent that a number of bottles or jars of material may be washed simultaneously, an arrangement which is useful \nth cla.s.ses in histolog}'. An outlet of ample capacity, at the outer left hand corner, empties the box effectively.
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32 BOOKS RECEIVED
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BOOKS RECEIVED
 +
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iC(Hitinued)
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ANNALS OF SURGERY: ANAESTHESIA NUMBER, Vol. 58, No. 6, December, 1913, A monthlj^ review of surgical science and practice, edited by Lewis Stephen Pilcher, M.D., LL.D., of New York, with the collaboration of J. William White, M.D., LL.D., of Philadelphia, Sir William Macewcn, M.D., LL.D., of Glasgow and Sir W. Wat.son Cheyne, C.B., F.R.S., of London; 986 pages including inde.x in vol. 58, $5.(X) a year in United States, single number $.51). J. B. Lippincott Company, Philadeli)hia, Pa.
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DIE BIOLOGISGHEN (IRUNDLAGEN DER SEKUNDAREN GESCHLECHTSCHARAKTERE, von Dr. Julius Tandler, o.o. Professor der Anatomic an der Wiener Univcrsitiit, und Dr. Siegfried Grosz, Privatdozent ftir Dermatologie und Syphilidologie an der Wiener Universitat. 23 text figures, 169 pages including index, 1913, 8 marks unbound and 8.80 marks bound. Verlag von Julius Springer. Berlin.
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beitra(;e zur frage nach ber beziehung zwisghen klinischem verlauf und anatomischem refund bei nerven- und
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GEISTESKRANKHEITEN, Bearbeitet und Herausgegeben von Franz Nissl, Heidelberg. Erster Band, Heft 1, 34 figures, 91 pages, 1913, 2.40 marks. Verlag von Julius Springer, Berlin.
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ZEITSCRIFT FUR ANGEWANDTE ANATOMIE UND KONSTITUTIONSLEHRE, herausgegeben unter Mitwirkung von A. Freiherrn v. Eiselsberg, Wien, A. Kolisko, Wien, F. Martius, Rostock, von J. Tandler, Wien, Erster Band, Erstes Heft (Ausgegeben am 21 Juni 1913), 96 pages (Preis des Bandes M. 28). Verlag von Julius Springer, Berlin.
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ANATOMIE DES ZENTRAIA'EHVENSYSTEMS. Siebzehnter,, der Sonderausgabe, Sechster Bericht, entlialtond die Leistungen und Forschung.sergebnisse, in den Jahren 1911 und 1912, von Prof. Dr. L. Edinger, in Frankfurt a.M., und Prof. Dr. A. Wallenberg, in Danzig, 115 j)ages including index, 1913, 6marks. A. Marcus und E. Webers Verlag, Bonn.
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13
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THE ARTIFICIAL PRODUCTION OF EYE ABNORMALITIES IN THE CHICK EMBRYO
 +
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CHARLES R. STOCKARD
 +
 +
Analomical Lahuralory, Cornell Medical College, New York City
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TWO PLATES
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During the springs oi 11)11 and 1912 a series of experiments were conducted on hens' eggs aiming towards a definite modification of development so as to produce typical defects. A large number of eggs was used and numerous methods of treatment with ^'arious chemical stimuli were em})loyed. The results, however, ha\'e not been of a definite nature, nevertheless they do indicate a decided tendency on the part of the developing central nervous system to respond to certain classes of stimuli in rather typical fashions. The responses are not in any sense specific for a given treatment but the same rather definite response may be obtained by a number of methods. This statement applies equally to other ex]:)eriments on the artificial i)roduction of ilefinite defects in the embryo. The earlier \iew that these defects were specific responses to the given chemical substance em])loyed as has been advocated by Herbst,' Hertwig, O.- the writer' and others is no doubt erroneous.
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The important fact, howe\er. is that a certain definite response on the part of the devol()]Miig organism may be consistontly ol>tained after carefully adjustetl treatments witli a large number of different substances. Since the response is the same in each
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' Herbst, C. Expoiinientolk' rnt(>rsuchunRoii, u. s. \v., Zcitschr. f. wissenst-h. Zool., 4, 189'J; Mitt. :i. d. Znol. St:u. zu Noapol, 1S'»3: Arch. f. Kntw-Mech. 4. I*<«16.
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- Hertwig, (). Urniund und S|)in:i bifida. Eiiif vorgloichpntlo inorphologisrhe tcratologisclie Studio an iiiis.spebildotrii Frosclioiorn. .\rrhiv f. Mikr. .\nat. Bd. 30, ISOi: Die RaiiiunikraiikluMt tierisclior KiMtnzollon. Ein Boitrag ziir cxporimoiitellen Zmiguiigs- uud Vcrerbungslehrc. .-Vrohiv f. Mikr. .\nat. Bd. 77, Abt. -2, 1011.
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' Stockard, C. R. The artificial production of cyolopian monsters: The "Magnesium embryo."' Jour. E\pr. Zool., (i, 1009.
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33
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THE .\N.\TOXIICAL KECORn, VOL. S, NO. '.' FEnnUAIlY, I'.M4
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34 CHARLES 1{. STOCK A HI)
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case it is vciy i)r()biibk' tluil the sul)stiiuc('s lh()U}i;li widely different act similarly on the embrj^onic organism, for example, in certain cases they may ser\'e simply to lower the developmental metabolism and thus prevent or arrest the formation of ]mrtirnlar structures.
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The hen's egg readily lends itself to chemical and mechanical ex])eriments and has been largely employed in ex])erimental teratology. It has long been known that by running the incubator at too high or too low a temjjerature or by reducing aeriation by varnishing the shell one is able to obtain a most varied gnni]) of monsters. P^er^ has used a great num))or of methods to produce monster chick embiyos. In 1899 he treated eggs with alcohol fumes before incubation and found that the fumes penetrated the shell and produced \'arious abnormalities in the embrj'os. Fere^ also repeated Preyer's^ experiment of removing the egg from the shell and allowing it to develop in glass dishes. Pre3er was only able to keep the eggs under observation in this manner for two or three days, while Fere devised a l^etter means of ventilation and succeeded in keeping the eggs alive for six days. Many of the embrj^os developing out of the shell showed abnormalities. Fere's reports merely record the experiments and mention the t^^^es of monsters obtained but no detailed or systematic study was undertaken and his exi)eriments have generally passed unnoticed. One must, however, api^reciate the rather ingenious and various methods of treatment which Fer6 employed.
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The experiments to l)e briefly described in the present communication are presented in order to show that the central nervous system and the eyes of the chick embryo become affected in a manner closel}' similar to that which I have recorded for the fish embry'os when treated with alcohol, ether and other substances.^
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V6r(', Ch. Influence du repos, sur les cffets de I'exposition priSalable :iux
 +
vapours d'alcool avant I'incubation flc I'couf dc poule. Compt. rend. Soc. do hiol. .51, IS'Ht.
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F<5r<5, C'h. Rernarqucs sur I'inrubation dcs oeufs de poule privds de leur coquillc. Conipt. rend. Hoc. de hiol. .52, 19f)0.
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Preyer, W. PhysioloRie sp^^ciale de Tenibryon. Trad, franc, p. 16, 1887.
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^ Stockard, C. R. The influence of alcohol and other anesthetics on embryonic development. Am. Jour. Anat., 10, 1910.
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ARTIFICIAL PRODUCTION EYE ABNORMALITIES 35
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Hens' eggs were exposed for different lengths of time to the fumes of alcohol and ether. The eggs used in the experiments had been laid for only two or three days. Shallow dishes were arranged with a wire screen bottom beneath which absorbant cotton soaked with 95 per cent alcohol was placed. Eggs were placed upon the wire screen and the dishes covered and left standing at the room temperature. During the two years several hundred eggs were treated in this manner.
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After the eggs have been exposed to the fumes for a short while the shell becomes covered with moisture, the condensed alcohol vapour and this -vapour penetrates the shell. The eggs were exposed for from twenty minutes up to thirty hours at room temperature. The shortest exposure that gave effects was three hours and forty-five minutes, though in many cases an exposure of as long as eight hours was non-effective. Exposures of from fourteen to twenty hours gave the best results. In these cases almost every embrj^o was abnormal yet most of them were able to continue development for several days at least. Exposures of twenty- three hours or more were usually fatal, the eggs failing to develop after being put into the incubator.
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The chief point to consider in the amount of exposure is the temperature. When the temperature is high evaporation is more rapid and more alcohol enters the egg in a given time.
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If eggs are placed in the incubator immediately after the treatment liquid oozes out of the pores in the shell on account of the slight expansion of the egg contents as the temjierature rises. A certain amount of the alcohol is no doul^t lost by this ])rocess. It is better, therefore, to allow the eggs to remain at room temperature for several hours after being removed from the fume dishes and before being placed in the incubator. Ford found that eggs put into the incubator immediately after treatment with alcohol fumes were not so decidedly affected as those treated for the same length of time but not subjected to the raised temperature until several hours after the treatment.
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In other cases eggs were exposed to the alc(^hol fumes while in the incubator. Weak alcohol solutions were place<l below the egg tray and (>vaporat(Ml slowly. This treatment was also
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36 CHARLES U. STOCKARD
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fontiiiuecl for difToroiit loti^tlis of tinio aiul in many cases gave more decided effects than those ol)tainod l)y the treatments before incubation.
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Ether fumes were also employed in the aijove manner. These fumes induce the same general types of de\'elopmental abnf)rmalities though they are more decided in action than alcohol fumes and kill the embr^'os nmch more readily.
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Several injection methods were used and a number of substances were injected into the egg but the results were indefinite and often negative. In many cases the injection was a failure in that it either coagulated the albumen in the -region, or injured the egg so that it did not develop.
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Following effective treatments with the fiunes of alcohol or ether the embryos were found to be small and behind the control in their rate of development. The abnormalities most abundant were of a general nature, in some cases the entire body of the embryo was absent while the area vasculosa was present containing blood islands and embrj^onic vessels. Other cases showed small embryos with the brain portion of the neural tube poorly developed. The cu'culation in many of the embrj'os was slow and sluggish and in such cases hydramnious conditions were present and the blood sinuses were also distended.
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A number of the embiyos showed various abnormal eye conditions and these are the defects of particiUar interest since exactly similar abnormalities have been gotten in abundance when developing fish eggs are subjected to the actions of ether and alcohol. In several experiments embiyos occurred with small poorly formed eyes which closely resembled the minute defective eyes most commonly found in alcoholized fish embryos.
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A few t>']oical cyclo]iean conditions were obtained showing different degrees of the defect. However, never more than three or four per cent of the embryos showed cyclopia even in the most successful experiments and in most instances cyclopia did not occur at all. Nevertheless, it is of importance to find that these treatments do occasionally induce the same variety of defects in the chick as was so abundant in many of the fish experiments.
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ARTIFICIAL PRODUCTION EYE ABNORMALITIES 37
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The monster monophthalmicum asymmetricum, that is, an individual with one eye of the normal pair perfectly de\'eloped and the other eye either absent or defec'ti\e to a marked degree, was commonly seen in the different groups of embrj'os, plates 1 and 2. This condition was more often found than cyclopia, yet it also was not as abundant as in fish embrj'os developing in solutions of alcohol or ether.
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The failure to obtain definite defects in large numbers in the chick embryos is no doubt due to the fact that the amount of treatment is nmch more difficult to regulate than in such an egg as that of the fish. The great variation in the size of hens' eggs, the amount of albumen as well as yolk, the thickness of the shell, etc., makes it almost impossible to treat a number of eggs to the same degree. The treatment must of course be delicately balanced in order to obtain such typical defects as cyclopia and monophthalmica since they only occur as responses to a certain injur}' or arrest at a critical developmental stageIt has also been found in a series of experiments which is being conducted to test the effects of alcohol and ether on the stnicture of the offspring from guinea-]iigs that a completely eyeless young animal was produced and the nervous systems of almost all the offspring show some defects due to the treatment."*
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During the winter of 1912 one of the incubators in the laboratory was placed in a room into which a ventilation system opened. The same system communicated with rooms in the chemical laboratory and fumes conveyed by the ventilator although rarelxnoticeable in odor were sufficient to injure the de\-elo]ung chicks. Many of the embryos thed during early stages. Tlie eggs were being used in tissue culture experiments l)v Dr. Hurnnvs and were usually o])ened after ha\ing de\elo])ed for alxmt twelve to eighteen days. Several of these large chicks were found to have only one lateral eye. They were similar to the early enihr>-os formed iii the abo\e (^x])eriments and were :v^ymmetrical mouo])htluilini(' monsters identical with those I have descrilie<l in
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Stockivrd, C. 1\. Tlu' oflfoct on tlu> DfTsprinj; of intoxii'.itinR the male parent
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iiui the transmission of the defects to suhsoquont generations. Am. Naturalist,
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vol. 47, 1013.
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38 PHAHLES M. STfUKARD
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fish embn'os. Pli()t{)g;ra]ihs of three of thes© large chick embryos are figured in ])hites 1 and 2, since tli(\v ilhistrate the defect far better than the young three and four day twisted enibrj'os. The fiunes injured the eggs and caused the same t\'pes of devel()])mental arrests or supression as are obtained with the other sul)stances discussed above. After tlie incul)ator was removed from tliis room tlie eggs in it develoj^jcd in a perfectly normal manner.
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These stnictiiral deformities and their ex])erimental production are recorded to enii)hasize the general nature of such defects and their wide occurrence among different tjq^es of embryos when treated with anj' substance which tends to arrest de\'elopment or lower their develo]miental rate and vigor. Elsewhere^ I have attempted to show how all abnormalities such as these eye structures may be explained merely as developmental arrests. Thus their wide occurrence in spite of their typical appearance.
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PLATE 1
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EXPLANATION OF FIGURES
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Tlirec views of an asyininetrical one-eyed cliick monster wliich occurred in Dr. Burrow's incubator. The ui)|)er photograph shows tlie c\'eless side, a small nodule of skin in the orbital depression represents an abortive eye-lid formation. The lower left figure represents the opposite side with a perfect ej'e, the fully developed lids are closed. The lower riglit figure giving a dorsal view of the head emphasizes the general asymmetry due to the absence of the one eye. The beak is i)ermanently crossed since the upper jaw is forced to incline towards the eyeless side while the lower jaw remains in a normal position. It is thus impossible to dose the beak as all the figures show.
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Ani. Joiirii. Anal., vol. 15, no. 3, 1913.
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ARTIFICIAL PRODUCTION EYE ABNORMALITIES
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CHARLES B. STOrKARD
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PLATE 1
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PLATE 2
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EXPLANATION OF FIGURES
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Two Other specimens of monster monophthalmicum asymmetricum. The huge eye of the embryo chick is seen on one side of the head while the other side is eyeless. Both of these embrj-os also show the twisted upper jaw and the permanentlj' open condition of the tnouth.
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40
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ARTIFICUL PRODUCTION EYE ABNORMALITIES
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CHARLES B. STOCKARD
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PLATE 2
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41
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A CASE OF PATENCY OF THE PERICARDIU.M AND ITS E.MBRYOLOGICAL SIGXIFK "AXCE
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R. A. McGARRY
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Department of Anatomy, University of Michigan
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ONE FIGURE
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During the winter of 1913 there was found in our laboratory an infrequent malformation of the pericardium in which there existed a large foramen, connecting the pericardial sac with the left pleural sac. Besides this condition there also occurred other anomahes of the coelomic derivatives, which if correctly interpreted, point back to an earl}- disturbance in the development of the general coelomic cavity. On account of the rarity of this condition, and on account of its broad embrj'ological significance, it was thought that the following report would not be out of place.
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Briefly, the history of the case is as follows: ^Male, sixty-five years old; family history not obtained. After being in the Xewberry State Hospital for eleven 3'ears, suffering from tenninal dementia, the patient died with sjTnptoms of gastritis. Death occurred in 1913. During his residence at the hospital no s^^nptoms were obser\pd which would point to the condition wo are describing.
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On examination of the Ixxly during the jirocess of dissection the rare condition was found of a large j^leuro-pericardial foramen. In addition to this there was also found a group of peritoneal disturbances; namely, a ventral hernia, left inguinal hernia, tendency to double femoral hernia, ami malposition of the colon. They will be described in that order.
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The opening iiotwoen the pericardial and pleural sacs appeared as an opening from 7 to S cm. in diameter. The edge was free throughout its course, which extended from above the pulmo 43
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44
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n. A. Mc'CAHRV
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iKiry Mi-tiMV. tlicnce over the root of the luiifi;. From tlicre it ari'luHl sliglitly forward, followiufi llic j:;roove l)ctwo(Mi tlio systoniic aiul puliuonary aortao. At the junction of the i)ulnionary artery with the rifi;ht ventricle the fold turned downward and backward, then upwaid to tenninate hack of the left atrium. Tiio free od.u;c continued laterally to the left, fonnins the left
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I"i|iurc 1. Left |)lcural cavity viewed from tlieloft side, witli the left luiitt removerl. The larne foramen in the mediastinal jileura, in front of the root of the left luiiK opens direeti}' into the jjcricardial sae, exposing the heart; /, areh of aorta an<l large vessels; 2, pulmonary aorta; 3, left aurieular appendage; 4, root of left lung; 5, left phrenic nerve appearing through the left mediastinal pleura; 0, diaphragmatic pleura.
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parietal layer of the pericardium, and to the ri^ht, forming:; the right co.>^tal pleiu'a. Through the opening could be seen the j)ulmonary artery and left auriculai' ai)))eii(lage, as sjiown in figure 1. The left phrenic nerve pass(>d between the two layers of the anterior edge of the foramen. Aside from the large opening in it, the pericardium was normal. There were no signs of adhesions or other disea»se except for a few adhesions over the apices
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PATENCY OF PERICARDIUM 45
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of the lungs. The upper lobe of both rij^ht and left lungs was partially di\'ided in each case, by a fissure from 1 to 2 cm. deep. Nothing abnormal was found regarding the diaphragm.
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 +
On examination of the peritoneum there was found a small ventral hernia, 1 cm. from the median line midway between the umbilicus and xiphoid cartilage. It pierced the transversalis fascia, both layers of the rectus sheath and the rectus muscle, appearing beneath the skin. The opening was 1 cm. in diameter. Through the opening protruded a tag-like appendage which appeared to be made up of a portion of the falsifonii ligament of the liver. A small vein and artery passed into it from the internal mammary \'essels. The left inguinal hernia was a very large oblique hernia extending down to the })ottom of the scrotum. It contained a large fold of the great omentum. In the region of both femoral rings there were distinct short funnelshaped pockets of the peritoneum extending into the femoral canals.
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The malposition of the colon was determined by the abnormal disposition of its peritoneal reflections. The peritoneal covering was more com])lete than usual. Thus the caecum and part of the ascending colon were completely surrounded, and were suspended free in the cavity by a mesentery. The ascending colon was flexed ventrall.y and upward upon itself so that the caecum was lying above the right lobe of the liver. The vermiform appendix, 10 cm. long, was found beneath the junction of the sixth costochondral articulation, at the level of the xiphoid cartilage of the sternum. It passed down medially between the caecum and ascending loop of the sigmoid. The sigmoid colon formed a large looj) with a broad mesentery. The upper limb of the flexure extended oblifiuely upward across the umbilical and hypogastric i-egions into the right iiypochondrium. where it, together with the caecum, caused a marked depression uj^on the anterior surface of the liv(M-. The flexure turned here and the lower limb passed downward and i)ackward through the right hypochondrium, and from thence downward into the true pelvis, having formed a loop about 1(> indues long. ]\ was supported throughout its whole liMigtli l)y a mesentery. The great omen
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40 K. A. McGAKHV
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(uni was iiiurli onlarji;e(l and formed, as has been mentioned, the contents of the left inguinal liernal sac.
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On examination of the Hterature I have been able to find eighteen cases of defective jiericardium. Three of these were found in foetuses and the remainder in adults. I have been able to examine the original articles of nine of these cases. Of the remaining nine, five were found in descriptions given by other writers, while the last four could not be utilized as the descriptions and references were either incomplete or the source unaxailable. The nine cases, the accounts of which I have had access to, are as follows:
 +
 +
Raillie (1788) reported a condition in a male of forty, in which the heart was found to lie free in the left pleural cavity. The mediastinum consisted of two laminae of pleura, inclined to the right side of the chest. Both laminae were connected throughout their extent by the intervention of a cellular membrane. This passed over the vena cava about 1 inch above the auricle. The heart was involved in the reflection of the pericardium, which became its immediate covering. This covering was very thin. The left phrenic nerve ran between the two laminae almost immediately under the sternum.
 +
 +
Curling ('39) reported a case in which, upon opening the chest, the heart was found completely exposed, lying loose in the cavity of the left pleural sac. There was no a])pearance of any j)ericar(jiuiii covering the heart. The only indication of a pericardium was a reflected fold which covered the pulmonary \-essels on the right side. The fold on the right side, close to the diaphragm, presented a small serous pouch with defined margin inferiorly and into which the appendix of the auricle i)rotruded. The anomaly was discovered in a male of forty-six.
 +
 +
Haly ('oOj reported a case of malformation of the j)ericardium in a male aged fifty-two. The malformation was discovered during a postmortem. The heart and left lung were were found to be in the left pleural sac. The heart was in close contact with the hmg, but connected in no way with the (iiai)iiragm. The membrane forming the common sac constituted the pleura of the lung ill one case, and the pericanliuni in llie oth(>r. The mem
 +
 +
 +
PATENCY OF PERICARDIUM 47
 +
 +
brane continued in the horizontal direction, after leaving the sternum lined the ribs on the left side, covering the outer and posterior surfaces of the lung. On its inner surface it was reflected at the root of the lung, directly upon the pulmonary veins, thence to the right pleura. The left lung was described as being covered by a false membrane. The phrenic nerve pas.sed in front of the arch of the aorta to reach the septum between the two pleural sacs.
 +
 +
Bristowe ('54) reports a peculiar pericardium found in a male of twenty-eight. The heart was much enlarged. The heart and left lung were both contained in the left pleural cavity. The lower part of the lobe of the left lung was firmly attached to the anterior surface of the left side of the heart. A fold of membrane existed at the upper right side of the heart. It commenced at the pulmonary artery, passed over the aorta and vena cava, descending to the diaphragm. From this point it was lost in the root of the left lung. The fold consisted of fibrous tissue covered on either side by pleura. It was widest at the right auricle, where it was about 1 inch in depth. The fold was adherent to the heart in several places. The right phrenic nerve took its normal course, but the left passed down between the layers of the membrane, about one-half inch from its edge.
 +
 +
Powell ('68) reported a case in which a foramen connecting the pericardium and left pleura was found. The communication was situated above, and anterior to the root of the lung. It was small and oval in shape, being less than 1 inch in diameter. There were no adhesions, and the pleura in general was very thin. The left lung was found collapsed, the pleura containing a little fluid. The pericardium contained some air and a little fluid, the heart being compressed backward. To all appearances the o})ening was a congenital one.
 +
 +
Bjornstrom ('71) reported an anomaly which occurred in a female of forty. Only about one-third of the right side of the heart was covered with jiericardium. The remainder lay free in the left jileural sac in direct contact with the lung. A large foramen coimected the pericardial and left pleural sacs. Only that poitioii of the parii^tal pericardiuni was found which formed
 +
 +
 +
 +
48 U. A. McCAKliY
 +
 +
the wall hotwocii tlio rifjlit lun^ aiui hoart. The portion which was hack of the ri^iit auricio wont over into the visceral leaf and snrrounded tlie iieart on the right side; from here it passed on to tlie sternum, where it continued as the left pleura.
 +
 +
Prunrose (,'01) reported a patency of the i)ericardiuni occurring in a male of sixty. An opening existed between the pericardium and left pleura whicli was al)out 3 inches in diameter. The structures wliicii sliowed through tlie foi'amen were as follows: aorta, from its appearance to about 1 inch beyond origin of the left subclavian artery; pulmonary aorta, from its origin to its bifurcation; and the left auricular appendage. No indications of adhesions were present. A number of other anomalies were present which involved principally the genito-urinary system.
 +
 +
Keith (,'07) leported two cases of malformation of the pericardium. The first case of deficiency of the pericardium was found in an anence])halic full-term child. The opening, just anterior to the root of the left lung, was about 1 inch in diameter, and through which the left auricular appendage protruded. It had a round smooth margin. The phrenic ner\-e descended in the anterior free edge of the foramen.
 +
 +
The other case occurred in a foetus, the subject of numerous malformations. It presented a large deficiency on the left side. Upon remo\al of the sternum a strong fi))rous membrane was found behind it, upon which the phrenic nerve descended. This proved to l)e the j)ericardium. wliich descended and divided, the left margin passing in front of and below the left lung. Turning back at the lower margin, it api)eared as a fold extending up from the diaphragm. The greater part of the left pleural cavity being occupied by the liver, stomach and spleen.
 +
 +
The five cases to which reference has been made by other writers included one in which the heart was found h^ing free in the left pleural cavity, dcxoid of pericardium, that was reported in the Philosophical Transactions, London, 1740, and referred to by Jiailli(! in 1788. The same author refers to shnilar cases recorded by C'olumbus, Bartliolinus, and Littre, in which no details were mentioned. Peacock ('68) , in his work on the malformations of the human heart, refers to a case by M. Breschet ('26), in whicli the
 +
 +
 +
 +
PATENCY OF PERICARDIUM 49
 +
 +
absence of the pericardium occurred in a male of twenty-eight. Another case was reported by Hud in 1848. He also mentioned a specimen in the St. Thomas Museum, London. Peacock mentions a case found by himself in a man of seventy-five. He, however, did not describe it. There were three cases of malformation of the pericardium for which I have not been able to get the original articles, the titles of which are given in the references at the end of this paper.
 +
 +
Not including my own case, we may summarize the hterature of the malformation of the pericardium as follows : (a) two cases of supposed complete absence of the pericardium ; (b) seven cases of incomplete pericardium, which is represented by a small fold of tissue along the posterior wall; (c) three other cases of incomplete pericardium, in which existed a distinct opening between the left pleural sac and pericardial sac, varying in diameter from less than one-half inch to over 3 inches; in six cases the condition was not definitely described, the only mention made being of both heart and lung lying in the left pleural sac.
 +
 +
The only attempt by any of the writers to explain these cases on an embryological basis, was made by Keith. This writer attributed the patency to, an extension of the lung bud growing into and expanding the communication between the pericardium and pleura."
 +
 +
Peacock thought that the pericardium developed as a continuation of the fibrous sheath of the vessels of the heart, which spread out over the heart, and formed its sac. He considered the foramen as due to a failure of fusion of the membrane on the left side.
 +
 +
None of the previous writers directed their attentions to the related serous cavities, and no examination was reported, of the peritoneum and its appendages.
 +
 +
Before entering into the embryological significance of the malformations it may be well to give a brief review of our present knowledge of the development of the coelom. It was early shown by His that the body cavity in the early embryo is divided into the pericardial and trunk cavities. The comnmnication between these spaces is calhnl the parietal recess. The parietal
 +
 +
THE ANATOMICAL HECOnO, VOL. 8, NO. 2
 +
 +
 +
 +
50 R. A. McGARRY
 +
 +
portion originally contains the heart, and is destined to become the pericardial coeloni. A portion of the parietal recess forms the pleural cavity; it surrounds the lung bud throughout its development, and becomes the pleural coelom. In the remainder of the parietal recess the liver and stomach develop, but are later evaginated and become part of the abdominal coelom.
 +
 +
For our knowledge of the details of the separation of these cavities we are indebted to Mall. He showed that at about the end of the fifth week, while the body is yet kinked upon itself, the line of separation appears between the pericardial and pleural coeloms. This is due to a constriction of the walls along the ductus Cuvieri, which lies on a ridge of tissue encircling the canal of communication between the two cavities. This forms the beginning of the pulmonary ridge. This ridge appears as a small elevation, in the sagittal plane of the body, running from the lobe of the liver, along the dorsal wall of the ductus Cuvieri, to the dorsal attachment of the mesocardium. Lying in the sagittal plane of the body opposite the fourth and fifth cervical nerves it receives into its substance the phrenic nerve, which passes posterior to the ductus Cuvieri.
 +
 +
Soon the lung bud, which has heretofore hung free in the pleural coelom beneath the pulmonary ridge, grows outward against it and causes it to bulge. With the rotation of the liver towards the head the ridge is divided into two parts: (1) the cephalic which has included in it the phrenic nerve, and ductus Cuvieri, and which later becomes the plcuro-pericardial membrane; (2) the caudal portion, which remains at the caudal end of the septum transversum and liver, on the one hand, and the body wall on the other. It later forms the pleuro-peritoneal membrane.
 +
 +
The pulmonary ridges from their beginning to their separation into the plcuro-pericardial anil pleuro-peritoneal membranes appear as two ear-like projections from the septum transversum, oxtondifig alang the ductus Cuvieri. They appear in the sagittal plane of the body at right angles to the plane of the septum transversum. The growth of the pleuro-pericardial membrane in the direction of the head and the growth of the pleuro-peritoneal membrane caudally results in a widening of the dorsal projection
 +
 +
 +
 +
PATEN'CY OF PERICARDIUM 51
 +
 +
of the septum transversum. The lung burrows into this space throwing the pleuro-cardial membrane and phrenic nerve to its medial side. Up to this time there has been a mere slit where the pleuro-pericardial membrane comes in contact with the root of the lung. At the time of closure the small ridge or pleuro-pericardial membrane, is very insignificant, its extension being due to a rapid growth of the lung.
 +
 +
Brachet showed that the canal connecting the ca\'ities was only constricted by the ductus Cu\neri, its complete closure being due to an active growth of the anlage of the pleuro-pericardial membrane, which takes place at about this time. This completely separates the pericardial from the pleural caWties. Immediately after this the rotation of the liver and setum transversum takes place which changes the relation of the pleuro-pericardial membrane from parallel to right angles to it. By this time the pleuro-peritoneal membrane stretches across the body to the tips of the embryonic ribs, thus completely closing ofif the abdominal ca\'it3'. This also alters the position of the phrenic nerve.
 +
 +
With the steps of the development of the coelom in mind, we are in position to understand something of the manner of occurrence of defects in the pericardium and other coelomic derivatives. In my own case it is evident that there was a general involvement of the coelom. We are not accustomed to thinking of pathologic processes in the embr\'o limited to the developing coelom. but it is evident that such must exist. It is well known that the neural plate passes through a period when it is particularly sensitive to injury while the adjacent tissues are unaffected, and thus we have a group of pathological conditions, as anencephaly, spina bifida, etc., that date from this period. In a similar way it is reasonable to suppose that the cells lining the coelomic space, may at some period be particularly sensitive, and abnormal conditions occurring at thl** time, would result in disturbances, either an over production or an under production, of the serous derivatives. Thus we might naturally expect congenital hernias, gastroptosis, enteroptosis, and other abnormal conditions of the peritoneum, occurring at the same time with abnonnal conditions of
 +
 +
 +
 +
.)2 H. A. mc(;auky
 +
 +
the pericardium and jilcura. which coiuiition is well illustrated * in our case. The occurrence of a patent pericardium is one aspect of a general condition. It is possible also in our case that in the process of subdivision of the general coelomic spaces an undue proportion was constricted off by the lower limb of the pulmonary ridge, resulting in an over production of peritoneum, and an under production of thoracic serous membrane.
 +
 +
Those cases in which a foramen occurred, including the one found in our laboratory, between the pleura and pericardium seem to be explained by supposing that in the early development of the embrj'o, some slight injury occurred to the general coelom, which resulted in a lack of development of the pleuro-pericardial membrane. The membrane, which was to form the wall between the heart and lung failed to fuse with the root of the lung bud, and the pleuro-pericardial foramen resulted. This view is also supported by the position of the phrenic nerve.
 +
 +
The explanation given by Keith ('06), according to whom the foran>en was due to the presence of the lung which kept the communication between the pleural and pericardial cavities open, could hardly be the cause, as the lung bud forms subsequent to the development of the fold, which separates the cavities.
 +
 +
The case in which only a small portion of the supposed pericardium was found, existing as a ridge or fold at the base of the heart, seem to be readily explained. It at once suggests itself that the condition, with which we were dealing, was due to a less complete separation of the pleuro-pericardial membrane than occurred in those cases presenting a foramen. Thus the heart and lung would lie in a sac, which if it had separated, would have ff)rmed the pericardium and pleura, the fold or ridge of membrane existing at the base of the heart being the embrj'onic remains of the upper portion of the pulmonary ridge. The phrenic nerve in these cases was found under the sternum, probably never having been included in the substance of the pulmonary ridge.
 +
 +
Those cases in which a total absence of the pericardium was supposed to have occurred are explained as follows: The upj)er limb of the i)ulmonary ridge totally failed to develop. Tlie con
 +
 +
 +
PATENCY OF PERICARDIUM 53
 +
 +
dition there is apparent. The heart and lung lie in one sac, which if correctly named would be pericardial, inasmuch as the left pleural sac had never become separated off. These cases must not be confused or connected with the cases described by Todd ('13) and others regarding the absence of the pleural sac in certain mammals. In those cases the pleural sacs were originally present, but in later life became obliterated.
 +
 +
The second case reported by Keith ('07) forms an interesting variation. Here the lung, heart and liver were found all occupying the same cavity. This condition must be explained by the involvement of both the pleuro-pericardial and pleuro-peritoneal membranes. As has been noted, the pericardial defects alwaj's are found on the left side. This apparently is associated with the asymmetry of the liver, and its rotation during the course of development, which would put a greater tension on the left pulmonary ridge, and predispose this to the defect.
 +
 +
Before concluding I wish to express my obligations to Professor Streeter at whose suggestion this report was undertaken.
 +
 +
CONCLUSIONS
 +
 +
1. Pericardial defects result from a disturbance occurring between the fifth and seventh weeks of embryonic life.
 +
 +
2. These defects always occur on the left side.
 +
 +
3. Other coelomic disturbances of the same period occur in the form of peritoneal abnormalities, such as congenital hernia, gastroptosis and other abnormal arrangements, and distributions of the peritoneum.
 +
 +
4. Congenital pericardial defects have not yet been clinically diagnosed and apparently produced no functional disturbance.
 +
 +
 +
 +
54 R. A. McGARRY
 +
 +
LITERATlllE CITED
 +
 +
liAiLLiE, M. 1793 Oil want of a i>cricar(lium in the human body. Tr. Soc. Imp Med. Chinirg. Knowledge, London, p. 1()12.
 +
 +
Baly, \V. 1850 Absence of pericardial sac, the heart lying in the cavity of the left pleura. Tr. Path. Soc. London, vol. 3, p. 60,
 +
 +
Br.\chet, a. 1897 Recherches sur I'eletion de la portion cephalique des cavitea pleuralcs ct sur Ic development dc la membrane pleuropericardique. Jour, de I'anat. et physiol., vol. 33.
 +
 +
Bjornstrom, F. 1871 Defect in pericardium. Upsala Larkereforenings Forhandlinger, p. 261.
 +
 +
Bristowe, J. S. 1854 Malformations of the pericardium. Tr. Path. Soc, Loudon, p. 109,
 +
 +
Chiari, H. 1880 Ueber einen Fall von fast vollstandigem defekte des Pericardium parietale. Wien. Med. Wachnschr, Bd. 30, p. 372.
 +
 +
Curling, T. B. 1839 Want of a pericardium. Tr. Med. Chir. Society, London, vol. 22, p. 222.
 +
 +
Gay, M. 1899 Di una speciale anomalia del pericardio. Lavori d. Cong. d. med. int., Roma, vol. 8, p. 437.
 +
 +
Hewsox, a. 1896 Absence of fibrous pericardium on left side. Proc. Assoc. Amer. Anat., Washington.
 +
 +
Keith, A. 1906 Partial deficiency of the pericardium. Jour. Anat. Physiol., vol. 6.
 +
 +
-Mall, F. P. 1901 On the development of the human diaphragm. Johns Hopkins Hosp. Bull., vol. 12.
 +
 +
1910 Die Entwicklung des Coeloms und des Zwerchfells. Handbuch d. Entwick. d. Menschen. Kcibel u. Mall., Leipzig, vol. 1, pp. 527-552.
 +
 +
Peacock 1868 Malformations of the human heart. London.
 +
 +
Powell, D. R. 1868 Deficiency in the pericardium. Tr. Patii. Soc, London, vol. 20, p. 99.
 +
 +
Primrose, E. J. 1901 Patency of -the pericardium, (ilasgow Med. Jour., vol. 56, p. 184.
 +
 +
Todd, T. W. 1913 Notes on the respiratory system of the elephant. Anat. Anz., Bd. 44.
 +
 +
 +
 +
THE PERCENTAGE OF WATER IN THE BRAIN OF THE SMOOTH DOG-FISH, MUSTELUS CANIS
 +
 +
GEORGE G. SCOTT
 +
 +
Department of Natural History, College of City of New York
 +
 +
Donaldson^ has shown that in the albino rat between birth and maturity the percentage of water in the brain diminishes from 87.8 per cent to 77.5 per cent. He calls attention to the fact generally known that the human brain at birth contains a greater percentage of water than at maturity and from the investigations of Weisbach and Koch he obtains as the percentage of water in the human encephalon the following: birth, 88.3 per cent; two years, 81.1 per cent; five years, 79.2 per cent; twentyfive years (mature), 77.0 per cent. Donaldson further says:
 +
 +
We reach the interesting conclusion that probably in all mammals we shall find approximate^ the same range in the percentage of water between birth and maturity and that the loss of water in them occurs in the same manner but that the time required for each successive step is determined by the intensity of the growth process characteristic for each species.
 +
 +
The present author in 1910 had obtained the percentage of water in the brain of a few smooth dog-fish but at the suggestion of Dr. Donaldson, has collected further data on this subject in order to see whether the above law holds true for the elasmobranchs, which occupy a place at the base of the vertebrate ladder.
 +
 +
The author collected the following data at the Biological Laboratory of the United States Bureau of Fisheries at Woods Hole, Massachusetts. He is greatly indebted to the Bureau of Fisheries for the material and facilities furnished him.
 +
 +
The data are not as complete as they might be but since the\' illustrate a difference between the elasmobranchs and the mam
 +
 +
Donaldson, H. II., Jour. Corap. Neur., vol. 20. no. 2, p. Ill), April, 11)10.
 +
55
 +
 +
 +
 +
56
 +
 +
 +
 +
GEORGE G. SCOTT
 +
 +
 +
 +
mals, this paper is presented at this time. The percentage of water in tlie brain of ninety-seven smooth dog-fi&li-, ]\Iustelus canis, was obtained. These were obtained from the laboratory trap in Buzzard's Bay and the brain tissue was removed on the same da}- that the fishes were brought into the laboratory. In
 +
 +
TABLE 1
 +
 +
Showing the percentage of water in the brain of the dog-fish, Mustelus canis, of increasing body length. Sex, male.
 +
 +
 +
 +
NUIIBSR
 +
 +
 +
LENGTH
 +
 +
 +
BBAIN WKIGBT
 +
 +
 +
WATBB IN BRAIN
 +
 +
 +
NX7MBBB
 +
 +
 +
LENGTH
 +
 +
 +
BRAIN WEIGHT
 +
 +
 +
WATER IN BRAIN
 +
 +
 +
 +
 +
cm.
 +
 +
 +
grams
 +
 +
 +
per cent
 +
 +
 +
 +
 +
cm.
 +
 +
 +
grams
 +
 +
 +
per cent
 +
 +
 +
1
 +
 +
 +
39
 +
 +
 +
1.39
 +
 +
 +
77
 +
 +
 +
27
 +
 +
 +
70
 +
 +
 +
2.60
 +
 +
 +
79
 +
 +
 +
2
 +
 +
 +
42
 +
 +
 +
1.42
 +
 +
 +
77
 +
 +
 +
28
 +
 +
 +
70
 +
 +
 +
2.61
 +
 +
 +
79
 +
 +
 +
3
 +
 +
 +
42
 +
 +
 +
1.48
 +
 +
 +
77
 +
 +
 +
29
 +
 +
 +
72
 +
 +
 +
3.17
 +
 +
 +
81
 +
 +
 +
4
 +
 +
 +
44
 +
 +
 +
1.41
 +
 +
 +
77
 +
 +
 +
30
 +
 +
 +
74
 +
 +
 +
3.36
 +
 +
 +
78
 +
 +
 +
5
 +
 +
 +
45.
 +
 +
 +
1.51
 +
 +
 +
79
 +
 +
 +
31
 +
 +
 +
75
 +
 +
 +
3.18
 +
 +
 +
78
 +
 +
 +
6
 +
 +
 +
52
 +
 +
 +
1.98
 +
 +
 +
79
 +
 +
 +
32
 +
 +
 +
75
 +
 +
 +
3.20
 +
 +
 +
78
 +
 +
 +
7
 +
 +
 +
55
 +
 +
 +
2.08
 +
 +
 +
79
 +
 +
 +
33
 +
 +
 +
75
 +
 +
 +
3.20
 +
 +
 +
78
 +
 +
 +
8
 +
 +
 +
56
 +
 +
 +
2.24
 +
 +
 +
74
 +
 +
 +
34
 +
 +
 +
76
 +
 +
 +
3.14
 +
 +
 +
78
 +
 +
 +
9
 +
 +
 +
57
 +
 +
 +
2.26
 +
 +
 +
80
 +
 +
 +
35
 +
 +
 +
77
 +
 +
 +
3. 52
 +
 +
 +
79
 +
 +
 +
10
 +
 +
 +
60
 +
 +
 +
2.24
 +
 +
 +
80
 +
 +
 +
36
 +
 +
 +
77
 +
 +
 +
3.55
 +
 +
 +
80
 +
 +
 +
11
 +
 +
 +
60
 +
 +
 +
2.33
 +
 +
 +
77
 +
 +
 +
37
 +
 +
 +
77
 +
 +
 +
5.77
 +
 +
 +
85
 +
 +
 +
12
 +
 +
 +
61
 +
 +
 +
2.35
 +
 +
 +
77
 +
 +
 +
38
 +
 +
 +
79
 +
 +
 +
3.44
 +
 +
 +
74
 +
 +
 +
13
 +
 +
 +
64
 +
 +
 +
2.50
 +
 +
 +
82
 +
 +
 +
39
 +
 +
 +
79
 +
 +
 +
3.41
 +
 +
 +
78
 +
 +
 +
14
 +
 +
 +
65
 +
 +
 +
2.13
 +
 +
 +
74
 +
 +
 +
40
 +
 +
 +
80
 +
 +
 +
3.45
 +
 +
 +
75
 +
 +
 +
16
 +
 +
 +
65
 +
 +
 +
2.67
 +
 +
 +
79
 +
 +
 +
41
 +
 +
 +
80
 +
 +
 +
3.33
 +
 +
 +
80
 +
 +
 +
16
 +
 +
 +
65
 +
 +
 +
2.80
 +
 +
 +
79
 +
 +
 +
42
 +
 +
 +
81
 +
 +
 +
3.78
 +
 +
 +
80
 +
 +
 +
17
 +
 +
 +
65
 +
 +
 +
2.61
 +
 +
 +
79
 +
 +
 +
43
 +
 +
 +
81
 +
 +
 +
4.16
 +
 +
 +
81
 +
 +
 +
18
 +
 +
 +
66
 +
 +
 +
2.59
 +
 +
 +
80
 +
 +
 +
44
 +
 +
 +
82
 +
 +
 +
3.38
 +
 +
 +
79
 +
 +
 +
19
 +
 +
 +
67
 +
 +
 +
2.79
 +
 +
 +
81
 +
 +
 +
45
 +
 +
 +
82
 +
 +
 +
3.25
 +
 +
 +
74
 +
 +
 +
20
 +
 +
 +
67
 +
 +
 +
2.91
 +
 +
 +
79
 +
 +
 +
46
 +
 +
 +
82
 +
 +
 +
3.65
 +
 +
 +
78
 +
 +
 +
21
 +
 +
 +
67
 +
 +
 +
3.35
 +
 +
 +
81
 +
 +
 +
47
 +
 +
 +
82
 +
 +
 +
3.65
 +
 +
 +
78
 +
 +
 +
22
 +
 +
 +
69
 +
 +
 +
2.94
 +
 +
 +
80
 +
 +
 +
48
 +
 +
 +
83
 +
 +
 +
3.47
 +
 +
 +
80
 +
 +
 +
23
 +
 +
 +
69
 +
 +
 +
3.17
 +
 +
 +
79
 +
 +
 +
49
 +
 +
 +
85
 +
 +
 +
3.60
 +
 +
 +
80
 +
 +
 +
24
 +
 +
 +
70
 +
 +
 +
2.77
 +
 +
 +
75
 +
 +
 +
50
 +
 +
 +
90
 +
 +
 +
4.06
 +
 +
 +
81
 +
 +
 +
25
 +
 +
 +
70
 +
 +
 +
3.05
 +
 +
 +
77
 +
 +
 +
51
 +
 +
 +
91
 +
 +
 +
3.89
 +
 +
 +
79
 +
 +
 +
26
 +
 +
 +
70
 +
 +
 +
2.94
 +
 +
 +
77
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
eaoli ease the following technique was employed. The sex, length and weight of each specimen was first recorded, then the brain case was opened. The olfactory tracts were severed close to the forebrain, a transverse cut made at the posterior margin of the fourth ventricle, the cranial nerves severed and the brain
 +
 +
 +
 +
WATER IN BRAIN OF DOG-FISH
 +
 +
 +
 +
57
 +
 +
 +
 +
carefully placed on clean filter paper. A longitudinal cut was then made through the brain and each half very carefully turned over on the filter paper until no further cerebral fluid was absorbed. The brain tissue was then placed in a watch cry.-tal and its weight determined. It was next placed in a desiccator over sulphuric acid. The desiccator was made a partial vacuum.
 +
 +
 +
 +
TABLE 2
 +
 +
 +
 +
Showing the percentage of water in the brain of the smooth dog-fish, Mustelus canis, of increasing body length. Sex, female.
 +
 +
 +
 +
1
 +
 +
2
 +
 +
3
 +
 +
4
 +
 +
5
 +
 +
6
 +
 +
7
 +
 +
8
 +
 +
9
 +
 +
10
 +
 +
11
 +
 +
12
 +
 +
13
 +
 +
14
 +
 +
15
 +
 +
16
 +
 +
17
 +
 +
18
 +
 +
19
 +
 +
20
 +
 +
21
 +
 +
22
 +
 +
23
 +
 +
 +
 +
BRAIN WEIGHT
 +
 +
 +
 +
42 44 45 56 60 62 62 62 62 62 62 62 66 66 67 69 69 70 71 72 74 74 75
 +
 +
 +
 +
grama
 +
 +
1.48 1.33 1.47 2.20 2.26 2.40 2.48 2.42 2.24 2.53 2.73 2.92 2.65 3.20 2.73 2.99 2.55 3.33 2.92 3.25 3.22 3.31 3.49
 +
 +
 +
 +
WATER IN BRAIN
 +
 +
 +
 +
per cent
 +
 +
78 78 78 77 79 78 80 80 77 78 79 80 76 81 79 79 79 76
 +
 +
 +
 +
76 SI
 +
 +
78
 +
 +
 +
 +
BRAIN WEIGHT
 +
 +
 +
 +
 +
 +
cm.
 +
 +
 +
grams
 +
 +
 +
24
 +
 +
 +
75
 +
 +
 +
3.27
 +
 +
 +
25
 +
 +
 +
75
 +
 +
 +
3.35
 +
 +
 +
26
 +
 +
 +
75
 +
 +
 +
3 .02
 +
 +
 +
27
 +
 +
 +
75
 +
 +
 +
3.&3
 +
 +
 +
28
 +
 +
 +
77
 +
 +
 +
3.48
 +
 +
 +
29
 +
 +
 +
77
 +
 +
 +
3.88
 +
 +
 +
30
 +
 +
 +
79
 +
 +
 +
3.58
 +
 +
 +
31
 +
 +
 +
79
 +
 +
 +
3.51
 +
 +
 +
32
 +
 +
 +
80
 +
 +
 +
3.24
 +
 +
 +
33
 +
 +
 +
81
 +
 +
 +
3.29
 +
 +
 +
34
 +
 +
 +
81
 +
 +
 +
3.27
 +
 +
 +
35
 +
 +
 +
82
 +
 +
 +
2.85
 +
 +
 +
36
 +
 +
 +
82
 +
 +
 +
3. .56
 +
 +
 +
37
 +
 +
 +
82
 +
 +
 +
3.50
 +
 +
 +
38
 +
 +
 +
89
 +
 +
 +
3.82
 +
 +
 +
39
 +
 +
 +
90
 +
 +
 +
4.22
 +
 +
 +
40
 +
 +
 +
90
 +
 +
 +
3.74
 +
 +
 +
41
 +
 +
 +
92
 +
 +
 +
4. -26
 +
 +
 +
42
 +
 +
 +
96
 +
 +
 +
4.11
 +
 +
 +
43
 +
 +
 +
97
 +
 +
 +
4. 28
 +
 +
 +
44
 +
 +
 +
99
 +
 +
 +
4. .58
 +
 +
 +
4.5
 +
 +
 +
104
 +
 +
 +
4.4.5
 +
 +
 +
46
 +
 +
 +
105
 +
 +
 +
4.49
 +
 +
 +
 +
WATER IK BR.UN
 +
 +
per cent 76 79 83 79 82 84 75 80 75 81 84 80 79
 +
 +
 +
 +
SO 80
 +
 +
78
 +
 +
79 7T 76
 +
 +
78
 +
 +
 +
 +
The brain tissue was then dried to a constant weight and the percentage of water computed. Since in this problem the percentage of water only was desired, the same great care to get e\'ery trace of brain tissue was not as necessary as in the ease where the exact weight of the brain at various ages was to be investigated.
 +
 +
 +
 +
58
 +
 +
 +
 +
GEORGE G. SCOTT
 +
 +
 +
 +
The chanpe in tlio wein;lit of the brain of INIustelus eanis and of increasing body weight has been carefully worked out by Kellicott ('08) whose paper will be referred to later. Tables 1 to 5 show the results obtained. Tables 1 and 2 show the percentage of water in the brain of smooth dog-fishes of increasing body
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
TABLE 3
 +
 +
 +
 +
 +
 +
 +
 +
 +
Showing the percentage of water
 +
 +
 +
in the brain of the smooth dog-fish, Mustelus canis, oj
 +
 +
 +
 +
 +
increasing body weight. Sex,
 +
 +
 +
male.
 +
 +
 +
 +
 +
 +
 +
nvuamK wbiobt
 +
 +
 +
BHAIN WXIOBT
 +
 +
 +
WATEB IN BRAIN
 +
 +
 +
NUUBBB
 +
 +
 +
WBIOBT
 +
 +
 +
BBAIN WEIGHT
 +
 +
 +
WATEB IN B|tAIN
 +
 +
 +
granu
 +
 +
 +
gramt
 +
 +
 +
,per cent
 +
 +
 +
 +
 +
grama
 +
 +
 +
grit'n*
 +
 +
 +
per cent
 +
 +
 +
1 218
 +
 +
 +
1.39
 +
 +
 +
77
 +
 +
 +
27
 +
 +
 +
1057
 +
 +
 +
3.05
 +
 +
 +
77
 +
 +
 +
2 264
 +
 +
 +
1.48
 +
 +
 +
77
 +
 +
 +
28
 +
 +
 +
1057
 +
 +
 +
3.55
 +
 +
 +
80
 +
 +
 +
3 280
 +
 +
 +
1.42
 +
 +
 +
77
 +
 +
 +
29
 +
 +
 +
1057
 +
 +
 +
2.80
 +
 +
 +
79
 +
 +
 +
4
 +
 +
 +
311
 +
 +
 +
1.51
 +
 +
 +
79
 +
 +
 +
30
 +
 +
 +
1088
 +
 +
 +
5.77
 +
 +
 +
85
 +
 +
 +
5
 +
 +
 +
326
 +
 +
 +
1.41
 +
 +
 +
78
 +
 +
 +
31
 +
 +
 +
1120
 +
 +
 +
2.79
 +
 +
 +
81
 +
 +
 +
6
 +
 +
 +
420
 +
 +
 +
1.98
 +
 +
 +
79
 +
 +
 +
32
 +
 +
 +
1244
 +
 +
 +
3.20
 +
 +
 +
78
 +
 +
 +
7
 +
 +
 +
451
 +
 +
 +
2.08
 +
 +
 +
79
 +
 +
 +
33
 +
 +
 +
1306
 +
 +
 +
3.18
 +
 +
 +
78
 +
 +
 +
8
 +
 +
 +
560
 +
 +
 +
2.26
 +
 +
 +
80
 +
 +
 +
34
 +
 +
 +
1337
 +
 +
 +
3.20
 +
 +
 +
78
 +
 +
 +
9 560
 +
 +
 +
2.61
 +
 +
 +
79
 +
 +
 +
35
 +
 +
 +
1368
 +
 +
 +
3.14
 +
 +
 +
78
 +
 +
 +
10 575
 +
 +
 +
2.24
 +
 +
 +
74
 +
 +
 +
36
 +
 +
 +
1399
 +
 +
 +
3.36
 +
 +
 +
78
 +
 +
 +
11 ' 591
 +
 +
 +
2.33
 +
 +
 +
77
 +
 +
 +
37
 +
 +
 +
1399
 +
 +
 +
4.16
 +
 +
 +
81
 +
 +
 +
12 653
 +
 +
 +
2.35
 +
 +
 +
77
 +
 +
 +
38
 +
 +
 +
1462
 +
 +
 +
3.44
 +
 +
 +
74
 +
 +
 +
13 1 669
 +
 +
 +
2.24
 +
 +
 +
80
 +
 +
 +
39
 +
 +
 +
1462
 +
 +
 +
3.38
 +
 +
 +
.79
 +
 +
 +
14 684
 +
 +
 +
2.91
 +
 +
 +
79
 +
 +
 +
40
 +
 +
 +
1462
 +
 +
 +
3.33
 +
 +
 +
80
 +
 +
 +
15 715
 +
 +
 +
2.50
 +
 +
 +
82
 +
 +
 +
41
 +
 +
 +
1555
 +
 +
 +
3.41
 +
 +
 +
78
 +
 +
 +
16 746
 +
 +
 +
2.13
 +
 +
 +
74
 +
 +
 +
42
 +
 +
 +
1586
 +
 +
 +
3.78
 +
 +
 +
80
 +
 +
 +
17 746
 +
 +
 +
2.67
 +
 +
 +
79
 +
 +
 +
43
 +
 +
 +
1648
 +
 +
 +
2.60
 +
 +
 +
80
 +
 +
 +
18
 +
 +
 +
746
 +
 +
 +
3.35
 +
 +
 +
81
 +
 +
 +
44
 +
 +
 +
1679
 +
 +
 +
3.25
 +
 +
 +
74
 +
 +
 +
19
 +
 +
 +
775
 +
 +
 +
3.71
 +
 +
 +
81 45
 +
 +
 +
1679
 +
 +
 +
3.52
 +
 +
 +
79
 +
 +
 +
20 840
 +
 +
 +
3.06
 +
 +
 +
80 I 46
 +
 +
 +
1773
 +
 +
 +
3.45
 +
 +
 +
76
 +
 +
 +
21 ' 933
 +
 +
 +
2.59
 +
 +
 +
80
 +
 +
 +
47
 +
 +
 +
1773
 +
 +
 +
3.47
 +
 +
 +
80
 +
 +
 +
22 ' 933
 +
 +
 +
3.17
 +
 +
 +
79
 +
 +
 +
48
 +
 +
 +
1990
 +
 +
 +
4.06
 +
 +
 +
81
 +
 +
 +
23 995
 +
 +
 +
2.77
 +
 +
 +
75
 +
 +
 +
49
 +
 +
 +
2021
 +
 +
 +
3.66
 +
 +
 +
78
 +
 +
 +
24 995
 +
 +
 +
2.94
 +
 +
 +
77
 +
 +
 +
50
 +
 +
 +
2053
 +
 +
 +
3.66
 +
 +
 +
77
 +
 +
 +
25 ! 995
 +
 +
 +
2.60
 +
 +
 +
79
 +
 +
 +
51
 +
 +
 +
2379
 +
 +
 +
3.89
 +
 +
 +
79
 +
 +
 +
26 1 1042
 +
 +
1
 +
 +
 +
2.94
 +
 +
 +
80
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
length, males and females respectively. Tables 3 and 4 show the percentage of water in the brain of fishes arranged according to increasing body weight instead of length.
 +
 +
Donaldson found that at different body weights the male brain contains a greater percentage of water than the female
 +
 +
 +
 +
WATER IN BRAIN OF DOG-FISH
 +
 +
 +
 +
59
 +
 +
 +
 +
brain in the case of the albino rat. Xot only is this sex difference true of the percentage of water, but as is commonly known, the male brain actually weighs more than the female brain in relation to the weight of the body. Kellicott,^ on the other hand, found that in the smooth dog-fish there was no sex difference as to total brain weight. He says, It is not possible to distinguish
 +
 +
 +
 +
T.IBLE 4
 +
 +
 +
 +
Shomng the percentage of water in the brain of the dog-fish, Mustelits canis, of increasing body weight. Sex, Female.
 +
 +
 +
 +
NUMBER
 +
 +
 +
WEIGHT
 +
 +
 +
BBAIN WEIGHT
 +
 +
 +
WATER
 +
 +
 +
NUMBER
 +
 +
 +
WEIGHT
 +
 +
 +
BBAIN WEIGHT
 +
 +
 +
WATER
 +
 +
 +
 +
 +
grams
 +
 +
 +
grams
 +
 +
 +
per cent
 +
 +
 +
 +
 +
grams
 +
 +
 +
grams
 +
 +
 +
per cent
 +
 +
 +
1
 +
 +
 +
280
 +
 +
 +
1.48
 +
 +
 +
78
 +
 +
 +
24
 +
 +
 +
1151
 +
 +
 +
3.48
 +
 +
 +
82
 +
 +
 +
2
 +
 +
 +
295
 +
 +
 +
1.33
 +
 +
 +
78
 +
 +
 +
25
 +
 +
 +
1182
 +
 +
 +
3.31
 +
 +
 +
79
 +
 +
 +
3
 +
 +
 +
342
 +
 +
 +
1.47
 +
 +
 +
78
 +
 +
 +
26
 +
 +
 +
1213
 +
 +
 +
2.73
 +
 +
 +
79
 +
 +
 +
4
 +
 +
 +
529
 +
 +
 +
2.20
 +
 +
 +
77
 +
 +
 +
27
 +
 +
 +
1244
 +
 +
 +
3.49
 +
 +
 +
78
 +
 +
 +
5
 +
 +
 +
560
 +
 +
 +
2.92
 +
 +
 +
80
 +
 +
 +
28
 +
 +
 +
1368
 +
 +
 +
3-27
 +
 +
 +
76
 +
 +
 +
6
 +
 +
 +
622
 +
 +
 +
2.73
 +
 +
 +
79
 +
 +
 +
29
 +
 +
 +
1368
 +
 +
 +
3.50
 +
 +
 +
78
 +
 +
 +
7
 +
 +
 +
637
 +
 +
 +
2.26
 +
 +
 +
79
 +
 +
 +
30
 +
 +
 +
1368
 +
 +
 +
3.51
 +
 +
 +
80
 +
 +
 +
8
 +
 +
 +
653
 +
 +
 +
2.42
 +
 +
 +
80
 +
 +
 +
31
 +
 +
 +
1493
 +
 +
 +
3.22
 +
 +
 +
76
 +
 +
 +
9
 +
 +
 +
684
 +
 +
 +
2.40
 +
 +
 +
78
 +
 +
 +
32
 +
 +
 +
1550
 +
 +
 +
3.58
 +
 +
 +
75
 +
 +
 +
10
 +
 +
 +
715
 +
 +
 +
3.20
 +
 +
 +
81
 +
 +
 +
33
 +
 +
 +
1617
 +
 +
 +
3.88
 +
 +
 +
84
 +
 +
 +
11
 +
 +
 +
746
 +
 +
 +
2. "24
 +
 +
 +
77
 +
 +
 +
34
 +
 +
 +
1679
 +
 +
 +
3.29
 +
 +
 +
81
 +
 +
 +
12
 +
 +
 +
746
 +
 +
 +
2.55
 +
 +
 +
80
 +
 +
 +
35
 +
 +
 +
1679
 +
 +
 +
2.85
 +
 +
 +
80
 +
 +
 +
13
 +
 +
 +
762
 +
 +
 +
2.48
 +
 +
 +
80
 +
 +
 +
36
 +
 +
 +
1835
 +
 +
 +
3.24
 +
 +
 +
75
 +
 +
 +
14
 +
 +
 +
809
 +
 +
 +
2.53
 +
 +
 +
78
 +
 +
 +
37
 +
 +
 +
1928
 +
 +
 +
3.56
 +
 +
 +
79
 +
 +
 +
15
 +
 +
 +
871
 +
 +
 +
2.65
 +
 +
 +
76
 +
 +
 +
38
 +
 +
 +
2364
 +
 +
 +
3.74
 +
 +
 +
80
 +
 +
 +
16
 +
 +
 +
871
 +
 +
 +
3.35
 +
 +
 +
79
 +
 +
 +
39
 +
 +
 +
2395
 +
 +
 +
3.82
 +
 +
 +
78
 +
 +
 +
17
 +
 +
 +
902
 +
 +
 +
3.33
 +
 +
 +
76
 +
 +
 +
40
 +
 +
 +
2.5S1
 +
 +
 +
4.22
 +
 +
 +
80
 +
 +
 +
18
 +
 +
 +
964
 +
 +
 +
2.99
 +
 +
 +
79
 +
 +
 +
41
 +
 +
 +
2846
 +
 +
 +
4.0.S
 +
 +
 +
77
 +
 +
 +
19
 +
 +
 +
1026
 +
 +
 +
2.92
 +
 +
 +
77 j
 +
 +
 +
42
 +
 +
 +
2892
 +
 +
 +
4.26
 +
 +
 +
78
 +
 +
 +
20
 +
 +
 +
1057
 +
 +
 +
'2.55
 +
 +
 +
79 1
 +
 +
 +
43
 +
 +
 +
3297
 +
 +
 +
4 11
 +
 +
 +
77
 +
 +
 +
21
 +
 +
 +
1057
 +
 +
 +
3.02
 +
 +
 +
83
 +
 +
 +
44
 +
 +
 +
3390
 +
 +
 +
4.45
 +
 +
 +
76
 +
 +
 +
22
 +
 +
 +
1057
 +
 +
 +
3.63
 +
 +
 +
79
 +
 +
 +
45
 +
 +
 +
3452
 +
 +
 +
4.28
 +
 +
 +
79
 +
 +
 +
23
 +
 +
 +
1151
 +
 +
 +
3.25
 +
 +
 +
77
 +
 +
 +
46
 +
 +
 +
4198
 +
 +
 +
4.49 1
 +
 +
1
 +
 +
 +
78
 +
 +
 +
 +
between the sexes with respect to brain weight." But what is the condition as regards the percentage of water? The average percentage of water in the brain of the forty-six females recorded here is 78.6 per cent, while that of the fifty-one males is 78.5 per cent. There is no sex difference in Mustelus canis as far as the
 +
 +
 +
Kellicott, W. E., .\m. Jour. Auat., vol. 8, no. 4, p. 207, December, 190S.
 +
 +
 +
60
 +
 +
 +
 +
GEORGE G. SCOTT
 +
 +
 +
 +
percentage content of water in the brain tissue goes. This is in agreement with the result obtained by Kellicott.
 +
 +
But what is the condition as regards the percentage of water in the brain at different ages?
 +
 +
Since there are no sex differences we can group together the males and females. Nothing is known of the exact age of the dog-fish but in general they increase in length and weight as they grow older. Kellicott, following the methods of Moenkhaus and Fulton with teleosts, has roughly estimated the ages as shown in table o.
 +
 +
TABLE 5
 +
 +
 +
 +
 +
Now since we are ascertaining the relation of the percentage of water in the brain to the age and since age is measured by length and weight, it is necessary to distribute the specimens concerning which we have records, according to the above schedule. Applying Kellicott's criterion we have table 6.
 +
 +
 +
 +
TABLE 6
 +
 +
 +
 +
(A) LENGTH MAI.E + FKMA.I.E
 +
 +
 +
 +
(B) WEIGHT HALE + FEMALE
 +
 +
 +
 +
1 year ^
 +
 +
2 years.
 +
 +
3 years.
 +
 +
4 years. .') years.
 +
 +
 +
 +
6 + 3 =
 +
 +
22 + 15 =
 +
 +
20 + 19 =
 +
 +
3 + 4 =
 +
 +
+ .5 =
 +
 +
 +
 +
9
 +
 +
37
 +
 +
39
 +
 +
7
 +
 +
5
 +
 +
 +
 +
Total, 97
 +
 +
 +
 +
7 + 4 = 11 22 + 18 = 40 18 + 14 = 32
 +
 +
4+3=7
 +
 +
0+7=7
 +
 +
Total, 97
 +
 +
 +
 +
We thus see that we have about the same distribution by length as by weight. It will be noted that the medium sized
 +
 +
 +
 +
WATER IN BRAIN OF DOG-FISH
 +
 +
 +
 +
61
 +
 +
 +
 +
are most numerous. The average percentages of water in the brains of the various groups just given are shown in table 7.
 +
 +
 +
 +
 +
 +
TABLE 7
 +
 +
 +
 +
 +
 +
 +
LENGTH
 +
 +
 +
WEIGHT
 +
 +
 +
AVEBAOE
 +
 +
 +
1 year
 +
 +
 +
per cent 77.8 78.5 78.9 79.4 77.4
 +
 +
 +
per cent per cent 77.9 77 8
 +
 +
 +
2 years
 +
 +
 +
78.7 78 6
 +
 +
 +
3 vears
 +
 +
 +
78.8 78 8
 +
 +
 +
4 years
 +
 +
 +
79.0 79 2
 +
 +
 +
5 years
 +
 +
 +
77.9 77 7
 +
 +
 +
 +
 +
 +
 +
,
 +
 +
 +
 +
As far as the above results go, there is no great decrease in the percentage of water with increasing age. This appears contrary to what Donaldson has found in the case of the albino rat. There he found a decrease of water of 10 per cent between birth and maturity.
 +
 +
I was able to secure seventeen specimens of young Squalus acanthias, the spiny dog-fish. These fish, as may be seen in table 8, are all under one year of age.
 +
 +
TABLE 8 Shotving sex, length, weight, brain weight and percentage of water in the brain of
 +
 +
young Squalus acanthias
 +
 +
 +
 +
 +
()2 GEORGE G. SCOTT
 +
 +
Moroover. eight females and two males from the standpoint of Icngtli would be regarded as reeentl}' born, according to the age criterion given above. But when we look at the weights we find these to be much greater than what is called for, namely, 75 grams. And yet it must be remembered tliat we are now discussing a species other than that for which Kellicott constructed his age table.
 +
 +
The average percentage of water in the brain of these seventeen Squalus acanthias is 81.4 per cent. On the whole this group is smaller in length and weight and so younger than the smooth dog-fishes, ^Mustelus canis. There is some slight indication then of a small decrease in the percentage of water in the brain between birth and the first year. This should not be emphasized, however, since we are dealing with two different species of fishes. Kellicott has shown that during the period of which we have data, the brain of Alustelus has increased from about 1.5 grams in weight to about 4.0 grams. During this time also it has decreased from about 0.6 per cent to 0.2 per cent of the total body weight. And yet we have seen that the percentage of water in the brain has remained quite constant. How can we account for this?
 +
 +
Mammals are characterized by determinate growth. As soon as maturity is reached the organs ha\'e reached their size limit. For example, the bones increase in length no further. On the other hand, fishes have indeterminate growth, that is, they grow as long as they live. As far as the brain is concerned, in the case of mammals growth is very rapid during the first few months. C)n the other hand, in fishes the brain grows steadily as long as the animal lives. As Kellicott says, After birth (smooth dogfish) the brain weight increases rapidly but at a slightly diminishing rate. Among the large individuals the diminution is much slower but is continued during life. Donaldson shows that the diminution in percentage of water is most rapid during the first thirty days of the albino rat's life, that is, when the central nervous system is growing most actively. Amphibians also possess indeterminate growtli. Tigerstedt,' reviewing the work of
 +
 +
» Tigcratedt, Textbook of hmnan physiology, 1906, p. .574.
 +
 +
 +
 +
WATER IN BRAEST OF DOG-FISH 63
 +
 +
Birge, says that he counted the motor cells in the spinal cord and nerve fibres in the anterior spinal roots in frogs of different sizes" and convinced himself that both either multiply from preexisting nerve elements or from other elements throughout life." He found "unmistakable relation between the weight of the animal and the number of cells and fibres. On the average for each 1 gram increase in weight, 52 motor fibres had been added."
 +
 +
The most significant difference between the rat and the dogfish, as far as our present discussion is concerned, is the postbirth condition of the two. The rat is born helpless, blind and cannot move about for some time. On the other hand, the dogfish is born, free — swimming, active and apparently mature with the exception of the reproductive system. Donaldson shows a correlation between the period of rapidly forming ner\'e cells and the percentage of water in the brain. Very possibly the dog-fish has a greater percentage of mature nerve cells at birth than the rat. We should expect a smaller percentage of water than in the case of the rat. This is borne out by the conditions in the young spiny dog-fishes discussed above. If the discoveries of Birge are correct and applj^ equally well to the dog-fishes, as we have considerable reason to believe, then the continued constancy in the percentage of water in the elasmobranch brain is due to the multiplication of new nerve cells and fibres keeping pace with the growth of the brain in other respects.
 +
 +
According to Donaldson's table, about seven-tenths of the percentage decrease in water takes place in the first one-eighth of the rat's life, between birth and maturity. There is a decrease of only three-tenths during the remaining se\'en-eighths of this maturing period, that is, it occurs during the first tliirty out of the total two hundred and forty days. The period of greatest loss in water is that during which profound neurological changes take place. May not these changes Uike place in the dog-fish in utero? The two cases make a strong argument for considering the change in water content of the central nervous system to be correlate<i with the growth intensity of tliis system. And that in the dog
 +
 +
 +
64 GEORGE G. SCOTT
 +
 +
fish the gre<atest change takes jDlace in-utero, while in the rat and man it is extra-utero. The collection of data from the brains of embryonic stages is necessary to decide this hypothesis.
 +
 +
 +
 +
A NOTE ON THE PRESENCE OF A MUSCULUS CLEIDO ATLANTICUS IN THE DOMESTIC CAT (FELIS
 +
 +
DOMESTICA)
 +
 +
RANDOLPH WEST
 +
 +
Laboratory of Comparative Anatomy, Princeton University
 +
 +
ONE FIGURE
 +
 +
So far as is known to the writer the musculus cleido-atlanticus (Gruber)^ has never been described as occurring in the cat, nor in any other mammal in which the clavicle is rudimentary. In order to avoid confusion, the nomenclature used by Reighard and Jennings- will be followed throughout this paper, and, in addition, the term cleido-atlanticus will be used to designate a muscle, hitherto not described in the cat, arising from the atlas and inserting into the clavicle.
 +
 +
Both the m. levator scapulae ventralis (levator claviculae) which arises from the atlas and inserts into the metacromion, and the m. cleido-atlanticus have been described as anomalies in man by Testut,^ under the common name of the m. cleido omo-transversaire and bj- Le Double,^ under the conunon name of the m. omo-trachelien. The m. cleido-atlanticus is found alone in the anthropoid apes, as well as in Nycticibus tardigradus and Cynocephalus anubis. while it is present in connection with the m. levator scapulae ventralis in the orang. Always one and occasionally both of these muscles occur regularly in all vertebrates except the fishes, birds and man. In some vertebrates these muscles may ha\e origins from the basi-occipit^il and from the posterior cervical vertebrae in addition to the atlantal origin. For a fuller account of the comparative anatomy
 +
 +
' Testut, Les anomalies musculaires chez rhoinme. 18S4, p. 97. ^ Reighard and Jennings, Anatomy of the cat. 1901.
 +
 +
' Le Double, Variations du sj'steme musonlaire de I'homme. 1S97. T 1, p. 235.
 +
 +
65
 +
 +
THE ANATOMICAL RECORD, VOL. S, NO. 2
 +
 +
 +
 +
66
 +
 +
 +
 +
RANDOLPH WEST
 +
 +
 +
 +
of the m. cleido-atlanticus the reader is referred to the articles of Testut and Le Double cited above.
 +
 +
The ni. cleito-atlanticus (4, fig. 1) was found hi one adult female cat and was present on both sides of the body. Out of some four hundred cats dissected in the laboratory this is the
 +
 +
 +
 +
 +
Fig. 1 1, M. clavotrapczius; 2, M. sternomastoideus; 5, M. cleidomastoideus; 4, M. cleido-atlanticus; 5, M. levator scapulae ventralis (levator claviculae); 6, M. occipitoscapularis (levator scapulae dorsalis); 7, M. splenius; 8. M. levator scapulae; 9, M. supraspinatus; 10, \I. acromiotrapezius; U, M. acromiodeltoidcus; 12, M. clavobrachialis.
 +
 +
 +
 +
first one in which this muscle has been observed. It arises in commf)n with the m. levator scapulae ventralis (5) from the posterior portion of the transverse process of the atlas. After about 0.5 cm. the two muscles separate, and the m. levator scapulae ventralis inserts into the metacromion. The m. cleido
 +
 +
 +
A MUSCULUS CLEIDO-ATLANTICUS IN THE CAT 67
 +
 +
atlanticus inserts into the lateral third of the clav-icle and into the raphe which lies lateral to the clavicle, between the m. clavotrapezius (1) and the m. clavobrachialis {12). About 1.75 cm. before its insertion it is joined on its medial border by the m. cleidomastoideus (3), which inserts into the medial two-thirds of the clavicle. The m. cleido-atlanticus is an elongated muscle, somewhat flattened at the clavicular end. It is about 6 cm. in length, 0.25 cm. broad at the atlas, 1 cm. broad at the clavicle and 0.5 cm. thick in the cat here described. The innervation is from the ventral ramus of the third cer\4cal nerv^e which also supplies the m. levator scapulae ventralis, the m. cleidomastoideus, the m. stemomastoideus {2) and several other muscles of this region.
 +
 +
 +
 +
68 EDITORIAL EXTRACTS
 +
 +
ANTI-\lVISECTION MORALS
 +
 +
It makes no diflference to an anti-vivisectionist how hard a blow she receives from the facts. She comes up smiling just the same. Dr. Keen, the famous Philadelphia surgeon, exposed recently a number of the latest lies, and Mrs. Henderson, vicepresident of the .Vmerican Ant i- Vivisection Society, came back with the most cheerful and unmoved assertion of her own opinion and interpretation against overwhelming evidence. Then comes along Dr. Crile. Mrs. Henderson had quoted Dr. Crile's book on "Surgical Shock," sajdng that it "repeatedly describes experiments followed by the words 'no anesthesia.' " Dr. Crile has studied his own book faithfully, and cannot discover any such words. We have not yet noticed ]\Irs. Henderson's answer to Dr. Crile, but feel sure that it will be just as cheerful as her answer to Dr. Keen. Harper's Weekly, January 24, 1914.
 +
 +
«
 +
 +
SCIENCE AND MERCY
 +
 +
The Anti-vivisectionists have been putting out a circular in Philadelphia, with the statement that Dr. George W. Crile made experiments on one hundred and forty-eight dogs "in an endeavor to learn the extent of the agon}- that can be inflicted on a living animal." Do the kind-hearted women who are backing this movement believe that Dr. Crile did anything of the sort? When they leave out all mention of anaesthesia, do they do it by accident? Surgeons until recently thought that when a patient was unconscious they could tear loose adhesions and manipulate tissues roughly without doing mischief. Crile's experiments were to determine whether this view was correct. He found that it was not; that serious injury could be caused by shock even when there was no consciousness. Reahzing the difference between psychic shock, which is prevented by anaesthesia, and traumatic shock, which is not prevented by anaesthesia, is an important step ahead, which has already resulted in a lower death rate and a shorter time for recovery. Crile, like other men of science who are called monsters of cruelty by these kind but ignorant sentimentalists, is the apostle of gentleness. Harper'.H Weekly, January 31, 1914.
 +
 +
 +
 +
PROCEEDINGS OF THE AMERICAX ASSOCIATION OF ANATOMISTS
 +
 +
THIRTIETH SESSION
 +
 +
At the University of Pennsylvania, Philadelphia, Pa., December 29,
 +
 +
30, and 31, 1913
 +
 +
]\IoxDAY, December 29, 10.30 a.m.
 +
 +
The thirtieth session of the American Association of .Inatomists was called to order by President Ross. G. Harrison, who appointed the following committees:
 +
 +
Committee on Nominations: J. Plaj-fair ^McMurrich, chairman; Robert R. Bensley, Henry ]\IcE. Knower.
 +
 +
Auditing Committee; Harry B. Ferris, chairman; Burton D. Alyers.
 +
 +
Tuesday, December 30, 12.00 m. Associatiox business MEETING, President Ross G. Harrison presiding.
 +
 +
The Secretary reported that the minutes of the Twenty-Ninth Session were printed in full in The Anatomical Record, volume 7, number 3, pages 91 to 98, and asked whether the Association desired to have the minutes read as printed. On motion, seconded and carried, the minutes of the Twenty-Ninth Session were approved by the Association as printed in The Anatomical Record.
 +
 +
Harry B. Ferris reported for the Auditing Committee as follows: The undersigned Auditing Committee has examined the accounts of Dr. G. Carl Huber, Secretary-Treasurer of the American Association of Anatomists and finds same to be correct with proper \ouchers for expenditures and l)ank balance on Deceml>er 20 of .'?213.03. (Signed) Harry B. Feiuus, Burton D. ]Myers; Philadelphia. December 30, 1913.
 +
 +
m
 +
 +
 +
 +
70 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
The Treasurer made the following report for the year 1913 :
 +
 +
Halancc on hand December 29, 1912 $318 .08
 +
 +
Receipts from dues, 1913 131o .39
 +
 +
Total deposits for 1913 $1033 .47 $1033 .47
 +
 +
Expenditures for 1913:
 +
 +
Expenses of Secretary -Treasurer, Cleveland Meeting $20.50
 +
 +
Postage 40.00
 +
 +
Printing ($11.90), typewriting ($8.75), envelopes ($2.50). ... 23.15 To 297 subscriptions to 1 volume of the American Journal of
 +
 +
Anatomy and 1 volume of the Anatomical record @ $4 .50. . $1336 .50 To exchange for foreign draft .29
 +
 +
Total $1420.44 $1420.44
 +
 +
Balance $213 .03
 +
 +
Balance on hand, deposited in the name of the American Association of Anatomists in the Farmers and Mechanics Bank, Ann Arbor, Michigan, December 26, 1913.
 +
 +
On motion of George S. Huntington the reports of the Auditing Committee and the Treasurer were accepted and adopted.
 +
 +
Tlie Committee on Nominations through its Chairman, J. Playfair McMurrich, placed before the Association the following names: President, G. Carl Iluber; Vice President, Frederic T. Lewis; Secretary-Treasurer, Charles R. Stockard. For members of the Executive Committee for term expiring in 1917, Warren H. Lewis and C. Judson Herrick.
 +
 +
On motion the Secretary was instructed to cast a ballot for the election of the above-named officers.
 +
 +
Moved by J. Playfair McMurrich, seconded by Robert R. Bonsley; That this Association accepts with regret the resignation of Dr. G. Carl Huber from the office of Secretary-Treasurer and desires to place on record its high appreciation of his services and its recognition of the prominent part he has taken in bringing the Association to its present prf)sporous condition and in advancing the cause of Anatomy on this conthient both by precept and example." Carried.
 +
 +
The Secretary presented the following names, recommended by the l^^xecutive Committee, for election to meml3ership in the American Association of Anatomists:
 +
 +
 +
 +
PROCEEDINGS 71
 +
 +
Edwin A. Baumgartner, Instructor in Anatomy, Universily of Minnesota.
 +
 +
Henry Bayon, Associate Professor of Anatomy, Tulane University.
 +
 +
Thomas H. Bryce, Professor of Anatomy, University of Glasgow.
 +
 +
Felix P. Chillingworth, Assistant Professor of Physiology and Pharmacology Tulane University.
 +
 +
Eleanor L. Clark, Research Worker, Johns Hopkins Medical School.
 +
 +
George W. Corner, Assistant in Anatomy, Johns Hopkins University.
 +
 +
Robert S. Cunningham, Johns Hopkins Medical School.
 +
 +
A. Campbell Geddes, Professor of Anatomy, McGill University, Montreal.
 +
 +
Stacy R. Guild, Instructor in Histology, Dept. Med. and Surg., University of Michigan.
 +
 +
G. V. Ariens Kappers, Director of the International Central Institute for Brain Research of Holland.
 +
 +
Howard S. Murphy, Professor of Anatomy and Histology, Ames, Iowa.
 +
 +
D. A. Rheinhart, Indiana University.
 +
 +
Arthur Robinson, Professor of Anatomj-, University of Edinburg.
 +
 +
Katherine Julia Scott, Johns Hopkins Medical School.
 +
 +
Paul G. Shipley, Assistant in Anatomy, Johns Hopkins University.
 +
 +
R. W. Shufeldt, Major Medical Corps, U.S.A. (Retired).
 +
 +
G. Elliott Smith, Professor of Anatomy, Victoria University, Manchester, England.
 +
 +
Perry G. Snow, Professor of Anatomy, University of Utah.
 +
 +
Johnso.v Symington, Professor of Anatomy, Queens University, Belfast, Ireland.
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Arthur Thomson, Professor of Anatomy, University of Oxford, England.
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J.\coB Thorkelson, Professor of Anatomy, College of Physicians and Surgeons Baltimore, Md.
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R.\ndolph West, School of Medicine, Columbia University, New York City.
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James Thomas Wilson, Professor of Anatomy, University of Sydney, Australia.
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On motion of E. A. Spitzka, the Secretary was instructed to cast a ballot for the election of all the candidates proposed by the Executive Committee. Carried.
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George S. Huntington proposed the following amendment to the Constitution. To substitute for the last sentence of Article II the following :
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"These officers shall be elected by ballot at the annual meetuig of the Association, and theu' official terms shall conmience with the close of the Annual Mooting."
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"At the annual mooting next procecUng an election the President shall name a Nominating Conmiittee of three members. This Committee shall make its nominations to the Secretary not less than two months before the annual mooting at which the election is to take ])laco. It shall ho the duty of the Secretary to mail the list to all members of the Association at least one month before the annual
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72 AMERICAN' ASSOCIATION OF ANATOMISTS
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meeting. Adtlitional nominations for 'duy office may be made in writing to the Secretarj' by any five members at any time previous to balloting."
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This proi)os(>d anuMidment to the constitution becomes a matter of record for this meeting and will be acted upon in due form at the next annual meeting. (See Section 2, Article VII, of the Constitution, published in Anat. Record, \'^ol. 4.)
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President Harrison announced that he had appointed J. Playfair Mc]\Iurrich to represent this association to meet with representatives from the American Society of Zoologists and the American Society of Naturalists for the purpose of formulating plans for the federation of these organizations with a view of obtaining coordination at the annual meetings.
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The question of pul)lishing abstracts of papers presented at the meetings was discussed by Knower, Huntington, ]\IcMurrich, Huber and others. The following motion, presented by George S. Huntington, was seconded and carried: Moved that beginning with the next annual meeting members intending to present papers at such meeting be reciuired to furnish the Secretary with an abstract for publication in the Proceedings of the Association at the time of sending in the titles for inclusion in the official program of the meeting.
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Henry McE. Knower moved that a committee of three be appointed from this Association for the purpose of standardizing the courses in biology required in premedical courses and leading to the stud}' of anatomy. Motion seconded by E. A. Spitzka, and carried. The President later announced as such Committee, Henry McE. Knower, Chairman; Frederic T. Lewis, Warren H. Lewis. On motion the business meeting adjourned.
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At the conclusion of the scientific program on Wednesday the following business was presented:
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C. Carl Hubor proposed the following amendment of Article \ I of the constitution: The first sentence of the article "The animal dues shall be $5.00" — it is proposed to amend to read "The annual dues shall be $7.00. This becomes a matter of record and will bo aftod upon at the next annual mooting (see Section 2, Article Wl of the Constitution).
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PROCEEDINGS 73
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On motion the Association tendered its sincere thanks and appreciation to Professor Piersol and the members of his staff, and the local committee, and to Provost Smith and other officials of the University of Pennsylvania for the very efficient arrangements made and for their hearty cooperation in furthering the success of this meeting.
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G. Carl Huber,
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Secretary-Treasurer of the Thirtieth Session of the American .\3s0clatl0n of Anatomists
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The following Scientific Program was presented and is here recorded by abstracts or titles.
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Monday, December 29, 10.30 a.m. to 12.30 p.m., President Ross G. Harrison, presiding.
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1. The development of the lymphatic system in the trout} Charles F. W.
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McClure, Princeton University.
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My investigations on the development of the lymphatic system in fishes have been confined to the vessels of the head and phan,Tix. The fishes thus far studied include Amia calva, Lepidosteus osseus, Salmo Gairdneri (steelhead trout), Salmo irideus (rainbow trout) and Salvelinus fontinalis (brook trout). The vascular system of between 600 and 700 trout embryos has been injected and embryos studied both in transparent mounts and in sections. Forty-two reconstructions aft^r the method of Born have also been made of the arteries, veins and h-mphatics in the head and pharynx regions of Amia, Lepidosteus and the trout, which illustrate the development of the l>Tnphatic system from the time of first appearance, up to the establisliment of a condition, in which a continuous system of channels is present. Since the injection method ha,^ been employed in following the development of the lympiiatics in the trout, I will confine my remarks, for the most part, to the conditions met with in this form.
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The injection method shows that the channel system (iumina) of the developing lymphatics, is not continuous at 'its inception with tliat of the veins, but is represented by a series of independent and discontinuous lymjih sacs or lymph spaces, which subsequently become confluent witii one anotlier and. at definite points, join \\\\\\ the veins, to form the continuous lym])hatic system of tlie adult. The ]>rinciple involved in tiie development of tiie l>'mphatic system tlierefore appears to be essentially the same as that met with in the yolk l)la.stoderm of vertebrates, where the continuous system of hunina of the blood-vascular plexus, is formed
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' Rciul bcfoio Section I, of the Seventeenth International Congress of Medicine held in London in 1913.
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74 AMERICAN ASSOCIATION OF ANATOMISTS
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through the confluence of independent and discontinuous vascular spaces and the endothehum which hnes these spaces, is formed from cells which possess a local origin.
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At the time when a continuous system of lymphatics is first met with in the trout embryo, they are represented, on each side of the body, by the following main vessels:
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/. The lateral pharyngeal li/niphatic. This vessel occupies a superficial position in the lateral wall of the pharynx and forms the direct anterior continuation in this region of the lymphatic of the lateral line of trunk. The lateral pharyngeal lymphatic may communicate wnth the precardinal vein at the cardino-Cuvierian junction, in common ^\^th the l^inphatic of the lateral line of the trunk; with the precardinal vein near the caudal end of the otocyst or at both of these points. These points of communication ^^^th the veins may be single or multiple in character.
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2. The subocitlar lymph sac. This is a relatively huge Ij-mph sac at this stage of development, which lies ventro-medial to the caudal half of each eye and drains into the veins, only through the lateral pharj'^ngeal IjTTiphatic, at the tjT^ical points of entry mentioned above.
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3. The medial pharyngeal lymphatic. This vessel lies medial to and is more deeply situated than -the lateral pharyngeal lymphatic. It runs an oblique course, in a postero-anterior direction, from about the middle of the lateral pharyngeal lymphatic, with which it often communicates, to open into the precardinal vein just caudad of the point where the latter leaves the cranial cavity.
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4. The precardinal or jugular lymphatics. These vessels develop along the line of the precardinal veins and drain into the lateral phar>nigcal IjTnphatic near the caudal end of the otocyst. In later stages the mesenteric lymphatics drain into the lateral pharyngeal lymphatic through this system of vessels.
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At such a stage of tlevelopment as that just described, all of the abovementioned l\Tnphatics, including the subocular Ij'mph sacs, can be readily injected from the veins. Also, at this time, blood can and often dose pass from the veins into the l.vmphatics. In one special case, blood was observed to pass from the precardinal vein into the left lateral pharyngeal IvTnphatic of a living trout embryo and, after completely filling the left .subocular lymph .sac, to flow back almost immediately into the vein. The passage of blood from the veins into the lymphatics ceases after the veno-l>Tnphatic valves have been formed and observations made upon the living trout embryo, lead me to believe that the passage of blood into the lymphatics, before the valves are formed, is not of any functional significance in the economy of the vascular system, but is due rather to certain local hydrostatic conditions, possibly related to the intermittent flow of the lymph into the veins, as well as to the handling of the embryo under observation. Whatever the case may be, I am convinced that the l>Tnphatics of the trout embryo are not transformed veins.
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The 8uf)ocular lymph sac can be observed in the living trout embryo almost from the time of its first appearance and, on account of the relatively large size it attains, is not paralleled by any other l>Tnph structure,
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PROCEEDmOS 75
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I know of, for convenience of observation and experiment. On account of its large size, the development of the subocular lymph sac is best followed in the steelhead trout (salmo Gairdneri), where it makes its first appearance in the embryo between the thirteenth and sixteenth days, depending upon the temperature of the water in which the embryos have been hatched. As far as I have been able to observe in the material at hand, the subocular K-mph sac makes its first appearance in the form of spaces or clefts in the mesenchyme which occur medial to the caudal end of the eye. These spaces finally become confluent to form at first a multilocular and then a single-chambered sac. For a period of from 5 to 7 days after its first appearance in the embryo, each subocular lymph sac serves as a local and independent reservoir for the reception and retention of lymph which it obtains from the head-region and which it retains, until the sac makes a connection with the lateral pharyngeal lymphatic, through which it then drains into the veins. Prior to the establishment of this connection, I have been unable to inject the subocular lymph sacs through the veins or the veins through the subocular sacs.
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Subocular hnnph sacs are also found in the embryos of ganoids, but differ from those in the trout in that they drain directly into the veins, in an unmistakable manner, during a very limited period of embrj'onic development. They then become detached from the veins (12 mm. Amia and 14 mm. Lepidosteus) and, as far as I have been able to determine without the aid of injections, remain detached from the veins, as well as from the rest of the l\Tnphatic system, even in embryos of Amia which have attained a size of 40 mm. in length. The area drained by the subocular hmph sac in the trout, appears to be drained in the ganoids by a lymphatic, not present in the trout, which opens into the anterior end of the lateral pharyngeal lym]5hatic. Whether the subocular lymph sacs of ganoids, like the caudal lymph hearts of some birds, are only evanescent structures which are not carri^^d into th^^ adult. I am unable to state at the present writing. In" consideration of the supposed relationship which exists between the teleosts and the ganoids, it would not be surprising to find a stage of development hi which the subocular lymph sac of the trout, like that of the ganoids, drained temporarily into the veins. Such a stage, however, I have thus far been unable to find in any of my injected trout embryos.
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Coincident ^\^th the develoi)ment and growth of the subocular lymph sacs in the trout, discontinuous and independent lymjih sacs or spaces are lieing formed, along the lines subsequently followed by the other main Ij'mph chamiels. These spaces or sacs never approach in size that of the subocular lym])h sacs, but like the latter. api)ear to serve :u*; indepemlent and temporary reservoirs for the reception of lymph, prior to the estal)lishnient of a comnumication between their lumina and that of the veuis. Those lymph sacs which lie contiguou>^ to the caudal end of the otocyst (otic lymjih .sac) ami to the carclina!-Cuvieri;m junction (cardino-( uvierian lymph sac), may establish a communication with the veins, which is imictically coinciilent ^^^th their first apix'arance in the mesenchyme and they are then capable of being injected.
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70 AMERICAN ASSOCIATION OP^ ANATOMISTS
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Those indei^onclent lymi)h sacs, however, which lie remote from those sacs or remote from tlie i)oints at wliich ])ennanent communications are estahhshed with the veins, camiot he injected from the veins, until after they have l)ecome confluent with lrmi)h sacs which lie o])posite to and communicate with the veins, at the specified points of communication which, as far as I know, are retainetl in the adult.
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Ultimately, all of the discontinuous lymph spaces or sacs become confluent to form a continuous system of vessels. The rate, however, at which this confluence takes place is extremely variable, not only amonp; different embr^'os of the same age, but even ujion opposite sides of the same embryo. In one series of steelhead trout embryos, hatched at a temjjerature of about 10.5°C\, both sul)ocular lymph sacs, in the majority of the embryos examined, had established a coimection with the lateral i)har>nfieal iymjiliatic on the twenty second day after fertilization, and could be readily injected from the veins. In some of the embryos of this same series, however, this coimection had been established on one side of the body only and the lateral pharyngeal hTnphatic of the opposite side, extended and could be injected to a point near the subocular lymph sac, but did not connect with the same. Injection experiments have proved conclusively that the subocular l^-mph sacs do not grow caudad. It is through a centripetal confluence of the lymph sacs or lymjih spaces which lie in the course followed by the lateral pharyngeal lym})hatic, that the latter vessel is formed, before its connection with the subocular lymph sac is established.
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2. The genetic relations of lymphatic and haemal vascular channels in the embryos of Am,niotes. Geo. S. Huntington, Columbia University, New York.
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In certain regions in amniote embryos Ijonphatic vessels develop, during tlie early stages, primarily for the purpose of conveying r(>d blood cells formed in situ in the adjacent haemopoetic mesenchyme directly into the venous channels. Functionally these early lympiiatic vessels are e.s.sentially haemophoric. During the period of this functional activity they offer no morphological criteria differentiating them from the adjacent haemal channels. Much of the confusion of terms and of interpretation found in the records of the recent investigations into the development of the lym])hatic system is due to the misconception of the early functional ciiaracter of these priinitiv(^ lymjihatics. They have, (jwing to their blood cell contents, been da.ssed indiscriminately as venous tributaries or venous derivatives. In the course of further dev«l()i)m('nt these early haemopiioric lymjihatics may, after p(>rforming their })riinitive function, atrophy completely and disappear as comjxments of the definite lymphatic system, as in the case of the proximal portion of the primitive ulnar lymphatic of the mammal. In other regions the early haemophoric lymphatics, after conveying the developing blood cells to their destination within the lumen of th(> large veins, are retained as functional lym])hatic. components. The jugular lymj^hsacs (anterior lymph hearts) of mammalian, avian and reptilian em
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PROCEEDINGS 77
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bryos are examples of this condition. Also, as recently discovered by Miller, the avian thoracic duct. The development of the systemic lymphatics in embryos of the three amniote classes can be compared in the region of the main axial channels (thoracic ducts).
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1. In the reptile (chelonia and lacertilia) the large adult periaortal lymphatic sinuses develop at first as small intercellular clefts in the spongy mesenchjnne surrounding the dorsal aortic arches and the median dorsal aorta. These spaces enlarge, approach each other, fuse and finally surround the aorta as a huge periarterial IjTnphatic sinus, with trabeculae in the interior, representing remnants of the original mesenchjTnal partitions between the components of the sac. This extensive periaortal lymphatic sinus of the reptiles represents the much reduced thoracic ducts of birds and mammals. It establishes secondary connections with the independently developed peripheral IjTnphatic channels, joins the jugular l3Tnphsacs, and through them attains its entry into the venous system.
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P>om its earliest inception in intercellular mesenchymal spaces the reptilian periaortic sinus is at no point in relation to the venous system. It is closely applied to the dorsal aorta, but there are, at the site of its development, no large embrj'onal venous channels corresponding to the mammahan azygos (post- and supracardinal) trunks. Consequently the developing thoracic, or rather coelomic, Ijonphatic sinuses of the reptile never come into intimate genetic or topographical relations with axial veins.
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Further, the axial periaortic mesenchj-me of the reptilian embryo is not the site of an active intraembryonic haemopoesis. Consequently, in strong contrast with the a\'ian type, the reptilian homologues of the thoracic ducts never become haemophoric.
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2. The bird follows the general reptilian type of development, with the follo^^^ng important modifications:
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The periaortal mesenchj-me of the chick is the site of a most active and abundant intraembryonic haemopoesis. IMasses of developing bloodcells (liffer(>ntiate as axial strands, the "mesenchymal chords" of Sala (1900), ventral to the aorta, directly from the indiflferent periaortic mesenchymal S3^ncytium. Subsequently the anlages of tiie thoracic ducts appear in this periaortic area as isolated intercellular mesench^Miial clefts and spaces. These spaces become confluent, receive the l)iood cells developed in the periaxial blood islands, convey them through the cliannels of the thoracic ducts to the jugular lymph sacs, and througii tiiem into the circulating venous stream. After this evacuation of their early blood contents the axial lymj^hatic channels are retained as the permanent avian thoracic ducts (Miller).
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8. In the mammal, as shown by a number of recent inv(\stigations, the anlages of th(> thoracic ducts tleveloji as independent intercellular mesenchymal spaces surrovuuling the tem]iorary ventro-medial tributary plexus of the azygos veins. Subsequently these venous radicles, enveloped by the growing lymjihatic s{)aces, become detached from the azygos veins, atrophy, and are finally replaced topographicallif by the
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78 AMERICAN ASSOCIATION OF ANATOMISTS
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mammalian thoracic ducts. This type of lymphatic development has been described by McClure and mvs(>lf as the "I'xtra-intimal," because the lumen of the lymphatic anlage is always cclal of the intimal lining of the degeneratinp; vein, which the resulting lymphatic channel is destined to replace.
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Hence each amniote class offers special and peculiar developmental conditions in this i)articular region. Differing at the first glance widely from each other, they all conform to a common genetic ground-plan, if the same is interpreted in terms of the relation of the first lymphatic anlage to the early periaxial development of blood cells. The reptilian embryo offers in this region the clearest and lea.st complicated illustration of the basic principle underlying all vi'rtebrate vasculogenesis in general and all vertebrate lymphatic development in particular, namely, the formation of a system of connected channels, developed bj^ fusion of originally sejiarate and independent intercellular mesench^Tiial spaces not complicated by any relation whatsoever to the systemic veins, nor charged with the haemophoric function of conveying red blood cells developed in situ into the general haemal circulation.
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In the bird the periaortic mesench\Tnal spaces and the resulting channels of the periaortic (thoracic) lymjohatic ducts become in the early development stages charged with the duty of conveying the products of the active periaortic mesenchymal haemopoesis of the bird, as free red blood cells, into the general haemal circulation. Hence, in the bird, we must recognize a distinct haemophoric stage in the ontogen\' of the axial (thoracic duct) lymphatic channel. In the mammal, the products of an early haemopoesis of the periaortic mesenchyme are conveyed directly into the blood vascular sj^stem through the ventro-medial tributaries of the azygos (supra-cardinal) axial veins. These tributaries having performed this function, atrophy and are replaced topographically l)v the anlag(\s of the thoracic ducts, which develop as independent intercellular mesench\Tnal clefts, surrounding the degenerating venous radicles as the "extra intimal" Ijinphatic anlages described in detail by Huntington and McClure. These mammalian " extra-intimal " l>'mphatic anlages finally replace altogether the early haemophoric ventromedial asygos venous plexus, unite with each other to form the channel of the thoracic ducts and make tiieir secondary centripetal connection with the venous system through the link of the jugular lymph sacs. In all three classes of amniote eml)ryos the final result of the genetic processes above outlined is identical, namely, the establishment of a periaortic or paraaortic lymphatic channel, the amniote thoracic duct.
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3. Early stages of vasculogenesis in the cat (Felis domestica) with especial
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reference to the mesenchymal origin of endothelium . H. von W. Schulte.
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From the Anatomical Laboratory of ( 'oluml)ia rniversity.
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The variety of the products of endothelium-mesenchyme (v. Szity,
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Huntington), connective tissue (Holl, Mall) and blood-cells (Maximow,
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Dantschakoff, Weidenreich, MoUier) would seem decisively to invalidate
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the floctrine of the specificity of endothelium advanced by Sabin and
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PROCEEDINGS / 9
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other American investigators, and to establish beyond peradventure the close affinities of endotheUum and mesenchj-me. But if these facts are duly recognized, there is no logical ground for attributing to endothelium a peculiar origin (preferably entodermalj, and mode of increase ^solely by homoplastic proliferation;, or an early and complete independence of the mesoderm, still less of going to the extreme of assigning to endothelium and blood the value of a fourth germ layer, the angioblast of His and Minot.
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In the splanchnopleure, in which the early phases of vasculogenesis have been chiefl}' studied, obser\-ation is rendered somewhat difficult on account of the precocity and extent of the vascular anlages and blood islands, which seem to have caused the scant}' but ever present mesenchyme to be overlooked, so that the Gefd^ssfaserblatt has come to be simply the Gefasshlatt of many recent observers.
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The somatopleure is a more favorable site for the study of the early phases of va-sculogenesis, because the process is less rapid, the vascular anlages do not preponderate and mask the presence of mesench^-me, and it is further ^\•idely removed from the entoderm, so that the verj' remote possibilit\- of an entodermal origin of endothelium is here completely excluded. It may be noted in passing that all investigators of the incipient stages of vasculogenesis in mammals are in agreement as to the mesodermal origin of blood and endotheUum fKolliker, Heap, Robinson, Janosik, Bonnet, Fleischman, Keibel. Van der Strich, Maximow, Felix).
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Prior to the appearance of the somites, the .space between the ectoderm and mesoderm is crossed by fine protoplasmic strands, the fibers of Aurel V. Szity, or interdermal cytodesmata of Studnicka, collectively the mesostroma of the latter author. Along these c^-todesmara cells migrate from the mesoderm and form the inception of the mesenchj-me. An identical migration occurs even earlier in the splanchnopleure, and in both situations long antedates the re.>olution of the sclerotomes into mesenchNTne. In embr>'os of two somites and older the migration continues but is reinforced by a separation of cells in groups from ridges of the mesoderm, a process described and figured in the splanchnopleure by Fleischman, with whose results my own are in close agreement. This process may be termed delamination. It is especially active along the lateral margin of the coelom in the position subsequently occupied b}' the umbilical vein. In some of these masses clefts appear; their enlargement is accompanied by flattening of the enclosing cells; thus separate endothelial vesicles are formed. Similar vesicles are produced, by the same process, above the intermediate cell-masses and have an imperfect segmental arrangement. The intervals between the vesicles are filled with mesenchyme with which their endotheUum is in s>Tic>tial connection. Some of these mesenchyme cells flatten; at first separated by considerable intervals, the flat cells soon coalesce to form strands and plates; in their protoplasm cleft like lumina appear, enlarge and ultimate coalesce with those of the endothelial vesicles, thus gradually establishing continuous vascular charmels. I'p to the stage of fourteen somites
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so AMERICAN ASSOCIATION OF ANATOMISTS
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tho umltilical vein and the associated jilcxus remain unconnected with the onijjhaloniesenteric vein and the juxta-neiiral anastomosis.
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Identical jirocesses give rise to these vessels also the migration of single elements into the mesostroma, delamination, the formation of discrete vesicles and their ultimate coalescence. Mesench\Tne is always present, but scanty in amount.
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The first formed vessels of the splanchnopleure are placed in the interval between mesoderm and entoderm. Subsequently they gain more intimate relations with the former layer. From the stage of eight somites they become enclosed l)etween i)rocesses of the visceral mesoderm. At the .stage of twelve somites and later many of these ])roce8ses contain funnel-like diverticula of the coelom, the walls of which are intimately united to the blood vessels; the funnels in many mstances seem to communicate ^^^th the mesenchjTnal spaces. The ])resence of these structures, and the further fact that in early stages, just as the first somites are forming, the lateral part of the \nsceral layer almost wholly resolves itself into mesenchyme, to such a degree that the wall of the coelom becomes incomplete, suggests an intimate morphologic resemblance between the coelom ami the tissue space, the further study of which might be expected to throw some light on the general problem of the relations between the coelom and the vascular apparatus ^s a whole.
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4. On the early contractions of the posterior lymph hearts ifi chick embryos — their relation to the body movements. Eleanor Linton Clark and Eliot R. Clark. The Anatomical Department, Johns Hopkins University, lialtimore.
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Living chick embryos were observed in a warm chamber, under the binocular microscope. Violent movements, involving the whole musculature of the embryo, were observed at all stages, from four days to the time of hatching. These movements were found to occur periodically: definite periodic spasms of bodily contractions were followed by distinct interv^als of rest.
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Definite pulsations of the posterior lymph heart were observed first in chicks of 6| days. The pulsations, at this .stage, were found to be intimately connected wnXh. the periodic movements of the embryo. In subsequent later stages, the IjTnph heart gradually becomes independent in its function.
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Chicks were ke))t alive and under continuous oliservation for from 3 to 5 hours and records kept of each lymph heart beat and of all boily movements, in different stages of embrvos.
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Stage \. Chicks of 6^ to 7 days (2(3-22 mm. before fixation). Here the l>Tnph heart invariably contracted several times during each period of body movements and never in the period of rest between s])asms. Moreover, a beat of the lymph heart was always accompanied ])v a movement of the tail. When an embryo of this stage was anaesthetized with chloretone. both body movements and lymph heart contractions ceased at the same time. When the effect of the chloretone wore off.
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PROCEEDINGS 81
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the periodic spasnjs and lymph heart pulsations returned simultaneously and continued as before.
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Stage 2. 7 to 7| days (22-24 mm.). The same as stage 1 except that occasional beats of the lymph heart were dissociated from movements of the tail.
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Stage 3. 8 days — 24^ mm. The lymph heart contracted several times during each periodic spasm of body movements and occasionally it contracted once, independently, during the period of rest. When the body movements were paralized by chloretone, the lymph heart pulsations continued. They did not occur in periodic groups, however, as before the addition of chloretone, but singly, at irregular intervals, from 4 to 8 times every minute. With the return of the body movements, the lymph heart was again observed to contract several times during each periodic spasm, but it also continued to beat, independently, several times in each period of rest.
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Stage 4. 82 to 9 daj^s (27-29 mm.). Fewer beats of the lymph heart occurred during the periodic .spasms, than in earlier stages, and more in the period of rest. When the body movements were eliminated by means of chloretone anaesthesia, the Ijonph heart beat, independently, at irregular intervals, — about 6 to 8 times per minute.
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Stage 0. Finally, in a chick of 11 days, the lymph heart pulsations were entirely independent of the periodic bodily movements. Beats were seen to occur during the periodic spasms, but the intervals between such beats were not shorter than between those occurring in the periods of rest, and we observed several spasms during which no hnnph heart pulsations occurred.
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AVe have studied, in cross sections, the same embryos observed in the living but we are unable, at present, to offer any conclusive anatomical explanation for the intimate connection between the early pulsations of the IjTnph heart and the periodic movements of the embryo, and for the gradual manner in which the hTuph heart becomes entirely independent.
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5. On certain morphological and staining characteristics of the nuclei of lymphatic and blood-vascidar endothe'iuni and of mesenchyme cells, in chick embryos. Eliot R. Clark, The Anatomical Department, Johns Hopkins University, Baltimore.
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The nuclei of lymphatic and blood capillaries in chick embr>'os possess morphological and staining characteristics which differentiate them from the nuclei of the surrounding mesenchyme cells. These differences were noted in cross sections of chick embryos in which the blood-vessels were completely injected with india ink, which were fixed in Helly's fluid, carefully dehydrated, imbedded in jiaraffin, sectioned, and stained with Ehrlich's hematoxylin and eosui onmge (^ and aunmtia: Embryo.s of from 4f to 8 days of incubation were .studied.
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The nuclei of lymphatic and l)lood-vessel cmlothelium have either a single nucleolus or a i>air of nucleoli which are definite discoid boilies, sharply marked out from the remainder of the nuclear material, with clear-cut, rounded outlines. The single luiclfohis varies much in shape,
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THE AJiJATOMlC.M. KKCOHD, Vol . S, NO. 2
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89 AMERK'.VN ASSOCL\TION OF ANATOMISTS
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Sell extend ou, into prongs and threads and 'tdo^^ ""t^have a char chromatm matenal lymphatic endothelium possesses
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r^coi^ertedhlve quite similar eharaeteristics, fum'shes a new proof ttattte lymphatic endothelium is derived from the vems. It also Sstts the study in serial sections of the earliest lymphatics.
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6. The development of the azygos ,ei,u a.s shown in i^^^^^^^'^^: Florence R. Sabin, Anatomical Laboratory, Johns Hopkins tni
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by some improved "^!^t^«^,.^^'to?al specimens of injected pig embryos
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Sir :s- s^3 iS^1^i^ -~. i'-; rri'n axr f.:;' ^ ^^-z:'^z:;.:^t;:jz
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veious inieetions. Pure venous '"J<^<^*'™f f"!;,^ (^^'^^^^^^ The >" TT:f"4aaeSr lir "^1™ ^i^c ^rat'fons is' ^^iT So™ from his
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Praparaten," pubhshed l)y h Hirzcl, ^3^^^; /;' ,^1^^,,.,,^ instead rtrtfl Xir Tt KS rrr t[;Lth wasHi,.^ are im the Wolffian bodies, the mam vems o the orcein ;^^ ^'^'^^^'T.^ ^^ ^^,^ surface vessels, a dorsal or the posterior cardinal vem, a ventral or
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PROCEEDINGS 83
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ventro-lateral vein and a mesial or the subcardinal vein of F. T. Lewis. The dorsal vein extends along the dorsal border and receives the segmental spinal veins. The ventral vein extends in the ridge in which lies the Wolffian duct and which marks a general boundary' between a mesial glomerular zone and a lateral tubular zone as seen from the ventral aspect. The vein lies mesial to the duct. The dorsal and ventral veins join at the anterior pole of the Wolffian bodies. The subcardinal vein runs obliquelj' along the mesial surface of the Wolffian bodies. It does not join the posterior cardinal vein at the anterior pole of the organ but rather at a short distance from the anterior pole. It lies ventral to the mesonephritic arteries in the angle between the Wolffian bodies and the root of the mesentery in the position described by Lewis. At the lower pole of the organ it anastomoses with the ventro-lateral vein. Opposite the middle of the organ is the large anastomosis between the subcardinal veins of the two sides making the mesonephritic vein of Minot. The right subcardinal differs from the left, as Lewis discovered in that its anterior end is continued forward into the caval mesentery' to the liver making the vena cava. The subcardinal veins are essentially the mesial veins of the Wolffian bodies, for only on the right side a short trunk of the veins which makes the anastomosis with the liver sinusoids Ues outside of the organ within the caval mesentery-. In embr>'o pigs 7 to 8 mm. long the mesial longitudinal vein is the largest of the three veins.
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Besides these three longitudinal veins there is a long series of parallel veins transverse to the longitudinal axis of the organ which run just beneath the capsule and connect the three longitudinal veins. It is these transverse veins which eventually become the main veins of the Wolffian bodies, that is the main roots of the vena cava. As seen from the lateral aspect, the transverse veins connecting the dorsal and ventral veins are small, of about uniform size and ver>' numerous. In injected specimens they give a ladder like effect to the lateral surface. They run parallel to the tubules. On the mesial surface in embryos 7 to 8 mm. long the transverse veins at the anterior pole cephalic to the mesial vein are ver>small. The first large transverse vein is the connection of the mesial vein \Nith the posterior cardinal. From this point caudalward there is a series of very large transverse veins crossing the dorso-mcsial surface of the Wolffian bodies and connecting the subcardinal vein with the posterior cardinal. They pass ventral to the mesonephritic arteries. The largest of them is opposite the middle of the organ where the two subcardinals anastomose, indeed the mesonephritic vein might as well be called an ana.stomosis of the two middle transverse veins. In embryos 7 to 8 mm. long most of Xhv blood from the mesial part of the Wolffian bodies passes l\v the sul)cardinal trmiks through the transverse veins to the posterior cardinal veins and the anastomosis between the right subcardinal and the liver is small. When the eml)ryo is 11 to 12 mm. long the ana.stomosis with the liver is large and the subcardinal veins are the main roots of the vena cava. By the time the pig is 1.') mm. long the vena cava has become very large and the miiUlle transverse veins are its largest roots in the Wolffian bodies, while the posterior cardinal and
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84 AMERICAN ASSOCIATION OF ANATOMISTS
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ventro-latcral veins have become limited to the anterior pole of the organ. It is at this point that the azygos veins Ijegin.
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There have been two theories concerning the origin of the azygos veins, the more accepted one that of Hochstetter that the azygos veins are at least in part transformed posterior cardinal veins: the other advanced by Parker and Tozier from the Harvard laboratory in 1897 and in the same year by Zumstein tiiat the azygos veins are new veins. That this latter view is the correct one I can prove by dissections of injected embryos showing the two veins in the same specimen. In stages below 14 mm. the spinal veins pass directly to the Wolffian bodies in a straight line parallel to the mesial sagittal plane from the spinal ganglia and the tissue dorsal to the aorta around the notochord is non-va.scular. At the stage of 14 mm. there develops from the spinal arteries a capillary plexus, ventral to the vertebrae. These capillaries begin in the cervical region and drain by many branches into the anterior cardinal vein and lower down into the posterior cardinal. In the body region a longitudinal vein develops in this plexus which retains as its permanent connections with the cardinal veins the branches which join the posterior cardinal vein at the point where it curves ventralward to make the duct of Cuvier. This point of connection, as is well known, is at first high up at the root of the neck and gradually shifts caudalward. The only part of the azygos system which is derived from the cardinal system is the ventral curve of the duct of Cuvier. The permanent pattern of the veins in the pig is as follows: on the left side a hemiaz^^gos and an accessor>' hemiazygos enter the heart through a permanent duct of Cuvier, on the right side the azygos vein joins the cardinal at the same level as on the left side but the duct of Cuvier is longer. Corresponding to the accessor>^ hemiazygos there is a larger oblique vein draining more than half of the prevertebral tissue of the first four vertebrae wiiich was de.scribed by Kampmeier as a vein which disappears as the thoracic duct develops. Injections show that it is a developing vein at the time when Kampmeier thought it disappearing. Injections of embryo pigs from 20 to 25 mm. long show the complete posterior cardinal veins together with the azygos and hemiazygos systems. The posterior cardinal vein is always farther ventrtd and farther lateral than tiie azygos. The azygos veins are dorso-lateral to the aorta. Eventually the posterior cardinal veins become tributaries of the azygos system.
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7. A comparative diidy of the embryonic blood vefisels and lymphatics in amphibia. Henry McE. Know er. University of Cincinnati In order to understand the development of the lymphatic system, it was necessary first to secure accurate knowledge of the primary arteries and veins and tlieir capillary beds, in relation to regions and organ rudiments, at different stages of the early development of the forms studied. It then became possible to make comparisons withm and outside of the group; and to examine and discuss safely the IjTnphatic system.
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Hence this paper is naturally divided, on the one hand, into a section devoted to an outline of the results of a stud>' of the primary vascular
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PROCEEDLNGS 85
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system of amphibia; with its origin, most important relations, and transformations, as well as a comparative study of these problems and the origin of the blood; while, on the other hand, the second section is concerned with the development of lymphatics in amphibia; the relation of this system to other systems of the body, especially to the tissue spaces and pronephros and mesonephros; the development of lymph hearts; as well as with a comparative discussion of these findings, involving a comprehensive working hypothesis of physiological and experimental nature for the development of the lymphatic system in vertebrates.
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The elaboration of proof of so extensive a program ^-dll, of course, demand much more space than is here available.
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The method of investigation is predominantly experimental and involves a study of each embryo as a whole. Injections were used not simply to secure a series of morphological forms for comparison, but rather to exhibit and fix for study relations o.' physiological balance between the various vascular beds (dorsal, ventral, lateral, anteroposterior) and the regions of the body, at different critical periods of the embryo's history. It is thus possible to show how, especially in the formative stages, pathways will be opened along lines determined by usual or extraordinary balances in pressure relation; and how in agreement with Mall (on the liver)and Thoma, Evans and Sterzi, and so forth, yet with additions, the main vessels are established in the amphibian embryo as a result of the fixat on of certain physiological streams f^o^v'ing more and more constantly through the capillary anastomoses of different regions.
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Young amphibian embryos are especially favorable for such study The simphcity of the entire organism, which can be cleared and viewed in one field; its availability for observation and experiment while alive; -and the important relationships to other forms which permit us to apply our studies to general problems; have, we believe, furnished us a special insight into the problems involved. This carries us some steps further, because it has been possible in the study of the system selected (that is, the lymphatic system) to keep more constantly in touch \\'ith the stages of the other systems of the body, whether arteries, veins, organs or tissues, as parts of one organic mechanism. The interaction of the parts as affecting the problem of development of the vessels and h'mphatics has been tested by experimental injections, and otherwise.
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Hoyer for the amphibia, and others for other groups, have made most important contributions l)y studying one system at a time, more or less as an entity, oitlier In' models or injcK'tions. They iiave aimed to arrive at morpiiological comparisons and genetic relations of the system.
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It is not to lie denied that many observations of living emlirvos, models, and injections, in our sense, have advimced our knowledge. Evans has brought this together in a most able manner ('13). These methods have not, however, ]iro\ed entirely adequate for reaciiing an appreciation of some very important problems of inter-<iependence of all systems as affecting lymphatics; nor for grasping some essentials in
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86 AMERICAN ASSOCIATION OF ANATOMISTS
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the (lovolojiniont of blood vessels and l\Tnphatics which might prove common to all methods of approach.
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Another great advantage in our studies has been the fact that many of the injections, by our sjiecial method, were of far earlier stages of both Urodeles and Anura than have been secured by others. This has enabled us to clear up some points in the establishment of primary vessels not other^^^se possible.
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Our previous work, experimental and other, has been confirmed and extended.
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I. Successful injections of young Amblystoma embryos before the postcardinals become defined, furnish a variety of specimens in the same or closely related stages, de])ending upon the jihysiological state of the embryo. It can be shown that the blood from the dorsal aorta leaves this vessel, behind the point where it begins, ventro-laterally all along its course, on either side. We do not find the extremely large sheets nor the same history as von Mollendorf, but can agree with some of his points. Each lateral stream branches into two, a dorsal and a lateroventral. The latter vessels run ventrally over the yolk in a fairly \nde plexus.
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In the next stages the blood returning from the bifurcated caudal ends of the aorta, tends to fix a pathway from behind to the pronephric sinus through the vitelline ])lexus, on either side, along and under the edges of the myotomes. This return stream to the j^ronephric sinus will become the postcardinal. It flows through the vitelline anastomosis, and tends to push forward over these outcoming streams, so that when later the vitellme arteries lose connections with the jiostcardinals, they are found beneath (ventral to) these. There is then, for a time, a free coimection from the aorta to the forming postcardinals and outward to the vitelline plexus. The dorsal or neural arteries run up from near the division of the latero-ventrals into their postcardinal (lateral) and vitel- ' line (ventral) branches.
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Anteriorly, in the region of the pronephric glomerulus, practically the same condition as behind is found. Several pronephric arteries are found running laterally from the aorta, in intimate association Avith the vitellines of this region related to the vitellines as the lateral vessels to the postcardinals are related to the vitellines in the posterior part of the V)ody. The glomerulus is not a mere saccular enlargement as formerly described, but rather a plexus. It has a venous drainage.
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The posterior cardinal is thus a fixation and separation of a venous return from lateral branches of the aorta. These branches are at first also in connection with the neural plexus through the dorsals, along the sides of the aorta. Hence the dorsal, lateral, and ventral aortic branches are to be regarded as primarily derived from one series of latero-ventrals which branch in three directions. Variations as found by Goeppert are numerous in the origin of laterals and ventrals from the aorta.
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In frog embryos the postcardinal loses its connection with the sides of the aorta at a very early stage, except in front and behind. Birds also exhibit a secondary condition in this respect, since Evans found no
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PROCEEDINGS 87
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aortic connections in the mid-body. The anterior and posterior regions remain more primitive. My experimental work of 1907 shows that in frogs the primary connections of aorta and cardinals can be forced to persist.
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The umbilical artery of higher forms, as well as the limb-plexus arises from lateral loops of the dorso-lateral aortic branches which are connected, as Hochstetter and Evans claim, from the beginning in the f rimitive maimer just indicated, with the postcardinal and splanchnic vitelline plexus. There is a fundamentally similar condition in amphibia, well shown in young Necturus embryos.
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The formation of the definitive arteries and veins of the various divisions of the digestive tract, as esophngus, stomach, liver, intestine, and hind-gut, have been studied. They arise as transformations from plexuses, secondarily, as a result of changes and movements in the tissues and organs of the regions concerned. This is in agreement fundamentally with Mall, Evans, Bremer and in many features ^^^th von MoUendorf, etc., for the estabhshment of the larger trunks in other forms.
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These studies go to prove a fundamental similarity between the primary vessels and plexuses of amphibia and those of other vertebrates. We find no ' essential' difference between the vascular .systems of anamniotes on which to base such distinctions as have recently been drawn by Elze. Differences are of degree rather than kind, and we regret that we cannot subscribe to a number of Elze's claims.
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Elze's use of our experiments to support his contention is entirely unwarranted; for although these frog embrj'os lived two weeks without a heart, they grew abnormal as they became more and more dependent upon skin breathing alone, in the absence of normal circulation; and, I should now add, in the absence also of a norma exc etory ai)paratus.
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There seem to be important bearings of our findings, taken in connection with the results of others and with our own experimental work, on the questions involved in the establishment of the angiol^last and first vessels; the extension of these in the body and over the yolk; and the origin of blood cells.
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On the whole, we agree with Bremer ('12) as to the almo.st simultaneous origin of aortae, early gill arches, and t' o vitoliino foundations of the postcardinals. We should modify von Mollendorf's results somewhat for our forms. The angioblast appears to us to consist first of an anastomosing mesh, including heart, early gill loo]is with the anterior part of the aorta and a venous return to the heart througii simple vitelline loops, lying dorso-laterally on the vi Ik. This mesh is fairly continuous. It ])rogresses backward on eitiier side of tlie aorta as the terminal loops of tiie aorta push back. In this way vaso-formative cells and homatopoetic cells are established as claimed i\v many authors, on either side, extending back from the heart, along the line of the aorta, and of the origins of the vitelline arteries to the base of tiie forming tail. As the embryo grows longer, the movement of the vascular rudiment is a general one, in one system of anastomosing looi)s, backward along the
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88 AMERICAN ASSOCIATION OF ANATOMISTS
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dorso-lat^riil :u>i)oct of the yolk and further out into the tail. It does not seem imjiortant for all parts of the extensive rudiment to exhibit a lumen at once. The loops are inHuenced by tissue activities to grow out, while the non-functional formative tips may not ever\'^vhere l)e clearly marked ofT from surroundinj; tissues in the early rudiments. Later, the vaso-formative activity of the cells of the rudiment lessens; while the endothehal tubes already formed extend by their own gro^vth in wide plexuses, both backward and ventraiward on the yolk and in the body. There is now more difference between the tissue cells and vessel walls.
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The wTiter's personal observations on these questions have not been made on the earliest non-injectii)le stages; but nevertheless, as he believes, on stages early enough to indicate the nature of the processes, and to show a definite bearing on his experiments of 1907.
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Since the line of extension of the angioblast lies along the roots of the vitelline arteries, that is, also the roots of the mesentery, as far as the base of the tail, it is significant that embryos from which the heart is removed at an early stage ('07) later exhibit collections of blood cells in the mesentery, as well as at the base of the tail.
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It must be stated here that a thorough study has also been made of the dorso-lateraf, neural, and other blood vessels in order to value properly the conflicting claims in regard to the lymphatics, especially in the region where these first appear.
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II. In turning to the l>nnphatics, we are met by two opposing views: on the one hand, that the lymphatics are outgrowths from the endothelium of the veins; and on the other hand, that they arise b\^ confluence of tissue spaces which run together centripetally to join the veins.
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Now, there seems to be no doubt that tissue activities initiate the origin jmd maintain the lymphatics as a system. But why should tissue spaces collect into relatively large vesicles and run together in such definite lines? Is it proven that such actually become a continuation of thelvniphatic .system? Why do we not find enlargements at the end of our vessels, repre.senting vesicles from tissue spaces, on injecting lymph capillaries, instead of invariably finding most delicate tips? Why should the main trunks of this sy.stem, communicating with the veins as they do, arise separately and by an entirely different method than that followed by the venous trunks, which are returns established through a previously functioning generalized plexus?
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The technique is evidently very good on both sdes, and in very many points there is possible convergence in interpretation. Both sides proceed on the assumption that nature is constant. Hence, it should not matter whether a stage is studied by models or injections or b}' combined methods; since there is a closer approximation to the truth in each specimen examined. It should be as possible to interpret the facts with the aid of good injections and sections and other sj)ccunens, as by making motiels to express the same facts and interpretations of a constant stage, similar .n many groups. It should be, if anything, easier to determine whether strands of endotlielium at the ends of a definite injectable system invade and tap uninjected spaces of connective tissue, than it is to
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PROCEEDINGS 89
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prove that certain indefinite spaces in the connective tissue combine to build up a system running centripetally in definite lines strictly comparable in various groups.
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Can we not accept whatever is proved by either side; and even go further, by associating the development of IjTnphatics with other systems of the body, and discover a cause in embrj^os of all vertebrates which will aid us in explaining this system? At least, can we not find a working h\'pothesis?
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Turning to the amphibia, we find it possible to make more definite statements about earlier stages, in both frogs and amblystoma, than have been hitherto possible. The first lymph vessels in the frog form a small and superficial dorso-lateral plexus, which drains into the pronephric sinus through a short vein. On this plexus in the frog, the anterior IjTtnph heart soon appears and facilitates the drainage into the venous channels surrounding the pronephric tubules. The Clarks have showTi a similar secondary appearance of the posterior l\Tnph hearts after the plexus is formed in birds ('12). The primary l\Tnphatic endothelial plexus may be thought of as being attracted by some chemotaxis, which arises in the tissue spaces as the mesenchjTiie becomes looser and more vacuolated. This phenomenon of outgrowth is to be observed about the time that the external gills begin to show distinctly, and when the pronephros is organized. The appearance of the first lymphatics at this stage, and in the region of the body where important physiological processes are being inaugurated, suggests strongly that this association is causal. We shall elsewhere give many reasons, and a mass of correlated facts, to justify the view that the early Iv-mphatic plexuses of embr>-os in all vertebrates are endothelial outgrowths, induced to invade vacuolating tissue spaces by changes in the metabolism of this region. The endothelial lymphatic vessels carry off the accumulated products more (lirectly and rapidly from the tissues than would be possible through tissue spaces. It is our view that they can thus be carried more rapidly to the pronephros for elimination. (See Abel, Jour, of Pharm.. 1912). The IjTTiph hearts appear later at the point of entrance of the plexus into the veins, just adjacent to the pronephros and facilitate the emptying of the plexus into the venous channels surrounding its excretorytubules.
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As development proceeds, the changes in the tissues l^ringing about vacuolization, spaces, and so forth, progress tailward and take place most actively just under the skin and dorso-laterally.
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Coincidentally, the lymphatic plexus travels l)ackward. spreading dorsally and ventrally beneath the skin as it moves. The stages are different in important features from those described !)>• Hoyer. whose older stages did not show the true nature of the plexus, though fundamentally we shall ))e in agreement. In this mamier the dorsal and ventral caudal trunks are laid down as the tissues of the tail favor their invasion. A tlelicate but rather extensively l>nnphatic plexus comes to overlie the veins at the i)ase of the tail l)efore the ap})earance of the ix)st^rior lymph hearts; (we understand Hoyer to be in :igreement with this, though his pupil Fedorowicz seems to disagree).
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90 AMERICAN ASSOCIATION OF ANATOMISTS
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At first the entire system of lymjihatics drains through the anterior lymph hearts mto the pronepliric sinus. With the inauguration of greater tissue activities in the region of tlie hind-body, with the development of the limbs and of the Wolffian body Anth its special venous channels, bathmg the tubules, a connection is established between the endothelial tubes of the lymphatics and certain branches of the lateral caudal veins. We think PVdoroA\icz's observations are incomplete, or on unfavorable material, and that his cell strands in the tissues near the veins before the posterior lymjih hearts appear will probably prove to be lymph terminals which have been attracted back, as we find, into this region from in front.
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Thus the vacuolated, and, as it were, the oedematous tissue spaces of the jiosterior portion of the body are now drained through the posterior lymph hearts into the veins of the mesonephros, where an elimination ma>' take place through the tubules which they surround. (These portions of the tubules, as well as the glomerular sections, are claimed by several authorities to be excretary, while the venous streams are passing through the renal-portal system toward the heart).
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This opens up some interesting problems of the functions of the different parts of the pronepheros and mesonephros as compared in embryos of other fonns. The functions of these bodies should also be recompared with those of the kidneys of adult sauropsida and mammals, including man. Since we know of no accurate studies along these lines.
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Consistenth' vnih these \'iews, the invasion of the viscera Ijy lymphatics from the roots of the mesenteries should follow the developmental activities of these organs in changing from a simple primary tube as the accompanying active histogenesis gives rise to new chemotaxis favoring this. This is true of the development of the thoracic duct in amphibia and in higher forms.
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In Urodeles there is essentially the same history; l)ut here an exceptionally extensive lymphatic plexus overlies the veins very closely, and invades the neighboring comiective tissue; while the numerous lymph hearts appear later connecting the two systems. Hoyer's recent ('12) figure for late salamander larvae, are not quite reconcilable, but can probably be corrected b}^ study of young and late amblystoma, if he has confused veins with overl>nng lymphatic vessels in incomplete injections of the trunk region, as seems possible.
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Comparisons of these facts and application of this working hypothesis to the embryos of other forms, including man and mammals, where the nature of the pronepheros appears to produce interesting variations, will be explained fuUj' el.sewhere.
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It seems clear that this view of the method aud supposed causes which bring about a 'taping' of the enlarging tissue spaces, permits us to use many of the valuable results, not only of the advocate of the importance of the ti.ssues and tissue spaces in the problem, but also of those who are impressed with the continuity of the endotheUum as it invades the body.
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Kxtra-intimal spaces may well prove to be lymphatic capillaries which have travelled along the veins and which undoubtedly exist in my specimens.
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PROCEEDINGS 91
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Though I have not seen convincmg cases, demonstrating bej'ond doubt the opening of hinphatic terminals into tissue spaces, this has been claimed by able observers; and though the necessity for this is not yet shown and the proof must be more final, it ^^•ill not be inconsistent \\ith my findings and conclusions, if such opening should be sho^\^^ to be estabUshed. Such a condition might facilitate the passage of substances into the endothelial hmphatic vessels when once this plexus had been induced to invade a region.
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At any rate, we must now take into account, in the embrj'os of all vertebrates, the relations of tissue metaboHsm, respiration, the function and character of h-mphatic drainage, with first the pronephros, and later the meso- and meta-nephros. There \vi\\ be found a remarkable time relation, and correlative association, in both normal, and experimented, and pathological embryos where the function of the kidneys, and so forth, are disturbed. This may lead to a dropsy' more or less chronic; which, in certain cases, may even possibly become a habit of a normal stage or species. The jugular sacs of mammals may be somewhat distorted by such influences.
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On motion a discussion of the several papers presented at this Session was deferred to the end of the Session and was participated in by George S. Huntington, Henry ^NIcE. Knower, Eliot R. Clark, J. Plaj'fair !McMurrich, C. F. W. IMcClure and Charles R. Stockard.
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Monday, December 29, 2.00 p.m. to 5.00 p.m Session for THE reading OF papers, President Ross G. Harrison, presiding.
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8. Experiments on the development of blood vessels in the blastoderm of the chick. Adam M. Miller, Anatomical Laboratory, Columbia University, John E. McWhorter, Surgical Laboraton,-, Columbia University.
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The object of these experiments on the living blastoderm of the chick has been to derive some evidence bearing on the question of vascularization of the area pcllucida and embryonic body. It was as.->umed that if the entire lateral half of the area opaca was removed from the blastoderm prior to the appearance of vascular anlagen in the area pellucida or embr>'onic bod}' and the blastoderm was then allowed to proceed in develo{> ment, it would be possible to test the validity of the view that blood vessels in the area pellucida and embrj'o proper arise in situ and not i\s ingrowths or sprouts from antecedent vascular anlagen in the area opaca. By examination of living blastoderms and serial transverse sections of blastoderms in successive stages of development, it was found that up to the stage in which the 'head process' (primitive axis) was clearly visible on surface view there were no cells between mesoderm and entoderm in the area pellucida or embryonic body.
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92 AMERICAN ASSOCIATION OF ANATOMISTS
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We sought, therefore, to remove the entire lateral half of the area opaca and the lateral portion of the area pellucida at a stage not later than the comploto formation of the primitive streak, and thus to prevent, in the further developing blastoderm, possible ingrowth of vascular anlagen from the area opaca of one side. This accomplished, it would follow that any vessels appearing in the remnant of the area pellucida or in the same side of the embryonic body subsequent to operation must have arisen in situ.
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Through a 'window' in the egg shell, and with the aid of a binocular microscope, an incision was made in the blastoderm at the proper stage which effectively separated the area opaca and a portion of the area pellucida on one side from the remainder of the blastoderm. The egg was then further incubated under conditions as nearly approximating the normal as possible. More than 50 blastoderms were operated on and allowed to develop subsequently for periods ranging from 20 to 72 hours.
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In general, development went on normally (barring slight retardation) on the uninjured side for at least 24 hours. In some cases the anlage of the heart on this side alone developed. This was probably due to the fact that the incision had been so close to the sagittal midplane as to remove the opposite cardiac anlage. Usually after 24 hours the embryo would become abnormal in contour, although the extraembryonic area continued to develop fairly regularly and the heart continued to beat.
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On the injured side, between the sagittal mid-plane and the line of incision, practically all the usual structures developed. The cut edges of ectoderm and entoderm healed together, thereby enclosing the mesoderm. The coelom appeared, although irregular in outline. The somites were found in their usual positions.
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Active vasculogenesis was foimd to occur not only in the remaining portion of the area pellucida but also in the embryonic body. Numerous blood islands of characteristic appearance, as well as vessels destitute of blood cells, developed in the splanchnic mesoderm. The aorta and the cardinal and umbilical veins ai:)]ieared in proper position. The cells comprising the i)lood islands were differentiated in loco from the mesoderm (mesenchyme), and the vessels appeared for the most part as series of isolated lacunae, in small part as solid cords which subsequently acquired lumina. In the earlier stages neither the blood islands nor the vessels were connected with vascular structures on the uninjured side.
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These results show that the removal of tiic entire lateral half of the area opaca at a stage prior to the appearance of vascular anlagen in the area pellucida does not prevent subsequent development of blood cells and vessels in the area pellucida or in the embryonic body on the same side of the sagittal mid-plane. It has been found, on the other hand, that after such an injury vascular structures develop in both localities. The conclusion is justifiable that the blood vessels of the area pellucida and embryo do not grow in from an extrinsic region but arise in situ.
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PROCEEDINGS 93
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Discussed by Knower and Huntington. In his discussion of this paper Dr. Huntington referred to the fact that Miller and McWhorter's manuscript had been submitted for publication to the Editorial Board of The American Journal of Anatomy and had been returned with what seemed to the authors to be irrelevant suggestions for improvement. The chair ruled these remarks as out of order. The chair was overruled. Huntington, Knower and McMurrich participated in the discussion that ensued.
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9. The origin and early development of the posterior lymph heart in the
 +
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chick. Randolph West, From the Anatomical Laboratories of
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Princeton and Columbia Universities.
 +
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Last year at the suggestion of Professor McClure and under his direction, the writer commenced the investigation of the earliest development of the posterior lymph heart in the chick, and the problem has been continued during the present winter under Dr. Huntington at Columbia University.
 +
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As only the early development of the posterior lymph heart has been considered, most of the embryos studied have been between 6.5 and 15 mm. in length, although one or two older ones have also been e.xamined. All of the embryos, with one or two exceptions, were injected with india ink through the viteline vessels, the injection being pushed to the point of extravasation for the haemal capillaries. They were then fixed in Zenker's fluid, sectioned, and stained with eosin and methylblue by Mann's method. A few embryos were preserved entire and cleared by Spalteholz's method.
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The posterior lymph heart arises, in the chick, in the mesench>Tne lateral to the caudal muscle plate and caudal to the hind limb bud. Before the lymph heart assumes the form of a single sac-like cavity there exists in this same area a plexus of l>Tn]jhatic vessels, whicii later coalesce to form the single cavity of the hnnph heart. Both tiie lymphatic plexus and later the lymph heart are in connection with several of the most anterior coccj^geal veins by means of tlieir lateral branches which pierce the caudal muscle plate, drain the lymphatics and then ])ass outward to drain a haemal ca])illary plexus, which bears a superficial relation to the lymphatic plexus. Concerning the origin and development of this iympatiiic plexus two main points have been observed. First, the lymiihatic plexus arises by the confluence of indejiendentmiinjectible lacunae, bounded at first by uidifferent mesencliyme cells whicli become flattened to form an endothelium. Second, both in the lymi^hatic endothelium and m the surrounding mesenchyme an actiAe haemopoesis is taking j^lace. It is also necessary to consider the growth of the superficial haemal capillary plexus in this neighborhood. This haemal cajiillary plexus extends its borders and becomes richer by the addition of numerous independent blood islands wiiich have been dift'erentiated from the mesenchyme.
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94 AMERICAN ASSOCIATION OF ANATOMISTS
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It mus: be rcnu'inhored that all of the processes alluded to; the space formation, the haeinojjoesis. the ormation of groups of l)lood cells to enrich the haemal ca])illarv ])lexus, take ]ilace onli/ m the mesench>nne lateral to the caudal muscle plate and caudal to the hind limb bud, and only during the short i)eri()(l of eml)ryonic history jugt prior to and during the formation of the lymjih heart.
 +
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First, then let us consider the extension of the haemal capillary plexus. In the 6.5 mm. embryo the mesenchAine lateral to the caudal muscle plate is indififerent. In the 7 mm. embryo the lateral branches of the coccygeal veins have pierced the muscle plate and groups of eosmophile cells have appeared in the mesenchyme. In the 8.5 mm. embryo the capillary plexus, drained bv the lateral branches of the coccygeal veins is present in the form of a few small vessels, and the groups of eosinophile cells are very abmidant. By the time that the embryo has reached the length of 10.5 or 11 mm. the groups of eosinophile cells have practically disappeared and the capillary plexus, now draining the area which they once occupied, has reached a high degree of complexity. So it seems reasonable to conclude that these groups of blood cells have been drained off b}^ the capillary plexus.
 +
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The first lymphatic anlagen were observed in the 10.5 mm. embryo. Up to this stage the mesenchyme lateral to the caudal muscle plate has been firm, but now for the fu-st time a distmct loosening of the mesenchjane may be observ^ed near the caudal muscle plate. In the 11 and 12 mm. embrj^o this space formation becomes more and more pronounced, and some of the spaces have acquired a connection \\ith the lateral branches of the coccygeal veins. In the 13, 14, and 15 mm. embryos the spaces have assumed a comparatively large size and many of those spaces .still discomiected with the veins are surrounded b}^ mesenchyme which is ])ecoming flattened to form an endothelium. Of course when these spaces become connected with the veins, the venous blood may back up in them, but this regurgitation of blood from the general circulation is not to be confused with the haemopoesis which is about to be described.
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The formation of groups of blood cells which enrich the haemal capillary plexus has l^een noted. In addition many mesench>Tne cells become rounded antl develop into either the white or the red blood cell line as described by Dantschakoff. Many of these blood cells become included in the mesenchymal spaces which form the lymphatic anlagen, antl when these spaces join the developing lym]-)hatic jilexus, the included l)lood cells gain access to the general circulation via the lym])hatic ])lexus and the coccygeal veins. Other of the blood cells having the power of ameboid movement may migrate through the vascular walls, while from the endothel um of the lymphatic plexus a very active haemopoesis is taking place after the embryos have reached the length of 12 mm.
 +
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All the evidence found from the study of injected embryos leads to the conclusion that the lymphatic plexus, which later enters into the fonnation of the po.sterior lymijh heart, arises by the confluence of independent mesenchymal spaces which connect secondarily with the
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PROCEEDINGS 95
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veins, that these spaces are bounded by mesenchyme cells which become flattened to form an endothelium, and that both in the endothehal walls and in the adjacent mesenchyme an active haemopoesis is taking place.
 +
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Discussed by Huntington.
 +
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10. Experimental mesothelium. William Cogswell Clarke, Department of Surgery, Columbia University.
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Following a purely physical injury which destroys the free surface cells of the peritoneum, pleura, or the lining cells of blood vessels, two possibilities exist as to how regeneration of the damaged zone proceeds.
 +
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(1) cells grow from the periphery of the given denuded area, taking origin from adjacent, previously existing and intact flat surface cells;
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(2) the exposed deep connective tissue cells making up the floor of the injured area as they proliferate, change in form, becoming flattened.
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These experiments were undertaken in reference to the latter possibility in the regeneration of surface cells to learn what happens as regards connective tissue cells in contact with a smooth surface, whether solid or fluid; in other words to learn what change in form takes place in the investing connective tissue cells in contact with the surface of a nonirritating foreign body, placed for a time in the subcutaneous tissue of a living animal.
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Non-irritating soUd and fluid foreign bodies were used: (1) thin, smooth, chemically clean sterile sheets of celloidin were selected as the best non-irritating foreign body. These foreign bodies were introduced into the Jiving subcutaneous tissue of animals through as small a wound as possible and left for varying periods. Sections were cut both at right angles to and in the plane of the surface cells; (2) paraffin was injected into the cornea, a vessel-free structure, in order to observe later the cells that are found in relation to the surface of the foreign body; (3) those surface cells were also observed which were in relation to stationary collections of fluid exudate in dead spaces or cavities present in the depths of a wound tlirough imperfect coaptation of the walls; (4) finally, in order to introduce the factor of friction as well as of pressure of the given foreign body, a mucous fistula was establisiietl. The duct of a dog's gall blatlder was obliterated by ligature and a rublier tui>e was led through the su])stance of the al)dominal wall from the fundus of the gall bladder through the skin of the left flank. At seven days the rubber tube was pulled out and the mucous secreted by the lining epithelium of the gall l)la(l(l(>r flowed continuously through the fistula. Since no bile entered the bladder, the fistula carried a nearly bland fluid. A section of the fistula was removed for study at the end of twenty-eight days.
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Where possil)Ie, sections of all the above specimens were cut in two l)lanes, one at right angles to tlie fining cells in contact with the surfaces of the above foreign bodies, the other tangential to the surface or lining cells. In the case of th(> fining cells in contact with celloidin. a silver salt, protargol. was employed to determine the presence or absence of a mosaic similar to that oi>served in silver iirejiarations of the peritoneal and pleural mesothelium.
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96 AMERICAN ASSOCIATION OF ANATOMISTS
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The sections showed that the cells in contact with the surface of the foreign bodies were changed in form in all the specimens into large, flat cells placed edge to edge result ng in a definite cellular sheet. The silver salt demonstrated a mosaic of black silvered lines marking the cell outlines of the lining or surface cells. The cells that existed in the mucous fistula were large cells forming at i)oints a continuous lining.
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The fact demonstrated in the above experiments that connective tissue cells are changed in form by physical agents into flat, closely disposed cells, the outline of which may be defined by silver salts, makes tenable the conclusion that the exposed connective tissue cells, exposed through sacrifice of surface mesothelial cells of pleura, peritoneum, or pericardium or of the lining endothelial cells of vessels, may become flattened by pressure or friction or both, resulting in regeneration of the surface cells.
 +
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Discussed by Huntington, E. R. Clark and Knower.
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11. The behavior of elastic tissue in the postfetal occlusion and ultimate
 +
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obliteration of certain blood vessels. J. Parsons Schaeffer, From the
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Anatom cal Laboratory, Department of Medicine, Yale University.
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The preliminary' paper, "The behavior of elastic tissue in'the postfetal
 +
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occlus on and obliteration of the ductus arteriosus (BotaUi) in Sus
 +
 +
scrofa," on this work appeared in the February number of the Journal
 +
 +
of Experimental Medicine, vol. 19, 1914, pp. 129-143. Work bearing
 +
 +
further on these problems is now in progress, the results of which will be
 +
 +
published subsequently.
 +
 +
A brief summary of the paper published in the Journal of Experimental Medicine is given here^vith :
 +
 +
1. A study of the histogenesis of elastic tissue in the embryonic ductus arteriosus of Sus scrofa is in accord ^v^th the theory that elastic fibrils are directly differentiated in the outlying i)ortion of the protoplasm of the early connective tissue cell.
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2. In the occlusion of the postfetal ductus arteriosus of Sus scrofa there is early a hypertrophy of the internal elastic membrane. Subsequently there takes place a marked delamination of the thickened internal elastic membrane in the production of new and independent elastic fibers and lamellae. The formation of new elastic fibers from jjrefonned elastic tissue is most abundant where the postfetal contraction of the ductus arteriosus is least marked. These new elastic fibers play an important part in the occlusion of the lumen of the postfetal ductus.
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3. A.side from the exterLsivo formation of elastic fibers from preformed' elastic tissue, in the occlusion of the postfetal ductus arteriosus of Sus scrofa, there are also some elastic fibrils formed from non-elastic elements, apparently from connective tissue cells.
 +
 +
4.. In some recent preliminary work on ligations of the common carotid artery there was found, after an interval of from eight to twelve days, at some points between the ligatures, a slight but ol)vious cellular thickening of the so-called subendothelial stratum. Some of these cells
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PROCEEDINGS 97
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ma}' have wandered from the other coats of the vessel, through the inner fenestrated membrane into the subendothelial stratum; others proliferated from cells in loco. Specific stains revealed near the periphery of some of these cells, that is, in the outlying portion of the exoplasm, ver>' dehcate, granular-appearing elastic fibrils, apparently the product of protoplasmic activity.
 +
 +
The reader is referred to the original paper for the details of this work.
 +
 +
Discussed by H. M. Evans.
 +
 +
12. The earliest blood-vessels in man. J. L. Bremer, Department of
 +
 +
Anatomy, Har\'ard ^ledical School.
 +
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Heretofore it has been generalh' supposed that in man, as in other vertebrates, the first blood vessels appeared in the yolk-sac, between the entoderm and the mesoderm. The early vascularization of the body-stalk and chorion in man, before the presence of intra-embrj'onic vessels, and before the formation of somites, has been long noted, but usually considered as e\idence of a ver\' rapid gro\\'th from the yolk-sac anlagen. In human embryos ^\-ith the medullary plate of about 1 mm. in length, and with recognizable yolk-sac vessels, several authors have described, in the chorion, chorionic villi, and body-stalk, irregular spaces in the mesoderm, some lined with endothelium, .some without defuiite lining; and recently Grosser and Debeyre have separately mentioned also blood islands in the body-stalk, near the allantois. In still younger embryos, with no vessels or blood islands in the yolk-sac, Jung and later Herzog have called attention to accumulations of cells, occasionally arranged around a lumen, seen here and there at the periphery of the mesoderm of the body-stalk, which Herzog regarded as the earhest anlagen of the yolk-sac blood vessels.
 +
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By the recognition of the fact that apparently isolatetl endothelial spaces, or angiocysts, may be comiected by solid cords of endothelium, as demonstrated in a former paper on the origin of the aorta. I was able to reconstruct, in a 1 mm. human embryo in the Harvard Embr^'ological Collection, and in the 1 mm. embryo described in 1913 by Grosser (who most kindly allowed me to study carefully this excellently preser\'ed specimen) continuous nets, composed of angiocysts and solid cords, extending in each embryo throughout the chorion, chorionic villi, and body-stalk. In Grosser's emi)ryo this net anastomoses at one point with the similar net in the yolk-sac; in the other embryo such anastomosis was not fomid. The 'irregular spaces' thus form part of a vascular system. Young blood corjiuscles can occasionally l)c seen within the angiocysts, and the blood island of Grosser is connectetl with the net.
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Grosser first called special attention to the epithelial layer of mesodermal cells, the mesothelium. which forms the coelomic surface of the yolk-sac and of the body-stalk in his 1 mm. embryo, eniiing abruptly at the junction of body-stalk and chorion. Moreover he pointeil out that this mesothelium. mstead of forming a .•^mootii surface. dipjxHl in irregularly, giving in sections the appearance of festoons. I found, in
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THK WATOMICAL RECORD, VOL. 8, .VO. 2
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98 AMERICAN ASSOCIATION OF ANATOMISTS
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both embryos, that the i)rolongations inward, toward the center of the body-stalk, often joined the angiocysts or the cords of the vascular net, and that cells resemblinp; young l)lood corpuscles occasionallj^ were included in these mesothelial strands. Some of the angiocysts not connected with the general net were seen to be inde])end('ntly connected by such strands witii the mesotliolium.
 +
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In the Herzog embryo, in which there are no blood islands or vessels in the yolk-sac, the mesothelium of the body-stalk is not a complete layer, much of the surface at tiie edge of the coelom being represented by mesenchymal processes or fibers. "Where present, liowever, the mesothelium occasionally dips inward, thus lining a funnel-shaped extension of the coelom, and in one case at least the end of this funnel can be traced to a solid cord of cells which runs out into the chorion. Other such cords in the chorion can be traced from the body-stalk for some distance, and can be seen to anastomose, forming a net. Herzog's ' blood vessels,' rings of cells on the outer border of the body-stalk, are found to be tangential sections of the festoons between funnels.
 +
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If we recognize this net of angiocysts and solid cords as vascular anlagen, then the presence of such a net in the chorion and body-stalk, unconnected probably' in one 1 mm. embryo with the vessels of the yolk-sac, and the presence of a similar though much less extensive net in a younger embryo, where yolk-sac vessels do not exist, shows that blood-vessels arise, which are not only independent of those on the yolk-sac, but even antedate the latter. My observations suggest that they originate from ingrowths of the mesothelium as a number of separated cords, angiocysts, or blood islands, which are soon connected by sprouts of endothelium; that these sprouts may extend along the chorion, as a net, enlarging here and there into angiocysts, and later connecting with the yolk-sac vessels.
 +
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Discussed by Schulte.
 +
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ISa. The relation between chemical constitution, physical properties, and
 +
 +
ability of the benzidine dyes to behave as vital stains. Herbert M.
 +
 +
Evans, Johns Hopkins University, Research Associate, Carnegie
 +
 +
Institute of Washington.
 +
 +
These experiments which will be published in extenso with W. Schulemann have shown in brief that the chemical constitution is of no direct influence on the capacity of the dyes to act as vital stains, but is of indirect importance inasmuch as it affects the phj'sical state of the solution of the dye in water. The entire series of dj'es of this class, that is. those made by combining two molecules of an amino-naphtol, naphtol or naphthylamine sulfonic acid with one molecule of a para-diamine base (benzidine, tolodine, dianisidine). act as vital stains in the sense here emi)loyed. for they are taken up and stored in the cytoplasm of those cells which react to trypanblue, Many of these dyes, however, do not diffuse sufiicientl}^ to give a general vital stain of the cells concerned in the whole body. These more 'negative' dyes are very sensitive to
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PROCEEDINGS
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99
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electrolytes which precipitate aggregated dye particles from them. The ultramicroscopic picture of such negative dyes in contrast to that of trypanVjlue reveals their greater richness in molecular aggregates and coarser suspended particles incapable of diffusion. The study has revealed the possibility of higher sulfonated combinations with diffusion rates exceeding that of trypanblue. Such dyes, however, are taken into the cell by virtue of the same forces concerned in the reception of the large particles of negative dyes on the part of cells contiguous to them. This is in turn identical with the forces concerned in the reception of larger particles (bacteria, carbon, and so forth) into the cell, an act long known as phagocytosis and having as its basis from the studies of Hamburger and others surface tension alterations. The research consequently extends downwards very appreciably the size of particles which are known to affect the cell and be received into it by virtue of surface or ' adhesive phenomena.' The cells whose protoplasm is especially sensitive in this way form a sharply defined group by themselves and deserve to be classed together with regard to this common peculiarity, that is, that of reacting to particulate matter. The experimental analysis of cells on the basis of their behavior towards various agents is certainly of the greatest worth in tracing the genetic relations and degree of specificity of cell types.
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13b. The physiology of endotheliuyn} Herbert M. Ev.vns, Johns Hopkins University, Research Associate, Carnegie Institution of Washington.
 +
 +
These studies had for their original aim, an analysis of the vital stain obtained by an injection of various benzidine dyes into the blood stream of living animals. The dyes were first used in this connection l)y Ehrlich and Shiga ('05) and by Nicolle and Mesnil ('06). Trypanblue may be taken as a type of the series. It is formed by the combination of two molecules of 1.8 amidonaphtol 3.6 disulphonic acid with one molecule of ortho-tolodine in alkaline solution, and hence may be represented by the formula :
 +
 +
 +
 +
NH? OH
 +
 +
 +
 +
OH NH2
 +
 +
 +
 +
NaOaS
 +
 +
 +
 +
NS=NJ
 +
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 +
CH3
 +
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\n=n/\A
 +
 +
 +
 +
CHj
 +
 +
 +
 +
SOaNa
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 +
NaOaS
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 +
 +
■SOaNa
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' The work reportrd is based (»n more extensive publieations i,part of which have as yet not appearcil) written by the author in collaboration with: (1) Werner Schuleinann and Felix Wilborn, "Die vitale Farbunp mit sauren FarbstofFcn." Jahresbcricht D. Schlesischen Gesellschaft fiir vaterlandische Cultur. Xaturwissensch. Scktion, Sitzunp voni '^^ Jan.. I'.M.'i Hreslau, 1013. ^2) Werner Schulcmann, "The action of vital stains belonging to the benzidine group," Science, 1014. (3) Ibid "The action of acid a«o dyes and related bodies."
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100 .■VMERIC.^N ASSOCIATION OF ANATOMISTS
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Wlicn 1 per cent aqueous solutions of some of these dyes are injected into the hving animals (by the intravenous, intraperitoneal, or subcutaneous route) there results a profuse coloration of the skin, raucous membranes, sclerae, etc., which is not inimical to health and persists for many days. The color imparted soon after injection is due merely to the free diffusion of the dye into the chief body fluids and tissue juices; but after a short time, the dye is taken up by certain cells in sufficient quantity to be seen as distinct 'dye granules' in the cytoplasm. The concentration of the dye in this manner is jjrobably a storage of the dye particles in intracellular localities or depots where it is relatively separate from the living protoplasm and the phenomenon is only shown by living cells, dead cells staining profusely and uniformly. These reasons justify the term 'vital stain.' All of the cells of the body do not behave in this way. In organs, which are mainly epithelial, the vital benzidine dye may be seen only in cells of the connective tissue framework. In common with most epithelia and with the central nervous system, the blood cells remahi free from any trace of the stain. On the other hantl certain cells react intensively to the dye and become filled with large ])rilliant granules and vacuoles which mark them out in sharp contrast to their mistained neighbors which have had equal access to the dye. Among these ' vitally stained' cells two tj'pes are predominate: (1) The clasmatocytes (resting wandering cells) of the comiective tissues and makrophages of the great serous cavities. (2) The endothelium in certain special localities (liver, IjTnph glands, bone marrow, spleen).
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In atklition to the intense reaction of these cells, certain other cells react less intensively to the stain and are normally foimd with much smaller, often very minute 'granules' of the stain. To such cells belong (1) The fixed connective tissue cells. ('2) The mesothelium, for example, lining the peritoneum and covering its organs. (The kichiey constitutes an exception to the usual negative behavior of epithelium towards the stain for it shows intense dye granules in the e])itlielium of its convoluted tubules, es]iecially those of the first order, and in addition free dye in the loops and in various ])ortions of the collecting system so that the stain intensifies the lines of Peter in its gross morphology; the liver cells also acce))t and store the dye).
 +
 +
The positive behavior of the endothelium in various localities towards the stains, and the negative reaction of the ijlood cells, offers an unusual opjiortunity to distinguish these two cells types in various proliferations due to infection, wound-healing, etc. Many experiments of this sort
 +
 +
A monograph. (4) S. J. Crowe, "Studies on the behavior of endothelium." (5) M. C. Winternitz, and F. B. Bowman, "Ueber die vitalc Fiirbung des Tuberkels," Ccntralbl. f. Bakteriologie, I Abt. G.5 Bd. 1912, Ilcft 4, 5. (6) Ibid "An experimental study of the histoRcncsis of the miliary tuberc-le in vitally stained rabbits," Journal of Experimental Medicine, 1914. (7) J. T. MacCurdy, "Experimentelle iJisioncn des Centralnervcnsystems, untersucht mit Hilfe der vitalen Fiirbung," Bcr. Klin. Woch. 1912, Nr. 36.
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PROCEEDEXGS 101
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have been made and the great proliferative capacity of the endothelium proven. It has been possible to establish beyond a doubt the endothelial nature of the giant cells and epitheUoid cells in miliary tubercles. (Evans, Bo\\'man, Wintemitz, Journal of Experimental Medicine, 1914), Similar clarity has been secured on the active rule of endothelium in experimental thrombosis and emboUsm.
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Much interest attaches to the hght these studies throw on the normal activities of endothelium. The v-ital stain shows that the great mononuclear cells which are set free in the h-mphatic sinuses of h-mph glands, especially in the medullary sinuses, behave identically %\ith the endothelium of these .sinuses and in contrast to the behavior of the mononuclear blood cells. The}' are stained deeplj- \'itally and hence in this respect related to the endothehum. Their actual origin from the endothelium may be seen in all cases where their active formation is called forth. The.se cells have long been known to pathologists and their endothelial nature championed by various observers, above all by F. B Mallorj-. The \-ital .stain establishes this view. These cells are in great abundance in the h-mph glands in cases of t^-phoid fever, anterior pohomyehtis, and a great variety of infections. Their importance in the defense of the body can hardh' be exaggerated. It is of interest that, whereas, singularly few of these cells exist in the general circulation, they may under the influence of disease or any excitant to their formation, appear in the general blood stream. They have in fact been seen in the peripheral blood (ear) by various clinical observers A\'ithout a correct interpretation of their nature being at that time possible (see for example, F. \'an Xiivs, "An extraordinarv blood," Boston Medical and Surgical Journal, CLVI, p. 390, 1907: W B. Bartlett, Pub. Mass Gen Hosp., Vol. 2, p. 390, 1908).
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The experimental production of such a comhtion (where the.se cells, endothel ocytes, exist in the general circulation) can be secured by a long continued injection of the benzidine dyes themselves and in these cases the cells in question are in brilliant contra.st to the mononuclear hematogenous elements by \'irtue of their dye content.
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It is highly probable that the endothehal cells of the organs in question, namely, l^Tuph glands, bone-marrow, liver and spleeh, are of the greatest importance in the defense against bacterial disease and that they form and set free the so-called anti-))odies in immunity.
 +
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Discus.sed by Bremer and Evans.
 +
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14- Concerning certain cytological characteristia^ of the erythroblasts in
 +
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the pig embryo, and the origin of non-nucleated erythrocytes by a process
 +
 +
of cytoplasmic constriction. V. E. E.\rMEL, Department of .\natomy,
 +
 +
Washington University Med cal School, St. Louis.
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 +
Tiic various views which have arisen in the history of the problem of
 +
 +
the origin of the non-nucloated erythrocyte may he briefly i^tatod as m duding that of intra-cellular nuclear disintegration, nuclear persistence,
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the hematoblast theory, intra-cellular formation, and the nuclear ex
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102 -VMERIC.\N ASSOCLA.TION OF ANATOMISTS
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trusion theory. With the exception of the hematobiast theory, all of these views are still being more or less seriously discussed, although at tlie present time that of nuclear extrusion appears to have the greater number of adherents In contrast to these theories the following results of a study of fresh and fixed blood and blood cultures are apparently indicative of another possible mode of origin for non-nucleated red blood corpuscles.
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It was found that the erj^throblast of 1 he pig embryo in place of being spherical, as generally described, may in the later stages of cytomorphosis assume a biconcave or cup shape; its nucleus becomes smaller, more compact, eccentric in position, and not infrequently flattened in form; mechanically rotated, the erythroblasts tend to orient themselves with the nuclear region remaining on the under side, as if loaded ; and that their reaction to changes in osmotic conditions indicates a structural difference between the nuclear and cytoplasmic poles. These observations were discussed with reference to the question of the correlation of the form of the definitive plastid ^vith the enucleation of the erythroblast, the formation of a lecithin containing membrane, hemoglobin differentiation, and the factors involved in determining the eccentric position of the nucleus.
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In some eighty culture experiments non-nucleated erythrocytes or plastids were observed to arise from the parent erythroblast bj^ a process of cytoplasmic constriction. In size, form, hemoglobin content and stain these culture plastids are comparable to the normal circulatory plastids. Observations on living and fixed material indicate the occurrence of a similar process within the embryo. These results accordingly raise the question whether the origin of non-nucleated red blood corpuscles by a process of cytoplasmic constriction rather than by nuclear extrusion or intra-cellular nuclear disintegration does not merit more serious consideration.
 +
 +
A more detailed description and discussion of the data is in press for publication in The American Journal of Anatomy.
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15. The formation of red blood cells in the developing thymus of the pig. J. A. BadertscheTR, Cornell University.
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16. The relations of mitochondria in cells multiplying by mitotic and amitotic division. E. V. Cowdry, Johns Hopkins Medical School. The object was to determine w^hether there are any changes in the
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number, shape or cytoplasmic arrangement of mitochondria during cell division.
 +
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Material: chick embryos, primitive streak stages to 31 somites. Technique: (1) Meves' iron hematoxylin method; (2) same, \vith counterstain of erythrosin; (3) Benda's method; (4) Bensley's anilin fuchsin methyl green method; (5) Bensley's anilin fuchsin toluidin blue method; (0) Bensley's anilin fuchsin methylene blue erythrosinate method and (7) janus green intravitam.
 +
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Results: 1,000 cells were studied by the first method in process of
 +
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PROCEEDINGS 103
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division; 907 were in mitosis and 93 in apparent amitosis. With regard to mitochondria in mitosis: Out of the 907, 73 showed a relative increase in number, 74 a decrease; of the same cells 4 showed larger mitochondria and 259 more granular ones; 361 out of the 907 cells were in the metaphase ; none of them showed mitochondria in the spindle. The observations on amitosis are incomplete.
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The general conclusion is that in the material studied, the number, shape and arrangement of mitochondria during mitotic div.sion is essentially the same as in non-dividing cells.
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17a. Ameboid movement in the corial melanophores of frogs. Davenport Hooker, Anatomical Laboratory, Medical Department of Yale University'.
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1. The pigment granules contained wdthin the melanophores of larv'al and adult frogs are carried in the cell cytoplasm and not in intracellular canals, a'ong rod-like structures nor in a speciahzed type of protoplasm. They show further, no definite relation or arrangement to one another nor to the nucleus.
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2. The melanophores of both larval and adult frogs lie in preformed spaces in the connective tissue and corium, respectivel}'. The melanophores of adult frogs fill the branches of their preformed spaces in the fully expanded phase, those of tadpoles do not
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3. The melanophores of adult frogs have expansion-phase patterns which are constant for each cell and which are forced upon the cells by their preformed spaces.
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4. The melanophores of both larval and adult frogs expand and contract ■within the spaces which enclose them. As the processes of expansion and contraction are performed by means of pseudopodia, these cells are ameboid.
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17b. The developynent of stellate pigment cells in plastyia cultures of frog
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epidermis. Davenport Hooker, From the Anatomical Laboratory,
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Medical department of Yale University
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The prevailing theory iii regard to the presence of pigment in the epidermis is that the cells containing it have wandered in from the underlying connective tissue and that the epidermis j^er se may not elaborate melanine. In this connection the following ol)servations may be of interest.
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In Harrison plasma cu'tures of the e])idermis of 3 to 4 mm. embryos of Kana pipiens, the elaboration of pigment was observed in some of the epidermal cells. At first appearing as a mass of b^o^^•n granules in the immediate vicinity of the nucleus, the pigment gradually spread throughout the entire cell. The ratio of i)ignient -forming cells to those which formed none was about 3 to 1. After the ehiboration of a considerable amount of pigment, these cells, either actively or passively migrated to a position below the non pigment-bearing cells. In this position, several assumed a stellate form by sending out pseudopodia. The cultures were at this time four montiis old. tiio plasma having been fre
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104 AMERICAN ASSOCL\TION OF ANATOMISTS
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qucntly renewed. The cells remained in this condition until the accidental destruction of the i)repara1ions, four and a half months from their hep^innins Whether these cells remain as the permanent pigment cells of the adult frop; epidermis is uncertain and even (juestionahle, hut the observations <lemonstrate that certain ei)idermal cells may elaborate pigment within themselves. Harrison ob.served the formation of pigment in cells of the medullary tube in lymph cultures. Study of tissues, especially in vitro, demon.strates that the ability to form pigment is normally very widespread throughout embryonic development.
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18. Vital staining of the interstitial cells of the testis. R. H. Whitehead,
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Anatomical Laboratory of the University of Virginia.
 +
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The theory advanced thirty years ago by v. Bardeleben that the interstitial cells of the testis are capable of passing through the walls of the seminiferous tubules and there f miction as Sertoli cells received no support from subsequent students of the subject until quite recently. The late E. Goldmann (Die aeussere u. innere Sekretion in Lichte der ' vitalen Faerbung,' Tuebingen, '09) in the course of an extensive study of various tissues and organs by \ital staining, especially w'ith pyrrholblau, investigated the interstitial cells of the testis. He injected subcutaneously into white mice 10 cc. of a 1 per cent watery solution of this dj^e everj' two or three days for ten days, and after killing the animals examined the tissues for the most part in frozen sections. The interstitial cells take the dye and so are readily recognized; the epithelium of the tubules is quite free from it. He states that the interstitial cells can be observed in all stages of migration up to complete entrance ^vithin the tubules. His observations were subsequently confirmed by J. Kyrle (Ueber die Regenerationsvorgaenge in tierischcn u. menschlichen Hoden, Wien, '11).
 +
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It is difficult to see how, if the observations of these investigators are correct, this i)ehavior of the interstitial cells could have escaped the many who have studied them in innumerable sections; and it seemed worth while to repeat the experiments, relying, how'ever, upon thin sections of imbedded material rather than u])on frozen sections. The organs were fixed in 10 per cent formalin, dehydrated in acetone (the dye is (juite soluble m alcohol and in water), cleared in xylol, imbedded in paraffin, and sectioned at 7 micra. Congo red was used as a counter stain; it stains quickly and brings out the walls of the tubules quite distinctly.
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In such sections the interstitial cells are not all stained \\ath the pyrrholblau, l)ut cells containing the blue grahis are sufficiently numerous U) allow conclusions. In none of the sections have 1 been al)le to see any evidence of the migration of interstitial cells into the tubules. Accordingly I conclude that the observations of Goldmami need further confinnation before they can be accepted.
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PROCEEDINGS 105
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Tuesday, December 30th, 9.30 a. m. to 12.00 m. Session for
 +
 +
THE READING OF PAPERS, PRESIDENT RoSS G. HaRRISON AND ViCE
 +
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President Thomas G. Lee, presiding.
 +
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19. The development and growth of the incisor teeth of the albino rat. William H. F. Addison and J. L. Appleton, University of Pennsylvania, Philadelphia, Pa.
 +
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30. Development of the pancreatic duct-system in the pig. George W,
 +
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Corner, Johns Hopkins University.
 +
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The author ha.s injected the pancreatic ducts of pig embrj'os, and reports the following observations: The youngest stage at which the injection of the ducts is possible is at 30 mm. total length. At this time the ducts form a capillar}- plexus with frequent anastomoses. At 40 mm. certain strands of the plexus begin to dilate, and at 50 mm. they have formed a well-marked main-duct. The picture so closely resembles the formation of blood-vessels from plexuses that it is suggested that there may be a flow through the pancreas at an early stage, thus bringing about the formation of the main duct-channel (In discus.sing the paper, Professor Bensley confirmed the .statement that the pancreas secret-es at a very early period). At 60 mm. there begin to grow out from the anastomosing capillaries little branching, non-astomosing t^\-igs, similar to those found by Laguesse in the sheep (by recoiLstruction from sections) and called by him primitive vesicles. These t\\igs replace the plexus, and grow into the great duct-tree of the adult. Above 110 mm. no anastomoses between ducts may be found by the injection method. This work will be pubhshed in full as part of a paper on "The structural unit and growi;h of the pig's pancreas."
 +
 +
Discussed by Bensley, Scammon and Corner.
 +
 +
21. On the pelvis of the human embryo. John Warren.
 +
 +
Two features of the development of the human pelvis were present^ at the meeting of Anatomists in December — one, the early development of the inguinal region and the formation of the gubemaculum testis, and secondly, the early development of the muscles of the jierineum and pelvic floor. Observations were made on human embryos of IS mm., 10.3 mm., 22.8 mm., 29 mm., 37 mm., and 42 mm. head-rump length, all taken from the Harvard ICmbryological Collection. The first apl^earance of the gubemaculum testis was obser^-ed in an embr>'o of 18 mm. It appears at first as a slight thickening in the lateral wall of the abdomen ijefore there is any trace of the abdominal musculature. This thickening forms a crest in the ventro-lateral wall of the al)domen. the inguinal crest, which becomes attached to the lateral portion of the urogenital fold, and in this way a .'^mall recess in the coeloni is cut off behind the inguinal (T(\«<t. In an emliryo of 1«) mm. the mass of connective tissue which represents the gubemaculum is more clearly diflferentiated.
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lOG AMERICAN ASSOCIATION OF ANATOMISTS
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and it streams out into the connective tissue of the abdominal wall ^\^thout any very distinct pcrijiheral limits. In an embryo of 22.8 mm. the three layers of the abdominal musculature are now distinct. The ^;ubemaculum can be clearly differentiated from them and its peripheral (nid is already presenting at the luture external abdominal ring. The ridge formed by the gubemaculum on the ventro-lateral side of the abdominal wall is very marked and in frontal section the gubemaculum appears as a roundish mass of mesenchyme with fairly distinct outlines. In an embrj'o of 29 mm. essentially the same conditions are found, but we have here the first traces of a processus vaginalis, which extends through two or three sections on the mesial aspect of the gubemaculum, forming a tiny pouch penetrating the substance of the abdominal wall. The elevation formecl by the gubemaculum over the ventral-lateral aspect of the abdominal wall is very striking. In an embryo of 42 mm. the gubemaculum appears as a large oval mass of tissue entering the al)dominal wall at the internal abdominal ring, which is clearly differentiated. The processus vaginalis extends through a dozen or fifteeen sections, being found principally on the mesial aspect of the gubemaculum, and also for a limited extent on its lateral aspect. At the external abdominal ring the gubemaculum becomes directly continuous with a fan-shaped mass of mesenchyme which spreads up and down in the subcutaneous tissue of the lower part of the abdominal wall. This represents the ligamentum scroti, and extends do\\Ti to the base of the future scrotal folds. As regards the development of the muscles of the perineum and of the pelvic floor, the first distinct tra- e§ of the levator ani muscle and of the external sphincter muscle of the rectum could be clearly observed in the 18. mm. embryo. They appeared as thickenings in the mesenchyme and were only fairly well differentiated from the surrounding tissue. In the 22.8 mm. enil)ryo the two muscles were very well marked. The levator ani muscle especially shows at this stage almost its exact adult relations to the rectum and to the genitalia. The topographical position of the future ischio-rectal fossa was very clearly defined. No trace could be observed at this stage of the muscles of the perineum, though the perineal nerves and vesse's were very distinct. In the 29. mm. embryo the levator ani and the external sph ncter were essentially the same as in the pre\^ous stage. The first trace of the ischiocavemosus muscle and of the bulijocavernosus muscle appeared as a thin superficial layer of fil)ers, lying in the first instance on the mesial aspect of the primitive crus penis, and on the lateral aspect of the future spongy portion of the penis. In the 37. mm; embryo all these muscles were very sharply defined. The external s]ihincter of the rectum formed a suprisingly thick ring-like mass of muscle, surrounding the lower end of the rectum. The levator ani was distinctly divided into two parts, — an anterior part, fairly thin which covered over the lateral wall of the rectum, and a thicker, rounded, posterior portion, which had no direct relation to the rectum. The bulbocavemosus and ischiocavemosus muscles were very clearly outlined and the perineal nerves could be traced directlj' mto them. Only a very ill-defined con
 +
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PROCEEDINGS 107
 +
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densation of mesenchyme gave a slight hint of the triangular ligament and of the transversus perinei muscle, these layers being apparently developed later than this stage.
 +
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22. A case of hemicerebellar atrophy in a chiUl. Oliver S. Strong,
 +
 +
Anatomical Laboratory, Columbia University.
 +
 +
The clinical symptoms were not carefully studied but the following were communicated, from memory, by the physician in charge.
 +
 +
The child was three years and four months old. It was small, its head was small and all its movements weak and unsteady. It sat up all day in a high-backed chair. It could walk, but with a very uncertain gait, staggering, and with a tendency to hold fast to chairs. It was unstead}' in grasping a proffered object. It could move its head slowly, and continuously moved it from side to side, usually humming a tune (without words). It had a marked bilateral nystagmus, exact type not noted. It was mentally very weak, appeared very dull, took little interest in toys, and so forth. It talked poorly and indistinctly, with scarcely any formed sentences. Death was due to measles and broncho-pneumonia.
 +
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Inspection of the external surface of the brain showed the follo'^ing: The left hemisphere of the cerebellum was entirely absent except a small lobe apparently representing the flocculus. The median lobe was present, though in a defect of this kind, obviously congenital, an exact identification of parts is difficult. The right ohve was apparently entirely absent, the left olive normal. The cranial nerves were apparently normal. T! e pons was very asymmetrical, the transverse fibers and middle peduncle were normal on the right side but enormously reduced on the left side, so much reduced that the VII and V nerves issued in immediate contiguity with each other. The pons protruded much more on the left side. The left pes was wider than the right.
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 +
A dorsal view of the brain stem, with the cerebellum removed, showed a curv^ature of the median line with the convexity toward the left. The left clava and cuneus were longer than the right, extending further cephalad. The two trigona hypoglossi were nearly sjTnmetrical, the left ala cinerea, the left eminentia abducentis and the left trigonum acustici also extended further cephalad than tht right. This as^Miimetri' of clavae, cunei, alae cinereae and trigona acustici would apparently be due to the unec|ual pressure upon the medulla of the asNTiimetrical cerebeLum. The left corpus restiforme was much small than the right.
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The right superior peduncle was much larger than the left. Some transverse cuts made through the cerebellum did not reveal any left nucleus dentatus. The inferior coUiculi were asymmetrical, the left being narrower, more prominent and protruding farther caudad and its brachium appearing less prominent than that of the right. The left superior coUiculus appeared to be largely lacking. There appeared to be some atrojihy in the jiostcrior frontal, central and possibly part of the parietal l()l)es of the right cerebral hemisphere.
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Sections wore made and stained i)y the Weigert-Pal method, somewhat modified. They showed the following:
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108 AMERICAN ASSOCIATION OF ANATOMISTS
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In the cervical cord no asymmetry was noted. The spinocerebellar tracts are present on l>oth sides ami the lighter areas, usually taken as marking the location of Hehvig's tracts, are present on both sides. There is no evidence of an absence of a rubro-s])inal tract on one side but this as\inmetrv ])robal)ly would no ' e discernible if present.
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In the medulla, whether there is an asymmetry of the arcuate nuclei is somewhat doubtful. No asymmetry was observed in the external nuclei of the columns of Burdach nor was there any noticeable as\'mmetry in the lateral nuclei. All of these three structures then, as far as they are connected with the cerebellum, would either be connected equally with each half or only with the median lobe and flocculus.
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The left olive is perhaps somewhat hypertrophied. The right olive is represented by a smal U-shaped mass of gray \\'ithout minor folds which extends from about the same level caudally to nearly the same level cephalad as the left olive. The caudal part of this atrophic right olive is the larger and there can also be made out vestiges of a median and dorsal accessory olive. The olivo-cerebellar fibers from left olive to right cerebellum are conspicuous, those from right ohve to left cerebellum nearly a))sent. It is obvious that the olive is almost entirely or, not improbably, entirely connected with the opposite half of the cerebellum, for the left fiocculus-like lobe and left half of the median lobe would l)e sufficient to account for the presence of the small right olive. The left central tegmental tract is much more conspicuous than the right. The right medial lemniscus is larger than the left. The reason for this is not entireh^ apparent. The right nuclei pontis are largely but not entirely absent. There is a small, atrophic left middle cerebellar peduncle. On the other hand the left nuclei pontis appear to be, perhaps, somewhat hypertrophied. The vicinity of the medial lemniscus is invaded by masses of gray apparently connected \\ith pontile fibers and representing aberrant pontile nuclei. Either from these nuclei or from the left pons, bundles of fibers resembling transverse pontile fibers cross the median line in company with the trapesius fibers and appear to join the opposite middle cerebellar peduncle. These fibers would appear to be aberrant t];;^nsverse pontile fibers. There could not be detected any marked a.symmetry of the perpendicular pontile fibers. The left crusta is about three times as wide as the right, mdicating the absence of the pallio-pontile fibers in the latter. The substantia nigra is correspondingly unequal. The central gray of the right locus coeruleus is thicker than the left and contains a number of bundles of aberrant fibers. These fibers apjjear to pass caudad to a region where it would seem they must be connectetl \Wth the juxta-restiform Ijody but this could not be determined with certainty OAving to defects in the series. These fibers also pass into the reticular formation accompanying or connected with peculiar .streaks of gray passing through the reticular formation ventro-latcrally. Some of these fibers ])os.sil)ly join the pons. Further cephalad, in the isthmus, a conspicuous bundle emerges from the central gray of the riglit floor of the ventricle and pa.s.ses ventrally in the raph^, possibly entering the pons.
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PROCEEDINGS 109
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There is a minute left nucleus dentatus and a very small left superior peduncle. The practical absence of this peduncle causes a marked asymmetry in the arrangement of the lemnisci of the two sides. The right nucleus ruber is largely absent, whether completely absent could not be established owing to a defect in the series.
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From the above it is evident that the afferent pallioponto-cerebellar path to the left cerebellar hemisphere and the efferent dentato-rubral path from the left cerebellar hemisphere are nearly entirely absent. Of the inferior peduncle, those spino-cerebellar connections, whether interrupted in cord or bulb, which are supposed to be afferent to the median lobe appear to be practically intact; the olivo-cerebellar part of the inferior peduncle however, is nearly absent and must be regarded as passing principally or entirely to the hemisphere, in accordance with the work of other recent investigators
 +
 +
Discussed by B. D. Myers and Harrison.
 +
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23. The morphology and development of the floor of the interhrain in
 +
 +
mammals. Frederick Tilney, From the Department of Anatomy,
 +
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Columbia University'.
 +
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The object of this paper is to present a study of the floor of the interbrain in mamals by means of the reconstruction method. This method was applied to several forms, among which were the adult cat, dog, rat, and rabbit. Observations were also made upon serial sections obtained from a number of other mammals including marsupials, rodents, ungulates, carnivores, primates and man. In the light of this study the third ventricle reveals itself as a more complex chamber of the brain than would appear from the usual description of it. Its complexity is due to the presence of several accessory recesses, each of which is indicated upon the surface by an eminence or protuberance. Some of these structures have previously been recognized but their phylogenetic significance has not been altogether clear. By reconstructions demonstrating the development of the diencephalon in the cat, it was possii)le to trace the ontogenetic history- of each element m the floor of the ventricle and in this way homologize the structures in the basal part of the mammalian interbrain with those in the same region of the selachian brain.
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A reconstruction model of the ventricular floor of the adult ilomestic cat shows the followhig recesses and emuiences, enumerated from the optic chiasm caudad toward the mamillary body.
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Accessory recess Surface eminence
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Recessus praeopticusl . . crista supraoptica
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Recessus intraopticusj
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Recessus tuberis eminent ia sacrularis
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Recessus infundibuli infundibulum
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Recessus processi infundibuli processus infundibuli
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Recessus premaniinillaris eminent ia premammillaris
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110 AMERICAN ASSOCIATION OF ANATOMISTS
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Several eminences appear on or adjacent to the floor, but contain no recesses. They are the emincntiao hiterales (protuberant lateral portions of the tuber cinereum) the corpora mammillaria and the interpeduncular ganglion.
 +
 +
The develo])inent of all of the above structures depends upon changes in three distinct areas of the interbrain. As thej^ appear in the 19 somite cat embryo these areas are the hypencephalon of Kupffer, the primitive optic groove and the lamina terminahs. The more important changes occur in the hypencephalon. This region in the 4 mm. embryo (about 26 somites) is divided by a ridge in such a way as to form a dorsal and a ventral sac.
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\'on KufTper has sho"SATi similar sacs in the development of selachians, ganoids, teleosts and amphibians. Corresponding evaginations have also been observed in the hj-pencephalon of sauropsids. In fish the dorsal sac gives rise to the posterior lobes, while from the ventral sac arise the inferior lobes and the saccus vasculosus.
 +
 +
In the 10 mm. cat embryo two small evaginations have made their a])pearance dorsal to the dorsal sac. The more ventral of these two evaginations becomes the corpora mammillaria, the more dorsal, the ganglion interpedunculare.
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Later stages in the development of the cat up to 70 mm. shows that the ventral sac gives rise to saccular eminence, inf undibulum and infundibular process. From the dorsal sac develops the praemammillary eminence. This latter eminence is a conspicuous' feature of the floor of the third ventricle in such forms as the hon, grizzly bear and leopard. It is present in all the mammals examined by the writer and, although somewhat obscured in the adult human brain, is well marked m the child.
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The evidence presented seems to justify the following homologies:
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Mammalian brain Selachian brain
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Eminentia saceularis lobi inf eriores
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Infundibulum and processus infundibulum saccus vasculosus
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Eminentiae laterales lobi laterales
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Eminentia praemammillaris lobi posteriores
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The intraoptic recess which communicates with the third ventricle and extends for a considerable distance through the optic chiasm into the optic nerve is the remnant of the primitive optic recess. Its clinical significance in its possible connection with choked disc due to increased intra-cranial pressure is, at least, suggestive. This problem will require further observations upon pathological material as well as experimental controls, the result of which \v\\\ be reported in a subsequent paper.
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£4' On the so-called 'BuWar' portion of the Accessory nerve. D. Davidson Black, Anatomical Department, Medical School, Western Reserve University
 +
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The following observations have been made from a series of transverse sections through the medulhi and upper three cervical segments of a new-bom balje, prepared by the pyridine Cajal method of Ransom.
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PROCEEDINGS 111
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This series represents a part of the material prepared in the course of a study of the calamus region which is as yet incomplete. However, certain facts bearing upon the relations of the so-called 'bulbar portion' of the nervus accessorius have been noted. These are of interest when contrasted with the usual description of the origin and relations of this structure obtaining in current texts.
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The origin of the spinal portion of X. XI has been definiteh' established and can be made out quite well in this series. The nucleus occupies a central and somewhat lateral position in the anterior horn in the cord, and extends upwards into the medulla to about the level of the lower third of the pjTamidal decussation. The cells are of tj^pical somatic type, and the emergent fibers pass to the periphery in the well known geniculate manner, so that in no transverse section is the whole course of these fibers displayed.
 +
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The ventro-mesial cell group of the anterior horn may be traced as a practically uninterrupted column into the hypoglossal nucleus.
 +
 +
Laterally the cells of the anterior horn become scattered, and lose their characteristic grouping when traced into the formatio reticularis of the medulla.
 +
 +
There is a very apparent interval between the cephalic extremity of the cervical accessory nucleus and the caudal end of the ambiguus cell group.
 +
 +
The dorsal nucleus of the vagus may be traced as a verv^ distinct cell column almost to the lower end of the p\Tamidal decussation. In other words, this nucleus overlaps that of the accesson,- nerv^e in the lower medulla.
 +
 +
There is thus a space between the cephalic extremity of the nucleus of the accessory nerve in the cord and the lower end of the cell group usually described as giving rise to its bulbar fibers, namely, the nucleus ambiguus.
 +
 +
In the interval, in the series described, there are numerous fibers to be seen taking their origin direct in the dorsal nucleus of the vagus, and passing to the periphery ventral to the substantia gelatinosa Rolandi. In their emergent course these fibers arc cur^-ed laterally and caudally so that in a transverse section their whole extent is not seen. These fibers presumably make up the caudal portion of what is usually described as the bulbar part of X. XI.
 +
 +
At a higher level, where the nucleus ambiguus becomes definitely recognizable, fibers arising from this source take the well known indirect course to the periphery, joining on their way fibers from the dorsal vagal nucleus, and passing ventral to the substantia gelatinosa Kolandi. This last point is tiie only one in which these fillers ditYer from those usually described as giving rise to the vagus projior.
 +
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(Conclusions: (1) There is no morjihological ground for the consideration of the bulbar XI apart from the vagus in the si>ecimen I have studied; its nucleus of origin is but the caudal jirolongation of the dorsal vagal nucleus. (2) That Kolliker's distinction between the emergent fibers of the bulbar XI and those of IX and X. leased on the observations
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112 AMERICAN ASSOCIATION OF ANATOMISTS
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that those of the former i)a.^s out ventral, wliile the hitter pass through or ilorsal to the substantia gehitinosa ]{()hin(H. is without significance. (3) The extent of the vagal and accessory nuclei corresponds practically to Kai)pers' findings in Dideljihys.
 +
 +
In view of the recent investigations of \'an Gehuchten, Molhant, Raiison, Kappers, ]\Ialone and others, together with the above oljservations, would it not be better to consider this structure as part of the vagus projier and restrict the term nervus asccessorius to the present spinal portion of this nerve?
 +
 +
Discussed by Streeter.
 +
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25. Further observations on the sound-transmitting apparatus in Uro rff'/fN'. H. D. Reed, Zoological Laboratory, Coniell University.
 +
 +
In 1909 Kingsbury and Reed' jmblished a paper in which they stated that tN-pically the somid transmitting apparatus in Urodeles is composed of two elements appearing at different ages of the individual and differing in origin. The element which they called 'columella' is the first to arise during develoj^ment and is wholly extraotic in origin. It appears as a cord of cells which is comiected from the very outset with the squamosum. The ventral end of the cord reaches the middle of the fenestra vestibuli where it spreads out into a broad plate which becomes jointed to the fenestral membrane. The other element called 'operculum' does not arise until just before transformation. It is otic in origin since the major part, at least, is cut out from the walls of the ear capsule caudad of the foramen. It acquires connection with the suprascapula through the M. opercularis. After the operculum arises the columella fuses to a greater or lesser extent with the cejihalic lips of the fenestra but retains its connection witli the suspensorium through the stylus and its ligament.
 +
 +
Certain forms, as for example Triton, Diemictylus, the Plethodontidae Desmognathidae and Amphiumidae, were found to ])ossess but a single (.'lement in the fenestra vestibuli. In Triton and Diemictylus this element possesses the connection with the suprasca])ula through the M. opercularis and in every respect of structure and relations 't is identical with the ojjerculum of the typical forms and develo]iment shows this to be true. The columella very early in larval life fuses completely with the cephalic lips of the fenestra.
 +
 +
In the rietliodontidac, Desmognathidae and Am])hiumidae the smgle fenestral element has the structure and relations of both columella and operculum. The ce])halic portion of the ))late possesses a stylus which is connected vnth the suspensorium while in the caudal portion is found the perilymphatic prominence \\'ith a muscle extending to the sujirascapula. The cephalic part of tiie plate is always fused at its ventral angle with the lips of. the fenestra.
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' H. I'\ KinKHl)iiry and II. D. Uecd. Tlit- coluinella auri.s in Anipliibia. .lour. Morph., vol. 20, H»0<), |)p. r)4(>-r>2S.
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PROCEEDINGS 113
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The natural inference is that the single element in these forms represents a fusion of the two elements, columella and operculum. A study of complete developmental stages shows that this is true but the greater part of the fenestral plate represents operculum or at least tissue which is otic in origin.
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A brief description of the development in Spelerpes bi.slineatus will illustrate the conditions in all. The fenestra in Spelerpes is morphologically larger than in Ambystoma since it represents both the primary and secondary- fenestrae of that form. The columella arises in the typical fashion but instead of spreading out to form a plate which fits into the fenestra it remains as a cylinder of cells extending horizontally across the fenestral membrane and when fully chondrified does not increase in size or in any way spread out upon the membrane. The connection with the ear capsule is very early estabUshed by theupw^ard growth of the lips of the fenestra. In the caudal portion of the fenestral membrane which corresponds in relative position to the operculum of Ambj-stoma separate centers of chondrification arise and through groT^-th eventually meet. In this way there is formed a sieve-like plate which fuses ^\^th the extraotic rod of cells. Later it becomes completely chondrified. The fully formed plate, therefore, represents two elements, which, while fused in the definitive structure, are distinct in their origin. The extraotic rod of cells becomes the stylus of the fenestral plate and constitutes the representative of the columella in these forms. The fenestral plate, while in no part is cut out from the ear capsule, is otic in origin and to be regarded as the equivalent of the operculum.
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The conditions as described above in Spelerpes are those which prevail in the Desmognathidae and Amphiumidae in all of which a single fenestral element is present. Siren possesses but a single fenestral element which is lacking in both suspensorial and shoulder girdle connections. The need of developmental stages for study leaves the nature of the plate unsettled.
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26. The tendency toward adjustment of posture in transplanted labyrinths, G. L. Streeter. University of Michigan (This paper \\-ill be printed in full in The Journal of Experimental Zoolog\', vol. 10. 1914).
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27. On the development, attachment and action of the teciorial membrane. Irvixg Hardestv. Tulanc University.
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The begimiing of the tectorial membrane ajipoars m foetal pigs of 3 to 5 cm. long as an imperfectly fibrous, transparent film lying iijx)n and produced by a thickening of the epithelium of the foetal cochlear duct along its axio-basal aspect. This b;md of tlucker epithelium l>ecomes the greater epithelial ridge" of the later stages.
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In foetuses of 6 to 9 cm., the greater ridge has become thicker and* broader ami appears only in the l>ase of the cochlear duct, due to the invasion of its axial side i)v the mesencylunal s>iicytium to form the vistibular lip of the spiral lamina. As this invasion proceeds, the :L\ial cells cease to prothice tectorial membrane and tiuis thr axial edge of the
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THK ANATOMIC.U. RECORD. VOL. 8, NO. 2
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114 AMERICAN ASSOCIATION OF ANATOMISTS
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nu'iul)raiu' remains thin and is licld adherent u])on the vostil:)ular Yip. The now thicker film ujwn the greater ridge shows structure characteristic of the tectorial memlirane. At the extreme lateral or outer margin of the greater ridge there is differentiating a line of cells, 2 or 3 wade, which cells are hroader than tiieir neighbors and when traced through the later stages heeome the rods of the organ of Corti, these cells and a few others about them increasing in height to from the "lesser epithelial ritlge" (anlage of the organ of ("orti) lateral to the greater ridge and tectorial nu'mbrane.
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The greater ridge increases in both width and thickness, acquiring its maximum width in foetuses from 13 to 16 cm. Its cells are steadily contributing thickness to the basal side of the tectorial membrane, comiected with it by 3 to 6 delicate fibers continuous from the distal end of each cell. The lateral or outer edge of tlie tlevelojiing t( ctorial membrane here conforms closely to the rounded lateral margin of the greater ridge, cu]5i)ing around this margin and fitting into the groove iietween it and the lesser ridge, the basal cells of this rountled margin coming to lie at almost right angles to the axis of the cochlea in order to i)e peri)endicular to the edge of the membrane they are forming.
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During the earlier stages of their differentiation, the cells of the lesser ridge (beginning organ of Corti) like\\ise produce a few filamentous threads and these; threads are seen extending from their cells of origin and adhering to tiie vestibular surface of the outer edge of the developing tectorial membrane. These threads disintegrate in the later stages and thus contribute no ])art of the adult tectorial membrane. In structure, the tectorial meml)rane consists of a hyaline matrix, jjrobalily keratin, in gelatinous form, in which ar(> imbedded the very numcn-ous fine fibres or threads of uniform size, the varying directions of which are determined by the varving directions of the cells producing the membrane during the different stages of the increase and decrease of the greater ridge. The filaments j^roduced l)v the cells of the early lesser ridge have ceased to grow in jiigs of 1() cm., are never embedded in a matrix as are those of the tectorial membrane, are largely di.sintegrated at 19 cm., and have totally disajipeared in foetuses near term.
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In jiigs from 13 to 10 cm. the cells forming the axial side of the greater ridge begin to decrease in height and number. Beginning at this axial margin, the cells gradually become divorced from the membrane they have produced, the process of divorce proceeding outwardly, the divorced cells receding and decreasing in number till they become the fewer, flattened cells lining the .spiral sulcus of the adult. The last cells to l)ecome separated from their iiroduct are thus those immediately adjacent to the inner sustentacular cells of the organ of ( 'orti. The recession and decrca.se in number is accom])anied by an a])i>reciable narrowing of the basal floor of the spiral sulcus. In foetuses of 15 cm., the width of the greater ridge may measure in the ai)ical coils of the cochlea twice the width of the basal floor of the spiral sulcus in the adult. In the ba.sal coil this decrea.se in width is only about one third of the width at 15 cm.
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PROCEEDINGS 115
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This developmental decrease of the distance between the orj^an of Corti and the vestibular lip of the spiral lamina results in the change in position of the organ of (.'orti with reference to the t\Tnpanic surface of the tectorial membrane and, of course, in a tearing free of the membrane from any attachment it may have with structures lateral to the vestibular lip of the spiral lamina. In the apical coils the membrane of the adult may come to extend not only over the entire organ of f'orti but also over from 9 to 13 of the cells of Claudius. Thus the tectorial membrane is only attached along its axial edge upon the vestibular lip of the spiral lamina. Its outspanning portion is of necessity free.
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From various measurements taken from 9 growth stages and from the adult, the most probable explanation of the final position, well under the tectorial membrane, acquired })y the organ of Corti is that it is due to a groAvth in width of the vestibular portion of the spiral lamina resulting in an outer or lateral projection of the membrane over the organ, and in greater part to an actual shifting axialward of the organ of Corti coincident with the disintegration of the greater ridge.
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In the adult ])ig the tectorial membrane is about 30 mm. long. In the apical turn it is about 5 times as wide and 5 times as thick as is its basal end; its area in section in the apical turn is approximately 21 times and its volume 95 times the area in section and the volume of its basal end.
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Teased fresh specimens of the tectorial membrane show that it decreases evenly from its larger, apical towards its smaller l^asal end and it has sufficient elasticity, probably due to the arrangement of its fibers, to maintain its position over and approximate to the organ of Corti. Longitudinally it is exceedingly flexible, offering practically no resistance to stress applied transversely to its long axis.
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An apparatus constructed to simulate the essential parts of the auditory apparatus is thought to indicate something of its functional action. The external meatus is represented by a large mouthed megaphone over the smaller end of which is stretched a piece of gold lieater's skin for the tympanic membrane. The cochlear duct is a narrow. thick-walle<l box, 42 inches long, with a wooden spiral lamina and thin wooden l)asilar membrane and with drum-skin covered ojienings rejiresiniting the fenestrae, at the basal ends of the scalae. The tectorial meml)rane is represented by a i)iece of very thick elk's hide pared to the shape and approximate i)ro]:)ortions of the membrane and softened, and its thin edge affixed uiion the vestibular lip of the s])ir;U lamina. At 6 equal intervals fine platinum wires are jiassed througii the membrane to make contact below witii small copjier jilates re])resouting the organ i>f Corti. the ])lates being continuous with wires and ca])able of being raised or lowered by means of adjustment screws Inuieath tiiebox. Batteries are connecttnl with tiie i)latinuni and copjier wires at each interval. The box, wiiich has a water-tight, glass top, is comjiletely filUnl witii ilistilled water, the top fastenc^l down without hiclusion of air, and a rejiresentative of the ossicles is i)laced pressing b(>twtM'n tiie tympanic niemlirane and the skin rejiresentijig the fenestra ovalis. Telephones are interposed in the circuits made by contact of the jilatiTUun wires with the copjxT plates.
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11(3 AMERICAN ASSOCIATION OF ANATOMISTS
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Ordinary organ roods, having kno\Mi vibration frequencies, were used chiefly in the oxijoriments. Tliese were sounded into the megaphone. It was found that any viljration from a stop upon the laboratory floor up to the note G below 'middle C" (196 vibrations per second) would throw the membrane into vibration throughout its entire length. This note caused the membrane to vibrato more strongh^ at the fourth inter\'al from its smaller end than at any other inters-^al, indicating a certain amount of resonance in this region. A, the next note above, produced vibrations at all intervals of the membrane except the sixth, the apical end. Middle C, 2(31 vibrations per second, was damped out at the fourth interv'al. Notes above F, which is 349 vibrations per second, produced vibrations in no part of the membrane. Occasionally a note other than G produced more pronounced vibrations at a certain intorwal than at others but evidence of the existence of resonance were unsatisfactory. x
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From results with this comparatively coarse and crudely constructed apparatus, it is suggested that notes up to a certain pitch throw the entire natural tectorial membrane into vibrations of corrresponding frequencies and that sensations of pitch are determined by the frequency of impingement of the membrane upon the auditor}^ hairs, intensity being determined by the amplitude and qualitj^ by the qualitrv of the wave motion imparted. Further, that the highest notes within the range of the auditory a])i5aratus throw, according to their frequency, only varying extents of the smaller, basal end of the tectorial membrane into vibration, being so damped out in passing toward the apex of the cochlea, overcoming friction, the inertia of the endolvinph and that of the membrane itselJf, as not to produce vibrations in the heavier, apical portions. Finally, since, if the tectorial membrane varying in mass as it does were cut into a number of segments, each segment would have a different natural vibration frequency, it is possible that it exercises a certain amomit of resonance. The diaphragm of the telephone possesses a small amount of resonance. The above results suggest a modification of the telephone theory of hearing.
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Wednesday, December 31, 9.30 a.m. to 1.00 p.m. Session for
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THE reading of PAPERS, PRESIDENT RoSS G. HaRRISON AND ViCE
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President Thomas G. Lee, presiding.
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28. Regeneration of medullated nerves in the absence of the embryonic nerve fiber following experimental non-traumatic degeneration. Elbert Clark, Hull Anatomical Laboratory, University of Chicago. In this study degeneration of the modullatod nerves was brought about in the domestic fowls by a ])rolong('d exclusive feeding of polished rice (finest fjuality of white table rice). There frequently resulted a pronounced paralysis of tlie logs which was always accompanied by marked degeneration in the medullatocl fil)ers of the sciatic nerve. Recovery of the fowls and regeneration of the nerves was accomplished by returning the fowls to an adequate nutritive diet.
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PROCEEDINGS 117
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In such fowls the nerve fibers are mtact during degeneration and all traumatic and infiamatory effect produced by cutting the tissues and the nerve or of tj-ing the latter are obviated; the process of degeneration can be stopped at almost any stage or greatly prolonged, and several stages of degeneration are to be observed in different fibers of the same nerv^e. In regeneration the possibility of an ingrowth o fibers from other nerves into the regenerating nerve under observation is eliminated and repair of the medullated nerves can be induced after any stage of degeneration.
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Ten to twenty percent of the medullated fibers of the nervus ischiadicus showed a complete fatty change of their medullated sheaths into globules of degenerated myelin and a segmentation or granulation of their axis C3^1inders. No multiphcation of the nuclei of the neurile mm a sheath could be observed and consequently no "embrj'onic nerve fibers" or "Band-fasem."
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During recovery these degenerated fibers attained new axis C3iinders and the medullary sheaths returned to normal. In other words, regeneration has been observed to follow degeneration in medullated ner\'e fibers without passing through the embrj'onic nerve fiber or Band-faser stage.
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By prolonging the degenerative process there resulted a multiplication of the nuclei of the neurilemma sheath. This and other experiments tend to show that the embryonic nerve fiber may be coincident -sNith a late stage of degeneration. It may not represent an early stage of regeneration and its presence does not signify an attempt at regeneration on the part of the medullated nerve fiber.
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In the absence of the embryonic nerv'e fiber, the degenerated myelin was absorbed with extreme slowness, persisting as droplets after one 3'ear and fourteen days. On the other hand, where the embryonic nerve fiber was formed the degenerated myelin quickly disappeared from the fiber. The conclusion is reached that the proliferating nuclei of the neurilemma sheath participate in the resorption of the degenerated myelin.
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In regeneration a new axis cylinder was attained by outgrowth and in the absence of the embryonic nerve fiber. The new axis cylinder grew do^^T^ the old medulary sheath which latter still contained large globules of degenerated myelin and fragments of the old axis cylinder. The outgrowing axis cylinder was seen to brimch, and in cross-sections of the n(Tves two new axis cylinders were obsers-ed ^\^thin the same old medullary sheath. The embryonic ners'e fiber could, of course, play no part in the formation of the new axis cylinder, either by autor^eneration or l)y outgrowth.
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No indications of regeneration were observed in the fibers of the spinal cord.
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Discussed by Sheldon.
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29. Some changes in the mrvou.'^ system of the metamorphosing tiulpoles of Rana pipiens. Elizabeth H. Dunn, Woods Hole, Miiss.
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118 AMERICAN ASSOCIATION OF ANATOMISTS
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30. The development of the cranial si/nipath^'tic (jancjUa. A comparative
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studij. Albert Kuntz, 8t. Louis rnivcrsitv School of Medicine.
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Tlie oliservations on wiiich the followiufi; conchisions resardinf; the development of the cranial syni))athetic f^anjilia in fishes are based were made on i)re)iarations of embryos of the common toad fish (Opsanus tail.) The .>^ix symiiathetic fianglia on the cranial portion of the s>Tnpathetic trmik are genetically related to the I sjiinal nerve and the X, VII, and \' cranial nerves. The majority of the cells giving rise to these ganglia are derived directly from the I spinal ganglion and the cerebral ganglia associated with the X, \TI, and V cranial nerves. Certain of these symixithetic ganglia receive cells also which advance perijiherally from the wall of the neural tube along the fibers of the motor nerve roots. The ciliary ganglion arises in the path of the oculomotor nerve. It is derived primarily from cells which advance peripherally from the wall of the mid-braui along the fibers of this nerve. As development advances the ciliary ganglion becomes connected with the Gasserian ganglion and the first sympathetic ganglion associated ^\^th the latter, through the radbc ciliaris longa. After this connection is established, a relatively small number of cells which wander out from the Gasserian and the first sympathetic ganglia are, doubtless contributed to the ciliary ganglion.
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In larvae of Amblystoma and Rana the ciliary ganglion bears the same genetic relationship to the oculomotor nerve and arises in essentially the same mamier as in embryos of Opsanus. The cranial division of the sympathetic nervous system is relatively feebly developed in the Am])hibia. The ciliar\' ganglion is relatively small in the larvae of both Am})lystoma and liana. Other distinct sympathetic ganglia probably do not occur in the crainal region in these types of Amphibia. However, sympathetic ganglion cells are incorporated in, or associated with, certain of the cerebral ganglia.
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In embr\'os of the turtle, the cilary ganglion arises at i\w growing top of the oculomotor nerve. The majority of the cells which take part in the development of this ganglion h:ive their origin in the wall of the mid-brain and advance peri])iierally along the oculomotor nerve, or are the direct descendants of such cells. As develo]iment advances, the ciliary y;anglion l)ecomes connected by a fibrous ramus with the ophthalmic division of the trigeminal nerve. After tiiis connection is established, a relatively small number of cells which advance peripherally from the Gasserian ganglion are contributed to the ciliary ganghon.
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The sphenopalatine ganglion arises, in embryos of the turtle, in the path of the great supcTficial petrosal nerve and soon becomes connected by fibrous rami with the maxillary division of the trigeminal nerve. It is derived from cells which advance ])eri])herally irom the geniculate ganglion and the Gasserian ganglion r(\s})ectively ahmg the great superficial petrosal and the maxillary nerves.
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(ianglia homologous with the otic and the submaxillary ganglia of the higher veiieljrates were not observed in embryos of the turtle.
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PROCEEDINGS 119
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In embryos of the chick the cihar}^ ganglion bears the same genetic relationships to the oculomotor and the ophthalmic nerves and arises in essentially the same maimer as in embryos of the turtle.
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The otic ganglion arises, in embr3^os of the chiek, in the path of a tract of sympathetic fibers which emerge, at the level of the geniculate ganglion, from the sympathetic plexus surrounding the carotid artery and continue cephalad. It is derived primarily from cells which advance cephalad from the superior cervical ganglion and cells which wander out from the geniculate ganglion.
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In proximity wHh the olfactory epithelium, in embryos of the chick, is located a relatively large ganglion which is primarily related to the great superficial petrosal nerve, but has fibrous connections also with the maxillary nerve. This ganglion, described by Rubaschkin' as being related to the trigeminal nerve, is probably homologous \vith the sphenopalatine ganglion of the turtle. It is derived primarily from cells which advance peripherally from the geniculate ganglion along the great superficial petrosal nerve, but probably receives cells also which advance peripherally from the Gasserian ganglion along the maxillary nerve.
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The relatively small submaxillar}^ ganglion, in the chick, is genetically related to the mandibular nerve.
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In embryos of the pig, as the writer has shown in an carher paper,^ the ciJiary ganglion is geneticalh' relatetl to the oculomotor and the ophthalmic nerves, while the sphenopalatine, the otic, and the submaxillary ganglia are genetically related primarily to the maxillary and the mandibular divisions of the trigeminal nerve.
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The results of a comparative study of the development of the cranial sympathetic; ganglia in embrj^os of tj^pes of the several classes of vertebrates, as above set forth, warrant the conclusion that during the process of evolution the sources of the majority of the cells giving rise to the cranial sympathetic ganglia have become shifted cephalad. Whereas, in the lower vertebrates the cranial sympathetic ganglia are genetically related to the cervical sym]iathetics, the first spinal nerve:?, and the X, IX, VII, V, and III cranial nerves, the great majority of the cells taking part in the development of these ganglia in the mammals are derived from the Gasserian ganglion and the wall of the mid- and hindbrain via the oculomotor and the several divisions of the trigeminal nerves.
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31. The tract of Lissaucr in the Rhesus monkey. S. W. Raxsom, Northwestern University Metlical School. The observations which I siiall report were madt^ on pyridine-silver
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and Pal-Weigert jirejiarations of tiu^ spinal conl of the Hliesus monkey. In a Pal-Weigert i)reparation of the fifth corvical segment the tract
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of Lissauer is located in the apex oi the columna jiosterior just lateral to
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' Aimt. Anz., Hd. 31.', pp. 497-5ir>.
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^ Tlie development of the cranial sympathetic ganglia in the pig. Jour. Comp. Neur., vol. 23, pp. 71-9G.
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120 AMERICAN ASSOCIATION OF ANATOMISTS
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the cntcrinp; fibers of the dorsal root. In comparison to the rest of the sul)stantia alba the tract is lightly stained. It contaias rather ^videIy seiiarated fine meduUated fibers. Most of these fibers run longitudinally in the tract but some run across.it from the dorsal root to the substantia gelatinosa Rolandi. Some medullated fibers enter the tract from the lateral portion of the dorsal root; but a study of the literature makes it clear that many of the medullated fibers in the tract are of endogenous origin.
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In a pjTidine-silver preparation of the seventh cervical segment the darkly stained tract of Lissauer fills the apex of the columna posterior and reaches from the suljstantia gelatinosa to the surface of the cord. An accumulation of subpial neuroglia is seen at the dorsal extremity. A neuroglia septum extends into the cord, separating the tract in question from the cerel)ellospinal fasciculus. The septum does not, however, reach the gray substance, and ventrally to it the tract of Lissauer spreads out into the lateral funiculus upon the lateral surface of the columna posterior. It goes over gradually into the fasciulus proprius of the lateral funiculus.
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\\'hc.n one compares the number of medullated fibers seen in a Pal^^'eigert preparation with the number of axons seen in pyridine-silver })reparations it is obvious that the non-medullated fibers of this tract far outnumber those which are medullated.
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The medullated fibers of an entering dorsal root pass over the tip of the tract into the cuneate fasciculus. The non-medullated fibers of the root separate out from among the medullated fibers before the root enters the cord and form a well defined lateral bundle. This lateral part of the entering root, consisting of non-medullated and a few fine medullated fibers, turns forward into the tract of Lissauer. This shows that the non-medullated fii)ers of the dorsal roots do not run \vith the medullated fibers into the fasciculus cuneatus but run in Lissauer's tract.
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There is a very close relation between the tract and the substantia gelatinose Rolandi. This substance contains many small nerve cells and non-medullated fibers. There is a constant interchange of fibers between it and the tract of Lissauer and everything points to it as the nucleus of reception of the non-medullated fibers of the tract and therefore also of the non-medullated fibers of the dorsal roots.
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In conclusion it may be said that tiie tract of Li.ssauer in the monkey, like that in the cat, is composed chiefly of non-medullated fibers. These represent the intramedullary continuation of the non-medulalted fibers of the dorsal roots and probal^ly terminate in the substantia gelatinosa Rolandi.
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Discussed by Sheldon, Hardesty and Hubcr.
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PROCEEDINGS 121
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32. Chorionic ducts and intra-chorionic cysts in young human embryos. Frederic T. Lewis, Harvard Medical School.
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33. Further observations on the supports of the rectum. T. Wixgate Todd, Western Reserve University, Cleveland, Ohio.
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In a previous paper (The anatomy of a case of carcinoma recti, Annals of Surgery, 1913, vol. 59, pp. 831-837) the speaker indicated the clinical significance of the follo^vdng structures: (Ij The function of the fascia propria of Waldeyer (recto-sacral aponeurosis of J. W, Smith) in making the rectum a self-contained organ; (2) The function of the lateral hgaments (les ailerons) as supports of the rectum; (3) The fact that the lateral hgaments arc mainh^ formed by the perineural tissue around the sacral nerves supplying the rectum, but also include the perivascular tissue around the middle haemorrhoidal vessels.
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In the present communication the speaker first postulated that only the type of rectal prolapse which commences at the anal margin should be retained under the heading of 'prolapse;' the other varieties being in reality types of intussusception.
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After a consideration of the various factors suggested clinically as causes of prolapse in infants, evidence was brought fon\-ard in support of the following contentions: (1) That the relative proportionate length and extensibility of the lateral ligaments in the infant at birth are approximately the same as in the adult. (2) That there is no 'laxity' of the lateral ligaments. (3) But that the rectum is already a peh-ic organ at birth while the bladder and uterus lie at a higher level. (4) That in consequence of the relative low position of the rectum and of the fact that it is not shielded by an overhanging sacral promontory, the organ is in a position of greater mechanical disadvantage in infancy than in adult life. (5) Hence in infants if the pelvic cUaphragm he weak, as in rachitis, there is every possibility of the occurrence of a temporary and limited procidentia of the rectum which does not require any operative measure for its treatment.
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34- On the occurrence of fat in the muscle fibers of the myocardium and of the atrio-ventricular system. H. HaysBullard, Anatomical Laboratories, School of Medicine, Universit\^ of Pittsburgh, Pittsburgh, Pa. In former papers ('12) I have presented data which indicate that the commonly accepted belief, to the effect, that microscopically \'isible fat does not occur m normal cardiac musele fibers, has arisen largely from the fact that the techinquo for fat demonstration, as usually employed is inadequate to show tlie normal fat content of muscle fillers. It is only l)v using sjiecial metliods upon fresli tissue that tiie full fat content is (iomonstrated. Fresh material is necessary, for fats are unstable comjKnmds, as is now recognized in' chemists but too frequently overlooked by histologists. For the demonstration of the fat content of muscle fibers and other tissues, Herxheimer's Scharlach R method offers mark.ed advantages.
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Boll ('1 1-'12) usingthe Herxheimer method, has shown in a remarkable series of feeding experiments that t\\v ' liposoine' content of skeletal mus
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122 AMERICAN ASSOCIATION OF ANATOMISTS
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c-le and of cardiac muscle is inHiienccd l)y the diet of the animal. He Ih'Hcvcs that some of the iii)S()mes' are fat droplets, while others are fat mixed with some substance other than fat. He finds that starved rats show few 'liposomes' in the striated muscle, while those which have been on a diet rich in fat show a marked increase in the 'liposome' content of the muscle fibers.
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Emjiloyinp; the Herxheimcr method together with other methods, during; i\w ])ast several years. I have examined the cardiac muscle of more than a hundred animals for the j^resence of microsco])ically visible fat. In about forty hearts, the muscle fibers of the atrio-ventricular system were also examined. The animals included the mouse, rat, cat, dog, o}:»ossum, sheep, jjig, ox, monkey and man. The results of this study, as here summarized, are later to be set forth in greater detail.
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Normal cardiac muscle fibers of mammals contain a varying amount of fat in the form of droplets which react to fat stains and can be demonstrated microsco])ically. The droplets of fat are arranged in rows between the fibrillae or muscle columns and in the central peri-nuclear sarcoplasm. In size the drojilets vary from 8 or 4 micra to the limit of microscojiical vision. In some animals the fat is uniformly distributed among the muscle fibers, each containing api)roximately the same amount; on the other hand, there are often two general types of fibers, one ty]3e is heavily charged with fat, the other tj'pe containing little. The fibers w^hich contain the large amount of fat correspond to the well known "dark fibers" of skeletal muscle, while those which contain little correspond to the light fillers.
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During the later weeks of f(^tal life fat is normall}' present in the cardiac fibers (man, ox, ])ig, cat, dog). Earlier stages were not examined.
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The normal fat content of cardiac muscle is not a product of degeneration, i)ut is brought in to the fiber to serve as a source of energ\' and food. The (juantity of fat in cardiac fibers is decreased in starvation and increased w'hen the animal is kept on a fat diet.
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Cardiac muscle fibers contain many granules which, after ai^iiropriate fixation, may be stained by the mc^thods of Altmann, Benda, Weigert (modified) and Heidenhain. These granules are the true interstitial granules of Kolliker, l)iobIasts of Altmann, chondriosomes of Regaud, and Q granules of Holmgren. Granul(\s of this ty]ie cannot l)e stained by fat .stains and are not fat, although there is .some evidence to show that they contain an albumino-lipoid.
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Little fat is normally ])resent in the muscle fibers of the nodal tissue of the heart or in the .stem of the bundle of His, even when the myocardial fibers are crowded with fat. Typical Purkinje fibers of the .sheep, pig and ox, contain a small (juantity of fat but the amount is increased as the fibers take on cardiac character. More fat is ])resent in the i'urkinje fibers of species such as man, dog and cat, in which the Purkinje fibers are hi.stologically similar to the cardiac type.
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Literature cited: K. T. Bell, 1911, Internat. "Monatschrift f. Anat. u. Phys., Bd. 28, 8. 297-347; iyr2, Journ. Path, and Barter., vol. 17, pp.
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PROCEEDINGS 123
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147-158. Also H. Hays Bullard, 1912, Journ. Med. Research, vol. 27, pp. 55-65; 1912, Amer. Jour. Anat., vol. 14, pp. 1-46.
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35. Marchi technique: safer and easier clearing and mounting of sections.
 +
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H. S. Steensland, From the Pathological Laboratory of S>Tacuse
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University, Syracuse.
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This communication is presented on the assumption that clearing Marchi sections in chloroform is generally regarded as the best technique at the present time. It is generally recommended that Marchi sections be cleared in chloroform and mounted in chloroform balsam because xylol and other clearing reagents, and xylol balsam, cause the black osmic acid staining of fat to fade. Clearing in chloroform, as recommended, presents certain wellknown difficultities in technique. These difficulties sometimes make the fate of valuable material uncertain, for example, material that has been obtained as a result of painstaking and time consuming experiment.
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Obviously it would be a great advantage if jNlarchi sections could be cleared in oleum origani cretici. Most of the d fficulties would be overcome. There would be no danger of drying and shriveling of the sections. The sections could be thoroughly blotted and flattened v\ith smooth (not embossed) filter paper. The chloroform l^alsam could be carefully applied. The retraction of the balsam from a part of the space between the coverslips and the slides would be practically done away with. It would he possible to turn over valuable material to a technician for clearing and mounting with much less fear of loss of material and >Aithout placing undue responsibility and strain upon the technician. When a large amount of material is to be handled it could be handled with much less strain and exhaustion. Large sections would be more safely handled, which is of special importance when the tissues involved are cut into serial sections.
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Ten years ago in the Pathological Laboratory of Syracuse University there were mounted a considerable number of Marchi sections. The technique made use of was the usual technique except that the sections were cleared in oleum origani cretici instead of chloroform. At the present time I have been unable to find any evidence of fading after comparison with control sections made from the original lilocks of tissue. The control sections were cleared in chloroform and mounted in chloroform balsam according to the prevalent metiiod.
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In order to put the matter to a further test some of the newly cut sections were placed in a dish of oleum t)rigani cretici. At intervals sections from the disii were mounted in chloroform balsam. No evidence of fading was found after ten days in the oil.
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Oleum origani cretici is tiuis t'vidently a very much safer and easier clearing reagent than chloroform to use in the JNlarchi technique.
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124 AMERICAN ASSOCIATION OF ANATOMISTS
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36. Technical experiences: (a) Cataloguing lantern slides; (b) Permanent dry-mounts of the laryngeal cartilages; (c) The use of large tissue sections for demonstraiion purposes; (d) Degreasing bones. G. L. Streeter.
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(a) Cataloguing lantern slides. A fairly good print of a lantern slide may be obtained by laying the finished lantern slide directly on blue print paper and printing either in the sun or before an arc light. Such a print plainly shows the subject and character of any ordinary lantern slide. This fact may be utilized in cataloguing lantern slides. By lirinting ones whole collection in blue print paper and mounting these prints in a loose leaf note book it makes it possible to look them over quickly for ascertaming what slides are in the collection and their respective number. The ^^Tite^ prints sLx slides at one time in an 8 X 10 printing frame on uniformly cut sheets. These sheets are then assorted more or less according to subject. On each picture the slide number is ^^Titten in and any other desired memoranda. The slides themselves are numbered and filed in the order of acquisition.
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(b) Mounting laryngeal cartilages. A permanent and convenient mount of the lar\iigeal cartilages and adjacent rings of the trachea may be made by dehydrating the cleaned cartilages in alcohol, transferring them into xylol and then saturating them with melted parafin. Such cartilages are easily mounted on a base by means of metal adjustable standards and are durable enough to be trusted in the hands of students as demonstration specimens. The disadvantage of the usual dr>' preparation of the lar>-nx hes in its tendency to shrink. This is largely avoided by the above method in which the natural moisture of the specimen is replaced by parafin. In the process of dehydration there is some danger of warping the cartilages, but this can be prevented by cutting out little wooden forms to which the cartilages are tighth' laced with thread, or by fitting them over or between tubular bottles of different sizes. They should be kept on these until they come out of the melted parafin. In the six preparations we have made at Ann Arbor we included the hyoid bone. The preparations show an interesting variation in the form of the cartilages and in the character of their ossification, so much so as to warrant the increase of our collection for the study of these particular features.
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(c) Demonstrntion sections. We have found in our laboratory that large stained celloidin sections mounted and projected like lantern slides form an excellent means of demonstrating certain features in regional and macroscopic anatomy. It may be suggested that where successful preparations of this kind are obtained there would be an advantage in cutting extra sections and saving them as duplicates to be exchanged for similar preparations from other laljoratories. The folk^N-ing sections, which had been prepared in the al)ove manner, were <lemonstrated ^\^th the lantern: (a) Transverse section through top of adult head showing layers of scalp, formation of cranial vault, dura, falx cerebri, superior longitudinal sinus, together with the bra'ui and the membranes directly covering it; (b) Cusp of adult semilunar valve,
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PROCEEDINGS 125
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flattened out to show distribution of connective tissue and formation of lunulae; (c) Transverse section through adult cavernous sinus; (d) Frontal section through adult larj-nx sho^\'ing false cords cut transversally and vocal hps together with cartilages and musculature; (e) Sagittal section through the adult temporomandibular joint; (f) Transverse section of adult penis; (g) Transverse section through neck of new-bom babe showing especially the distribution of fascia ; (f) Sagittal section of finger of newborn babe showing metacarpal and three phalangeal bones with epiphyses, joints and muscle attachments.
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(d) Degreasing bones. The bones of the extremities from fatty subjects may still have after maceratoin a large amount of fat in them. Most of this may be easily, economically and safely removed by placing them in a drying oven and sweating the fat out. A fatt\' femur after being in an oven at 110° C. for two hours loses 2.5 per cent in weight by removal of the fat. On coming from the oven the bones are briefly rinsed in cold gasoline and are then bleached in potassium permanganate followed by sulphurous acid. They are then ready for study. We have found that we can increase the durability' of fragil bones b}' immersing them in melted paraffin. This darkens the bone but does not interfere with its suitability for student use.
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37. On the nature of fat cells. H. G. Weiskotten axd H. S. Steensland,
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From the Pathological Laboratory of Syracuse University, S\Tacuse.
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^\^len rabbits receive intravenous injections of maximal sublethal doses of saponin large territories of the marrow undergo necrosis. The parenchymal cells and fat cells soon undergo autolysis lea^•ing mainly the free fat droplets, originally contained in the fat cells, to represent the original architecture of the narrow. The fat droplets appear to remain largely in the original loci of the fat cells, in which they were contained.
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Subsequently there occurs apparently complete regeneration of the marrow with the restoration of the original proportions of parench>-mal cells and fat cells. By examination of sections of the marrow from animals at various stages after injection it appears to be possible to determine the manner in which the fat cells are regenerated and to determine the nature of these fat cells.
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To a large extent the necrotic tissue is invaded first by free endothelial cells. These cells tend to arrange themselves at the peripher>' of individual fat droplets and to fuse together into multinucleated c>-toplasmic masses, which envelop the fat droplets. These masses constitute the wellknowii foreign body giant cells. Subsequently a large part of the cj'toplasm of these cells disappears, the nuclei decrease in numl>or and the c\i;oi5lasm Ijecomes retluced to the thin envelope characteristic of the ordinary fat cell. In this envelope there j>ersist one or more nuclei, wliich become crescentic as the cytoplasmic layer becomes tliin, like the nucleus of the ordinar>' fat cell. The disappeanmce of nuclei evidently is brought about by a process of nuclear resor])tion or karyolysis.
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One possibility that arises is that the fat cells originally do not become completely necrotic before the contained fat droplets become surrounded
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126 AMERICAN ASSOCIATION OF ANATOMISTS
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by forcipi hody piant colls: that the foreig:n body giant cells disappear jind then* remain the original fat cells.
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In the manner described the fat cells are regenerated to a large extent before the parench>nnal marrow cells are regenerated Mainly after the fat cells are restored the hemoblastic centers develop in the corresponcfmg regions and the marrow is completely regenerated.
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The concept that we wish to jiresent. on the basis of what has been described, is that fat cells are endothelial cells containing what may be called, by way of comjiarison, a physiological foreign body, namely fat. Ordinarily, in our experience, fat cells are regarded as mesenchymal cells or fii)roblasts or connective tissue cells in whose cytoplasm fat has been stored up.
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In general, in many forms of lesion free fat occurs and is taken up by foreign body giant cells. This may be in situations in which fat cells are not normally' i^resent. In such cases the foreign body giant cells do not survive in the locus as fat cells, perhaps because fat cells do not normally exist in the locus.
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That foreign body giant cells are formed as a result of the fusion of endothelial cells has been shown by the work of Mallory and his pupils.
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38. The development of the septum atriorum. Robert Retzer, University of Chicago.
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39a. The passage of the ovum through the uterine epithelium in Geomys hursarius, tvith demonstration of wax reconstruction^^. Thomas G. Lee, Institute of Anatomy, Universitj of Minnesota. Within the order of Rodentia there exists a greater variety in the implantation of ovum and formation of decidual cavity than in any of the other main divisions of the Mammalia. The rage of variation extends from those forms, like the rabbit, in which the whole of the uterine lumen is utilized, to that of mouse and rat, where only a restricted portion of the uterine cavity is transformed into a decidual cavity. Then follows tho.se peculiar form.s, as C'itellus (.spermophilus), in which the WTiter in 1902 and 1903 described for the first time a rodent in which the trophobla.stic layer of cells at close of segmentation caused the destruction of a small area of the uterine epithelium at the antimesometrial portion of uterine cavity, followed by an outgrowth of trophoblastic cells into the mucosa to form a nutrient organ, followed by the atrophy and disappearance of this organ upon the completion of the allantoic placenta at the mesometrial jwrtion of the uterus; the whole of the uterine cavity being utilized for a decidual cavity, as in the rabbit. And la.stly are found those forms in which, as in man, the ovum passes entirely through the uterine epithelium and a new decidual cavity is formed in the mucosa and independent of the uterine lumen. The first rodent of this type to be describerl was the guinea-pig, so beautifully worked out by ( Iraf Spec. . In ( leomys we find a second rodent of this tyjie, but with the following important points of difference from the guinea-pig which are shovx-n in the.se reconstructions. In the guinea-pig the ovum passes
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PROCEEDINGS 127
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through the uterine epitheUum at close of segmentation, and while it is very small in volume, the small perforation is quickly closed and the uterine ca\'ity completely separated by epithelium from the new decidual cavity. In Geomys, on the contrary, the ovum perforates the uterine epithehum in the blastula stage, and when of .so large a diameter that the edges of the large rounded perforation of the uterine epithelium camiot grow together as in the guinea-pig, or be filled with a fibrin plug as in man, this opening persi.sts during the entire preplacental period. The epithehum at the lip of perforation is somewhat everted and gives a point of attachment to a zone of the trophobla.stic layer of the blastocj'st. The dorsal portion of the trophobla.stic layer extends across the opening, and by this zonal attachment to the epithelial lip completely shuts off the uterine lumen from the new decidual ca^^ty. The cells of the mucosa are broken down and the decidual cavity is rapidly enlarged. The blastocyst sinks down into this cavity but continues to be suspended by the above described zonal attachment to the lip of the epithelial perforation. This zone \vi\\ ultimately form the outer margin of the allantoic placenta. A detailed description of the unique preplacental development in Geomys with plates will be published in the near future.
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39b. An improved electric tnicrqscope lamp, with demonstration. Thomas G. Lee, Institute of Anatomy, University of Minnesota. This lamp was devised by the ^^Titer to meet the demand for a small compact and portable lamp for indi\'idual staff or student use in the Minnesota Institute of Anatomy, and has proved to be so satisfactorythat it is here demonstrated for the benefit of the members of the Association. The lamp consists of a .small vulcanite base fitted vriXh a silvered reflector and a socket into which can be screwed as desired either a 2, 4 or 6 candle-power Mazda lamp ^\^th miniature ba.se: a metal cap supported by 3 rods which fit into the base shuts off all side fight and gives the necessary ventilation. In the top of this cap is an opening the same size as the base of the Ai)l)e conden.sor. A device on the top of the metal cap holds in place over this opening the ordinary blue or ground glass plates commonly used with the Abbe condenson thus giving at all times monochromatic light of miiform inten.sity. The bai?e is fitted with flexible electric fixture ^^^re terminating in a small plug which fits into a socket in the table top. The entire lamp is small, about two inches in diameter and in height, so that it readily fits in under the Abl>e condenser when the mirror is jiusiied to one side. When not in use. the lamp can be put away in the student's lock<'r with the rest of his outfit. A stock automobile Mazda bull> of standanl make of volts. 5 watts, alternating current is used in this lamp. It is the smallest availal^le, the least expensive, and will withstand rough u.sage. In fitting up the lalxjratory tables a step down transformer is connected with the feed wire. This reduces the current used from 110 volts to (> volts. These transformers are small, inexjiensive, and can be had of any capacity desired, are used in the tradt- in sign-lighting apjiaratus. The wires leading from trans
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128 AMERICAN ASSOCIATION OF ANATOMISTS
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former are run underneath the tables and connected to the sockets wliicli are set into table top at any desired point. A detailed description of this apparatus with illustrations ^\^ll appear in the near future.
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JfO. The growth of organs iti the albino rat as effected by gonadectomy. S. Hatai, The Wistar Institute of .\natomy.
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1. Except in the remaining sex gland itself, the partial removal of the sex glands does not produce any significant alterations in any of the ductless glands aside from a general tendency to a slight increase. Apjxirently this increase in the remaining gland is sufficient to compensate for the functions of the lost gland.
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2. The total removal of sex glands, however, induces alterations in all the other glands, ])articularly in the thymus and hypophysis. The sujirarenal glands show opposite reactions in the two sexes. In the case of the males, the suprarenal glands show an increase of 15 per cent, while in the female there is a 20 per cent reduction.
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3. The total removal of the sex glands tends to increase the resemblance between the two sexes, or in other words, to reduce the chfTerences in those secondary characters which, in the normal animal, are modified according to sex.
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41. Ganglion cells of the terminalis nerve in the dogfish. Paul S. McKiBBEN, The Western Universitj^. Ontario, Canada.
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J!^2. The fate of the ultimo branchial body in the thyroid. B. F. Kingsbury, Cornell University.
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43. The position of the normal stomach, mth observations on the movements
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of the diaphragm. Burton D. Myers, Indiana Universit}' School of
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Medicine.
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Fort}' young adults, nineteen to twenty-six years of age, twenty-eight men and twelve young women, were given a buttermilk-barium sulphate meal. Their stomachs were then examined fluoroscopically.
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Prior to giving the meal, copper washers were fixed with adhesive tape to the abdominal wall in the mesial sagittal plane, one on the processus x\'phoideus, a second at the transpyloric plane, a third on the umljilicus, and in the young women, a fourth was placed at the intersection of the intertubercular plane and the linea alba. These washers, plainly visible on the fluoroscopic screen, give the chief horizontal i:)lanes and the midsagittal ])lane. An adjustable diaphragm made it possible to cut the rays to a vertical slit, to a horizontal slit, or to a very small square opening, in which latter case, the rays are nearly parallel.
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Inasmuch as in the young women, only a thin kimona intervened between the washers and the thirteen inch-s(iuare fluoroscopic screen, while in the case of the men, tlu; screen was jilaced innnediately upon the wa.shers and alxlominal wall, the error due to divergent rays is negligible, and checked \)\ narrowing the diapiiragm.
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Sheets of very tiiin tracing paper were piacc^d upon the fluoroscopic screen and tracings made of the stomach while hlling, when full, in deep
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PROCEEDINGS 129
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est inspiration and fullest expiration accompanied by contraction of abdominal walls. Tracings were also made of the diaphragm, showing its normal position, its swing in normal respiration, and its extreme positions in forced inspiration and expiration. These same tracings were repeated with the individual in horizontal position (on back). X-ray photographs were made of five cases, for comparison and check.
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In males, when standing, the average position of the lower border of the stomach was found to be one inch below the umbilicus, the extremes being from one inch above to three inches below this plane. In females, when standing, the lower border of the stomach was found to be three inches below the umVjilical plane, the extremes being one and threeeighths to four and one-half inches below the umbilical plane. When standing, the stomach is either J- or cow-horn shaped. The pyloric valve points upward, backward, and to the right. When lying down, the pyloric valve is one-third of an inch below the transpyloric plane, and in 12§ per cent of cases, it points upward, backward, and to the left; the descending portion of the duodenum then lies posterior to the pyloric portion of the stomach.
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The cardiac stomach is not a storehouse for food, as commonly stated, but when standing, a gas pocket. The stomach fills from above downward, the upper border of its contents remaining, during filling, at the level of the esophageal opening.
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The stomach is always as big as its contents. Its shape depends upon the quantitj' of its contents, the position of the body, the distention of adjacent viscera, peristalsis, and respiration. In certain cases even the beat of the heart gives a blow to the stomach wall which cau.ses a wave to run across the surface of its contents.
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The stomach is normally in a state of tonic contraction so that when one lies down, the portion of the stomach over the vertebral column tends to empty and contract while the fundic portion accommodates an increased portion of the stomach contents.
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In the erect position, the fundic portion of the stomach looks upward, not backward as stated by His and Cunningham. The surfaces are not up and down, but anterior and posterior, or antero-superior and posteroinferior as we stand or lie down. The greater curvature is not higher but lower than the lesser. The lesser curvature does not Ijecome convex when the stomach is filled, filling l)eing accommodated by distention of th(^ greater curvature. The position of the incisura angularis, with reference to the pyloric valve, varies with the high or low position of the pyloric valve.
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Tiic normal position of the dia]>hragm is higher when one is in the horizontal, than when in the erect jwsition. Xot infrequently, Ci^ntraction of the abdominal wall is accompanied by descent of the dia])hra^i. Though some females employ costal respiration almost entirely, as do some men, others show as great a swing of the diajihragm in normal respiration and as great extremes of movement of diai^hragm in forced insj)iration and expiration :i:s is found in men.
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THE ANATOMICAL BECORD, VOL. 8, NO. 2
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130 AMERICAN ASSOCIATION OF ANATOMISTS
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44- The form of the stomach in mammalian embryos. Chester H.
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Heuser, The Wistar Institute of Anatomy.
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In The American Journal of Anatomy ('12, vol. 13, pp. 477-503), F. T. Lewis described the form of the stomach in young human embryos and the development of its primary subdivisions. During the past year, with the aid of Bullard Fellowships awarded at the Harvard Medical School, the writer has made a similar study of the embryonic stomachs of the albino rat, pig and sheep, and the work is approaching completion. In all of these animals as in man, the epithelial stomach is a ea rl^' - subdivided into cardiac and pyloric portions, separated by the angular incisure. The pyloric portion is often onl}^ obscurely subdivided into an antrum and vestibule, but the cardiac portion clearly presents a corpus and fundus. The early development of the gastric canal is a notable feature in all the animals studied, as could be seen in the series of wax reconstructions which were presented as a demonstration.
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45. On the -phylogenesis of the heart. A. G. Pohlman, St. Louis University.
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The first sign of a division in the heart occurs in the lung-fish with the appearance of an incomplete auricular septum. The next step is found in the amphibian with an incomplete division of the bulbus by the spiral valve (see below) in addition to the incomplete auricular septum. The third stage is found in the reptile with the complete separation into two auricles and the completed division of the bulbus and the appearance of an interventricular septum. The fourth stage comes in the crocodile family with complete division of the heart into four chambers, the right side having greater capacity than the left. The fifth in the bird and mammal with a four-chambered heart and equal capacity on the two sides. Just as the foramen ovale appears as a functional compensation for the inequality of return to the two sides of the heart in the fetal bird and mammal, so the foramen of Panizza may be a functional adaptation to the unequal quantities of blood expelled by the two ventricles. This latter point is not thoroughly understood. There is no proof of a segregation of arterial and venous blood throughout the vertebrate scale excepting in the postfetal bird and mammal and possibly in the crocodile family.
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Demonstration of reconstruction of the bulbus cordis in the frog. This reconstruction shows: (1) that the spiral valve cannot function in the manner described as a means of separating the bulbus into an aortic and pulmo-cutaneous compartment; (2) that the carotid arteries arise by a common opening; (3) that this opening is again in common with that of the right aortic arch ; (4) that the left aortic arch has an entirely independent opening about at the level of the pulmo-cutaneous opening and is distinct from the right aorta. Both left aortic and pulmocutaneous openings have a valve which is wanting in the right aortic opening; (5) that the spiral valve may be interpreted as an incomplete division of the bulbus analogous to the incomplete division of the auricle
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t/^/y
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fiD'
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ERRATUM
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The Anatomical Record, volume 8, number 2, February, 1914, Abtract 44, Chester H. Heuser, page 130, line 9, for nearly read early.
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. PROCEEDINGS 131
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and the relations of the left aortic arch and pulmo-cutaneous artery are suggestive of a phylogenetic step completed in the turtle.
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1. Demonstration of the canalis cranio-phar>'ngeus in the rabbit showing the possibilities in experimental work in this form of determining the relation of naso-pharyngeal irritations upon the hypophysis and upon the pharyngeal hypophysis and its bearing on the adenoid question. Preparation of Dr. Eugene Senseney.
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2. Demonstration of elastic ligaments in the middle ear region of the chicken which may afford resistence to the pull of the tensor tympani. Preparation by INIr. Wilson and Mr. Shores.
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3. Trilocular heart with pulmonary stenosis in a child of ten 3'ears (case of Dr. Ralph Thompson) to show transposition of vessels and an absolute lack in separation of arterial from venous circulation.
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j^. Some notes on early twin human embryos. James Crawford Watt,
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Anatomical Laboratory of the University of Toronto.
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These twin embryos are Xos. V and VI in Prof. J. Playfair McMurrich's collection. They are respectively 2.75 mm. and 3.35 ram. in length. They are almost identical in development, but one has a very deep concave dorsal bend, while the other is almost flat. Embr\'o V has 17 to 18 paired somites, Embryo VI has 18 to 19. They thus serve to fill in an interval hitherto lacking in good specimens.
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In the alimentary system the buccopharj'ngeal membrane is just rupturing, the pharj-nx has three gill-pouches and a medium thyroid depression. Connection with the \o\k sac is very extensive. The cloaca is small but is divided into rectal and bladder bays.
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The notochord is still attached to the gut throughout much of its extent. In places it shows the remains of a notochordal canal and a chord of cells extending from the medullary plate to the notochord in both embryos and also from the notochord to the cloaca in Embn,-o V, represents the neurenteric canal. These are the oldest embn.'os recorded which exhibit these remains.
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The urinogenital system of Embryo VI consists of five pronephric tubules on each side, united to the Wolffian duct. Behind are ten to eleven mesonephric vesicles on each side, not united to the duct, which extends from the ninth to the sixteenth mesodermic segments. In Embryo ^' the duct on the left extends from the nintii to the sixteenth segment and receives seven pronephric tubules, and on the right it extends from the seventh to the sixteenth segment and receives eleven tubules. There are five to seven mesonephric vesicles behind these. Many of the tubules exhibit nephrostomes and there is an external glomerulus in the ninth segment of Embr>'o \T. There is evidence of dysmetamerism, as many tubules occur in pairs in the segments on each side.
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The heart is a simjile S-shaped tube. Only the large embryological vascular trunks are develojied, including two branchial arch vessels on each side. The brain sliows three primary vesicles, optic vesicles, hypophysis, and seven ncuromeres in the hind brain \\\X\\ four ganglia — tri
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132 AMERICAN ASSOCIATION OF .\NATOMISTS
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geminal, aciisticofacial, glossopharviigcal and vagus — attached to definite neuromeres. A complete and full description of the embrj^os will be published shortly.
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Jf7. Notes on the skull of a kuvian fetus of 50 mm. C. C. Macklin, Anatomical Laboratory of the University of Toronto. The skull described occu]:)ies a position intermecUate between the 28mm. stage of Levi and the 80-mm. stage of Hertwig, and is interesting in that it shows indications of a reduction of the lateral walls of the chondrocranium in the form of small isolated remnants of cartilage situated dorsally and lateralh'. Other similar isolated cartilages also occur, among wl ich may be mentioned a rudiment of the aUcochlear commissure; an ephemeral representative of a primitive nasal concha, seen in the middle meatus of the nasal cavity; and a small mass in the orbit, lying against the nasal capsule. A minute additional paraseptal cartilage is noted, attached to the nasal septum, and related to the vomerine anlage, while the anterior paraseptal cartilage presents an interesting transitional stage in which it may be directly compared ^^^th that of such form as the rabbit, and the paraethmoidal cartilage, related to the lacrimal bone and duct, is also well developed.
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The condition of the structures surrounding tl e foramen magnum throws some light on the development of this region, especially in regard to the part played by the occipital vertebra, which is, in this stage, rather distinctly outlined. A detailed description of the skull, with figures showing its reconstruction, ^\•ill shorth' be published.
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48. The development of the pancreas in selachians. Richard E. Scammon,
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Institute of Anatomj^ L^niversity of Minnesota.
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The pancreas of selachians is remarkable in that it arises from a single diverticulum which has generally been described as dorsal in position. It is, however, very difficult to determine the exact position of this anlage by the customary means of reconstruction. For this purpose, therefore, I have applied the method of gra])hic reconstruction devised by Weber. This method, which seems to me a most valuable device for studying the early stages of the larger glands, has apparently been employed only by its originator some ten years ago in an extensive study of the earliest stages of developme^nt of the liver and pancreas in Amniotes. The details of this procedure can hardly be given in the space allotted here. The}^ may be found in Weber's original work (Arch. D'Anat. microsc, T. 5, '03), and will be again presented in this paper in its final form. In general terms, it is a modification of the graphic method of reconstruction in which the varying thickness of the e])ithelium of the reconstructed archenteron is represented in corresponding varying shades of color so that one may stutly the various areas of epithelial thickening in much the same way that one interprets the elevations of land in a topographic map.
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A reconstruction made in this mamier of the midgut of an Acanthias embryo 5.2 mm. in length, which is of a stage well preceding any indica
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PROCEEDINGS 133
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tion of the pancreas as an outpouching, shows in the future pancreatic region of thickened epithehum which includes not only the dorsal zone of the gut but extends well ventrally. This pancreatic area is connected with a large thickening ventral and anterior to it which constitutes the liver anlage. These two thickenings, the pancreatic and hepatic, constitute, with the thickened epithelium connecting them, a ring which passes obliquely completely around the archenteron. The existence of such a pancreatic-hepatic ring was pc^stulated long ago by Brachet and has been demonstrated to a great extent in .\mniotes Vjy Weber.
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Reconstructions by Weber's method of the midgut regions of embn,'os of Acanthias 7.5, 9 and 10 mm. in length, show a gradual breaking up of this ventral hepatic segment. Between the two the epithelium remains somewhat thickened and in this occurs a particularl}' thickened patch which occupied the same position as does the anlage of the ventral pancreas in the higher vertebrates. This thickened plate never produces an outpouching and disappears in older embryos. While the dorsal outpouching of the pancreas is a single one, there is in Acanthias at least, an early indication of chvision into right and left lobes. This di\'ision is not very distinct and can hardly be demonstrated \\ithout Weberian and plastic reconstructions. In Acanthias the left lobe lies anterior to the right and is the smaller. It forms in embryos from 15 to 35 mm. in length a distinct antero-ventral mass which later is to a considerable extent incorporated in the descending limb of the gland. In such other selachians as I have studied this lobe lies posterior to the right one. This is probably because the left lobe is not differentiated until the gland begins to separate from the gut and in all selachians except Acanthias separation takes place antero-posteriorly. I do not think that the bilobed dorsal pancreas is to be regarded as a primitive condition. Rather it is produced b^- the clock^\•ise rotation of the gut and the formation of the spiral valve. Bilobed dorsal pancreas anlagen are fomid in mammals and in selachians but have not been clearly demonstrated elsewhere unless one accepts the observ^ations of von Kiippfer the value of which has been rendered doubtful by the work of Piper antl Nicolas. It seems then that the bilobed form of dorsal pancreas is limited to those forms in which the clock\Nise rotation of the gut (common to some extent to all vertebrates) takes place at an early period and that this form of pancreas is due to that rotation.
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A more complete statement of the development of the selachian pancreas will be published in the near future.
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49. The development of the gall bladder and bile duds in amblystoma.
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E. A. Baumg.\rtner, Institute of Anatomy, University of Mume.^ota.
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Models of embryos 4.5 mm. long show that the liver anlage is a ventral, somewhat caudal i)rojection of the gut lumen caudal to the heart. That this does not corresjwnd to tiio caudal hci)atic duct describotl in chick is shown by later stages. In models of embryos ai>out 7 mm. long we see this early ventral outpouching has turned cranialward. In the ventral wall where the primitive common duct joins the gut lumen a me
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134 AMERICAN ASSOCIATION OF ANATOMISTS
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dian depression shows the earUest anlage of the gall bladder. In stages of about 9 mm. length the folds have become numerous and are the anlage of radicles of the main hepatic ducts. That they are not entirely formed by the tumieling in of blood vessels as has been described by Shore, is shoA\'n by the fact that furrows are found in which no blood vessels are present. The earl}- anterior, and laterally extending duct shows begimiing constriction and elongation into right and left hepatic ducts. A little later the gall bladder has shifted to the right and is no longer widest transversely. The cystic cfuct also has shifted to the right, now being attached to the ventral side of the right hepatic duct. The shifting of the gall bladder is accompanied by a shifting of the entire caudal part of the liver due to the sinistral and ventral growth of the stomach and duodenum.
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From graphic reconstructions of late embryos we see an arrangement of the biliary apparatus as shown in the following outline:
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Common duct
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left hepatic duct right hepatic duct
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It. lat. ramus . It. med. ramus rt. med. ramus rt. lat. ramus
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branches — lat., med. lat., med. med., lat. med., lat.
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cystic duct
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Occasionally the left medial and right medial rami join to form one duct which subdivides as a single stem. This is a secondary union and per.sists in the adult. Also in some cases the cystic duct was found to be one subdivision further removed, that is, it was attached to a radicle of the lateral branch of the right hepatic ramus.
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In embryos between 10 and 12 mm. in length, division and growth of the early duct into right and left hepatic ducts and of these into rami takes place. A graphic reconstruction of a 13 mm. stage shows that this has taken place. The gall bladder here is now longest postero-anteriorly and the short cystic duct extends upward and to the left. A model of a 14 mm. embryo shows that the gall bladder has shifted more to the right and that its duct which is attached to the extreme anterior end extends somewhat upward and to the left.
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A model of the biliary apparatus of a slightly older embryo shows greater development of the duct system. The gall bladder is longer anteroposteriorly, its duct is attached more caudally and is almost horizontal. In a 15 mm. embryo there is a short common duct, but the right and left hepatic ducts are longer. The right lateral shifting here is more marked. The cystic duct extends horizontally to the left. This stage marks the extreme caudal attachment of the cystic duct to the gall bladder.
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PROCEEDINGS 135
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At the 20 mm. stage the lateralward shiftmg is very marked. The right hepatic duct is now somewhat dorsal to the left. Here the right and left medial rami have imited to form one duct. The gall bladder has increased very materially in size, particularly in its caudo-cranial diameter. The cystic duct has shifted toward the anterior end and now projects to the left and dowTiward. The extreme of the lateralward shifting has been