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THE
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ANATOMICAL RECORD
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EDITOR JOHN LEWIS BREMER
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Harvard Medical School
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VOLUME 21 APRIL— JULY, 1921
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PHILADELPHIA
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THE WISTAR INSTITUTE OF ANATOMY AND BIOLOGY
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CONTENTS
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NO. 1. APRIL, 1921
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C. B. Moore. Infections in the female urethra. Ten figures 1
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Richard E. Scammon. A simple tracing apparatus for making topographic reconstructions. Three figures ig
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Richard E. Scammon. A note on the relation between the weight of the thyroid and
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the weight of the thymus in man 25
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George B. Wislocki. Observations upon the behavior of carbon granules injected
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into pregnant animals 29
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Proceedings of the American Association of Anatomists. Thirty-seventh session 35
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Proceedings of the American Association of Anatomists. Abstracts 43
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Proceedings of the American Association of Anatomists. Demonstrations 88
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American Association of Anatomists. Constitution 92
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American Association of Anatomists. Officers and list of members 95
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NO. 2. MAY, 1921
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George L. Streeter. Migration of the earvesicleinthe tadpole during normal development. Eleven figures 115
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Eleanor Linton Clark and Eliot R. Clark. The character of the h'mphatics in
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experimental edema. Five figures 127
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S.E.Whitnall. Some abnormal muscles of the orbit. Twofigures 143
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H. E. Radasch. The determination of thepercentage of the organic content of compact bone 153
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Eben J. Carey. Studies on the structure and function of the small intestine. Twentytwo figures 189
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Naohide Yatsu. On the changes in the reproductive organs in heterosexual parabiosis of albino rats. Seven figures 217
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Howard H. Bell. Diverticula of the duodenum. Two figures 292
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NO. 3. JUNE, 1921
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Tanzo Yoshinaga. a contribution to the early development of the heart in mammalia, with special reference to the guinea-pig. Twenty-three figures 239
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James W. Papez. Abnormal position of the duodenum. Seven figures (two plates). . . 309
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W. M. Baldwin. A study on the depth of penetration of ultraviolet light-ray energy in the embryo of the tadpole 323
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E. Blankfein. An example of dissociation of the branches of the a. profunda fcmoris. One figure 329
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Z. P. Metcalf. Some laboratory notes. Three figures 331
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NO. 4. JULY, 1921
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Juan C. XaSJagas. On the patency of the foramen ovale in Filipino newborn children.
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Three figures 339
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Sabas E. Yap. Musculus sternalis in Filipinos. Two plates (ten figures) 353
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Chas. W. Metz. a simple method for handling small objects in making microscopic
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preparations 373
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Lee D. Cady. A microscopical study of the sinoventricular bundle of the rabbit's heart ;
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with reference to the data relative to its functional interpretation, especially in terms
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of a source of replacement of degenerated myocardium. One plate (five figures) 37.5
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R. Bennett Bean. Remarks on teaching anatomy 391
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With the commencement of the present volume (April) of The Anatomical Record a change has been made in the editorial management. At the recent meeting of the American Association of Anatomists a committee was elected to appoint editors for the two journals of the society, and to serve as an advisory committee for those so appointed. In the case of The A natomical Record the choice fell on me, and it was decided that I should assume the duties of editor at once. Although given the privilege of selecting one or more associate editors, I have decided not to do so for the present, at least, trusting that fellow members of the society will be willing occasionally to give me the benefit of their opinions of certain articles quite informally.
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The policy of the journal will not be materially changed, but an attempt will be made to hasten the publication of accepted articles, to adhere a little more closely to the original plan of The Record, and to differentiate it more clearlj'- from The American Journal of Anatomy.
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In order to accomplish these results, it will be necessary to limit the length of the articles printed. No definite rules can be laid down, but in the opinion of the advisory committee papers of five or ten printed pages will usually be much more acceptable than those necessitating greater elaboration; while notes on laboratory methods, preliminar}^ reports, etc., will be considered appropriate subject matter. All contributors are earnestly and confidently requested to cooperate in this policy.
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At this time there are many articles alread}^ accepted by the former editorial board of The Record and ready for publication. These wdll, of course, be given precedence over later contributions. I have no hesitation in assuming their value, appreciating as I do, and as, I am sure, do all the readers of The Record, the careful and efficient work and the scientific discrimination of the former managing editor and his associates.
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JOHN LEWIS BREMER.
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All contributions and correspondence should be sent to
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J. L. Bremer, Harvard Medical School, Boston, Mass.
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THE ANATOMICAL RECORD, VOL. 21, NO. 1 APRIL, W2\
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Resumen por el autor, C. B. ]Moore, Leland Stanford Junior University.
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Infecciones do la uretra femcnina.
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A causa de su estructura, posicion y niecanismo de desplazaniiento, la uretra femenina es muy propensa a la invasion bacterial. En ella se han encontrado una gran variedad de organismos. El gonococcus es el mas importante, por su tendencia hacia la cronicidad y sus efectos nocivos. En las glandulas para-uret rales de Skene pueden presentarse infecciones supurativas cronicas, y tambien en las estructuras vestigiales de la glandula prostatica, las cuales emiten pequefias cantidades de pus de modo indefinido en la uretra anterior, sin que exista ningun sintoma local, por cuya causa no se descubren frecuentemente. La destrucci6n completa de estas glandulas, tal como puede conseguirse niediante el electro-cauterio, parece ser el unico tratamiento f[ue puede terminar de modo pcrmanente las afecciones de dichas partes.
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Translation by Jos6 F. Xonidez Cornell Medical College, New York
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AUTHOR 8 ABSTRACT OP THIS PAPER ISSUED BY THE BIBLIOGRAPHIC SERVICE, MARCH 28
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INFECTIONS IN THE FEMALE URETHRA
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C. B. MOORE
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Division of Obstetrics and Gynecology, Stanford School of Medicine, San Francisco
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TEN FIGURES
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In order to understand better the infections which occur in the female urethra and especially their tendency often to chronicity and the frequency with which they escape detection, a clinical and laboratory study of female urethras has been made during the last three years, together with a review of some of the literature which might be of assistance. The work in the laboratory comprises some bacteriological investigations and histological examinations of urethras of the newborn, infants, and adults of different ages. For the clinical studies, which were done at the same time in the Women's Clinic of the Stanford University School of Medicine, a new instrument was devised which has proved very satisfactory for the purpose of examinmg and treating the anterior urethra. Photographs of the microscopic sections and the instrument are appended below.
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Because of its structure and location, the female urethra is very prone to bacterial invasion and retention, and for this reason is of distinct clinical interest both to the obstetrician and to the gynecologist. Infections occur here to a great extent only during the child-bearing period and it is not an unconnnon focus of infection during pregnancy.
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The female urethra is a fibromuscular structure about 35 nun. in length, lying dorsally to the symphysis pubis and \Tntrally to the distal end of the anterior vaginal wall with which it is intimately associated. It is composed mostly of involuntary muscle fibers interwoven loosely with white fibrous and elastic tissue carrying numerous nerves and blood-ve§sels in its meshes, the corpus spongiosum. External to this appears two definite
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2 C. B. MOORE
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muscular coats, the inner, or longitudinal, and the outer, or circular coat. The latter forms a large ring, the unstriped sphincter, in the region of the vesicular neck; its reinforcement with striped muscle makes the striped or voluntary sphincter. The mucosa lining the canal is stratified squamous epithelium to a varying extent in the anterior end, stratified columnar epithelium in the intermediate region, and a transitional variety in the posterior end near the l^ladder. At the meatus of some subjects, especially nulliparous ones, the mucosa is extended into two lateral folds, called by Kelly (1) the labia urethrae. They vary in size and shape and undoubtedly assist in protecting the urethra from bacterial invasion from without. The urethral meatus usually lies about 10 mm. from the anterior vaginal wall. In some subjects it lies even closer than this, sometimes a few millimeters. In the mechanism described below the meatus may come even to lie in a plane with the anterior vaginal wall.
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The most important feature of the mucosa and the one giving rise to most, if not all, of the pathology is the glands, the most important ones of which are those of Skene. There are also many mucous or sinus glands found throughout its course. The latter structures are lined with short colunmar epithelium and aie sometimes called Littre glands. Skene's glands, usually two in number, lie beneath the nmcosa posteriorly and near the meatus. They are individual, anatomic structures different from the crypts or sinus glands. Doctor Skene (2), of Brooklyn, in 1880, was the first one to discover these structures and realize their importance and to investigate their anatomy and some of their pathology. Dr. J. Kocks (3), of Bonn, and Prof. Max Schtiller (4), a couple of years later, also investigated and described these para-urethral glands. The former considered them vestigial structures of the wollfian tubules.
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These glands have their genesis in the prostate which is present in both sexes (5). The first anlage of the prostate in the female appears in embryos of 50 mm.; in the male of 55 mm. At first the prostate consists of solid epithelial buds which extend into the suirounding mescnchyirre from the epithelium of the urogenital sinus, an early anterior division of the cloaca. Part of
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INFECTIONS IN THE FEMALE URETHRA 3
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the anterior division of the cloaca goes to make the l)la(kler and the urethra. These buds are most numerous on the dorsal surface, less so on the sides, and rarely on the ventral surface, although the}^ may at times appear aiound the whole periphery. Those on the dorsal surface develop and branch, while those on the ventral surface remain simple and mostly degenerate. In the male these buds become enveloped in a fibromuscular mass to make the prostate gland. Some of the ducts which were not included in the formation of the prostate gland form accessory glands. According to Keibel and ]\Iall, in the female embryo few glands are formed, three being the maximum number. These may undergo development and form the above-mentioned Skene's glands or ducts. This condition may possibly explain the different degrees of urethral infections in the female, at least to some extent. Since the glands are under retrogressive influences, the}^ may not appear in some cases; in others they ma}' be simple and shallow, in which case the infection is near the surface and therefore more easil}^ cured; in others they may attain greater development, in which case infections become deep-seated and with poor drainage. This latter type leads to the chronic case described below which has been so difficult to cure.
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In the embryo there are still other glands which de^'elop in this region. These are the small sinus glands. They appear around the entire periphery of the urogenital sinus in the embryo of 60 mm. These glands have the character of those of Bartholin, but do not attain to the same development. The gland of Bartholin, also developed from the urogenital sinus, comes to lie outside of the urethra, for which reason it does not enter into the present topic. Thus it is revealed from embryonic studies that there is considerable glandular development in this region. According to the distribution of these glands, the urethra is sometimes divided into an anterior and a posterior urethra, the former being the glandular region and the latter the nonglandular region (6) .
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The structure of Skene's para-urethral glands is described as follows (7): Upon each side, near the floor of the urethra, are
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C. B. MOORE
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two tubules extending from the vicinity of the meatus for 7 mm. to 15 mm. beneath the mucosa. The mouths of these tubes open upon the surface usually on either side of the median line about 3 nmi. from the outer border of the meatus. The upper ends of the tubules terminate in a number of di\'isions which branch off into the muscular walls of the urethra. These racemose structures are lined by a compound epithelium composed of three layers. The deepest layer is composed of young roundish cells having large, granular nuclei which make up the major portion of the cells. Next above this is a layer of cells of a somewhat spindle shape with prominent nuclei. They are young cells at a more advanced stage than those of the first layer. The next, or outermost, layer is composed of fully de\'eloped columnar epithelium with distinct nuclei arranged at the base of the cells. At the mouth or duct of the gland the columnar cells give place to a sciuamous epithelium resembling that of the anterior urethra. The structure of the epithelium of these glands gives evidence of considerable functional activity, which function is the production of a rather viscid nmcus. The purpose of this secretion is undoubtedly to lubricate and protect the anterior urethra. Because infections of these glands had been found only in adults between the ages of twenty and thirty-five years, it has been stated that they appear to reach their best development between these ages (1). In our clinic they have been found to occur in patients between the ages of twenty and forty-eight years inclusively. The fact that they do not apparently appear in ages under twenty remaiiiS to be explained. Possibly it may be due to a difference in the epithelial lining in very young patients. I have repeatedly examined the anterior urethras of young girls with chronic vaginitis, but have never succeeded in finding a suppurating focus in the urethra.
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A great variety of organisms have been recovered from the human urethra (8): gonococcus, streptococcus, staphylococcus, diplococcus, colon bacillus, diptheria group of bacilli, pneumococcus, smegma bacilli, typhoid and typhus, pseudogonococci (an organism morphologically like the gonococcus, but Grampositive in reaction), and tuberculosis, and spirochaetae. The
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INFECTIONS IN THE FEMALE URETHRA 5
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Micrococcus catarrhalis (a Gram-negative diplococcus resembling the gonococcus) has also been found in the urethra (9) ; also in the vagina (10), from which locality it may easily gain entrance to the urethra. A Gram-negative diplococcus ha\'ing the form of the gonococcus, but with variations in size, has been demonstrated in preparations from fresh cultures (11). In smears taken from apparently normal urethrae, near the external meatus, we have always found some bacteria. Typhoid, typhus, and tuberculosis gain entry by invasion from within during the general infection of these diseases. A primary tuberculosis urethritis has yet to be definitely demonstrated. The inclusion bodies of Lindner (8), believed by many authorities to be the bacterium causing trachoma, have been recovered from the female urethra, the newborn of which patient had a conjunctivitis at the time. This same organism can be isolated from the infant's conjunctiva if smears are taken during the early onset of the inflammation. Virus from the mother's urethra, or from the infant's conjunctiva, or from a case of true trachoma will, when applied to the eyes of a monkey or human adult, produce trachoma. It is only when the germ gains entrance to the eye of the adult that true trachoma arises. So often has this been noted and by so many different observers that trachoma has been considered a venereal disease.
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Infections in the urethra may be pathogenic or non-pathogenic, and also pj^ogenic or non-pj^ogenic. Because of its great prevalence and the extent of its ravages, the gonococcus is the infection of greatest importance. From the suppurating discharge expressed from the urethra Gram-negative intracellular diplococci can occasionally be demonstrated. But there are a gieat number of cases in which a great number of bacteria can be recovered without showing any presence of this bacterium, at least in smears made directly from the discharge. Knowing that the character of the gonococcus changes more or less during long habitation in the tissues, and also that a great variety of flora follow in its wake, chronic suppurating cases may be considered probably of Neisser origin unless otherwise demonstrated. Such a type of case may be shown in the following laboratory reports taken from the record of the Stanford Women's Clinic:
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6 C. B. MOORE
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No. 66510. July 22, 1918. Purulent-looking discharge expressed from urethral gland. Laboratory report of smear: jMany pus cells and a few Gram-negative intracellular diplococci.
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August 29, 1918. Purulent-looking discharge expressed from urethral gland. Laboratory report of smear: Many pus cells and epithelial cells and a few Gram-negative intracellular diplococci.
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January 29, 1919. Purulent-looking discharge expressed from urethral gland. Laboratory report of smear: Many pus cells and Gramnegative and Gram-positive bacilli; no Gram-negative intracellular diplococci.
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March 3, 1919. Purulent-looking discharge expressed from urethral gland. Laboratory report of smear: Many Gram-negative bacilli; no Gram-negative intracellular diplococci.
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In subsequent smears no Gram-negative intracellular diplococci were found, although a purulent-looking discharge could be expressed every time the patient was examined. Such a case clearly indicates a great difficulty encountered in any bacteriological search for this bacterium.
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In some cases Gram-negative, intracellular diplococci may be present in the urethra without giving rise to any urethral signs or symptoms, as illustrated in the following record :
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Xo. 74194. Cervicitis. Thick, mucopurulent discharge from the cervix. No discharge from the urethra; anterior urethra clear. Laboratory report : Cervical smear : Manj^ endothelial cells and a few Grampositive bacilli. No Gram-negative intracellular diplococci seeri. Smear from anterior urethra: Gram-negative intracellular diplococci. Many Gram-positive diplococci and bacilli.
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What organism this is we cannot say at present. It appears that this bacterium is either in the incubation stage or else has remained here without producing any pathology.
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B. coli infections producing suppurating para-urethral glands have been described by Fellner (12).
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The changes in the urethra following pathogenic infections may be divided into two classes: those due to simple inflammation and those due to suppuration. In the former the lesion is like that of inflammation of a mucous membrane. These usually disappear in time or else yield to urinary antiseptics, except possibly some few chronic cases aff"ecting the intermediate region. The squamous epithelium of the anterior urethra does not offer
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INFECTIONS IN THE FEMALE URETHRA 7
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proper soil for the invasion of bacteria. Luys (6) has described the changes due to gonorihoeal infections. Tuberculosis (13) and syphihs (14, 15) have their specific lesions, which are described under these diseases.
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The pyogenic infections are very important because of their frequency and chronicity. However, it should be noted that there can be expressed from some female urethras a material which is not one of suppuration. Sometimes a thick, creamy discharge, sometimes cheesy in consistency, can be expressed in which smegma bacilli have been found. At times one may be able to express a considerable amount of this material from the urethra. Occasionally a thin or thick white discharge is seen in the anterior urethra or can even be expressed directly from a gland, a material looking like that seen in the vagina at the time. This discharge has apparently passed from the latter plac0 and lodged in the anterior urethra or gained access to a gland. The stained smears from each locality are alike. This condition is demonstrated in the following record:
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No. 78639. Moderately thick whitish discharge in vagina. Moderateh' thick whitish discharge expressed from gland in floor of anterior urethra, right side. Smears made from each locality. Laboratory report: Urethral smear: Examination shows many epithelial cells which are sc|uamous in type and have been denuded in masses. No pus cells nor lymphocj^tes seen. Many bacteria of various types, including large and small bacilli and small diplococci. Vaginal smear: Shows moderate number of squamous epithelial cells, a few lymphocytes, but no pus cells; numerous bacteria of various tj'pes, including large and small bacilli and small cocci occurring singly, in pairs, and in masses.
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On two subsequent examinations at intervals of seven days, the same discharge was expressed from the same region of the urethra. Because the excretion resembles that seen in the vagina, macroscopically and microscopicallj', it is probable that the process was initiated by extension from the latter place or vice versa, and apparently does not extend beyond that of desquamation. In the chronic cases with suppurating infections we have a condition in which the original surface infection has disappeared; the bacteria have penetrated into the glands which offer the best soil for bacterial growth. In these minute
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8 C. B. MOORE
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epithelial pockets chronic inflammation with suppuration may go on indefinitely and without a local symptom. At every examination of these patients one or more drops of pus can be expressed into the urethral meatus from these suppurating glands.
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When the duct of a suppurating gland becomes occluded there will be formed a para-urethral abscess which may vary from the size of a marble to that of a large walnut. In the larger abscesses the mucous membrane and vascular capillaries have been destroyed in places and the process has extended into the adjacent tissue. In this way blood sometimes becomes mixed with the pus.
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An important point which may be considered here is the way in which the discharge from the urethra may be carried up into the parturient tract of an obstetrical patient. In his description of the function of Skene's glands, namely, lubrication during coitus, Kelly has described a mechanism of displacement and eversion of the urethra which may be seen to take place when a finger is introduced into the vagina. At the first contact the labia urethrae are separated. This opens the urethral orifice. The tendency of the act of penetration is to displace the distal end of the urethra dorsally. As the vaginal wall becomes impinged upon, the displacement will become even more marked and the urethral orifice directed into the vagina. Thus during the examination of an obstetrical patient the urethral meatus tends to become directed toward the examining finger. Pressure on the anterior vaginal wall expresses any infected contents of the urethral glands, which are then carried up into the vagina by the penetrating finger. For this reason, unless one be exceedingly careful, a digital examination of an obstetrical patient had better be done per rectum. Also by this same mechanism infections may be carried to or into the urethral meatus. This is probably the way in which B. coli enter the urinary tract in the newly married, giving rise to what is called by Sippel (16) 'Kohabitation Cystitis und Pyehtis.' No matter how sHght the abrasion of the urethral meatus which is directed into the vagina during the act of penetration, colon baciUi, which are
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INFECTIONS IN THE FEMALE URETHRA 9
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commonly present in this region, become rubbed in and thereby enter the urethral lymphatics and ascend. Some of these cases of B. coli infection disappear spontaneously; others lose their acute character, if they had any, and continue without symptoms, a chronic condition with acute exacerbations of pyelocystitis' commonly called by the laity 'bilious attacks.' This is also a probable way in which pyelitis of pregnancy develops.
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Whene\'er a suppurating discharge can be expressed from the urethral glands I do not think it worth while to treat the infection with antiseptic instillation into the urethra or even directly into the ducts of the gland. ]\Iany of the cases so treated continue to discharge pus with little or no mterruption. If the patient is kept under observation long enough, it will sometimes be found that what was thought to be cured was only pus-free for a time and has returned to its former suppurating condition.
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Anterior urethral glands can easily be destroyed with the electric cautery and the suppurating condition terminated if the cauterization is sufficiently done. AATienever it is certain that the discharge expressed from the urethra is pus the anterior urethra should be cocainized with a 10 per cent solution of cocaine and the skenoscope (17) introduced. Sometimes one may be able to see the entrance to the ducts. With a finger in the vagina and pressure applied along the urethra, pus may be seen to appear at one or tw^o spots on the mucosa. In one instance, I saw as many as three drops appear at the same time in different places, and in a lateral position, not in the usual position on the floor of the urethra. At times one will be surprised to find that he is unable to express any discharge from a urethral gland, although some emerged from the meatus on examination before the instrument was introduced. This may be due to the fact that all of it had been expressed either from a gland or from the anterior urethra where it was lying. To tell whether or not it has come from a gland it is necessary to make the examination with the anterior urethra exposed so that the definite locality of any discharge may be seen. In case of failure to express anj^ excretion for the reason just mentioned, the patient may be requested to return for another exammation in a few days. The
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10 C. B. MOORE
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instrument is then introduced for the preliminary search. The gland will be found to have filled again, especially so if pus had been found, and the discharge will be seen to emerge from its orifice on pressure. With a small wire a search is made in each drop of pus for the entrance to the duct into w^hich the wire is passed as far as possible. This will act as a guide to direct the passage of a small wire electrocautery. Cauteiize until as much tissue is destroyed as one thinks advisable. Failing to find the entrance to the duct one may cauterize the region with no guide other than the eye. If on a subsequent visit the treatment has been found to be unsuccessful or pus has appeared from another locality, the treatment should be repeated. I have never seen any ill effects follow this treatment and no recurrence after the second cauterization, which is usually more thoroughly done than the first one. Healing is very prompt. Also, I have never seen any suppurating gland further than a few millimeters from the meatus; never beyond easy reach of the cautery, and never more than one or two in number, on one occasion three. This fact, together with Keibel's and Mall's embryonic studies, leads me to believe that all of these cases are those of skenitis.
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Para-urethral abscesses which cannot be emptied through the duct should be treated surgically by incision and drainage.
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I wish to thank Dr. Frank Ellsworth Blaisdell for his help and assistance in examining the histological sections and for his contributions of microphotographs which accompany this paper. Thanks is also due others of my confreres whose interest has been an encouragement.
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INFECTIONS IN THE FEMALE URETHRA H
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LITERATURE CITED
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1 Kelly Howard A. 1933 Labia urethrae and Skene's glands. American
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Medicine, vol. 6, pp. 429 and 465.
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2 Skene, A. J. C. 1880 The anatomy and pathology of two important glands
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of the female urethra. American Journal Obs., vol. 8, p. 265
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3 KocHS, J. 1886 tJber die Gartnerschen Gauge beim Weibe. ' Arch, f . Gyna kologie. Red. von Crede; Bd. 20. Berlin.
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4 ScHtJLLER, Max 1883 Ein Beitrag zur Anatomie der weiblichen Harnrohre.
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o) Virchow's Archiv flir pathoiogische Anatomie und Physiologic und fiir klinische xMedicin, Bd. 94, S. 405. b) Festschrift f. Bernard Schultz, Berlin, Bd. 4, S. 16.
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5 Keibel, Franz, and Mall, Franklin P. 1912 Human embryology, vol.
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2, chap. 19, p. 965. J. B. Lippincott Company, Philadelphia and London.
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6 LuYS, George A textbook of gonorrhoea, pp. 66-75. Bailliere, Tindall &
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Cox, Covent Garden, London.
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7 Van Cott, Joshua M. 1888 The histology and pathology of Skene's
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glands. Brooklyn Med. Jour., vol. 1, p. 132.
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8 Konigstein, H. Urethritis non-gonorrhoeal bei Mann und Frau. Hand buch der Geschlechtskrankheiten, Bd. 2, S. 518-575.
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9 Avers, W. 1912 The Micrococcus catarrhalis as a cause of inflammation
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in the genito-urinary tract. Amer. Jour. Surg. N. Y., March, p. 101.
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10 GuRD, Eraser B. 1908 A contribution to the bacteriology of the female
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 +
genital tract with special reference to the gonococcus. Jour. Med. Research, vol. 18, N. S. 13, p. 291.
 +
 +
11 Steinschxeider 1893 tJber die Cultur der Gonokokken. Berliner klin ische Wochenschrift, July 24, S. 969.
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 +
12 Fellner, Otfried O. Einige Falle von paraurethraler Eiterung bei Weib.
 +
 +
Monatschr. f. Geburtsh. u. Gyn., Bd. 25, S. 319.
 +
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13 Hart.mann,H. 1935 Tuberculosehypertrophiqueet stenosantedel'urethre
 +
 +
chez la femme. Bull, et M. Sec. de chir. de Par., N. S., T. 32, pp. 956-958.
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14 Douelle, M. 1901 Chancre syphilitique de I'urethre chez une femme.
 +
 +
T. D. mal. cutan. et syph.. Par., T. 13, pp. 467-471.
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15 Lewembach, G. 1903 Die gummose Erkrankung der weiblichen L'rethrae.
 +
 +
Ztschr. f. Heilk., Wien u. Leipzig, 6 pi.; S. 51-91.
 +
 +
16 Sippel, A. 1912 Aufsteigende Infektion der Harnwege bei frisch verhei rateten Frauen. Kohabitation Cystitis und Pyelitis. Dut. med. Wochensch., Jun. 13, Bd. 28; S. 1138.
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17 Moore, C. B. , 1918 Chronic gonorrhoeal skenitis. Treatment with the
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electrocautery. Jour. Amer. Med. Assoc, Dec. 21, vol. 71, p. 2056.
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PLATE 1
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EXPLANATION" OF FIGURES
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1 Cross-section of a female urethra near meatus of a newborn baby. G, glands; U, urethral canal. Abundant squamous epithelium.
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2 Higher magnification of a region on figure 1. All sections of this specimen show this type of epithelium.
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3 Cross-section of the whole specimen of a female urethra near meatus of a nine months' baby. As disclosed in embryonic studies, the glanudular budding is greater on the dorsal side.
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12
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INFECTIONS IN THE FEMALE URETHRA
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C. B. MOORE
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PLATE 1
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' ' ' <f ■ -■■ ' \ "s. ^
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^T^'^-^^'*^'-^
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.V,
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\
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PLATE 2
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AXATION f)F FIG
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4 Cross-soot ion of a foinalc urethra iioar meatus of a nine months' baby ; made from a region of figure 3. G, gland; U, urethral canal.
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5 Cross-section of a female urethra near meatus of a twenty-three-year-okl subject. Epithelium is squamous. This is undoulitedly a Skene's gland. V , urethral canal; D, duct; G, gland.
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6 Higher magnification of a region on figure 5, but made lo,, mm. posterior to the section made of the latter. This section shows colunmar epithelium of the urethral canal, U , and the gland, G.
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7 Cross-section of a female urethra near meatus of a forty-three-ycar-old subject. G, gland; E, epithelium; U, urethral canal.
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INFECTIONS IN THE FEMALE URETHRA
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C. B. MOORE
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PLATE 2
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-■
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1^^^
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k
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/ /
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i|t^^^^N«r
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15
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PLATE 3
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KXPLANATION OF FIGURES
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8 Dniwing of a .sagittal .section through the center of a female pelvis representing the urethral displacement on vaginal penetration.
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9 Instrument in position for examinat ion and treatment. Exposure of drops of pus (A) in different localities of the urethra in different subjects.
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10 Skenoscope.
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16
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INFECTIONS IN THE FEMALE URETHRA
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C. B. MOORE
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PLATE 3
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Resumen por el autor, Richard E. Scammon, Universidad de Minnesota.
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Un sencillo aparato de calcar para hacer reconstrucciones topograficas.
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Este aparato ha sido ideado para hacer reconstrucciones graficas de fetos y otros objetos pequenos. Consiste esencialmente de dos partes: Una placa de vidrio cuadriculada, cuyas lineas distan entre si un centimetro, colocada sobre un tablero, y un ocular con un eje 6ptico establecido mediante un pequeiio orificio superior y una cruz formada por dos cerdas cruzadas, situada inferiormente.
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En la base del ocular se ha cortado un cuadrante para permitir la orientacion de aquel con referenda a las lineas de la cuadricula. Los hordes del cuadrante son biselados y divididos en una escala milimetrica para medir pequenas distancias. Los ejemplares que se desea reconstruir se colocan sobre el tablero de la base, y despues de orientarlos con referenda a la linea basal de la cuadricula dividida en centimetros, se dibujan en papel cuadriculado por medio de una serie de lecturas sucesivas tomadas con el ocular.
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Translation by Jos6 F. Nonidez Cornell Medical College, New York
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AUTHOR S ABSTRACT OF THIS PAPER ISSUED BY THE BIBLIOGRAPHIC SERVICE, MARCH 28
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A SIMPLE TRACING APPARATUS FOR MAKING TOPOGRAPHIC RECONSTRUCTIONS
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RICHARD E. SCAMMON
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Institute of Anatomy, University of Minnesota
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THREE FIGURES
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The study of certain phases of the anatomy of the fetus and infant is hindered somewhat by the lack of any simple method of making topographic reconstructions of the various organs and regions. Graphic reconstruction from microscopic sections, which is so successful in embryologic work, is generally impracticable here, for the preparation of even a few sets of serial sections of this material requires an almost prohibitive amount of time and labor, and the thorough decalcification necessary for the larger specimens usually causes serious shrinkage and distortion in the process of embedding. The usual methods employed in the study of adult topography are also inadequate for this work. Topographic reconstructions of the adult are generally made either by graphic reconstruction from free-hand transverse sections after the method first suggested by Henke or by plotting from fixed points which are estabhshed by setting long pins or skewers in the body in certain definite positions before dissection is begun. But to make accurate reconstructions of the smaller structures of the fetus and infant the sections must be cut so thin that they are extremely fragile and subject to distortion. And the fixed point method is very inconvenient both because of the difficulty in placing the pins firmly in position in the delicate tissues and because these pins make the subsequent dissection of the smaller regions almost impossible.
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The apparatus which is described here was devised to overcome some of these difficulties, and after a considerable trial has been found sufficiently useful to warrant the publication of
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19
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THE ANATOMICAL RECORD, VOL.
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20
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RICHARD E. SCAMMON
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an account of it. It consists essentially of a tracing stand, covered by a glass grating, and an eyepiece.
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The stand is shown in figure 1. Its base is a slab of hardwood, 25 inches long, 17 inches wide, and 1.5 inches thick. Seven inches above this base is a sheet of heavy plate glass inclosed in a strong hardwood frame, which is supported at its corners by four brass rods. At one end these rods or legs are connected with the frame by hinges and firmly attached to the base-board
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l-ATe GLASS ETCHED IM ICf
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Fig. 1 Stand of reconstruction apparatus.
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with screws. At the other their upper ends are screwed to the frame of the plate, but their lower ends are covered by rubber caps which rest freely on the base-board. This permits the frame to be raised so that large objects may be easily placed on the base-board below.
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The glass plate is ruled with a centimeter grating and the lines of this grating are numbered or lettered consecutively at its margin. The middle longitudinal and the middle cross line of the grating are ruled a little heavier than the others and are filled with pigment to distinguish them as base lines (fig. 3).
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A SIMPLE RECONSTRUCTION APPARATUS
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21
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\ Thejteyepiece is a brass tube 4 inches long and 0.8 inch in diameter (fig. 2, A). Its upper end is closed by a screw cap which contains a central pinhole opening (fig. 2, JB). At the bottom of the tube are cross-hairs of spun glass or very fine wire which are set a]^little|above its lower opening and cross in the optical
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Fig. 2 Eyepiece of reconstruction apparatus. A, entire eyepiece; B, detail of screw cap with pinhole opening; C, detail of quadrant base.
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axis of the tube directly in line with the pinhole opening in the cap. The lower end of the tube is set in the center of a circular plate of brass 2.4 inches in diameter and 0.2 inch thick. One quadrant of this base is cut away, its margins being so adjusted that they fall directly in line with the cross-hairs of the eyepiece.
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22 RICHARD E. SCAMAION
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The edges of the quadrant are beveled and are graduated in milhmeters, the zero points of the scales lying exactly 1 cm. from the optical center of the eyepiece (fig. 2, C).
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The method of using the apparatus is simple. The specimen to be reconstructed is fixed firmly in a tray or better set in a base of plaster of Paris or hard wax. It is then placed on the base-board and adjusted so that its midhne corresponds approximately with the midline of the grating on the glass plate above it. Orientation points are then established by marking the specimen with dots of indelible ink or by setting small pins in it. At least three such points should be established as far apart as possible and in regions which will not be disturbed in the course of the subsequent dissection. A large sheet of coordinate paper is now numbered to correspond with the numbering of the grating, and base lines corresponding to those of the grating are drawn upon it. The exact position of the orientation points and the outlines and superficial landmarks of the specimen are now determined by successive readings with the eyepiece which is passed over the grating. As these determinations are made they are recorded in their proper places on the coordinate paper, and the first plot giving the outlines of the specimen is completed by connecting these points. After the outline is made the specimen may be dissected layer by layer and as the different structures are exposed they may be outlined in their proper positions on the plot by replacing the specimen under the grating, adjusting the orientation points to their recorded positions, and taking the necessary readings with the eyepiece. With a little practice this process can be carried out quite rapidly. Readings with the eyepiece to half-centimeters can be made directly from the lines of the grating and readings to half-millimeters by using the scales on the margins of the quadrant. The specimen should be strongly illuminated when the readmgs are made. Orthographic projection is assured by the use of the eyepiece with a vertical optical axis established by the pinhole opening and crosshairs. It is possible to make the reconstruction at any magnification desired by modifying the scale of the coordinate paper.
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A SIMPLE RECONSTRUCTION APPARATUS 23
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A
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Fig. 3 Reconstruction of the abdominal and thoracic viscera of a full-term newborn infant. Made by H. J. Bower and W. C. Stillwell with the apparatus herein described. The reconstruction has been retraced and reduced to onehalf the original (natural) size. The centimeter scale of the grating is shown at the margins of the drawing. 'A-A and 0-0 are the longitudinal and cross baselines.
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24 RICHARD E. SCAMMON
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The chief sources of error in making reconstructions of this kind are due, first, to changes in the form of the specimen which may occur in the course of dissection and, second, to variations caused by the improper adjustment of the eyepiece. The first may be avoided, in a great measure, by partially embedding the specimen in a firm base of plaster or wax as mentioned above and by care in dissection. The second can be entirely eliminated if care is taken to see that the margins of the quadrant are either parallel or at right angles to the lines of the grating before each reading is made.
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An example of a reconstruction by this method of the thoracic and abdominal viscera of a full-term stillborn infant is shown in figure 3. The original plotting has been retraced and inked, the pubhshed figure being one-half the size of the original.
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-v^
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Resumen por el autor, Richard E. Scammon, Universidad de Minnesota.
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Nota sobre la relacion entre el peso de la tiroides y el del timo en el hombre.
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La variaci6n de peso del timo y la tiroides en adultos jovenes, en apariencia normales (determinados por los datos de Dustin y Zunz) es muy grande. Los pesos de estos organos demuestran la existencia de una correlacion ligeramente negativa en la madurez temprana. Los pesos del timo y la tiroides del recien nacido varian tambien considerablemente, pero presentan una ligera correlaci6n positiva. Las conclusiones de Dustin y Zunz sobre el valor de estos datos como prueba de una correlacion funcional entre el timo y la tiroides no reciben confirmacion en los estudios del autor.
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Translation by Jos6 F. Nonidoz Cornell Medical College. New York
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ACTHOR S ABSTRACT OF THIS PAPER ISSUED BY THE BIBUOGR.VPHIC SERVICE, MARCH 28
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A NOTE ON THE RELATION BETWEEN THE WEIGHT
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OF THE THYROID AND THE WEIGHT OF
 +
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THE THYMUS IN MAN
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RICHARD E. SCAMMON
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Institute of Anatomy, University of Minnesota
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In a recent publication Dust in and Zunz (1) have recorded some interesting observations on the weight of the thyroid and the thymus in early maturity. Their data are quite unique, consisting of weighings of the thj^oids and thymi of thirtyeight indi\dduals who, with one exception, died within fortyeight hours after receiving wounds in battle, and who came to autopsy within twelve hours or less after death. We are thus furnished with a series of records of the weight of the thymus in presumably normal young adults which greatly improves our knowledge of the later ponderal changes of this organ.
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Dustin and Zunz have analyzed this material by means of tabulations and a graph in which the thymus weight is plotted against the thyroid weight. They found a negative correlation between thymus weight and thyroid weight in man, and they conclude that their results support the experimental findings of Gley (2) and others who have observed an increase in the thymus following thyroidectomy in amphibia.
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Although this series of cases is very small for any statistical study, its unique character and the importance of the conclusions which have been drawn from its examination seem to warrant its further analysis by some of the simpler biometric methods. Accordingly, the standard de\dation and the coefficient of variation have been determined for the thymus and thyroid in the series and also the coefficient of correlation between the two organs. These determinations were fo^st made for the entire series of cases as given in the original article, and second for the same series with the omission of four cases which seem to be of doubtful value.
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25
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26 RICHARD E. SCAMMON
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In the complete series the average weight of the thyroid is 32.0 ±2.4 grams, the standard deviation 21.8 grams, and the coefficient of variation 0.68. The average thymus weight is 15.6 ±0.7 grams, the standard deviation 7.07 grams and the coefficient of variation 0.45. The coefficient of correlation between the thyroid and the thymus is —0.265 with a probable error of ±0.102.
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The second calculation was made from the series after the omission of the following cases.
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Case 1, in which the weight of the thyroid was 134.54 grams, nearly four times the average weight of the group and over two times the weight of the next member of the series. It can scarcely be doubted that this great enlargement was associated with thyroid disease.
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Cases 2 and 11, in which there was a complete involution of the thymus. As these cases were individuals aged twenty-five and twenty-eight years, respectively, it is most probable that the thymi had undergone accidental involution, presumably in some previous illness.
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Case 38 was a youth but fourteen years old and cannot be properly included with a series of young adults, since the thymus undergoes profound weight changes in adolescence.
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In the selected series, with these four cases omitted, the average thyroid weight was 26.6 ±1.41 grams, the standard deviation 12.26 grams, and the coefficient of variation 0.45. The average weight of the thymus was 16.2 ± 0.64 grams, the standard deviation 5.49 grams, and the coefficient of variation 0.33. The coefficient of correlation of the thyroid and thymus was —0.156 with a probable error of ±0.107.
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These calculations show a negative correlation between the weight of the thyroid and the weight of the thymus in the complete series, as Dustin and Zunz suspected. But this correlation is so low and the probable error is so large that we are hardly justified in attaching any particular significance to it. This seems the more probable since when the four cases which are of very doubtful value are omitted the correlation drops to from — 0.265 to —0.156 and the probable error remains almost un
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WEIGHT OF THE THYROID AND THYMUS IN aiAN 27
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changed. A slight negative correlation might well exist between the two organs, since the thyroid follows the scheme of general body growth and increases a little in weight during the third decade, while the thymus decreases in absolute as well as relative weight after early adolescence. But this negative correlation does not warrant the assumption of a functional relation between the two organs; a similar correlation might be expected between the thymus and any of the viscera which follow the general scheme of the growth in mass of the body as a whole. ' In order to test this relation in another way I have calculated the coefficient of correlation of the thyroid and thymus in a series of twenty-five full-term newborn children. The data for this series were taken in part from the lists of cases reported by Valtorta (3) and Lomer (4) and in part from my own records. The average weight of the thyroid in this series was 3.4 ±0.24 grams, the standard deviation 1.8 grams, and the coefficient of variation 0.53. The average thymus weight was 14.2 ±0.90 grams, the standard deviation 6.7 grams, and the coefficient of variation 0.47. The coefficient of correlation of the thymus and thyroid was -1-0.19 with a probable error of ±0.08. Thus in the newborn, as in the adult, the variability of the th>^Tlus and the thyroid is very great and the correlation between the two organs is quite small. But, in contrast to the adult, the sHght correlation w^hich does exist in the newborn is a positive one.
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These figures indicate that any correlation which may exist between the weights of the thyroid and the thymus is inconstant in postnatal life, and they offer fittle if any support to the concept of a direct functional relation between the two organs.
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LITERATURE CITED
 +
 +
1 DusTiN, A. p., ET ZuNz, E. 1918 A propos des correlations fonctionnelles
 +
 +
entre le thymus et le corps thyroide. Journ. de Physiol, et do Pathol. Gen.,T. 17, pp. 905-911.
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2 Gley, E. 1909 Glande thyroide et thymus. C. R. Soc. Biol. Paris, T. 66,
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p. 1007.
 +
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3 Valtorta, F. 1909 Richerche sullo sviluppo dei visceri del feto. La indi vidualita nel neonato. Ann. Ostet. e Ginecol., T. 31, pp. 673-713.
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4 Lomer 1889 Ueber Gewichtsbestimmung der einzelnen Organe Neugebo rener. Zeitschr. f. Geburtsh. u. Gynakol., Bd. 16, S. 106-130.
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Resumen por el autor, George B. Wislocki, Johns Hopkins Medical School.
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Observaciones sobre el comportamiento de la tinta china inyectada en animales durante la prefiez.
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Experimentos llevados a cabo durante muchos afios han venido a demostrar que las partfculas inertes que flotan en la circulaci6n materna no pueden atravesar la placenta y penetrar en el feto. La explicacion de este fen6meno, mediante el cual el material en suspension no atraviesa la placenta o las membranas fetales, no ha sido hallada mas que para un grupo de substancias, esto es, los colorantes vitales. Estos colorantes, conforme Goldmann ha demostrado en el caso de la rata y raton, son absorbidos y acumulados en el epitelio cori6nico y las celulas de la membrana vitelina, y de este modo se previene su penetracion en el feto. El autor ha inyectado granulos de carbon suspendidos en acacia (tinta china) en una serie de conejillos de indias, conejos, gatos y perros prefiados. Los animales fueron sacrificados despues de unos cuantos dias y los tejidos examinados. El autor ha podido observar que los granulos de carb6n se depositan en el higado, bazo, pulmones y medula 6sea de la madre. En la placenta, membranas fetales y 6rganos de los fetos no pudo hallar carb6n, ni aiin estudiandolos bajo el microscopio. La conclusi6n que se deriva de la repulsi6n de las particulas de tinta por las celulas de la placenta y membranas fetales es que dichas celulas son incapaces de absorber o fagocitar material extrano de tamano grosero, flotante en la sangre. El limite del tamafio de las particulas que pueden absorber debe estar localizado entre el de una suspensi6n grosera, tal como la tinta china, y una dispersi6n ultramicrosc6pica, como el azul trypan.
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Translation by Jos6 F. \onidrz Cornell Mediral College. \ew York
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AUTHOR S ABSTRACT OF THIS PAPER ISSUED BT THE BIBLIOGRAPHIC SERVICE, MARCH 28
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OBSERVATIONS UPON THE BEHAVIOR OF CARBON GRANULES INJECTED INTO PREGNANT ANIMALS
 +
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GEORGE B. WISLOCKI
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Department of Anatomy, Johns Hopkins Medical School
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It has long been known that certain cells of the body possess the power of removing foreign particulate matter from the bloodstream. Thus, when foreign particles, such as the carbon granules of india ink, are injected into the circulation of an animal, they are completely removed from the blood-stream in a remarkably short period of time. Gross and microscopic examination of the tissues of the animal reveals that the endothelial cells in certain organs have removed the ink from the circulation. The endothelial cells lining the sinusoidal channels of the liver and spleen are found heavily laden with the foreign particles. In addition to the granules of carbon which have been actually phagocytized, aggregations of the particulate matter into tiny clumps are found within the lumen of the blood sinuses. The bone-marrow in many animals is the site of a similar but subordinate process.
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The question of the behavior of the cells of the placenta toward particulate matter circulating in the blood-stream has been only incompletely investigated. Recent writers on the problem of placental transmission, namely, Zuntz ('04), Kehrer ('08), and Hofbauer ('10), concur in the statement that particulate matter does not pass from the maternal into the fetal bloodstream. The explanation of the failure of suspended material to pass through the placenta or fetal membranes has not been 'given except for one group of substances, namely, the vital dyes. The vital dyes, which are ultramicroscopic dispersions of certain of the acid azo dyes have been rather fully investigated by Goldmann ('09). He showed that when these dyes are introduced into the blood-stream of a pregnant mouse or rat,
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29
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30 GEORGE B. WISLOCKI
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they stain the maternal tissues, the placenta, and the outermost fetal membrane, but fail to stain the fetus. He discovered that the reason for this apparently was that the dye-stuffs were absorbed and stored by the cells of the chorion and \dtelline membrane and thereby prevented from entering the fetus.
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It has, however, not been determined w^hether more coarsely dispersed substances than the Vital dyes,' such as the carbon granules of india ink, are similarly phagocytized and stored bj^ the cells of the placenta and fetal membranes or whether they are completely rejected by these cells. In the literature one finds numerous brief statements regarding the fate of coarse particulate substances injected into the blood-stream of pregnant animals. The earlier experimental work is surprisingly contradictory and but little unportance can be assigned to most of it, as the observations were made on an insufficient number of animals and the methods employed were often open to criticism. Thus, Reitz ('68) described cinnabar (red sulphide of mercury) in the tissues of a rabbit fetus after injecting the mother; Caspary ('77) reported a similar result with cinnabar in a rabbit; Perls ('77) recorded the passage of cinnabar and ultramarine into the fetuses in several rabbits and dogs; Mars ('80) observed the passage of a number of emulsified substances into rabbit fetuses, and, finally, Pyle ('84) stated that he observed the passage of ultramarine into a series of rabbit fetuses.
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On the other hand, Hoffmann and Langhan ('69) failed to find cinnabar in the fetuses of a rabbit which they injected; Fehling ('77) and Ahlfeld ('77) reported the failure to find india ink in the liver, kidneys, or blood of the fetuses of several rabbits, and ]\Iiropolsky ('85) obtained similar negative results with cinnabar.
 +
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Krukenberg ('88), who can be said to have undertaken the first thorough investigation of this kind, injected a suspension of barium sulphate into one series of pregnant rabbits and a non-pathogenic organism, B. prodigiosus, into another series. Neither particles of barium sulphate nor organisms were recoverable from the tissues of the fetuses. His experiments left little doubt that particulate materials, such as he employed, are not transmitted from mother to fetus.
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CARBON GRANULES INJECTED INTO PREGNANT ANIMALS 31
 +
 +
Hofbauer ('10) obtained similar results after injecting colloidal silver and silicium into several pregnant animals. Neither of the substances could be found in the fetal organs.
 +
 +
Finally, Goldmann ('09) undertook his experiments with acid azo dyes, and showed that they, too, were not transmitted to the fetus. Goldmann's report contains the only description of the microscopic examination of the placenta and fetal membranes. In the mouse and rat the giant-cells, the chorionic ectoderm of the labyrinth, and the epithelium of the vitelline membrane were found heavily laden with granules of dye; these cellular accumulations of the dye-stuff were looked upon as evidencing the protective mechanisms of the fetus.
 +
 +
In the present experiments a filtered solution of India ink was used. The ink was administered intravenously to a series of pregnant animals, consisting of one dog, three cats, three rabbits, and three guinea-pigs. The amount of ink injected was regulated according to the size of the animals, the guinea-pigs receiving 1 cc, the rabbits and cats 5 cc, the dog 15 cc, on two successive days. The animals were sacrificed one or two days after the last injection.
 +
 +
The gross distribution of the india ink was essentially the same in all the species of animals examined. At autopsy the liver and spleen were found to be deep black and the lungs presented a grayish appearance. The bone-marrow in the rabbit was of the same color as the liver and spleen; in the guinea-pig it was not so black, while in the cat and dog its color appeared to be normal. The uterus appeared unstained. The placentae, fetal membranes, and the fetuses showed nothing to the naked eye suggesting the presence of ink particles in these tissues. The remaining organs and tissues of the animals appeared normal. The findings in gross, therefore, indicated that the injected ink granules had in whole or greater part been segregated in the liver, spleen, bone-marrow, and lungs, and that none had been deposited in the placentae, fetal membranes, or fetuses.
 +
 +
Microscopic examination revealed the characteristic deposition of the carbon particles in the endothelial phagocytes of the liver, spleen, and bone-marrow. Particles, in part free and in part
 +
 +
 +
 +
32 GEORGE B. WISLOCKI
 +
 +
phagocytized, were also found, to a slight extent, in the interalveolar septa of the lungs. In the remaining organs and tissues of the body, with the exception of a few particles occasionally caught in a blood vessel or phagocytized within an endothelial cell, the carbon granules of the India ink were conspicuously absent.
 +
 +
No carbon particles could be found on examining the placentae. The chorionic epithelium, which in varying patterns is the predominating tissue in them all, showed no evidence of having absorbed particles of ink. The endothelial cells, which in the cat's and dog's placentae completely line the maternal vessels, had not the power of phagocytizing ink particles as had the endothelium of the liver, spleen, and bone-marrow. None of the ink-particles had agglutinated in either the maternal vessels of the dog's and cat's placentae, or in the corresponding sinuses of the rabbit's and guinea-pig's placentae, as they do in the sinuses of the liver and spleen. In the columnar cells of the chorion which flank the placentae of the dog and cat, known respectively as the 'green' and 'brown borders,' no carbon was visible. Nor were particles of ink discovered in the cells covering the vitelline membrane which in the rabbit and guinea-pig forms the outermost fetal membrane and faces the uterine mucosa.
 +
 +
The absence of particles of india ink in all these localities is surprising, since in vitally stained animals these same cells, namely, the chorionic epithelium and the epithelium of the vitelline membrane, are heavily laden with minute granules of trypan blue.
 +
 +
The conclusion to be drawn from the rejection of the ink particles by the cells of the placentae and fetal membranes is that they are incapable of absorbing or phagocytizing coarse, foreign particulate matter afloat in the blood-stream. The limit of the size of particles which they are capable of accepting must lie somewhere between that of a coarse suspension, such as india ink, and an ultramicroscopic dispersion, such as trypan blue. Trypan blue in turn, although absorbed by the chorionic epithelium and fetal membranes, is incapable of entering the
 +
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CARBON GRANULES INJECTED INTO PREGNANT ANIMALS 33
 +
 +
fetal circulation as true solutions have been shown readily to do. Trypan blue, however, may be on the border line of transniissibility, since traces of it actually enter the fetal circulation in the rabbit and guinea-pig.
 +
 +
LITERATURE CITED
 +
 +
Ahlfeld, F. 1887 Zur Frage ueber den Uebergang geformter Elcmente von
 +
 +
Mutter auf Kind. Centralbl. f. Gyn., Bd. 1, S. 265. Caspary, J. 1877 Zur Genese der hereditaren Syphilis. Vierteljahrresschr.
 +
 +
f. Dermat u. Syph., Bd. 4, S. 491. Fehling, H. 1877 Beitraege zur Physiologie des placentaren Stoffverkehrs.
 +
 +
Arch, f Gyn., Bd. 11, S. 523. GoLDMANN, E. E. 1909 Die aeussere und innere Sekretion des gesundcn und
 +
 +
kranken Organismus im Lichte der ' vitalen Faerbung. ' Teil 1 . Beitr.
 +
 +
z. klin. Chir., Bd. 64, S. 192. HoFBAUER, J. 1905 Grundziige einer Biologie der menschlichen Plazenta.
 +
 +
Wien und Leipzig. Hoffman, F. A., ujio P. Langbrhans 1867 Ueber den Verbleib des in die Circulation eingeflihrten Zinnobers. Virchow's Archiv f. path. Anat.,
 +
 +
Bd. 48, S. 304. Kehrer, E. 1907 Der plazentare Stoffaustausch in seiner physiologischen
 +
 +
und pathologischen Bedeutung. Wurz. Abhandl. a. d. Gesammtgeb.
 +
 +
d. prakt. Med., Bd. 7, S. 17. Krukenberg, G. Experimentelle Untersuchungen iiber den Ubergang geformter Elemente von der Mutter zur Frucht. Arch. f. Gyn., Bd. 31, S. 313. Mars, A. 1880 Ueber den Uebergang geformter Elemente aus dem Kreislauf
 +
 +
der Mutter in den des Foetus. Jahresbericht ueber d. gesammte Med.,
 +
 +
Virchow-Hirsch, Bd. 1, S. 81. MiROPOLSKY, M. 1887 Du passage dans le sang du foetus des substances solides
 +
 +
contennes dans le sang de la mere. Archives de Physiologie, T. 6, p.
 +
 +
101. Perls 1879 Lehrbuch d. allgem. Pathol., Bd. 2, S. 266. Pyle, J. P. 1884 An experimental research on the utero-placental circulation.
 +
 +
Phila. Med. Times, vol. 14, p. 711. Reitz, W. 1868 Ueber die passiven Wanderungen von Zinnoberkornchen durch
 +
 +
den thierischen Organismus. Berichte der Wiener Akad. Math.
 +
 +
naturw. Classe, Bd. 57, S. 8. ZuNTz, L. 1908 Der Stoffaustausch zwischen Mutter und Frucht. Ergebnisse
 +
 +
der Physiologie, Bd. 7, S. 403-443.
 +
 +
 +
 +
THE ANATOMICAL RECORD, VOL. 21, NO. 1
 +
 +
 +
 +
THIRTY-SEVENTH SESSION
 +
 +
Wistar Institute of Anatomy and Biology, Philadelphia March 24, 25 and 26, 1921
 +
 +
Thursday, March 24, 9.30 a.m.
 +
 +
The Thirty-seventh Session of the American Association of Anatomists was called to order by President Charles F. W. McClure, who appointed the following committees:
 +
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Committee on N ominations for 1921: Professor Ross G. Harrison, Chairman, and Professors Henry H. Donaldson and G. Carl Huber.
 +
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Auditing Committee: Professor F. T. Lewis, chairman, and Professor Stacy R. Guild.
 +
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The remaining morning session was devoted to the presenta ■ tion of scientific papers.
 +
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Friday, March 25, 11.30 a.m. Association Business Meeting, President Charles F. W. McClure, presiding.
 +
 +
The Secretary reported that the minutes of the Thirty-sixth Session were printed in full in The Anatomical Record, volume 18, number 3, pages 211 to 218. On motion, seconded and carried, the minutes of the Thirty-sixth Session were approved by the Association as printed in The Anatomical Record.
 +
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Professor F. T. Lewis reported for the Auditing Committee as follows: The undersigned Auditing Committee has examined the accounts of Doctor Charles R. Stockard, Secretary-Treasurer of the Association of Anatomists, and finds the same to be correct with proper vouchers for expenditures and bank balance on December 29, 1920, of 8164.40.
 +
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[Signed] F. T. Lew^s,
 +
 +
Stacy R. Guild
 +
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35
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36 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
The Treasurer made the following report for the year 1920:
 +
 +
Balance on hand January 20, 1920, when accounts were last
 +
 +
audited $173.12
 +
 +
Receipts from dues 1920 2,521.-43
 +
 +
Total deposits $2,694.55
 +
 +
Expenditures for 1920:
 +
 +
Expenses Secretary-Treasurer, Washington Meeting $36.08
 +
 +
Postage and Telegrams 44.90
 +
 +
Printing and Stationery 160.75
 +
 +
Collection and exchange on drafts 3.67
 +
 +
Stenography, typewriting 48.75
 +
 +
Wistar Institute, subscriptions to Journal of Anatomy,
 +
 +
Anatomical Record, etc 2,236.00
 +
 +
Total expenditures $2,530.15
 +
 +
Balance on hand $164.40
 +
 +
Balance on hand deposited in the name of the American Association of Anatomists in the Corn Exchange Bank, New York City.
 +
 +
On motion the report of the Auditing Committee and the Treasurer were accepted and adopted.
 +
 +
The Committee on Nominations, through its Chairman, Professor H, H. Donaldson, placed before the Association the following names for members of the Executive Committee, term expiring 1924, Professors S. W. Ranson and R. J. Terry.
 +
 +
On motion the Secretary was instructed to cast a ballot for the election of the above named.
 +
 +
The Secretary presented the following names recommended by the Executive Committee for election to membership in the American Association of Anatomists:
 +
 +
Abbott, Maude E., A.B., CM., M.D., Curator of the Medical Museum, McGill University, Montreal, Canada.
 +
 +
Allen, Edgar, Ph.B., A.M., Instructor in Anatomy, Washington University School of Medicine, ^555 McKinley Averiue, St. Louis, Mo.
 +
 +
Alford, Leland Barton, A.B., M.D., Associate in Clinical Neurology, Washington University School of Medicine, Humboldt Building, St. Louis, Mo.
 +
 +
Blair, Vilray Papin, A.M., M.D., Associate in Clinical Surgery, Washington University School of Medicine, Metropolitan Building, St. Louis, Mo.
 +
 +
Brooks, Barney, B.S., M.D., Associate in Clinical Surgery, Washington University School of Medicine, 4918 Forest Park Boulevard, St. Louis, Mo.
 +
 +
 +
 +
PROCEEDINGS 37
 +
 +
Dart, Raymond A., M.B., Ch.M., M.Sc, Demonstrator in Anatomy, University College, Gower St., London, W. C. 1, England. Temporary Address: Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Davis, Warrex B., M.D., Instructor in Anatumv, Jefferson Medical College 135 S. 18th Street, Philadelphia, Pa.
 +
 +
De Carlo, John, M.B., Instructor in Topographic and Applied Anatomy, Jefferson Medical College, IIU Ellsicorth St., Philadelphia, Pa.
 +
 +
Dendy, Arthur, D.Sc, F.R.S., Professor of Zoology, University of Loyidon, King's College, Strand W. C, London, England.
 +
 +
Garcia, Arturo, A.B., M.D., Professor of Anatomy, College of Medicine and Surgery, Manila, Philippine Islands.
 +
 +
Graves, William W., M.D., Professor of Nervous and Mental Diseases, St. Louis University School of Medicine, Metropolitan Building, St. Louis, Mo.
 +
 +
Gregory, William King, A.M., Ph.D., Curator of Comparative Anatomy, American Museum of Natural History, 77th Street and Central Park West, New York City.
 +
 +
George, Wesley Critz, A.M., Ph.D., Associate Professor of Histology and Embryology, University of North Carolina Medical School, Chapel Hill, North Carolina.
 +
 +
Hartman, Carl G., Ph.D., Associate Professor of Zoology, University cf Texas, Austin, Texas.
 +
 +
Hausman, Louis, A.B., M.D., Instructor in Psychiatry, Johns Hopkins Hospital, Baltimore, Md.
 +
 +
Hill, Eben Clayton, A.B., M.D., Instructor in Anatomy, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
HuGHSON, Walter, S.B., M.D., Assistant in Anatomy, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
IxouYE, MicHio, J\I.D., Professor of Anatomy, Tokyo Imperial University, Tokyo, Japan. '
 +
 +
Levi, Giuseppe, M.D., Professor of Anatomy, University of Torino, Torino, Italy.
 +
 +
Meaker, Samuel R., A.B., M.D., Teaching Fellow, Department of Anatomy, Harvard Medical School, Boston, Mass.
 +
 +
Naxagas, Juan Cancia, M.D., Assistant Professor of Anatomy, College of Medicine and Surgery, Manila, Philippine Islands. (Temporary address — Dept. of Anatomy, Johns Hopkins Medical School, Baltimore.)
 +
 +
Nicholas, John Spangler, B.S., M.S., University Fellow in Zoology, Osborn Zoological Laboratory, Yale University, New Haven, Conn.
 +
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NoNiDEZ, Jose F., Sc.M., Sc.D., Instructor in Anatomy, Cornell University Medical College, 1st Avenue and 28th Street, New York City.
 +
 +
Patten, Bradley Merrill, A.M., Ph.D., Assistant Professor of Histology and Embryology, School of Medicine, Western Reserve University, 1353 East 9th Street, Cleveland, Ohio.
 +
 +
Perkins, Orman C, A.M., Assistant Professor of Anatomy, Long Island College Hospital, 335 Henry St., Brooklyn, New York.
 +
 +
Sachs, Ernest, A.B., M.D., Professor of Clinical and Neurological Surgery, Washington University School of Medicine, 97 Arundel Place, St. Louis, Mo.
 +
 +
Shellshear, Joseph Lexden, :M.B., Ch.M., Demonstrator of Anatomy, University College, Gower St., London, W. C. 1, England. (Presetit address— Dept. of Anatomy, Johns Hopkins Medical School, Baltimore.)
 +
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38 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
Smith, David T., A.B., ^Medical Student, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Stone, Leon Stansfield, Ph.B., Assistant in Anatomy, Medical College, Yale University, New Haven, Conn.
 +
 +
Stone, Robert S., B.A., Assistant in Anatomy, Peking Union Medical College, Peking, China.
 +
 +
Stopford, John Sebastian B., I\I.D., Professor of Anatomy, University of Manchester, Manchester, England.
 +
 +
Swingle, W. W., Ph.D., Instructor in Zoology, Yale University, New Haven, Conn.
 +
 +
van der Horst, C. J., Ph.D., Zoologisch Laboratorium, PI. Muidergracht 34, Amsterdam, Holland.
 +
 +
Walmsley, Thomas, M.D., Professor of Anatomy, Queens University of Belfast, Belfast, Ireland.
 +
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WooLLARD, Herbert T., M.D., Demonstrator of Anatomy, University College, Gower St., London, W. C. 1, England.
 +
 +
On motion, the Secretary was instructed to cast a ballot for all the candidates proposed by the Executive Committee. Carried.
 +
 +
The Secretary then announced the following names as dropped from the list of members on account of non-payment of dues for the past two years:
 +
 +
Dr. a. E. Amsbaugh, Letterman Hospital, San Francisco. Dr. Robert S. Outsell, University of Minnesota. Dr. John A. Kittleson, University of Nebraska, Omaha. Dr. William E. McCormack, University of Louisville. Dr. George Walker, Johns Hopkins Medical School.
 +
 +
It was announced that the Executive Committee had voted to hold the next annual meeting at Yale University, New Haven, Conn., during the last week of December, 1921. The Federation of Biological Societies holds its meeting in New Haven at the same time.
 +
 +
A Committee on Editorship of Journals was elected by the Executive Committee following the last meeting: C. R. Stockard, Chairman; CM. Jackson, G. L. Streeter, R. J. Terry and C. R. Bardeen.
 +
 +
The Committee on Editorship of Journals reported as follows :
 +
 +
 +
 +
PROCEEDINGS 39
 +
 +
PROPOSED ORGANIZATION OF A JOURNAL COMMITTEE
 +
 +
OF THE AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
AND ITS DUTIES.
 +
 +
1. There shall be organized a Journal Committee composed of five members elected by the Association.
 +
 +
2. The Committee shall be estabHshed in 1921, as follows: Ten members of the Association shall be nominated by the Executive Committee of the Association. Additional nominations may be made from the floor. Members of the Advisory Board of The Wistar_ Institute shall not be eUgible for nomination in 1921. Election shall be by ballot. The five receiving the largest number of ballots shall constitute the Committee. In case of a tie, the choice of those thus tying shall be by lot. Of the five thus chosen, the one receiving the greatest number of votes shall serve for five years, the next for four years, the next for three years, the next for two years and the next for one year.
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3. At the annual meeting in 1922, and subsequent years, one member shall be elected to serve for five years. Members are chgible for reelection. At least two nominations shall be made by the Executive Committee of the Association and other nominations may be made from the floor. The election shall be by ballot.
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4. In case of resignation of a member of the committee, the place of the member thus resigning may be filled temporarily by appointment by the Committee itself until the next annual meeting of the society. At this meeting the place vacated shall be filled by nomination and ballot as outlined in Section 3, except that the election shall be for the balance of the unfulfilled term.
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5. The duties of the Committee shall be:
 +
 +
(a) The selection of a responsible Editor for The American Journal of Anatomy and of a responsible Editor for The Anatomical Record.
 +
 +
(b) The appointment of Associate Editors, if such are desirable, shall be made by the committee in consultation with the responsible Editor concerned.
 +
 +
(c) In conjunction with the responsible editors of the two journals and with the Director of The Wistar Institute, the outhning of the broad, general pohcies in the conduct of the journals.
 +
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(d) The making of an annual report to the Association concerning journal policies.
 +
 +
The report of the Committee was formally adopted by the Association.
 +
 +
The Executive Committee in conformance with Section 2 of the report later nominated ten members of the Association as candidates for membership on the Journal Committee of five. One other name was added by nomination from the floor.
 +
 +
 +
 +
40 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
^lembers of the Association then cast their ballots for five of these names with the following result :
 +
 +
C. E. Stockard was elected to serve for five j^ears;
 +
 +
G. L. Streeter to serve for four years;
 +
 +
CM. Jacksox to serve for three years; •
 +
 +
C. R. Bardeex to serve for two j'ears; and
 +
 +
F. T. Lewis to serve for one year.
 +
 +
The terms of service were arranged according to Sec. 2 of the report.
 +
 +
A proposed change in the constitution afTecting the length of term for the several officers of the Association was voted upon and defeated.
 +
 +
The president announced the nomination by the Executive Committee of Charles R. Stockard as the representative of the Association in the Division of Medical Sciences of the National Research Council.
 +
 +
On motion the nomination was accepted and the nominee elected to represent the Association.
 +
 +
The business session then adjourned.
 +
 +
Saturday, March 26. A Short Business Session followed THE morning Scientific Session.
 +
 +
The President announced that he had appointed Professor Ross G. Harrison as a delegate to represent the Association at The Second International Eugenics Congress which meets in New York City, September 22-28, 1921.
 +
 +
The Journal Committe reported the selection of Charles R. Stockard as Managing Editor of The American Journal of Anatomy, and John Lewis Bremer as ^Managing Editor of The Anatomical Record. ""
 +
 +
The place on the Journal Committee made vacant by the selection of Dr. Stockard as a Managing Editor was filled until the next annual meeting by the appointment of Dr. Ross G. Harrison.
 +
 +
President McClure was requested to present the greetings and best wishes of the Association to Professor George A. Piersol who was ill at his home in Philadelphia and unable to attend the meetings.
 +
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 +
 +
PROCEEDINGS 41
 +
 +
Professor S. W. Ranson introduced the following resolution:
 +
 +
Resolved: That the Association express its sincere thanks and appreciation to The Wistar Institute of Anatomy and Biology and to the local committee for the exceptional faciUties and accommodations which have served to make the meeting a marked success, and for the cordial hospitality that has been so generously extended to all in attendance.
 +
 +
Unanimously voted.
 +
 +
On motion the Session adjourned.
 +
 +
Charles R. Stockard,
 +
 +
Secretary of the Thirty-Seventh Session of the American Association of Anatomists
 +
 +
 +
 +
ABSTRACTS
 +
 +
 +
 +
/. On the development of the ameloblasts of the molars of the albino rat, with special reference to the enamel-free areas. William H. F. Addison and J. L. Appleton, Jr., University of Pennsylvania.
 +
 +
The crowns of the molar teeth in the albino rat, as in other rodents, have enamel-free areas on the cusps. These areas are always destitute of enamel from the time of first formation of the crown. The development of the enamel organ in these teeth is interesting, because of the differences which the functional and non-functional ameloblasts exhibit at different stages. The structure of the young enamel organ is similar to that of ordinary mammalian teeth. Up to the time of first formation of enamel and dentine (seen at first day after birth in first molar), all the cells of the ameloblastic layer are similar in size and structure. Soon after enamel formation has begun, however, differences appear in the formative and non-formative ameloblasts. Both classes of cells continue to grow for a time, but the non-formative cells grow more slowly and never attain the height of the formative cells. By the time the formative cells have attained their greatest height, the non-formative cells have begun to diminish in size. This diminution in size continues until the tooth erupts. At sixteen days the functional ameloblasts of the first molar measure 21^ and over in length and the non-formative cells about 7^. The developmental history of the enamel organ shows that this condition of enamel-free areas is secondary to the condition where enamel covers the entire crown. This again is evidence that persistently growing teeth (in which enamel is always to some degree lacking) have been derived from rooted teeth.
 +
 +
2. The oesirous cycle in the mouse. Edgar Allen (introduced by R. J. Terry),
 +
 +
Washington University School of Medicine.
 +
 +
Using Stockard and Papanicolaou's method of diagnosing oestrus by the cell contents of the vaginal fluid, I have studied the cycle in the mouse. The changes are similar to those in rats reported by Long-Evans ('20). The average duration of the cycle is from four to six daj's. External signs are a poor criterion of 'heat,' occurring in less than 60 per cent of cases, where oestrus was shown to be present by cell changes. During oestrus there is little uterine discharge, the changes in the vaginal contents being due primarilj' to an alternate infiltration into, and absence of leucocytes from, the vaginal epithelium, and a periodic formation and destruction of the granular and horny layers. There is no bleeding into the lumen of the uterine cornua, nor any extravasation of red blood corpuscles into the stroma, but only a slight destruction of the mucosa by leucocytosis. There is a hypersecretion of the uterine glands during oestrus resulting in distention of the cornua, effected by a constriction of the cervix; the vagina being usually dry. Goblet cells are abundant in the epithelium of the oviducts. In some mice ovulation is spontaneous at every oestrus, so that
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43
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44 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
the ovaries are chiefly masses of corpora lutea. In others, where regular cycles have been recorded, no recent corpora lutea are present, while there are many atretic follicles which can be grouped to correspond to the recorded 'heat' periods. Consequently, all mice do not ovulate spontaneously during oestrus, and some ovulate only sporadically.
 +
 +
3. Ovogenesis in the sexually mature mouse. Edgar Allen (introduced by R. J. Terry), Washington University School of Medicine.
 +
 +
The question of the formation of definitive ova (those ovulated during sexual maturity) is still an open one. According to different investigators, they have been derived from, (1) the primordial ova; (2) from an embryonic proliferation of the germinal epithelium; (3) from a similar proliferation between birth and sexual maturity, and, (4) in a few instances by the continuance of ovogenesis from the germinal epithelium during the sex life of the individual. Kingery derives the definitive ova, in the mouse, from the germinal epithelium during a period from three to forty days after birth, stating that it does not continue after that time. At sexual maturity cyclic changes appear in the genital organs. The period preceding oestrous is the period of augmented growth. In ovaries of several mice killed at this time I have found a complete series of stages in ovogenesis from the germinal epithelum identical to those figures for earlier stages by Kingery. Therefore, ovogenesis is not complete at birth or before puberty, but continues on into sexually mature life, and the germinal epithelium of the ovary is homologous to that of the testis tubules.
 +
 +
4. On monozygotic human twins. Leslie B. Arey. Northwestern University Medical School.
 +
 +
Two specimens of early monozygotic human twins, each case unique of its kind, are presented. The first comprises twin embryos, each 12.3 mm. long, contained within a single amnion and chorion; except for some shrinkage of the entire specimen, the embryos are normal. Each possesses its own umbilical cord and yolk-stalk; the latter are inserted separately on a common yolk-sac. This furnishes for the first time direct proof of the origin of human identical twins from a single ovum. The second specimen is of normal monochorionic twin embryos, each lying within its own amnion. One member of the pair (11.5 mm. in length) has a normal yolk-stalk and sac (4.5 x6 mm.); the other individual (12 mm. long) lacks these structures completely, as gross and microscopic examination prove. Certain inferences are suggested: 1) Human monozygotic twins do not result from the separation of blastomeres or blastomere clusters at the earliest stages of cleavage, but from a later fission of the inner cell mass. 2) Nevertheless, the human ovum appears' to be rather rigid or determinate in its development; at least, in this case one embryo received all the yolk-sac formative cells. 3) The yolk-sac is not necessary for growth or differentiation; in fact, the twin individual lacking a yolk-sac is slightly the larger, while the correlation of menstrual age and body size coincides with the norm. 4) The yolksac and -stalk are not prerequisite to vasculogenesis; here was performed, as perfectly as ever may be expected, a natural experiment of ablation which demonstrates the independence of the embryo from such angioblastic ingrowths.
 +
 +
 +
 +
PROCEEDINGS
 +
 +
 +
 +
45
 +
 +
 +
 +
5. The 7nolor cortex of the brain of the sheep. Charles Bagley, Jr., Psychiatric Clinic, Johns Hopkins University.
 +
 +
A demonstration covering the histological study of the cortex of the brain of the sheep was given at the 1916 session of the American Association of Anatomists. The present communication is limited to the motor area of the brain of the sheep.
 +
 +
The motor cortex, as outlined in the early studies on the basis of histological structure alone, has been studied through means of electrical stimulation and some important differences brought out. The chief difference is the extension forward of the motor area to the most anterior pole of the brain and the elimination of an area of large pyramidal cells posterolateral to the principal motor area in the superior frontal convolution. Six areas can be satisfactorily outlined, the first three in the superior frontal convolution. Stimulation of the first two areas in the posterior extremity of the gyrus produces response in the limbs of the same and the opposite sides, while stimulation of the third area gives conjugate movement of the head and ej'es to the opposite side. Area 4 lies between the olfactory sulcus and the outer prolongation of the coronal sulcus, and when stimulated gives contraction of the face muscles, more marked in the lower lip of the opposite side. Area 5 is just to the outer side of the coronal sulcus in the mesial portion of the middle frontal convolution; stimulation of this area gives response in the face muscles of the same side. The cortex giving response to electrical stimulation has been extirpated in three parts and the material stained by the Marchi method. The first extirpation area was the entire superior frontal convolution and included areas 1,2, and 3. The second extirpation area included stimulation area 4, namely, that for the control of the opposite face muscles, while the third included area 5. Degeneration is clearly' demonstrated in the fibers of the pyramidal tract in all of the extirpation specimens; these fibers cannot be traced beyond the upper cervical cord.
 +
 +
6. The morphologic index. R. Bennett Bean, University of Virginia.
 +
 +
A new index has been devised wherebj^ any measurable character of a race, a group, a type, or an individual may be represented by a single numerical symbol. This sj^mbol is plus or minus, depending upon whether it is above or below the world average of the character. The morphologic index is actually the percentage above or below the average. This may be illustrated by contrasting a few morphologic indices of the Scotch and Negrito.
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Morphologic
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indices
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CHARACTER
 +
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SCOTCH
 +
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 +
APPROXIMA.TE WORLD AVERAGE
 +
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 +
NEGRITO
 +
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 +
Stature
 +
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+10.30
 +
 +
-18.75
 +
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-2.50
 +
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+0.96
 +
 +
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cm.
 +
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165
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80 SO 52
 +
 +
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-6.07
 +
 +
 +
 +
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+18.75
 +
 +
 +
CpnlTilip indpv ....
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+3.75
 +
 +
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Skeletic index
 +
 +
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-2.88
 +
 +
 +
 +
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46 AMERICAN ASSOCIATION OF ANATOMISTS
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The nasal index differentiates the Scotch and Negritos more than do the other three factors, and the stature is the next best differentiator.
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The actual stature may be obtained from the morphologic index by multiplying the world average by the morphologic index and adding the result to or subtracting it from the world average. The actual stature of the Scotch is 175 cm. and of the Negritos is 148 cm. The nasal index, cephalic index, etc., may be obtained in like manner.
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We may take the morphologic index of any group of Scotchmen or Negritos, or of any type within the group, or of any individual, and compare them ip many ways.
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The morphologic index gives a numerical symbol that is simple, exact and convenient. It enables one to see at a glance the extent of variation from the world average, and thus to evaluate any factor, to determine its usefulness as a differentiator of race, group, type, or individual. It may also obviate the use of such terms as dolichocephalic, mesocephalic, brachycephalic; leptorrhine, mesorrhine, platyrrhine; leptoprosopic, mesoprosopic, euryprosopic; macroskele, mesatiskele, brachyskele.
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7. The value of sections of the body in teaching sxirgical and medical anatomy. Ch.\rles W. Bonney, Jefferson Medical College.
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The obect of this paper is not to describe the preparation of the sections of the body nor to discuss their value in teaching descriptive anatomy. The former is thoroughly understood by modern anatomists, the latter in use in numerous American Medical Colleges. It is desired to emphasize the value of sections in teaching applied, surgical and medical anatomy. For that purpose they have been employed at the Daniel Baugh Institute of Anatomy of the Jefferson Medical College for the last seven years. A brief description of the methods used together with illustrative examples will be presented. Lantern slides will be used.
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8. The middle period in the development of the cloaca in chick embryos. Edward A. BoYDEN, Harvard Medical School.
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This abstract deals with a portion of a comprehensive study embracing the development of the hindgut and associated regions in four species of bird embryos. Attention is called at this time to only a few points of interest: to the expansion of the allantois within the body cavity to form a pars coelomica of that organ; to the formation of a temporary urodaeal sinus w'hich resembles in a striking way the adult urodaeal chamber of certain snakes and lizards which functions in these animals as a dorsal bladder; and to some new facts concerning the origin and nature of the bursa of Fabricius.
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Up to this time the primordium of the bursa has been usually described as a swelling in the posterior dorsal wall of the cloaca caused by the coalescence of vacuoles arising within the cloacal membrane during the fifth and sixth days of incubation (cf. Lillie, p. 317). This description gives the bursa a unique origin, setting it apart from all other derivatives of the gut tract and adding one more difficulty to the interpretation of an organ which has been a bone of contention among anatomists since its discovery in 1604 by Fabricius, who ascribed to it the function of a receptaculum seminis. As a result of a quantitative study of
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PROCEEDINGS 47
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chick embryos between the fourth and fifth days of incubation, designed originally to explain the nature of accessory diverticula found between the rectum and anal plate, it has been possible to demonstrate that the primordium of the bursa appears a day earlier than hithert supposed and in the form of a caudally directed diverticulum whose cavity at first is in direct continuity with the cavity of the cloaca. In its later development the bursa unites with the protodaeum in a manner that closely resembles the union of the proctodaeum with the anal sacs in turtle embryos. And there are other resemblances between these two organs which superficially suggest an homology. Whether this proves to be true or not it is probable that the bursa should be classed with those derivatives of the gut tract, likewise arising as diverticula, whose functions are now obscure, but whose histogenesis suggests lymphoid degeneration.
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9. The earhj morphogenesis of the cerebral hemispheres of Amblystoma. H. S.
 +
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BtTRR, Yale University, School of Medicine.
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A study of the early morphology of the cerebral hemispheres was suggested by some interesting results obtained in an experimental study of regeneration in the forebrain of Amblystoma. Evagination of the lateral wall of the neural tube occurs in the region of the confluence of the S. limitans and the S. diencephalicus ventralis and involves that portion of the lateral wall which intervenes between it and the lamina terminalis anteriorly. In this region lies the anlage of the olfactory bulb and the adjacent secondary olfactory centers, the latter crossed by the S. diencephalicus medius. The point of most rapid growth lies at the anterior end of the S. ventralis and seems to involve a short portion of the neural tube which lies between it and the lamina terminalis. Relatively little of the wall of the forebrain is evaginated, the definitive hemisphere growing very largely through the rapid increase in the number of cells forming the outpouching. This growth occurs principally at the anterior pole, producing rapid anterior elongation of the hemisphere. Growth in the dorsal and posterior region is much slower though greater than in the ventral region where growth is largely produced through the thickening of the walls. The successive development of fiber-tract systems shows that many nuclei develop in the hemispheres as a result of the ingrowths of the fiber tracts into the region involved. The nucleus medianus septi part'^nlarly shows evidence of growth after the appearance of the portion of the median forebrain tract which runs to it. From previous experimental work it can be stated that the primordia of the gray nuclei will develop to some extent without the ingrowth of tract systems, but the complete size development occurs only after nervous connections are established.
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. 10. The growth of the external dimensions of the hitman body in the fetal period and its expression by empirical forrmdae. (Lantern.) L. A. Calkins (introduced by R. E. Scammon), Department of Obstetrics and Gynaecology, Tniversity of Minnesota.
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 +
A graphic and mathematical analysis of measurements of seventy external dimensions of the body of upward of 400 preserved fetuses 2.3 to 54 cm. in length. The uncorrected curves of these dimensions (plotted against body length) are of three types: a) straight lines; b) curves approaching straight lines, but deflected upward toward their terminations; c) curves approaching straight lines but
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48 AMERICAN ASSOCIATION OF ANATOMISTS
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deflected downward toward their terminations. Many larger specimens were injected. An extensive study of this technique shows that this causes the upward trend in most b curves, and that when eliminated they become straight lines. All downward deflected curves are of head dimensions affected by birth-molding. Observations on comparatively unmolded heads (breech extractions and caesarian sections, prove that these also are really straight. Only five curves (medianline measurements of upper parts of the body probably affected by head flexion) are not straight after elimination of artifacts.
 +
 +
External bodily dimensions plotted against body length (being, in general, straight lines) are expressed by the empirical formula, Y = aX ± b (Y, dimension; X, body length; a and b, constants). The constant b is positive for the head, zero for the thorax, and negative for the abdomen, pelvis and extremities.
 +
 +
It may be concluded: 1) The relative growth rates of the external body dimensions are established in the third month and remain unchanged until birth. 2) The growth of the external body dimensions in the fetal period follows the law of developmental direction.
 +
 +
n. Studies an the dynamics of histogenesis. IV. The biomechanical interaction of differential growth as a factor in the origin of bone. Eben J. Carey, Marquette School of Medicine.
 +
 +
Increased density or condensation is the chief physical property which characterizes osseous tissue. Is this quality self -engendered in the tissue' involved or is it the mechanical resultant of the interaction of differential growth? In a former communication by the writer evidence was presented in support of the idea that embryonic bone is the immediate consequence of induced stresses and not the product of an anticipated function. Many workers on bone development consider that stresses are induced in, and strains manifested by the skeleton only after birth when the body weight is sustained. If such is the case, why does bone form in the upper extremity of man at all? Experiments which have been devised to disprove the mechanical origin of bone have not carried their point. The fact that the blastemocartilaginous skeleton is an area of accelerated longitudinal growth and that the surrounding soft parts are retarded in longitudinal growth has been entirely overlooked.
 +
 +
Two areas in syncytial continuity and manifesting differential growth, as the skeletal and soft areas in the limb, exert an interaction. The zone of accelerated growth drags along the one of retarded growth, the latter in turn tends to slow down the speed or deflect the course of the former. This active interplay between growing parts tends to a dynamic equilibrium, but as long as one growing part is dominant and the other subdominant, growth and the resultant interaction and differentiation continue. The effect of interaction in the experimental production of double monsters is excellently treated in a recent monograph by Stockard (Am. Jour. Anat., 1921, vol. 28, pp. 115-277).
 +
 +
The stresses induced in the origin of bone are the result of growth and resistances. The accelerated growing blastemochondrogenous skeleton meets the foUowmg resistances: 1) Opposed growth of contiguous skeletal segments; 2) weight of related soft parts; 3) reactive elasticity of traction of the soft parts retarded in growth; 4) active muscular pull. It is imperative, therefore, that, 1) Growth and 2) Resistances to growtli be understood by the cmbryologist before
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 +
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PROCEEDINGS 49
 +
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he can appreciate the importance of each factor. Both are active and formative during development, both are absolutely necessary to the realization of form and neither processes can be looked upon as more important in development than the other.
 +
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12. V. The law of density of a growing tissue: On the progressive augmentation of femoral density as the resistances to the grouih of the femiir increase. Ebex J. Carey, Marquette School of Medicine.
 +
 +
With the rapid increase of limb weight, and with increase of opposition to growth at the ends of the femur, together with the resistances manifested by muscular reaction, the density of the femur increases progressively. This increase in density is concomitant with the relative decrease in femoral volume as the growth of the limb advances. In an 18-mm. embryo the volume of the femur constitutes one-third of the entire limb, whereas its density is 0.33. In a 20-mm. embryo femoral volume is one-fourth that of the limb and its density is 0.37, whereas in the 50-mm. embryo the volume of the femur is one-seventh and the density is 0.43. The density of the femur in a 200-mm. embryo is 1.6 and the volume is one-sixteenth that of the limb.
 +
 +
THE LAW OF DENSITY OF A GROWING TISSUE; The density of a growing tissue 2S directly proportional to the resistances (pressure) encountered during growth.
 +
 +
13. VI. The law of relative volume of a growing tiss^ie: On the relative decrease of femoral volume as the resistances to the groivth of the femur increase. Eben J. Carey, Marquette School of Medicine.
 +
 +
The various steps in the increase of skeletal density, from the blastemal to the cartilage period, and, secondly, from the cartilage to the osseous period, in skeletal condensation, are considered simultaneously with those changes, extrinsic to the zone of femoral formation. During the early stages of development, the weight of the entire hind limb is supported by the femur's acting like a cantilever beam. The weight of the limb increases rapidly.. In an 18-mm. pig embryo the femur constitutes one-third of the volume of the limb and supports a weight of 0.013 grams. In a 20-Dam. embryo the femur constitutes one-fourth the volume of the limb and supports a weight of 0.018 gram, whereas at the oO-mm. stage of the developing embryo, the femur constitutes one-seventh of the volume of the limb and supports a weight of 0.25 gram. Later at the 20-cm. stage the femur constitutes only one-sixteenth of the volume of the limb, but it supports the greatly increased weight of 30 grams. In addition to sustaining the above weight, the femur is opposed in growth by the accelerated growth centers located proximally and distally. Finally, as development continues, the resistance presented to longitudinal femoral growth by the contracting musculature and elastically reacting soft parts are opposing factors to be considered as extrinsic pressure limiting the relative volume of the femur to the thigh, as growth continues.
 +
 +
THE LAW OF RELATIVE VOLUME OF A GROWING TISSUE: The relative volume of a groiving tisstie is inversely as the resistances (pressure) ichich it bears.
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50 AMERICAN ASSOCIATION OF ANATOMISTS
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14. VII. On the torsion of the developing femur. Eben J. Carey, Marquette School of Medicine.
 +
 +
That the femur undergoes a torsion during development has not been previously observed. This twist is objectively evident by observing the ventral aspect of a closely graded series of developing femora from the time the femur is approximately 3 mm. in length until it is 30 mm. in length. In a 3-mm. femur the head is in a direct line with a plane projected through the mid-ventrodorsal aspect of the shaft cutting through the center of the articular surface for the patella. This is objectively evident in a 3-mm. femur. With the next marked advance in development in a 9-mm. femur we find the head displaced mesiad. This torsion of the femur through an arc of 90° is in reality due to the torsion and development of the greater trochanter influenced by the traction of the attached gluteal muscles. This twist of the femur corresponds in time with the beginning and ending of limb rotation and with the period of greatest growth, differentiation, and activity of the thigh musculature.
 +
 +
15. VIII. The law of joint formation: Bio-mechanical interaction of differential gruvth as a factor in the origin of joints. Eben J. Carey, Marquette School of Medicine.
 +
 +
The blastemal skeleton of the acetabulum and the femur is apparently continuous. The femur, tibia, and fibula, and the foot plate progressively appear in the order named by the direct extension of the accelerated proliferation of the blastemal skeleton, comparable to the progressive caudal formation of metameres in th^ chick embryo. The first radical change from the apparently continuous to the segmental skeleton is seen in an embryo, 16 mm. long, by the appearance of a faintly curved line of compressed nuclei in the region of the future hipjoint. In an embryo 18 mm. in length another compression line is detected in the region of the future knee-joint.
 +
 +
1. By the continued opposition to growth between the contiguous centers of the segmental blastemal skeleton, mechanical compression occurs revealing the location of the future joint cavities.
 +
 +
2. The contour of the opposed surfaces constituting a joint is dependent on the intensity of the force of growth, per square millimeter of cross-section, of growing segments opposed in action, together with the force of muscular pull. That segment will possess the ball of a ball-and-socket joint which possesses the greater force of interstitial growth, longtitudinally per square millimeter of crosssection.
 +
 +
3. Joints, therefore, are not the cause of skeletal segmentation, they themselves are the mechanical resultants of compression of prior centers of accelerated growth, opposing each other in action in the segmental blastemochondrogenous skeleton.
 +
 +
4. THE LAW OF JOINT FORMATION: The contour of the opposed surfaces forming a joint is dependent xipon the intensity of the force of interstitial growth, per square millimeter of cross-section, of the segments forming a joint and upon the resistances to the growth of each skeletal segment.
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PROCEEDINGS 51
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16. IX. The law of direction of myogenesis: The bio-mechanical interaction of differential growth as a factor in the origin of muscular tissue. Ebex J. Carey, Marquette School of Medicine.
 +
 +
Is the physical property which characterizes the initiation of muscular differentiation, namely, specific elongation of the nuclei and spongioplasm, caused by a factor intrinsic or extrinsic to the zone of myogenesis? The writer has presented evidence of direct observation which proves that the latter and not the former is the case. In other words, muscle is the resultant of the tension, pulling out or traction to which a syncytial mass of mesenchyme is intermittently but progressively subjected by a related region of cells accelerated in growth.
 +
 +
It was shown formerly that the dominant zone of accelerated growth in the intestine is the epithelial tube. By expansion of the epithelial tube in spiral growth the surrounding mesenchyme was drawn out in tension resulting in helieoidal muscular differentiation. In the limb the zone of accelerated growth is the central segmental skeletal core. This draws out by traction the surrounding mesenchyme resulting in skeletal muscular differentiation. The zone of accelerated growth in the cardiac area is the progressive increase in the whirling volume of the bleod. This draws out the surrounding mesenchyme in tension corresponding to the direction of the vortex of blood resulting in spiral muscular differentiation. The detail proofs for these assertions will soon be published.
 +
 +
THE LAW OF DIRECTION OF MYOGENESIS: The elongation of a developing muscle is in the direction of the accelerated growth of an extrinsic dominant zone ichich draws out in tension the mesenchyme forming the muscle.
 +
 +
17. The development of the aster in the artificial parthenogenesis of the sand-dollar egg. Robert Chambers, Cornell University Medical College.
 +
 +
No noticeable changes occur in the cytoplasm or the nucleus of the eggs until long (half an hour or more) after both the butyric-acid and the hypertonic-solution treatments. The visible phenomenon peculiar to the parthenogenetically induced egg consists in the manner in which a fluid substance begins to separate out of the egg cytoplasm, preparatory to the formation of the preliminary single aster. In the sperm-fertilized egg radiations appear immediately about the sperm head, and the accumulation of the fluid substance is from the very start through the agency of the ray-like channels of the growing aster.
 +
 +
An optimum parthenogenetic treatment causes vacuoles to appear which fuse to form a central clear area about which radiations develop until an aster is formed corresponding exactly with the fully developed sperm aster of a normally inseminated egg. From now on the procedure is similar to that occurring in a sperm fertilized egg.
 +
 +
Over-treatment causes the appearance of many vacuoles scattered throughout the egg resulting in multiple asters. Under-treatment may result in the formation of a single aster which, however, periodically disappears and reappears as a single aster. A successful treatment not only causes a separating out of a liquid from the egg cytoplasm, but also induces a polarity within the resulting clear area to enable it to form two centers about which an amphiaster_may develop.
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52 AMERICAN ASSOCIATION OF ANATOMISTS
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18. The reaction of living cells in the tad-pole's tail toward injected starch granules. Eliot R. Clark and Eleanor Linton Clark, University of Missouri. Small quantities of starch (corn-starch and arrow root) were injected into the
 +
 +
transparent tails of frog larvae and the region of injection studied in the living during the subsequent hours and days.
 +
 +
Uncooked starch, boiled starch, and starch cooked just to the point of gelatinization were tried. The larvae were fixed in iodine at different periods of time after the injection.
 +
 +
Toward the uncooked starch granules the response was similar to that displayed toward foreign bodies, such as carbon and carmine. Leucocytes approached the starch grains and engulfed them and the starch remained inside the leucocytes indefinitely (over a month).
 +
 +
The boiled starch grains disintegrated within the first half hour after injection and after an hour no stain was obtained after treatment with iodine. Wandering cells moved toward the injection site.
 +
 +
In the case of the semi-cooked starch, near-by wandering cells moved very rapidly toward the injected material and within twenty minutes leucocytes began to emigrate from neighboring blood-vessels in very. large numbers. Within an hour the starch grains were all inside of leucocytes. The diapedesis of leucocytes continued for six hours or more. Leucocytes staining blue with iodine were demonstrated from three to four hours after the injection. The further stages in digestion were not followed since the characteristic reaction of dextrin or of glycogen was not obtained and our microchemical tests for sugar, injected into the tail fins, were unsuccessful.
 +
 +
Starch cooked to the point of gelatinization proved to be a most powerful chemotactic agent for leucocytes. The other tissue cells showed no response toward injected starch.
 +
 +
19. Cyclic changes in the ovaries and xderus of the soiv, and their relation to the mechanism of implantation of the embryos. George W. Corner, Johns Hopkins Medical School.
 +
 +
The author has completed a detailed study of the follicles, corpora lutea, and uteri of a large series of pregnant and nonpregnant animals killed at known stages throughout the oestrous cycle. The cycle averages twenty-one days in length. Ovulation is found to occur during oestrus; the corpora lutea complete their formation about the seventh day, and remain in full development from the seventh to the fifteenth day, thus surviving just long enough to cover the period of attachment of the embryos. If no embryos are present the corpora lutea degenerate about the fifteenth day.
 +
 +
A few daj^s before and during oestrus the uterine epithelium is in a state similar to that described by Stockard and Papanicolaou and by Long and Evans in the small rodents; but during the growth period of the corpus luteum the uterus undergoes histological changes culminating, from the eighth to the tenth day, in a state of enhanced epithelial activity. At this time the embryos, when present, are still unattached and are being shifted into position for implantation. From the tenth to the fifteenth day (the period of implantation), further elaborate changes take place by which the epithelium is brought to a state characteristic of early pregnancy in the implantation stage. If no embryos are present the same changes occur, but subside after the fifteenth day.
 +
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PROCEEDINGS 53
 +
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These results indicate that there is a correlation between the state of the corpus luteum and that of the uterus by which the uterus is prepared, after each ovulation, to receive embryos. A detailed and illustrated monograph will appear in the publication of the Carnegie Institution.
 +
 +
20. Digestion of different proteins by the mesenchyme and its derivatives in the tadpole. (Lantern.) Vera Danchakoff, Columbia University.
 +
 +
Though well known to exist within the multicellular organism the phagocytic digestive activity of the mesenchyme has not been much studied. Little is as yet known regarding the amount of digestive work accomplished in the organism by the mesenchyme, if given opportunity. Neither is the extent known to which this activity becomes a factor in the resistance which a multicellular organism offers to the growth of heterogeneous tissues even of such a great proliferative capacity, as, for example, the tumors.
 +
 +
The adult splenic mesenchyme of the fowl, as shown by me last year, is capable of ingesting and digesting, one by one, cells of a mammalian proliferating tumor. The mesenchyme and its derivatives, in the form of small wandering cells, in various tadpoles, will be shown to possess the power of digesting various proteins. The mesenchj'mal tissue within the tail of different tadpoles can be fed on finely particulated fibrin, edestin, coagulated albumen, and lecithin, the particles being of the size of a small fraction to a few diameters of a mesenchymal cell. The response to the sudden appearance of a large quantity of injected material is rapid from the part of the mesenchymal and wandering cells. Four to six hours after injection a great number of mesenchymal cells and of cells of the small lymphocyte type are found around and within the injected mass; about twenty-four hours after the injection all but the largest particles are ingested, and after three to four days no trace of the injected material is found.
 +
 +
The results of these experiments illustrate the great digestive capacity inherent in the mesenchymal and small lymphocyte cells of the amphibia during the tadpole stage. These cells can most effectively take care of comparatively huge masses of injected particulated protein, and like physiologically balanced unicellular organisms, if given opportunity, successfully perform their own digestive activity.
 +
 +
21. Further morphological evidence for the digestive capacity of adult splenic mesenchymein the fowl. Vera Daxchakoff and S.M. Seidlin, Columbia University. A new morphological evidence for the digestive capacity of the mesenchj-me
 +
 +
was brought forward by Danchakoff last year. The splenic reticular cells of the adult fowl were shown to be capable of surrounding and digesting the living cells of an actively proliferating mammalian tumor (the Ehrlich sarcoma). The encircling of the tumor cells by the mesenchyme, followed by digestion, as observed in Danchakoff's experiments, is the result of the immediate encounter of two living tissues. A further study of the digestive capacity of the mesenchyme was required in order to ascertain whether the living tumor cells were treated by the mesenchymal cells in the same manner as dead particles of mammalian protein would. Small particles of catgut were intimately mi.xed with mash of adult splenic tissue and grafts of this tissue made on the allantois of seven days chick embrj^os.
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54 AMERICAN ASSOCIATION OF ANATOMISTS
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 +
The study of the grafts after five days' growth has shown the particles of catgut partlj' digested, partly attacked by the mesenchyme. Mesenchymal cells isolated and in the form of more or less huge plasmodia surround the catgut particles, the latter showing distinct indentations, which in outline often correspond to mesenchj^mal cells. The mesenchymal plasmodia close to the partly digested catgut contain vacuoles. The process of digestion where the catgut particles are small is very similar to that exercised by the mesenchyme against the cells of the Ehrlich sarcoma. The splenic mesenchymal cells of the adult fowl seem to be capable of exercising phagocytic and digestive activity regardless of whether this activity is directed against sterilized particles of heterogeneous dead tissue or against living heterogeneous tumor cells of certain physicochemical constitution.
 +
 +
22. A new interpretation of the morphology of the nervous system. Raymoxd A.
 +
 +
Dart and Joseph L. Shellshear (introduced by R. J. Terry), University of
 +
 +
London.
 +
 +
His ('68) promulgated his principle of ectodermal origin of neural tissue. Balfour and others extended this hypothesis to postulate a neural tube origin of all neuroblasts. Beard, Piatt, Landacre, and others have shown that a large proportion of the cranial ganglionic elements arises in the ectoderm lateral to the medullary area from certain areas called 'placodes.' Observations by J. P. Hill, Elliot Smith, and the authors have demonstrated a similar peripheral but entodcrmal origin in placodes for the visceral elements in the VII, IX, and X cranial nerves throughout Vertebrata. A radical revision of current conceptions is therefore necessitated.
 +
 +
The ' placodal' principle of a peripheral origin for all neuroblasts of the peripheral nervous system is of general application. The only point of agreement between students of the ontogeny and phylogeny of the sympathetic system is of the first appearance of the so-called 'primary anlagen' peripherally and in inextricable relationship with the mesodermal structures supplied thereby. That the sympathetic system develops independently of the neural tube was shown by Weber in 1851. A mesodermal origin of these neuroblasts must therefore be postulated and is demonstrable.
 +
 +
But these are not the only mesodermal neuroblasts. Concurrently with the differentiation of the somite from indifferent cells into the various 'supporting tissues' of the body there arise from similar 'indifferent cells' of the primitive somite the neuroblasts for the innervation of these tissues. The somite, then, has this jiroperty in common with definitive placodes previously described by various authors; it gives rise to a) neuroblasts and 6) supporting tissue. A rational phylogenetic and ontogenetic explanation is provided in this way for the proprioceptive senses. The anterior horn cells of the neural tube must, however, be appreciated as primarily 'extraneural.' The neural tube itself is considered as a series of bilaterally segmented placodes. The data entail further a revision of the conception of neurobiotaxis as put forward by Ariens Kappers. This principle is given wider application for the interpretation of the movements of sensory neuroblasts which move away from the 'source of stimulus.' The nervous systems of Vertebrata and Invertebrata are harmonized by the 'placodal' conception, nnd on hypothesis is promulgated to account for the origin of the
 +
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PROCEEDINGS 55
 +
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former. Finally, the problems of segmentation and the mesoderm are deemed to be more correctly appreciated from the new point of view.
 +
 +
23. Degeneration phenomena in the pelvic gland of the male Necturus. A. B.
 +
 +
Dawson, Loyola University School of Medicine.
 +
 +
Pelvic glands of males, killed during the late autumn and winter, exhibit degeneration phenomena similar in many respects to those recently described by Saguchi ('20) in the frog's pancreas under the title, 'physiological degeneration. ' Although numerous cells are degenerating, the gland is secreting actively. Nucleoli are not demonstrable in the normal cells and it seems impossible to interpret the large eosinophilic central corpuscle of the 'chromocyte' as being a result of nucleolar hyperchromasy. The nucleus undergoes successive changes characteristic of Flemming's chromatolysis. Some degenerating cells escape directly into the lumen of the tubule; others, however, are sooner or later taken up by neighboring normal secreting cells. Within the normal cells the plasma of the degenerating cells is digested and absorbed rapidly. The degenerating nuclei usually become separated into several portions, either by direct fragmentation or a process of gemmation, and are ultimately eliminated, along with the secretion of the normal cell, into the lumen of the tubule. No phagocytosis was observed in connection with this degeneration and no mitosis was evident at this period of the year. These intracellular corpuscles, derived from degenerating gland cells, resemble 'nebenkerne' and have been so interpreted by many investigators working on glands. The small spherical nuclear fragments simulate basophilic secretion granules.
 +
 +
Pelvic glands from animals killed in July present a very different picture. The lumina of the tubules are reduced to a minimum and mitotic figures are encountered very frequently. Large phagocytes filled with disintegrated cells are numerous.
 +
 +
2^. The growth of the brain and the spinal cord in the human fetus and its expression by empirical formulae. Halbert L. Dunn (introduced by R. E. Scammon), University of Minnesota.
 +
 +
A quantitative study of the growth of the brain and its parts and of the spinal cord in a series of 156 human fetuses ranging from 4 to 56 cm. in crown-heel length. The growth of the central nervous system in the fetal period follows, in a general way, the growth of the body, and its increase in weight and volume may be expressed by formulae similar in type to that expressing growth in body weight. Further analysis shows that three distinct subdivisions or varieties of this general type of growth may be recognized in the central nervous system. These are, 1) cerebral growth, which shows a slow but steady increase prior to five and one-half or six months (ca. 30 cm. CH) and a constant and more rapid growth from that time to birth; 2) brain-stem and cord growth, which proceeds comparatively rapidly previous to the sixth fetal month and comparatively slowly thereafter, and, 3) cerebellar growth, which is characterized by a slow rate of growth prior to the seventh fetal month and by an extremely rapid rate of increase thereafter.
 +
 +
 +
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56 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
25. Hematological and respiratory conditions in the larval stages of the lungless amphibians, Batrachoseps attenuates and Aneides lugubris. V. E. Emmel, University of California.
 +
 +
In attempting to correlate the remarkable occurrence of non-nucleated erythrocytes in Batrachoseps attenuates (Am. Jour. Anat,, vol. 16, p. 180; Anat. Rec, vol. 18, p. 232) with physiological factors, a comparative study was undertaken between this animal and Aneides lugubris. Both amphibians are lungless, have similar environments, but differ widely hematologically. It became necessary to carry the investigation into the larval stages. We were fortunate in securing one set of eggs for each species. A number of larval animals were removed from the egg before hatching and blood preparations made. In the larval Aneides all erythrocytes were nucleated, but in the larval Batrachoseps, on the contrary, non-nucleated erythrocytes were almost as abundant as in the adult.
 +
 +
It thus becomes evident that whatever physiological factors may be responsible for the marked hematological differences in these two species, they must be already operative before hatching. The larval respiratory gill structures show striking differences. Aneides has a very broad, three-lobcd, leaf-like gill membrane, permeated by a complex capillary network. Batrachoseps has a simple, slender, three-fingered gill structure, traversed by a single vascular loop for each finger-like process. In Aneides the blood corpuscles pass th'ough the gill capillaries in a single file, whereas in Batrachoseps the blood is carried through each vascular loop as a column of corpuscles in the manner of a small arteriole. In contrast to Aneides, therefore, we have in the larval Batrachoseps a respiratory mechanism relatively deficient in capillary exposure of the blood. This condition is apparently compensated for by the increased oxidation efficiency of the thin non-nucleated erythrocytic discs, thus furnishing a phylogenetic precursor of the erythrocytic efficiency finally attained in mammals.
 +
 +
(Further studies on the physiology of reproduction include abstracts 26 to 34-)
 +
 +
26. Proportio7i of ova producing full-term young in the rat. Joseph A. Long and Herbert M. Evans, University of California.
 +
 +
We are beginning to appreciate the widespread and customary occurrence of departures from perfect functioning of the mammalian reproductive apparatus — departures which reduce fertility. These may be due to fault with ovary, tube, or uterus. They are occurring continually. During the last three years we have recorded the number of young in 625 litters of the rat. The average lies between six and seven. During this period of time fifty animals were sacrificed within one day after ovulation and at least one oviduct and ovary cut serially. In all instances the eggs from this ovulation were encountered in the tube and were enumerated. An average was found of 4.8 eggs in each oviduct or 9.6 eggs per ovulation. Other material in which the eggs could not be enumerated with reliability, but in which the corpora lutea of a single ovulation could be counted, was studied. This showed that five corpora per ovary or ten per ovulation represented the average. The animals from which data were secured concerning the number of eggs or corpora were treated in every respect as to food, cage space, etc., identically with the animals in which the number of litter young was
 +
 +
 +
 +
PROCEEDINGS 57
 +
 +
recorded. They were also in many cases litter mates of such animals. Evidently, then, under these conditions nine or ten ova are represented by only six or seven offspring carried to term.
 +
 +
27. On the production of the condition of 'pseudopregnancy' by infertile coilvs or mechanical stimulation of the cervical canal in the rat. Joseph A. Long and Herbert M. Evans, University of California.
 +
 +
We have previously shown that the advent of the next oestrus is delaj^ed when the rat is allowed to mate with a vasectomized male or when the cervical canal is stimulated by the momentary insertion of a small glass rod. This pause, which we have proved to result from delayed ovulation, may be due either to some sort of direct repression of follicular growth or to a continuance of life of the corpora lutea which in the case of cattle have apparently been shown to hold off follicular growth and oestrus. The corpora lutea in these cases come to resemble those of pregnane}'. As we have previously explained, we are to understand this remarkable response as a contrivance to insure implantation. The fact that deciduoma are difficult to produce during normal oestrous cycles, but can be produced after cervical stimulation, is in strict harmony with the idea that changes are thereby provoked which facilitate implantation. We may suppose something has occurred to ' activate' the corpora lutea. The corpora are affected through humoral paths, since these phenomena all occur with the transplanted ovary. But nervous pathways are probably concerned in initiating the change, for the products of abrasion of the cervical mucosa do not themselves cause these changes (Freyer; see below). The designation 'pseudopregnancy' is justified on further grounds than because of the prolongation of life span of the corpora lutea. Most striking is a change in the character of the vaginal epithelial mucosa. In pregnancy the vaginal mucosa becomes a high stratified epithelium, but with its surface cells columnar instead of squamous in type. Furthermore there ensues a characteristic vacuolization of its middle cell laj^ers, a phenomenon beginning about the tenth day of gestation and reaching its greatest expression on the sixteenth day. These changes are inaugurated in the vaginal mucosa ten or more daj's after mechanical stimulation of the cervical canal.
 +
 +
28. On the cause of the effects produced by stimulation of the cervical canal in the rat. M. G. Freyer (introduced by H. M. Evans), University of California. The delay in the appearance of the next oestrus and the condition of so-called
 +
 +
pseudopregnancy produced by mechanical stimulation of the cervical canal in the rat has been shown by Long and Evans to take place in animals in which ovarian transplantation has recently been carried out. We can, hence, not refer this effect to the nervous connections of the ovary itself. It seemed possible that the slight injury to the cervical epithelium might lead to hormonal products which when absorbed and reaching the circulation thus affect the ovary directly or indirectly by means of some other endocrine gland.
 +
 +
At the suggestion of Doctors Evans and Long, six careful experiments were carried out in order to test this point. Epithelial scrapings were made from the lower portions of the cervical canal of six animals which were in the pro-oestrous period or at the transition between pro-oestrus and oestrus. This material, obtained under aseptic precautions, was immediately injected into the perito
 +
 +
 +
58 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
neal cavity of six other animals which happened to be at the same stage of the oestrous cycle. The succeeding oestrous cycles in the recipient animals were of normal duration. None of the characteristic effects of cervical stimulation were obtained. It would hence appear that the initial part of this mechanism is actually mediated by nerve impulses which, however, produce humoral changes so that the corpora lutea of recently transplanted ovaries, which can only be reached by the blood stream, are in some way invigorated and continued in function.
 +
 +
29. A characteristic histology of the vaginal mucosa during lactation. Joseph A. Long and Herbert M. Evans, University of California.
 +
 +
During lactation the vaginal smear in the rat resembles closely the picture found during the dioestrous interval of the normal oestrous cycle, i.e., it consists of polymorphonuclear leucocytes and a variable content of irregularly sized epithelial cells. Nevertheless, the histology of the vaginal mucosa at this time differs widely from that found in the dioestrous pause. We have previously established the fact that ovulation does not occur during lactation. Ovulation is always heralded by characteristic changes in the structure of the vaginal mucosa and also in the vaginal smear. In both pregnancy and lactation ovarian function is manifested by actively secreting corpora lutea which in turn may be viewed as repressing all follicular growth and activity. We have shown in the preceding section that a characteristic vaginal histology occurs throughout gestation. It is also a fact that during gestation the vaginal smear resembles that of the normal dioestrous pause. Similarly during lactation characteristic changes occur in the vaginal mucosal histology without changes in the smear. The epithelium in one respect resembles that found in pregnancy in that it possesses a surface layer of cylindrical cells. But the gravid vaginal mucosa is high, that of lactation low. While on the second day of suckling this mucous membrane may consist of four or five cell layers, by the fourth day more than three layers are seldom encountered, and on the sixteenth day, when lactation may be assumed to be at its height, most of the mucosa consists of but two cell layers, the superficial of which is constituted by cubical or low cylindrical elements. The strict dependence of this characteristic epithelium upon the performance of the mammary glands, which divert and limit ovarian function to the corpora lutea, is illustrated in the most striking way when the young are removed. Within forty-eight hours after removal of the young the low columnar mucosa of lactation gives place to a high, stratified squamous epithelium.
 +
 +
30. On the production of deciduomata during lactation. Joseph A. Long and Herbert M. Evans, University of California.
 +
 +
Our preliminary experiments seemed to indicate that deciduoma were not easily produced by the contact of foreign bodies with the uterine mucosa during lactation. We were consequently under the impression that the rarity of conception during lactation might be referable to an unfavorable implantation reaction in some way associated with lactation. We have continued our operations upon the uterus during lactation. Typical deciduomata can be produced when the procedure is carried out at any time after the fourth day of lactation and the animal sacrificed one week after the operation. It is consequently neces
 +
 +
 +
PROCEEDINGS 59
 +
 +
sary to refer the well-known comparative immunity from a second gestation which characterizes the early period of lactation in all animals, to the lack of ovarian changes associated with both heat and ovulation, not to difficulties in implantation of ova. The existence of a vigorous dcciduoma reaction during lactation when uterine atrophy normally occurs would appear to establish conclusively the relation of this response to the existence of functional corpora lutea, for in all conditions in which functional corpora are present the response can be elicited.
 +
 +
31. Cijclic changes in the manmiary gland of the rat associated voilh the oestrous cycle. Monroe Sutter (introduced by H. M. Evans), University of California.
 +
 +
The exact mechanism responsible for £he assumption of function on the part of the mammary gland has received a considerable amount of attention during the last few years. Although an indirect nervous connection between mammae and uterus exists (influence of suckling on uterine contractions), it has been generally assumed that the development of the mammary apparatus is due to hormonal influences. As is well known, these hormones have been variously supposed to come from corpus luteum, placenta, or foetus. I have been encouraged by Doctors Evans and Long to study the changes which may be observed in the mammary glands of virgin female rats at various steps in the oestrous cycle. The study of sections was eventually abandoned and gross mounts were made of spreads of the entire glands which had been stained and cleared.
 +
 +
The following conditions have been detected: Toward the end of the prooestrous stage (stage of Long and Evans) the mammary tree exhibits long, slender branches which have a few almost naked twigs projecting from them. Close inspection reveals that there are many minute bud-like processes on the twigs and on the main branches at infrequent intervals. In the next stage, oestrus (stage 1 of Long and Evans), when cornified epithelial cells are found in the vaginal smear, undoubted evidence occurs of pronounced growth in the mammary tree. The small buds on the mammarj- twigs have sprouted out to varying degrees and new ones have appeared. Instead of appearing generally smooth and naked, the branches and twigs are irregular and covered with numerous projecting buds. The size and shape of the branches vary greatly from branch to branch and in a given branch. This great variability appears to be one of the most marked characteristics of rapid growth. By the time leucocytes have appeared in the vaginal smear, evidences of further growth in the mammary tree can be seen in the increasing complexity of the secondary branches. By this time we know that ovulation has normally occurred and young corpora lutea have been formed. The end branchings of the mammary tree often form transparent bulb-like projections which vary greatly in shape and size. This complexity of the tree and some slower growth of it undoubtedh' continue until near the nest pro-oestrous stage when, possibly due to degeneration of the corpora lutea, regression occurs.
 +
 +
There is thus a regular cycle of growth changes imposed upon the mammary ducts, and although these are undoubtedly accelerated and are maintained by the corpora lutea, they may be detected and are quite marked before the corpora are formed.
 +
 +
 +
 +
60 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
52. On the rapid maturation of the ovary by trans-plantation of the youthful gonad to adults. Joseph A. Long and Herbert M. Evans, University of California. In order to determine whether we could produce an experimental precocitj^ in
 +
 +
the development of the remainder of the reproductive sj^stem, we attempted to transplant adult ovaries into young animals. As a matter of fact, an exchange of ovaries was carried out between immature animals from twenty to thirty days of age and adults between five and six months of age. The adult grafts succumbed, but in every instance the immature ovaries were vascularized and grew rapidly, although these also in some instances did not continue to function. It is, however, remarkable that in all instances at least one set of Graafian follicles and corpora lutea were produced by the infantile ovaries in adult hosts. Furthermore, these changes took place in from six to eight days and brought on typical oestrus of the adult host as seen by changes in the vaginal smear, behavior, etc. It is apparent that endocrine influences of the adult tissues are responsible for provoking this sudden maturation of the sex gland, which normally occurs from one to two months later.
 +
 +
53. The method of opening of the vagina in the rat. K. O. Haldeman (introduced by H. M. Evans), University of California.
 +
 +
At birth the lumen of the vagina extends caudal to within 1.2 mm. of the external surface of the body. The structure closing the vagina consists of a solid, branching core of stratified squamous epithelium surrounded by compact connective tissue. This condition persists until, at about the age of thirty to forty days, several centers of cornification appear in this epithelial core and vesicles containing desquamated cornified material and leucocytes are formed. The vesicles enlarge and coalesce so as to form a lumen through the epithelial core. The first external sign of impending opening is a turgescence and wrinkling of the future lips of the vagina. Occasionally a median cord extends dorsoventrally across the vaginal orifice for several days after opening. Frequently a plug of cornified material protrudes from the opening soon after it is established. Sections through the vaginae prior to their opening in animals older than thirty days showed large masses of cornified material, non-cornified cells, and leucocytes in the lumen near its distal end. In some cases small areas of the vaginal mucosa were covered with cornified epithelium. Five cases were studied to determine whether or not ovulation had occurred, and in no instance was this a fact. These isolated patches of epithelial cornification must not be confused with the complete cornified transformation of the vaginal mucosa accompanying oestrus.
 +
 +
54. On the association of continued cornification of the vaginal mucosa irith the presence of large vesicles in the ovary and the absence of corpus formation. Herbert M. Evans and Joseph A. Long, University of California.
 +
 +
It has already been shown that in the normal oestrous cycle of the rat cornification changes in the vaginal mucosa are associated with the enlargement and maturation of follicles and that these changes cease at about the time of ovulation. Normally the cornified stage lasts about thirty hours.
 +
 +
As a rare anomaly (seven cases in about 800 rats) cornification of the vaginal mucosa may be greatly prolonged; instances of 2, 3, 5, 7, 11, 11, and even 21 days
 +
 +
 +
 +
PROCEEDINGS Gl
 +
 +
have been observed. In one case in which cornification had persisted for five days and in two cases of eleven days the animals were tested and oestrus found to be still present. All of the seven rats were killed while this phenomenon was still in progress, and the ovaries examined in serial section. The most striking thing about them was the presence of large, fluid-filled vesicles, many of these possessing a thick, apparently healthy granulosa layer which together with the basement membrane is invaginated at many points by blood-vessels and containing what appeared to be normal eggs. Others were clearly undergoing degeneration, leading to the formation of large, thin-walled vesicles devoid of ova. In addition, the ovaries were notable by reason of the absence of normal healthy corpora lutea, those present being apparently in process of degeneration — quite markedly so in the one case of twenty-one days.
 +
 +
We have observed similar long cornified stages in the vaginal smears of two cases in which the ovaries were transplanted to the rectus muscle and in which also the ovarian findings resembled the above. This fact would appear to support convincingly the idea that these ovarian changes produce their effects on the vagina through humoral rather than nervous pathways.
 +
 +
{Experiments on the endocrine relations of the ovary in the rat include abstracts
 +
 +
35 to 38.)
 +
 +
35. The effect of thyroid feeding on the oestrous cycle of the rat. Herbert M. Evans and Joseph A. Long, University of California.
 +
 +
Thyroid obtained daily from freshly slaughtered beeves was fed in doses varying from I gram to an entire half gland. The rats used for feeding as also those for controls were selected from a large stock because they exhibited approximately regular four-day cycles.
 +
 +
In all cases thyroid feeding was accompanied by an increased consumption of food, but decrease in body weight. On the one hand, when the doses were larger (j to I gland) loss in body weight was pronounced and some animals succumbed, the cycle being greatly lengthened or inhibited altogether. On the other hand, when the doses varied from J to U grams daily, amounts also sufficient to produce loss of weight with increased consumption of food, the oestrous cycles were usually not greatly disturbed. There consequently do not appear to be specific effects of thyroid substance on the oestrous cycle.
 +
 +
36. The effect of thyroidectomy on the oestrous cycle of the rat. Herbert M. Evans and Joseph A. Long, University of California.
 +
 +
Both thyroids were removed from three groups of rats which lived a long postoperative life: thirty-one adults, seventeen young rats 37 to 54 days of age, and eleven suckling ones. In all cases there was no doubt but that by far the largest part of the thyroid was excised, and in the youngest rats the operation was performed under binocular microscopes. The mortality from the operation is low. In the case of the adults the operation was usually followed by a pause in the oestrous cycles of 6 to 27 days, but in turn succeeded by normal oestrous cycles, about twenty of which were observed.
 +
 +
The operations on both the young and suckling animals influenced appreciably neither the time of maturity nor the lengths of oestrous cycles. Several of the second group after reaching an age of several months were autopsied and
 +
 +
 +
 +
62 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
found to possess what appeared to be lobes of regenerated thyroid tissue in many cases almost of the size of normal glands. Sections found these to be thyroids which had regenerated in spite of the effort which had been taken to secure complete ablation.
 +
 +
37. The effect of feeding the anterior lobe of the hypophysis on the oestrous cycle of
 +
 +
the rat. Herbert M. Evans and Joseph A. Long, University of California.
 +
 +
Four sets of experiments were carried on, in two of which fresh glands were fed and in two dried hypophysis from Armour & Co. and from Parke-Davis & Co. In all cases the feeding was begun at weaning, on the twentj'^ -first to twenty-third day, litter mates being used as controls. Daily observations were made to determine the opening of the vagina and cyclical changes in the vaginal smear. A total of fifty-five rats was used for the experiments and fifty-four for controls.
 +
 +
The anterior lobes were dissected from the glands of freshly slaughtered cattle and were ground, weighed, and fed within six hours of slaughtering. A half gram was given each rat, which had been isolated in a clean metal box where it could be seen that the total amount given was consumed, after which the animal was returned to its cage and given ordinary food. In one set the controls were not fed differently from their mates except for the hypophysis; but in the other set the controls were given in addition \ gram of raw liver daily to offset the possible nutritive value of the fresh hypophysis. Each rat was weighed at intervals of four days. In both sets the hypophysis-fed animals and controls showed neither significant differences in growth nor in the age of maturity and lengths of subsequent oestrous cycles. In the case of ten adult rats the total food intake was limited to 6 to 10 grams of the fresh anterior lobe and rolled barley. Their oestrous cycles (ten to twenty of which were observed) were not sensibly altered.
 +
 +
Similar tests were conducted with the dried commercial substance, except that no controls were given fresh liver. But for the fact that large doses could not be given without producing intestinal disturbances, the results were not substantiallj' different from those given above.
 +
 +
38. The effect of the anterior lobe administered intraperitoneally upon growth,
 +
 +
maturity, and oestrous cycles of the rat. Herbert M. Evans and Joseph A.
 +
 +
Long, University of California.
 +
 +
The anterior lobes were dissected from fresh glands, were immersed five minutes in 30 per cent alcohol, rinsed thoroughly in sterile Locke's solution, triturated with a small amount of sand, and centrifuged for about half an hour, care being taken to carry out all manipulations aseptically. The supernatant fluid from centrifuging was injected into the peritoneal cavity in amounts from i to 1 cc, according to the age of the rat, the first dose being given at an age of about fourteen days. At the beginning a similarly obtained fluid substance from liver was given some controls, but soon discontinued because of its toxic effect. Every animal was weighed at intervals of five days, beginning with the twentieth day of age. To date daily observations have been carried to the eightieth day. The subjoined table shows a greater rate of growth of the experimental animals as compared with their controls, a disparity which is increasing.
 +
 +
At the same time the effect of the anterior lobe has been to repress sexual development by delaying .sexual maturity and lengthening the oestous cycles, in some cases oestrus being entirely inhibited.
 +
 +
 +
 +
PROCEEDINGS
 +
 +
 +
 +
63
 +
 +
 +
 +
In the case of five adult rats with previously regular four-day cycles, doses of 1 to 2 cc. of the anterior lobe fluid substance caused an immediate cessation of the four-day rhythm, the smaller doses permitting oestrus to recur at longer intervals, the larger inhibiting it altogether. These results are in marked contrast to the lack of effect produced by oral administration of the anterior hypophysis. As far as the influence on sex function is concerned, they are in marked contrast to prevalent opinion.
 +
 +
 +
 +
AGE
 +
 +
 +
38 EXPERIMENTAL ANIMALS
 +
 +
 +
38 LITTER MATE CONTROLS
 +
 +
 +
days
 +
 +
 +
grams
 +
 +
 +
grams
 +
 +
 +
14
 +
 +
 +
20.2
 +
 +
 +
19.02
 +
 +
 +
20
 +
 +
 +
31.6
 +
 +
 +
33.14
 +
 +
 +
25
 +
 +
 +
48.6
 +
 +
 +
46.2
 +
 +
 +
30
 +
 +
 +
61.7
 +
 +
 +
60.0
 +
 +
 +
35
 +
 +
 +
80.6
 +
 +
 +
70.7
 +
 +
 +
40
 +
 +
 +
95.6
 +
 +
 +
86.2
 +
 +
 +
45
 +
 +
 +
117.6
 +
 +
 +
109.0
 +
 +
 +
50
 +
 +
 +
140.8
 +
 +
 +
126.1
 +
 +
 +
55
 +
 +
 +
159.5
 +
 +
 +
139.25
 +
 +
 +
60
 +
 +
 +
177.0
 +
 +
 +
153.3
 +
 +
 +
65
 +
 +
 +
197.2
 +
 +
 +
165.6
 +
 +
 +
70
 +
 +
 +
214.5
 +
 +
 +
173.7
 +
 +
 +
75
 +
 +
 +
227.8
 +
 +
 +
183.5
 +
 +
 +
 +
39. The digestion and assimilation of fatty food as determined by the aid of the
 +
 +
dark-field microscope, and a fat-soluble dye {American sudan). Simon H. Gage,
 +
 +
Cornell University.
 +
 +
The findings on the above reported at the last meeting of the Association have been repeatedly verified on people of various ages and on animals of widely different species. That is, with a dark-field microscope one can determine by the number of particles (chylomicrons) present: a) Avhether the fat taken with the food is being digested and absorbed; b) the time required for the process; c) the comparative digestibility of a given fat by different individuals and different species of animals; d) the comparative digestibility of different fats by the same individual or animal.
 +
 +
In the further study of the subject it has been found not only possible to determine the appearance, increase, diminution, and disappearance of the fat particles (chylomicrons) in the blood or chyle by the dark-field microscope, but with the naked eye it has been easy to follow the digested fat from the intestines to the lacteals, to the lymph nodes and to the cisterna chyli, and through the thoracic duct to the blood-vessels, and in the blood-vessels to all parts of the body. This was made possible by the use of a fat-soluble dye (American sudan), which when once dissolved by the fat, sticks so tight to it that it never lets go through all the processes of digestion, although they may involve splitting the fats into fatty acids and glycerin or even the formation of soaps and their absorption and res\^nthesization by the intestinal epithelium. The color serves as a label, so to speak,
 +
 +
 +
 +
64 AAIERICAN ASSOCIATION OF ANATOMISTS
 +
 +
and enables one to follow it in all its wanderings, and to see where it is finally deposited when assimilated.
 +
 +
Contrary to the general assumption that the fat is placed in temporary storage when it disappears from the blood, and is only very slowly and after considerable time finally deposited in the permanent fat reservoirs or adipose tissue, it was found that the fat was very quickly deposited in the adipose tissue of the entire bodj', but especially and most markedly in the adipose tissue of the omentum, mesenteries, and kidneys. The pink-stained fat is abundantly and easily recovered from the chyle, the blood and the adipose tissue thus leaving no doubt as to the nature of the pink substance.
 +
 +
40. Cinematomicrographij of serial sections. W. F. Schreiber, Stacy R. Guild,
 +
 +
and L. G. Herrmann, University of Michigan.
 +
 +
By combining photomicrographic and cinematographic methods a film has been produced on which are pictures at a low magnification of all the serial sections of an embryo, with the individual pictures so oriented with reference to each other that, when projected onto a screen by the usual moving-picture apparatus, the images overlap in much the same way that the individual wax plates used in making a model are overlapped. Whereas the successive pictures of an ordinary film gave temporal impressions, the attempt here is to give spatial impressions. It is hoped that the method will be useful as an aid in the teaching of embryology to large groups of students, especially as a supplement to the study of serial sections by the individual members of the group. The projection of the film available at the present time will constitute the major part of the presentation of this paper.
 +
 +
il. The Jiervons system as a factor in the resistance of albino rats to ■parathyroidectomy. Frederick S. Hammett (introduced by H. H. Donaldson), The Wistar Institute of Anatomy and Biology.
 +
 +
Studies made on the susceptibility of albino rats to acute parathyroid tetany resulting in death showed that animals which had been gentled by petting and handling were less frequently affected by removal of the parathyroids than were rats lacking this treatment. Three hundred and four rats were operated. In one group the parathyroids alone were removed, in another, the entire thyroid apparatus, and in a third the thyroid apparatus was removed in two stages, at an interval of two weeks. About 13 per cent of the gentled rats died in acute tetany after these procedures, while about 78 per cent of the not gentled rats died within forty-eight hours after operation. These results are taken to indicate that the gentling induces a condition in the nervous system such that the demand of the organism for the parathyroid secretion is lessened to the point where the rat survives though the secretion is lacking. Since the condition of high neuromuscular tension present in theratesnotgentledimpliesaheightened metabolism of that phase of activity concerned with muscle tone, it is possible that in these rats there is thus produced a greater amount of some toxic by-product than in those gentled, and that removal of the parathyroids also removes the mechanism for the destruction or neutralization of this toxic compound and the animals consequently succumb to the excess of the hypothetical compounds so formed.
 +
 +
 +
 +
PROCEEDINGS 65
 +
 +
42. An ada-ptation of the fire-assay method for the determination of gold and silver in animal tissues. Samuel Hanson (introduced by H. M. Evans), University of California.
 +
 +
Methods hitherto employed in quantitative determination of gold and silver in animal tissues have not been entirely advantageous. The titration method of Voigt for the estimation of silver is inconvenient and its accuracy uncertain. The electrolytic method of Caldwell and Leavell is complicated and time-consuming. The well-known fire-assay method may be adapted to determine very small quantities of gold and silver in animal tissues with a high degree of accuracy. The tissue for estimation is dried and pulverized. Two grams of the powdered tissue is transferred to a glazed paper and thoroughly mixed with 60 grams of silver-tested litharge, 20 grams of sodium carbonate, and 15 grams of silica. The mixture is transferred to a clay crucible and covered with 10 grams of sodium carbonate. The charge is fused in the muffle at a high temperature until no suspended droplets of lead are seen. The stage is usually reached in thirty minutes. The fused material is next poured into a conical iron mold, the lead settling on the bottom of the mold, while the fused material, or slag, collects at the top. If the fusion has been properly carried out, the slag is transparent and free from particles of lead or carbon. The slag is removed and the lead hammered into the form of a cube with blunted corners. Such a lead button should weigh between 25 and 30 grams and is placed in a red-hot bone-ash cupel in the gas or electric furnace and the cupellation continued at a temperature sufficiently high to prevent heavy fumes. The cupellation may be regarded as completed when the residue suddenly loses its brightness and appears as a small bead. The bead is weighed on the assay balance to 0.01 of a milligram. After weighing the bead, the silver, if present, is dissolved and the bead reweighed. The latter weight, of course, represents the quantity of gold present, if both gold and silver are present, while the difference between the two weights corresponds to the amount of silver.
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43. On the rapidity of absorption of colloidal gold from the peritoneal cavity. Samuel Hanson (introduced by H. M. Evans), University of California.
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The phenomena of absorption of dialyzable substances from the peritoneal cavity have been extensively investigated. Phenolsulphonephthalein, for example, is absorbed from the peritoneal cavity at a known rate, evidently chiefly by way of the blood capillaries, and the mechanism of its absorption can probably be satisfactorily explained by assuming that the physical processes of osmosis and filtration are operative. In the case of the absorption of colloids and suspensoids, however, the situation is different. The experimental work done with this class of substances, with the exception of the recent paper by Cunningham and Shipley, is almost exclusively qualitative. The absorption of colloidal gold furnishes an excellent opportunity to obtain quantitative data in this field, for gold may be estimated in tissues with high accuracy (see above), and its colloidal solution made according to the method of Paal is stable and largely physiologically inert. Solutions estimated to contain 1 per cent metallic gold in physiological saline were used. Injections were made into the peritoneal cavity of rats, 1 mgm. of metallic gold per 10 grams of body weight being given. After various intervals the animals were sacrificed and the
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THE ANATOMICAL RECORD, VOL. 21, NO. 1
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66 AMERICAN ASSOCIATION OF ANATOMISTS
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amounts of gold found in the liver determined by the fire-assaj- method given above. The rapidity of absorption of the gold as determined by its deposition in the liver is remarkable, 8 per cent of the amount injected being found at the end of the first hour and 22 per cent at the end of two hours. According to Dandy and Rowntree, about 50 per cent of phenolsulphonephthalein injected intraperitoneally is absorbed within one hour. This substance diffuses readily through animal membranes and its smallest particles are probably represented by the molecular dimension; the size of the gold particles is in contrast very many fold greater, yet they traverse the peritoneal boundary at a rate at least one-sixth as rapid.
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U. The developtnent of the balancer in Amblystoma. Ross G. Harrison, Yale
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University.
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As shown by Bell in Diemyctylus, the development of the balancer is determined by a patch of differentiated ectoderm overlying the mandibular region. When this ectoderm is transplanted to other regions of the embryo in Ambh^stoma punctatum, even as early as the medullary-plate stage, a normally constituted, though somewhat smaller, balancer develops. If it is replaced by ectoderm from the trunk, the front of the head, or from the gill region, no balancer develops. Removal of the mandibular mesoderm does not affect the development of the balancer, if the ectoderm is healed back in place, nor does the removal of the ganglion crest (experiment of L. S. Stone), though cells from the latter lie directly under the base of the outgrowing organ and normally probably provide its mesodermal C(}re. Amblystoma tigrinum lacks balancers. If, however, proper ectoderm of A. punctatum is transplanted to the former species, a normal balancer with mesenchyme and blood circulation develops. The reciprocal operation apparently suppresses the balancer, though only one experiment has given this result. Owing to faulty placement of the graft in others, regeneration from the host occurred. The peculiar membrane which supports the balancer develops in the strange as well as in the normal location. Its staining qualities and the imbedding of its base in mesenchyme might lead one to regard it as a dermal bone, as Latta has done. However, it is never formed except beneath the specific balancer ectoderm, and the evidence favors its interpretation as a basement membrane.
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45. Amiiosis in ciliated cells. Frank Helvestine, Jr. (introduced by H. E.
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Jordan), University of Virginia.
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In 1898 V. Lenhossek and Henneguy independently expressed the opinion that the basal bodies found in ciliated cells are derivatives of the centrosome. The corollary of this hypothesis, namely, that on account of the preemption of the centrosome in the formation of basal granules, ciliated cells must necessarily proliferate by amitosis, was later expressed by Jordan ('13), and he supported this conclusion by data derived from a comparative study of the ciliated epithelium in the ductili pffcrentes and epididymes of a number of vertebrates.
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Saguchi ('17) confirms Jordan's results as regards vertebrates, but states that in invertebrates mitosis is the exclusive mode of division of ciliated cells. He describes cells undergoing karyokinesis as either not having cilia or as losing their cilia before the process of division takes place. Saguchi concludes from his obser
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PROCEEDINGS 67
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rations that basal bodies and cilia are derived from mitochondria. His descriptions and illustrations do not bear out this conclusion, but rather add to the evidence of a centrosomal origin of the basal bodies.
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In mj' material of the gills of the fresh-water mussel, Cyclas, no relationship between mitochondria and basal bodies, other than spatial, is discernible. Indirect evidence supports the view of the derivation of the basal bodies from the centrosome. In this form certain ciliated cells divide extensively only by amitosis. Saguchi admits that cells of ciliated epithelium dividing by mitosis possess no cilia at the time of division and my material confirms this observation. Such cells cannot properly be called ciliated cells and it can accordingly not accurately be said that ciliated cells divide bj' mitosis.
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In view of the agreement between Jordan ('13) and Saguchi ('17) regarding an exclusively direct method of division in ciliated cells of vertebrates, and Saguchi's failure to find in invertebrates any cells with cilia in indirect division, and my demonstration of extensive amitotic divisions in ciliated cells of Cyclas, the general conclusion seems warranted that ciliated cells both in vertebrates and in invertebrates divide only by amitosis.
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46. Develo-pment of the innoviinaie artery in the pig. Chester H. Heuser, Johns Hopkins Medical School.
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In a closely graded series of injected embryos ranging in length from 3.8 mm. to 40 mm. which was prepared for a study of the transformations of the aortic arches and the related vessels, the development of the innominate artery can be followed from its primitive condition until its adult form is attained. The cephalic border of the bulbous ventral aorta in the 7-mm. embryo gives rise to the large third aortic arches and the rudimentary external carotid arteries. In embryos of S mm. the ventral ends of the third arches carry the external carotids so that the common carotids are alreadj' indicated. In succeeding stages beyond 8 mm. the ventral portions of the third and fourth arches are united into common trunks which gradually increase in length. This trunk is especially long on the right side and is a part of the innominate arterj^, but as the arch of the aorta becomes established from the left fourth arch the left common carotid becomes shifted over so that it arises also from the innominate. This condition can be seen in stages of about 21 mm. In older embryos the connections remain the same, but the innominate artery increases greatly in length, as seen in stages measuring 40 mm. or more.
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47. Extirpation and transplantation of thymi in larvae of Rana pipiens. Margaret Morris Hoskins, Medical College of Virginia.
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The operations were performed by E. R. Hoskins in the spring of 1919 and the report is based on a study of preserved material. Records were kept of the growth and development of the larvae and showed no effect from the experiments in this respect. The operations were of three types: complete and unilateral extirpation of thymi and transplantation of thymic tissue from one larva to another. The grafts grow well and have the appearance of normal thymic tissue. The effect of the operations on the thymi, the spleen, and on the endocrine glands has been studied from dissections and from histological preparations. When one thvmus is removed there is no compensatory hypertrophy of
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68 AMERICAN ASSOCIATION OF ANATOMISTS
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the remaining one, and the engrafting of thymic tissue does not affect the thymi of the host. None of the operations affects the spleen in size of appearance. The gonads, thyroids, and parathyroids also remain unchanged. In some instances the hypophyses of thymectomized larvae appear to be hypertrophied, but this is not always the case. Histologically the hj'pophyses of the operated animals are normal.
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48. Embryonic myeloschisis. (Stereo-lantern.) N. William Ingalls, School of Medicine, Western Reserve University.
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The three human embryos considered naturally fall into a series of increasing teratological and pathological severity. This also applies to the embryonic adnexa. No. 83, G. L., ca. 7 mm., condition fair, chorion quite large, villi large and numerous but somewhat altered, amnion thickened, magma excessive, cord and yolk sac small, vessels indefinite. Sacral myeloschisis extending over 2.5 mm. on summit of sacral convexity, neural folds everted, prominent and sharply defined. No. 288, G. L., ca. 12 mm., condition poor, color not very good, chorion of fair size but thin, villi not well developed, hydramnios, no exocoelom, cord small, no yolk sac found, only traces of vessels. Medullary defect measures 2.5 X 4 mm. , extending from thoracic into sacral region. Area involved is spread out on dorsum of embryo, its surface very slightly elevated, margins irregular. In No. 46 the disturbance has been much more severe. G. L. 14.5 mm. , distinctly pathological, color muddy and opaque; chorion large and haemorrhagic, villi very short and scattered, hydramnios, no exocoelom, amniotic fluid slightly turbid and viscid, neither vessels nor yolk sac to be seen, cord short and markedly distended. Extensive defect involves most of cord, secondary loss of substance; marked encephalic malformation, head very small, eyes approximated, mouth gaping, nasal and palatal deficiencies. General anasarca of embryo.
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49. The effects of various types of inanition upon growth and developjnent, with special reference to the skeleton. C. M. Jackson, University of Minnesota. According to Liebig's 'law of the minimum,' as applied to animal growth by
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Bunge and by Osborne and Mendel for mineral and protein factors of the diet, the deficiency of any essential factor results in failure of the growth of the body as a whole, and not in the production of abnormal tissues. However, during inanition of various types there occurs a malcorrelated growth, certain organs increasing abnormally, others decreasing, with retarded or stationary body weight.
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During underfeeding of young rats on a balanced diet (deficient in calories), this disproportionate growth affects practically all organs of the body, the extent varying widely in different organs ; also according to age, and length and intensity of the inanition (Jackson, Stewart, Barry). Persistent skeletal growth has likewise been observed by other investigators in underfed calves, puppies, rats, and malnourished infants.
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In rats on qualitatively inadequate protein diets, Osborne and Mendel found skeletal retardation proportional to that of the whole body; but more recently Mendel and Judson ('16) found persistent skeletal growth in mice. Kudo ('21) finds markedly persistent skeletal growth in rats with restricted water supply.
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PROCEEDINGS 09
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Absence of essential salts results in disordered or inhibited skeletal growth, in invertebrates (sea-urchin, sponges) as well as various mammals. With calcium-poor diets, the body weight may continue increasing, while the skeleton is retarded, with 'pseudorachitic osteoporosis.' True rachitis apparently depends upon a deficiency in ' fat-soluble A' vitamine. Phosphorus deficiency likewise retards skeletal development, with histological resemblance to scorbutus (which, however, is also due to vitamine deficiency).
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50. Studies of lymph nodes. II. Response of hjmph nodes to irritation. (Lantern.) Thesle T. Job, Loyola University School of Medicine.
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By injecting subcutaneously India ink in either distilled water or weak solutions of ammonium hydroxide, a condition simulating a low grade or a virulent infection may be initiated. By this method a less complicated picture is obtained but, nevertheless, just as true as when cancer cells or bacteria are injected. Thus it can be demonstrated that, in the case of ink in water, the granules are carried by phagocytes, mainly, to the first node in the drainage line. This node becomes progressively pigmented to a solid black. Then the second node in the drainage is pigmented, and so on. This being a non-irritative process, no new h^mphoid tissue is formed. If ink in ammonium h3'droxide be used — the ammonia being a strong irritant — the first node in the line of drainage is only partly pigmented before the second node begins to receive pigment ; the lymphat ic collateral circulation about the node is enhanced and an actual building up of new lymphoid tissue is begun. The significance of these results is pointed out and a practical application made.
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51. On the origin and development of the posterior lymph hearts in anuran embryos. (Lantern.) Otto F. Kampmeier, College of Medicine, University of Illinois. The first evidence of the beginning of the posterior lymph heart on either side
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is manifest in 10 to 11 mm. embryos (Bufo vulgaris) as an accumulation of mesenchymal cells around that part of the lateral lymphatic plexus situated just lateral to the posterior vertebral vein at the level of the eleventh spinal ganglion. By gradual distention and coalescence, the vessels of the lymphatic plexus within the area of mesench3"mal accumulation become transformed into a globular chamber, the posterior lymph heart. The lymph-heart anlage becomes temporarily separated from the surrounding lymphatic network, the number and position of the points of separation being relatively constant in different individuals. Two points of junction are reestablished between lymph heart and plexus, one situated on the dorsal and the other on the ventral side of the heart; later such points of entry are increased in number. The muscular coat of the lymph heart is developed from the cells of the original mesenchymal accumulation around the lymph heart plexus.
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Before the efferent valve (between lymph heart and posterior vertebral vein) is formed, blood corpuscles are found in large number in the heart cavity. There is evidence that at times the embryonic posterior lymph heart itself may function as an haemopoietic center; certain it is that during its development, it, like other embryonic lymphatics, is haemophoric, that is, transports along with its lymph flow developing blood cells to the blood stream. Not only does the number of posterior lymph hearts differ among species of Anura, but it may also differ among members of the same species, and may even be different on the two sides of the same individual.
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70 AMERICAN ASSOCIATION OF ANATOMISTS
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62. Peripheral migration and distribution of medullary cells in the absence of spinal ganglia and dorsal nerve-roots in embryos of the chick. Albert Kuntz, Saint Louis University School of Medicine.
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Embryos of the chick were subjected to an operative procedure at the close of the second day of incubation (forty-eight hours) by which the neural crests and the dorsal portions of the neural tube were destroyed throughout a series of successive segments. These embryos were allowed to live until the close of the fifth day of incubation. Ventral nerve-roots are present in all segments in which the motor niduli awere not destroyed. Cells of medullary origin are present in these nerve-roots and along the course of their fibers. Some of these cells advance along the visceral rami and give rise to ganglia of the sympathetic trunks, others become distributed along the nerve-fibers and give rise to neurilemma. In segments in which but a small ventral portion of the neural tube remains intact, even though ventral nerve-roots but no visceral rami are present, the primordia of the sympathetic trunks are absent.
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53. Nerve terminations in the lung of the rabbit. (Lantern.) O. Larsell, Northwestern University.
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Sensory nerve endings are found in the epithelium of the bronchial tree and its various subdivisions as far as and including the atria. These appear on anatomical grounds to consist of three types, probably receptive to different methods of stimulation. The most constant position in which sensory terminations are present is at the point of division of the various orders of branches of the bronchial tree. Motor terminations are also present, not only in the smooth muscle fibers of the bronchi and their branches, but in the pulmonary artery and its branches, including the arterioles. A few nerve fibers are also present in the tunica media of the pulmonary veins. The sensory innervation is by fairly large myelinated fibers from the vagus. The motor innervation of the bronchial musculature appears to be of the typical preganglionic and postganglionic arrangement. The preganglionic fibers terminate in characteristic pericellular networks about the cells of the intrapulmonary ganglia, and from these nerve cells processes are given off which pass to the smooth muscle bands, to terminate in relation to the unstriated muscle cells. The source of the fibers to the pulmonary vessels has not yet been determined.
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54- The growth of the organs and systems of the single comb White Leghorn chick.
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Homer B. Latimer, L^niversity of Minnesota.
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In plotting the gross weight of the eighty-six chicks upon age in days (from day of hatching to 251 days) the resulting curves show three phases; first a slow initial rise, then a rapid increase, and later a second period of slow growth. The curve for the females begins to fall below that of the males, beginning at about seventy or eighty days. The curves of the different organs and systems may be placed in four groups as follows:
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1. Those which tend to parallel the growth of the body as a whole, or the muscles, ligamentous skeleton, digestive tract, lungs, heart, kidneys, suprarenals, and integument. The curves of the percentage weights of these organs on the net body weight show a more or less rapid decline, with the exception of the musculature which increases from about 25 per cent up to nearly 50 per cent of the net body weight.
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PROCEEDINGS 71
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2. This group is characterized by a rapid initial rise of the growth curve, followed by a slowing of the rate of growth. In this group are the brain and eyeballs and linear measurements (body length, etc.).
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3. The ovary, oviduct, testes, and comb and wattles grow very slowly at first, followed by a rapid prepubertal rise, in both absolute and percentage weight.
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4. The thymus and the feathers at first grow in weight a little more rapidly than the body, followed by a decrease in weight, both relative and absolute.
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When the gross body weight is substituted for the age in days, the chief differences in the curves are a more precipitous rise at first and in some cases a loss of the second flatter part of the curve.
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55. The description of the coats of blood vessels contained in Galen's De anatomicis administrationihus , Liv. VII., Cap. V. A comment on its accuracy. Frederic T. Lewis, Harvard Medical School.
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The description is as follows: Venae totius corporis ex peculiari una constant tunica; nam exterior membrana ipsis nonnunquam obhaerescens, ubi colligari quibusdam aut fulciri ac contegi desiderant, illuc solum accedit. Arteriae vero duae peculiares tunicae existunt: exterior sane qualis venae est: interior autem crassitie hujus fere quintupla, insuper durior, in transversas fibras dissoluta; exterior autem, quam etiam venae obtinent, rectis fibris, et quibusdam mediocriter obliquis, transversis nullis, contexta est. Interior arteriae tunica crassa duraque ceu cutem quandam interna superficie continent, telae araneorum manifesto persimilem, in magnis quidem arteriis perspicuam, quam nonnulli tertiam arteriae tunicam statuunt: quarta vero alia peculiaris ei nulla est, sed veluti quibusdam venarum, ita quoque arteriis alicubi obhaerescit et circumtenditur membrana tenuis contegens aut affirmans aut connectans ipsas vicinis particulis.
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56. The formation of vacuoles in the cells of tissue cultures owing to the lack of dextrose in the media. Margaret R. Lewis. Carnegie Laboratory of Embryology.
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Cells cultivated in media lacking dextrose show numerous vacuoles in twentyfour to forty-eight hours, after w^hich degeneration rapidly ensues. When the usual amount of dextrose (0.25 per cent) is included in the media, the vacuolation, degeneration, and final death of the cells are retarded for several days. If a medium containing from 0.5 to 1 per cent dextrose is used, the cells continue in an apparently healthy condition for a much longer period of time, sometimes two or three weeks, during which vacuoles fail to appear. Ultimately, however, the cells in such cultures may exhibit vacuoles. Dextrose is an important part of the medium for tissue cultures, and it seems to be necessary in order to maintain the normal metabolism of the cells under the conditions of tissue cultures.
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57. The characteristics of the various types of cells found in tissue cultures from chick embryos. Warren H. Lewis, Carnegie Laboratory of Embryology. Each type of cell that migrates out of the explant onto the coverslip does so in
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a manner peculiar to its type. The blood cells and clasmatocytes pursue very irregular and uncertain paths, each cell retaining its complete independence, in that they rarely adhere together to form any sort of pattern. In marked contrast to these wandering cells are the ectodermal and endodermal cells which always migrate out in the form of a sheet or membrane, the borders of the cells
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72 AMERICAN ASSOCIATION OF ANATOMISTS
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adhering to their neighbors in more or less even lines. Intermediate between these two extremes are the mesenchyme, endothelial and smooth muscle cells which form loose reticuli, in that the cells tend to adhere to one another by their processes rather than by the cell borders. The cells of each type form, however, their own peculiar characteristic pattern of reticulum. Isolated ectodermal and endodermal cells occur and still more frequently isolated mesenchyme, endothelium and smooth muscle cells. Still different are the characteristic outgrowths of long multinucleated strands from the striated muscle and the long slender nerve fibers from both the sympathetic and central nervous systems. Both the muscle strands or buds and the nerve fibers have a tendency to form anastomosing plexuses, the nervous ones being more elaborate and complicated. The various other types of cells which migrate onto the coverglass do so each in a characteristic formation of characteristic cells. These characteristics both of the individual cells and of the types of growth are retained throughout the life-history of the culture, or until marked degeneration changes take place. There is no dedifferentiation after they have grown out on the coverslip, although cell division is frequent.
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58. S77iooth muscle and endothelium in tissue cultures. Warren H. Lewis, Carnegie Laboratory of Embryology.
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Smooth muscle from the amnion and endothelium from the sinusoids of the embryonic chick liver form a somewhat similar reticulum in the cultures. They resemble one another much more than they do the ordinary mesenchyme from the subcutaneous tissue. The smooth muscle cells have a rather thick homogeneous ectoplasm and in the living cell no indications of fibrillae are to be seen unless the cells are subjected to a sudden change. The fibrillae that have been occasionally observed under such conditions were gradually lost, the ectoplasm becoming homogeneous again. On fixation under the microscope the striae and fibrillae appear as the coagulation of the ectoplasm proceeds. The fibrillae are coagulation products of a peculiar kind of ectoplasm. They are not always parallel, but may in different parts of the spread-out cells run in groups at different angles. The peculiarity of ectoplasm which causes it to coagulate into fibrillae of varying sizes is probably a molecular thing, and it is to the latter that the contractile substance owes its peculiar properties. Our observations are in entire accord with those of Mrs. Lewis on smooth muscle.
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Endothelial cells often show somewhat similar striae or fibrillae on fixation. The condition is never so marked as in smooth muscle, but it suggests that there is an unusual amount of contractile substance in endothelium which is interesting in connection with recent physiological work on the contraction of the capillaries by Dale, Krogh, Bayliss, and Hooker.
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69. Preliminary remarks upon the Junctional variations of the normal human mammary gland. Joseph McFarland, University of Pennsylvania. In the study of cases of a morbid condition of the human mammary gland known as 'abnormal involution,' a variety of appearances were encountered that were very puzzling. The difficulty seemed to lie in uncertainty as to what was and was not to be regarded as normal, and part of the evolution and involution of the gland. Books and journals did little to help one out of the dilemma.
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PROCEEDINGS 73
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Text-books of histology, for the most part, describe and illustrate the structure of the mammary tissue in such manner as to lead one to suppose that, except at the time of lactation, all glands look alike.
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With a view of finding out what variations in structure and appearance the normal mammary gland presents, about 200 apparently normal glands were collected, sectioned, and studied. From this work it has become evident that a number of structural types will have to be established, and it is believed that in the future it will be necessary to call the attention of the student to each of these types, in order that he shall not later be surprised and confused by finding that the structure of a gland that he is called upon to examine in the pathological or hospital laboratory does not correspond with what he has been taught and shown as a student.
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60. The influence of the lateral-line syste7n in the devclopmint of the skeleton. Roy L. AlooDiE, University of Illinois, College of Medicine.
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The study of the lateral-line canals in ancient Amphibia and primitive fishes shows a definite correlation with certain peripheral osseous elements of the head. This fact suggests that during development there may be a relationship between the formation of the canals and the initiation of osseous development.
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Young catfishes, Ameiurus nebulosus, were cleared by the potash method and the relationship of both lateral-line canals and developing skull bones was studied. It was found that the lateral-line canals were all laid down prior to the deposition of any osseous material, but those bones which touch on the canals were the latest of the cranial elements to form. This indicates that the lateralline canals have no influence on the initiation of osseous development, but that the canals do modifj^ the forrp of the bones which they touch. The factor which causes the initiation of osseous deposition must be looked for elsewhere.
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61. On the specificity of regenerating limb-buds in adult newts. C. V. Morrill, Cornell University Medical College.
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The present paper is a preliminary report on a series of transplantation experiments (still in progress) to test the specificity of regenerating limb-buds in the adult of the common spotted newt (Diemyctylus). The subdivisions of the problem are as follows: a) Will regenerating limb-buds retain their laterality if transplanted to opposite side of the body? h) Will a regenerating bud (e.g., from an anterior limb) retain its specificity if transplanted tj the stump of a different kind of limb (e.g., to a posterior limb stump)? c) Is there any observable difference between autoplastic and homoplastic transplantations?
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For the purposes of the experiment, regenerating buds were transplanted when about one-eighth of an inch long and just beginning to show indications of digits. In order to test out the various possibilities outlined above, anterior limb-buds were transplanted to the stumps of posterior limbs of the same and of opposite sides, and posterior limb-buds to posterior stumps of opj)osite sides. In some cases the buds used were taken from the same individual (autoplastic), in other cases from a difTerent one (homoplastic). In this way seven different categories of experiments were made possible, though all have not yet been tested. The results in general show that in most cases the regenerating bud first loses most of its external and internal differentiation and becomes reduced
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74 AMERICAN ASSOCIATION OF ANATOMISTS
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to a conical knob consisting of a layer of epithelium and an internal mass of more or less indifferent cells. There is undoubtedly some mingling of the tissues of transplant and stump. Subsequently a redifferentiation takes place; the bud lengthens out again and digits appear. In all cases so far examined the original laterality of the bud seems to be entirely lost, that is, the transplant develops into a limb corresponding in this regard to its new site. Regarding anterior and posterior specificity, the results are not uniform. As a rule, the original specificity is lost, but in one case an anterior limb-bud transplanted to the stump of aposterior limb of the same side (homopleural), but on a different individual (homoplastic), developed into an anterior limb. Aside from the case just cited, no differences between autoplastic and homoplastic transplantations have as yet been detected, but the number of experiments is too small to warrant any conclusion. In all the types of experiments, reduplications occasionally appeared, as might be expected. Double limbs are of course the most common, but in two cases triple limbs developed. These are at present too young to interpret with certainty.
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62. Studies on the mammary gland. VIII. Gross changes in the mammary gland in the female albino rat during the period of involution. Frank J. Myers and J. A. Myers, University of Minnesota.
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Virgin animals of known age and weight were allowed to become pregnant, deliver, and nurse their young. In all cases the litters were weaned at the end of three weeks, after which the mammary glands of the mothers were collected at intervals ranging from six hours to five weeks. The glands were spread out on sheets of cork and cleaned according to the method previously described (Myers, '16). At the end of six hours the masses of glandular tissue are considerably enlarged. This enlargement which is probably due to the accumulation of milk continues through the forty-eight-hour stage. In the four-day stage the masses of glandular tissue have decreased considerably in size, while at the end of five days the glands are not more than one-half the size of those taken at forty-eight hours. In the stages taken at the end of two and three weeks the glands very closely simulate those of adult virgin animals. The most noticeable steps in involution occur during the latter part of the first week, and by the end of the second and third weeks the glands have returned approximately to their resting stage.
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6S. Regulation of posture in the forelimb of Amblystoma punctatum. J. S. Nicholas (introduced by R. G. Harrison), Yale University.
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The limb-bud of the right side of the embryo has been subjected to rotations of 90°, dorsoantorior or clockwise and dorsoposterior or counterclockwise, in order to study the factors which cause rotation in transplanted limbs. Regulatory recovery occurs, being practically complete in the normal location and partially so in abnormal locations. As a rule, the limb moves through the shorter arc in recovering its normal posture, that is, the recovery process is generally in the reverse direction from the imparted rotation. Exceptions to this rule, occurring in dorsoposterior operations, show that occasionally growth factors increase the imparted 90° rotation, causing the limb to attempt recovery through the greater arc or in the same direction as the imparted rotation.
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PROCEEDINGS 75
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Irrespective of imparted rotation, girdle formation is in normal relation to the dorsoventral axis of the embryo, that is, it is never upside down, although it may be reversed in regard to the anteroposterior axis. The regulation of posture is primarily dependent upon the formation and size of the girdle. This is shown in heterotopic operations. The intrinsic musculature which grows back from the limb blastema to the girdle also apparently influences the recovery of the limb to its normal posture. The limb undergoes rotation as a whole. In contrast to this, the readjustment which occurs in the girdle is not by means of movements of the whole aggregate as shown by the position of portions of the pronephros which have been implanted with the limb-bud.
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6 4. The developmental topography of the thymus, with particular reference to the changes at birth and in the neonatal period. (Lantern.) Gustave J. Noback, University of Minnesota.
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The thymus in the late fetus and stillborn child has a typical form and quite constant relations. Its lateral surfaces are convex and bulge against the medial surfaces of the lungs which rarely extend at all on its anterior surface. The thymus very rarely extends at all on the anterior surface of the right ventricle of the heart.
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The thymus in liveborn infants has a typical form and relations which are similar to those found in young children. It is elongated and molded so that its anterior, lateral, and posterior surfaces bear the impress of all the organs with which it is in contact. Its lateral surfaces usually show marked convexities which are occupied by the lungs which pass over the anterior surface of this organ. Unlike the fetal thymus, it extends on the right ventricle. The change from the broad or fetal type of thymus to the elongate and molded type found in the liveborn and in the young infant bears a direct relation to the establishment of respiration. The organ is compressed from side to side by the medial surfaces of the expanding lungs. It i's also compressed anteroposteriorly by the anterior borders of the lungs which advance medially and become much thickened early in the establishment of respiration.
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65. The postnatal growth and developynent of the female reproductive tract in the albino rat. H. L. Osterud, University of Minnesota.
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This study of the weights and microscopic structure of the ovaries, uterine tubes, uterus, and vagina of 125 rats (including thirty postpartum primiparae) shows that in adult virgin rats the tubes may attain a maximum growth of twentysix times their birth weight, the ovaries seventy-four times, the vagina 138 times, and the uterus 197 times. All four organs exhibit four-phase growth curves. The most rapid growth occurs first during the first three weeks (lactation period) and later shortly after the sixtieth day of age. The prepubertal growth increase comes distinctly earlier in the uterus and vagina than in the ovaries. After maturity the variability especially in the uterine weight is astonishing (from 0.055 to 0.494 per cent of the body weight). The maximum uterine weight in virgins far exceeds that in postpartum primiparae after completed uterine involution. The uteri of these postpartum primiparae, however, display the tendency to a similar great growth if kept from the males for sufficient time. The extreme cases strongly suggest a parallelism between this great uterine growth
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76 AMERICAN ASSOCIATION OF ANATOMISTS
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and ovarian activity, associated also with large hypophysis and perhaps thyroid. Failure of this great growth in some females is extremely dijERcult to account for except in cases of distinctly poor nutrition. Volumetric study of the ovaries offers no role in this uterine variability to the interstitial tissue. Definite correlation in the size of uterus and vagina is fairly evident, while the frequent apparent failure of the ovary to show similar correlation is probably due to its great cyclic fluctuation.
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66. Developmental competition in its relationship to the sex ratio. George N. Papanicolaou, Cornell University Medical College.
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The average sex ratio in a stock of 3472 guinea pigs is 106.54 when the individuals born in all litters are considered. On comparing the ratios from different-size litters great discrepancies are found. In litters of one the sex ratio is 112.58; in litters of two, 112.07; in litters of three, 97.95; in litters of four, 108.73, and in litters of five, 141.02. These variations may be explained on the following principles derived from a careful analysis of the developmental conditions in guinea pigs:
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1. There is a competition between developing germ-cells and embryos in the ovary and the uterus.
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2. In the competition males have some advantage over the females.
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3. Competition is higher in the larger litters (by a litter is meant the number of codeveloping germ-cells and embryos).
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4. In litters consisting of embryos of the same sex competition is higher than in mixed litters.
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5. The competition is stronger among females than among males.
 +
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In agreement with these statements there is a higher percentage of complete elimination of large litters, consisting chiefly of females than of any other large litters. This elimination produces the high sex ratio for the litters of four and five. The originally large litters in which the subsequent elimination is partial result in births of one and two. Elimination being more severe on the female members causes the production of a higher sex ratio than occurs among individuals produced in litters of three. Litters of three have the lowest sex ratio and approach nearest an expected condition, having suffered little or no prenatal mortality. This explanation is supported by a study of more than 100 litters with early partial absorptions which gave the high sex ratio of 123.37.
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67. A note on the relation of the auricle and external auditory canal to drum-membrane mechanics. A. G. Pohlman, Saint Louis University.
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The writer presented certain comparative data at the last meeting of the Association on the problem of middle-ear mechanics. This evidence favored the 'string-telephone' theory of sound transmission and opposed the usualh' accepted theory of mass reactions. Practically all modern writers (^^rightson-Keith and Zimmermann excepted) agree that the drum membrane-ossicular chain route is the highly efficient one for so-called 'bone-transmitted' sound. Modern investigators of cochlear mechanics with few exceptions base the responses in the inner ear upon mass movements in the periotic fluid (functional relation of stapes basis to fenestra cochlease). It is essential that the reactions in the drum membrane to energies of optimum or minimum force be carefully studied. It appears that
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PROCEEDINGS 77
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the dampening-out effect of the external auditory canal upon the sound pulses entering the external meatus through diffraction is more than compensated through the action of the auricle. An explanation of the Weber phenomenon or the Rinne-negative ear test does not appear satisfactory on the basis of the mass response conception. The increased efficiency of bone-transmitted sounds (mastoid and teeth) and the decreased efficiency of air-transmitted sound in pathological conditions of the middle ear is more readily explained by the 'stringtelephone' theory. This is also the case in the interpretation of instances of voluntary contraction of the M. tensor tympani and the dampening-out effect of heightened drum-membrane tension due to plus pressure in the external canal. A definite conception of drum-membrane mechanics is essential to the correct analysis of inner-ear responses.
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68. The determination of the perce7Uage of the organic content of bone. H. E. Radasch, Jefferson Medical College.
 +
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The percentage of the organic substance in compact bone is given as 32 to 33 per cent. How that was determined is not apparent from the general literature. In order to determine the real percentage and to try to find out, if possible, the methods used by the early observers, experiments were made in various ways. After carefully preparing pieces of femur, tibia, and fibula, one set of pieces was weighed, then calcined, then weighed again. The loss indicated the amount of incinerable organic substance in compact bone. At twenty to sixty years the average per cent found was 40.75. In the adult cat this green weight per cent was found to be 38.32 per cent, while in the rabbit (two-thirds grown) the average was 38.90 per cent. By other methods the moisture, alcohol-soluble and ethersoluble substances were removed and the fixed organic content determined. The average amount of moisture at twenty to sixty years is 8.42 per cent and the ratio of fixed organic substance to the dried bone is only 34.92 per cent. The average amount of alcohol-soluble material is 8.46 per cent and the ratio of the fixed organic substance to the extracted bone is 32.36 per cent. The average amount of ether-soluble substance is 9.27 per cent ; the ratio of the fixed organic substance to the extractable bone averages 31.34 per cent. It seems, though, that the standard weight should be that of green bone, and if this be accepted, then the organic substance averages 40.75 per cent.
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69. The distribution of the acid cells of the stomach. H. E. Radasch, Jefferson Medical College.
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It is customary to state that the acid cells are found in the cardiac and fundal portions of the stomach, but there seems to be no definite statement as to the point or region at which they cease to exist. It was, therefore, determined to make a sort of survey of the stomach so as to see if it were possible to give any definite boundary to the acid-cell distribution and also to note any difference in distribution. For this purpose human and rabbit stomachs were fixed in toto and then, when dehydrating in 85 per cent alcohol, were cut. A strip J inch wide of the entire lesser curvature was first cut out, then one of the entire greater curvature and one of the ventral or dorsal surface, attempting to follow the long axis of the surface. These pieces (uncut) were then completely dehydrated, cleared in cedar oil and absolute alcohol (equal parts) and then pure cedar oil,
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78 AMERICAN ASSOCIATION OF ANATOMISTS
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and infiltrated in paraffin and then blocked without cutting into segments. After the paraffin had hardened the long strips were then cut into pieces If to 2 inches long (the width of the cut of a Spencer microtome) and sectioned. Such long strips may readily be cut into shorter strips by using a safety-razor blade. The stomach of the rabbit was run through whole, and if it would fit into the microtome was sectioned whole. If too large, the stomach block was cut into two pieces and sectioned in that condition. It was intended to study the stomachs in the stillborn also, but the material at hand at the time was unsatisfactory, but this will be taken up later.
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70. The sublenticular portion of the internal capsule and the thalamic radiation to the temporal lobe. S. W. Ranson, Northwestern University Medical School. In dissections of the internal capsule its sublenticular portion is seen to be
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composed of two strata. The upper stratum, immediately beneath the lentiform nucleus, is formed by the temporopontine tract. These fibers run directly lateralward into the temporal lobe. The lower stratum forms the roof of the inferior horn of the lateral ventricle and is composed for the most part of the temporothalamic fasciculus of Arnold. This bundle emerges from the thalamus near the external geniculate body, and forms a large strand directed forward in the roof of the inferior ventricular horn. A few at a time these fibers curve outward and then somewhat backward into the white matter of the temporal lobe. Another and smaller bundle of fibers can be traced from the stratum zonale in an arched course around the thalamus following the tail of the caudate nucleus. Passing through the sublenticular portion of the internal capsule, this fascicle flattens out in the roof of the inferior horn of the lateral ventricle under cover of the ependymal lining and can be traced forward to the anterior part of the temporal lobe. It lies on the ventricular surface of Arnold's bundle, and may be designated as the fasciculus thalamotemporalis arcuatus. It was seen by Probst ('05) in the brain of a monkey with an experimental lesion in the thalamus and by the same observer in the brains of microcephalic idiots.
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71. The so-called hibernating gland. A. T. Rasmtjssen, University of Minnesota. For this structure many other names have been proposed : adipose gland, lipoid
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gland, cholesterin gland, brown fat, organ of hibernation, hibernating mass. From about fifty papers available, its history consists of four periods. I. 1670 to 1817, during which it was generally regarded as part of the thymus. II. 1817 to 1863, during which it was generally recognized as distinct from the thj'mus, but still as a haemopoietic gland. III. Since 1863 it has generally been classed as a form of adipose tissue which serves as reserved food. IV. Its internal secretory character has been emphasized during the last ten years and recently ('20) as a factor in the etiology of deficiency diseases. From the reports of others on over forty species of animals and personal examination of numerous marmots (in which this structure is prominent), it is clear that histologically there is no similarity between it and the thymus. There is no evidence of any haemopoietic function. It is also different fron ordinary adipose tissue. The cells are rarely if ever unilocular. The nucleus is never flattened much. It never loses all its fat. During hibernation it supplies only about one-thirtieth of the material consumed, and hence, as far as bulk is concerned, is not an important
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PROCEEDINGS 79
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food reserve. While the cytoi)lasm of the cells is rich in small granules (in addition to the fat globules) and the organ surprisingly vascular, more careful cytological and physiological work must be done before its close relation to the suprarenal cortex, corpus luteum, or other ductless glands can be affirmed.
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72. On the growth in weight of the human body and its various parts and organs in the fetal period and its expression by empirical formulae. Richard E. Scammon, University of Minnesota.
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The growth in weight of the entire body in the fetal period presents, when plotted against total body length, a concave curve which may be expressed by the empirical formula, Y = (aX), when Y is the weight of the body in grams, X is the total body length in cm., and a and b are empirically determined constants. The absolute weights of the trunk, the extrernities, and the head also follow this course of growth and may be expressed by the same formula with modified constants. This form of growth is typical of almost all the organs of the body — certainly of the heart, kidneys, spleen, thymus, liver, stomach, pancreas, suprarenals, thyroid, eyeballs, brain, and spinal cord and, in all probability, of the lungs, testes, and uterus as well. The growth of these structures may be expressed by formulae of the same general form as that of body weight, although each appears as a minor variant of the common type. So far no evidence has been found of a grouping of these prenatal curves in categories comparable with the main classes of postnatal growth curves. Similar findings regarding the type of growth of the body and its pacts and organs are obtained when weight is plotted against age in fetal months.
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73. The visual pathway and the paranasal sinuses. J. Paesons Schaeffer, Jefferson Medical College.
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Recent clinical reports prompted me to undertake a more detailed study of the anatomic relationships between certain portions of the visual pathway and the paranasal sinuses than hitherto attempted in my work. An anatomic basis was sought for certain clinical manifestations. Some were cleared up, others remain obscure and require further study. It is well to recall that the optic nerve, the optic commissure, and the optic tract are formed in order by the same axones with cell bodies located in the retina and that, strictly speaking, one is dealing with a partially decussated brain tract, the fibers of which are medullatcd in the retro-ocular portion, but lack a neurolemma. Clinical findings arc in accord with this. The portions of the visual pathway that particularly concern us here are the so-called optic nerve and the optic commissure. The great variations in size, shape, number, and type, and the variations in symmetry and asymmetry of the paranasal sinuses preclude any constancy in the topographic relat ionships with the optic nerve and the optic commissure. The sphenoidal sinuses and the posterior ethmoidal cells are of first importance in this connection; however, the other sinuses may be a factor. Very, commonly the most intimate relationships exist.
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Clinically it has been found that paranasal-sinus disease may give rise to ocular complications without external signs of orbital inflammation. Optic neuritis, neuroretinitis, phlebitis, etc., are encountered. More important, since it often occurs with but slight ophthalmoscopic change, is the occurrence of a central
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80 AMERICAN ASSOCIATION OF ANATOMISTS
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scotoma. The scotoma may be unilateral or bilateral, the latter despite the fact that but one side may be affected. The above conditions may rapidly advance to a state of blindness. It is surprising, however, how rapidly these conditions clear up, even the blindness, if the optic manifestations are early recognized and paranasal-sinus treatment properly and efficiently carried out. Want of such recognition and treatment early means permanent blindness from optic-nerve atrophy. Here an appreciation of the topographic anatomy of the optic pathway and the paranasal sinuses is of the greatest importance to those dealing with the eye and the nose clinically. Apropos in this connection is the report of a prominent ophthalmologist who in consultation found a patient totally and permanently blinded by an ill-advised curettage of the sphenoidal sinus, resulting in complete destruction of the optic chiasm. The underlying anatomy of the foregoing clinical findings will be discussed. Lantern.
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74. Relation of nutrition to the oesirous cycle. Katharine J. Scott and Herbert
 +
 +
M. Evans, University of California.
 +
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In the study of the oestrous cycles of several hundred rats. Long and Evans reported a very considerable variation in cycle length, although in over 80 per cent of some 2000 observations, cycles of six days or less were found. These observers had had occasion to note the immediate impairment of ovarian function by increased cycle length whenever experimental animals were submitted to one or more days of undernutrition. Papanicolaou and Stockard have now established similar facts on the delay of the next oestrous of guinea-pigs due to undernutrition. The suggestion was near at hand and was, in fact, made by the lastmentioned workers that the considerable variation in the length of the oestrous cycles observed in our colony of rats might be referable to chance nutritive deficiencies unintentionally and inevitably introduced by feeding table scraps. We have submitted this question to test by placing some twenty-one animals upon our usual 'table-scrap' rations and twenty-one litter mates upon a diet employed by McCollum and certified to have yielded excellent growth and reproduction in this species over a number of yearrs. The McCollum diet consists of:
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grams
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Wheat (whole) 67.5
 +
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Casein 15.0
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Whole-milk powder 10.0
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Sodium chloride 1.0
 +
 +
Calcium carbonate 1.5
 +
 +
Butter fat 5.0
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 +
The animals at all times had access to an abundance of the food and of fresh water. At the beginning of the observations all of the animals were about 100 days old and the observations to date have extended over fifty days, opportunity being thus afforded for the observation of ten or more normal oestrous cycles. During this period the rats on the standard ration made an average gain in weight of 49 grams; those on the table-scrap diet, a gain of 42 grams. The average length of all cycles observed in animals on either ration was the same and was almost exactly five days. In the case of both diets about half the animals exhibited an uninterrupted series of oestrous cycles of six days or less in length and in each group of twenty-one animals three or four individuals showed more marked
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PROCEEDINGS 81
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irregularity. Furthermore, two other larger groups of animals composed of ninety-five and seventy individuals, respectively, and of almost identical age but not litter mates were placed, the one on the standard ration, the other on table scraps, and a similar study of their oestrous cycles instituted. The data obtained w^ere concordant with the above. It cannot be considered, therefore that the irregularity which may be observed in the lengths of the oestrous cycle.s of young adult rats is always due to nutritive deficiency. We would not by this statement mean to deny the great importance of nutrition in maintainingthe oestrous rhythm. Studies of the effect on the oestrous rhythm of experimental undernutrition both qualitative and quantitative are under way.
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75. The develoj)ment of the pharynx, and the histology of its adult derivatives, in turtles. Ralph F. Shaner, Harvard Medical School.
 +
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The pharynx of Chrysemys marginata develops five pouches. The last pouch, with the postbranchial body, arises from a common stem. There are six aortic arches and five nerve placodes. The second, third, and fourth pouches end secondarily in a common cervical sinus. The first three pouches have patent clefts. From the first pouch develops the auditory tube and the tympanicmastoid cavity. The second bears a dorsal knob of doubtful significance, which vanishes with it. The third and fourth develop persisting dorsal and ventral outgrowths. The fifth develops a transient dorsal (thymic) rudiment and then disappears; the postbranchial is then attached to the fourth pouch. The thyroid gland develops entirely from a median ventral diverticulum. The dorsal and ventral outgrowths of the third pouch separate off as a single independeni complex closely adherent to the carotid artery. The dorsal moiety becomes a large, lobulated, persistent, anterior thymus; the ventral one is transformed into an anterior parathyreoid, which is enclosed within the adult anterior thymus. The two outgrowths of the fourth pouch and the postbranchial body separate off as another independent complex, closely adherent to the systemic arch. The dorsal outgrowth persists as a variable posterior thymus ; the ventral as a large posterior parathyreoid. The postbranchial body develops chiefly on the left side ; it breaks up into numerous secretory vesicles. The three organs constitute the tiny aortic body, w^hich appears in the adult, attached to the aorta. The lobules of each thymus are divided into cortex and medulla, the latter containing thymic corpuscles. Each parathyreoid is made up of cords of epithelial cells, surrounded by vascular sinusoids. The postbranchial vesicles are of two t3'pes and contain a definite secretion.
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76. The presence of a head cavity in a human embryo of 4 inm- Joseph L. Shellshear (introduced by G. L. Streeter).
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The cavity is situated immediately posterior to the otic vesicle and mesial to the glossopharyngeal complex, and probably corresponds to Van Wijhe's 1st post-otic segment. Spindle-shaped cells arising from it are continuous with a clump of cells of a similar character situated mesial to the vagus complex. From this latter group of cells a migration is taking place which passes posterior to the vagus apparatus and is interpreted as the migration of the hypoglossal musculature.
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82 AMERICAN ASSOCIATION OF ANATOMISTS
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The cavity is regarded as homologous with the head cavities which give rise to the eye musculature. This type of cavity is peculiar to the median somatic or axial mesoderm and distinct from the coelom which is formed by a splitting of the lateral somatic mesoderm.
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n. On the reaction of the living blood cells to dyes. M. E. Simpson (introduced by
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H. M. Evans), University of California.
 +
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A drop of blood was caught on a cover and immediately brought in contact with a slide on which was a thin, dry film of dye. The method has been previously employed by Pappenheim, Rosin, and Bibergeil. Somewhat less than two hundred dye substances were carefully studied. The following generalizations may be made:
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1. The dyes frequently collect in a definite set of granules, 'the segregation apparatus,' which can be differentiated from, 1) refractile granules (probably lipoid); 2) degeneration vacuoles; 3) specific granules, and, 4) mitochondria.
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2. With some dyes a certain proportion of the granules enlarge rapidly, the vacuolar structures resulting therefrom having been described by Ferrata and termed 'plasmasomes.' But Arnold has used this term much more widely. Rosin and Bibergiel called them 'dye sphere formations.' They evidently correspond to what Renaut termed 'grains de segregation' in the connective-tissue cells. Dubrueil called them ' vacuoles a grains de segregation ; ' Hammar referred to them as 'purpurgranula,' whereas Evans and Scott, in their study of the reaction of connective tissues to vital stains, described the same .system of structures as 'the vacuolar apparatus.'
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The segregation apparatus may be considered as a reaction on the part of the living cell for the purpose of segregating and isolating various foreign materials forced upon it. The ability to thus segregate dyes is common to all the white cells of the blood, but the extent of the segregation apparatus is characteristic for each cell type and may be used as a valuable point of distinction between the different kinds of mononuclear cells. The transitionals of Ehrlich or monocytes of Naegeli show the reaction to the greatest degree. Probably all dye groups contain members which would be handled in this way by the cell. The reaction is perhaps given most typically by certain of the oxazine, thiazine and azine dyes, but dyes showing the widest variation in chemical and physical properties appear to give this response.
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78. The ingestion of melanin pigment granules by tissue culture cells grown from the embryo chick in Locke-Leins solution. David T. Smith (introduced by W. H. Lewis), Carnegie Laboratory of Embryology.
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In cultures of chick embryos, melanin pigment granules from the retina of the chick, pig, dog, and man (newborn child) were taken in by clasmatocytes, fibroblasts, endothelial cells, white blood cells, and cells from lung, liver, kidney, intestine, and amnion by a process which appears quite different from that by which the amoeba ingest food. Peripheral nerve cells, striated muscle cells, and red blood cells did not ingest the granules. When a granule was free in the culture fluid it exhibited both Brownian movement and an actual progression from place to place; when attached to the cell wall it was motionless; after passing into the cytoplasm it displayed the jerky motion characteristic of pigment
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PROCEEDINGS 83
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granules in the true pigment cells, and finally, when a vacuole developed about a granule it reverted to Brownian motion. The granules were not taken into preformed vacuoles; but later, as they moved back and forth in the cytoplasm, a vacuole developed about each one or about each small clump of granules. The granules then exhibited Brownian movement, became swollen, disintegrated, and were reduced to debris.
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Granules in the true pigment-producing cells are always individual and discrete bodies of about the same size and shape. The individuality and discreteness are common properties, but size and shape vary in cells of different origins. The granules in normal pigmented cells are never found clumped into vacuoles or broken up into debris. It can therefore be determined by the appearance of the granules whether they have been produced or ingested by the cell. This fact should help us to settle the old question of pigment-producing versus pigment-carrying cells.
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79. Some modifications induced by parabiotic union of the hypophysectomized to the normal tadpole. Philip E. Smith, University of California. It appears of interest to determine whether the disturbances resulting from early hypophysectomy in the tadpole may be modified by a vascular interchange between the normal and the pituitaryless individuals, and to observe any compensatory alterations that may occur in the normal member of the pair. Hypophysectomized individuals were united at an early stage (5 mm.) to normal larvae. Both members of four pairs completed metamorphosis, and several pairs reached a nearly maximal larval size. In every case the pigmentary and endocrine disturbances typical of hypophysectomy were modified. Albinism, though evident, was only partial. Examination of the living animal and of cutaneous whole mounts revealed the fact that the xantholeucophores were not as broadly expanded, the epidermal melanophores not as scanty in number, as poor in melanin content, nor as contracted as in the typical hypophysis-free tadpole. The thyroids of the albinous member, instead of being diminutive, as would otherwise have been the case, were nearly normal in size, while those of the normal mate exhibited a slight hypertrophy. The adrenal cortex while reduced did not appear to suffer the same great reduction as that which normally occurs in the typical Albino. The vascular interchange did not modify the greatly reduced and atypical neural lobe of the Albino, nor did it appear to have caused an hypertrophy of the hypophysis of the normal member of the pair.
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80. Upon the essentiality of the buccal component of the hypophysis for the continuance of life. Philip E. Smith, University of California. The above-mentioned parabiotic pairs were united in several ways, one of which, a union of the corresponding sides of the tail-stalks, is of especial interest here. Two such pairs completed metamorphosis. It is obvious that the attachments would be severed by metamorphosis. One pair completely separated; in the other an atrophic connecting strand persisted. Both members of each pair displayed the usual activity up to three or four days prior to the completion of metamorphosis. The hypophysectomized members then became more sluggish and exhibited a slowed respiration. One of them died just after the separation, the other just before the separation would have taken place. The separation
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84 AMERICAN ASSOCIATION OF ANATOMISTS
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in no way embarrassed the normal member of either pair. These members displayed their usual activity. In two other pairs joined by their heads, metamorphosis did not result in the death of the hypophysectomized specimen, probable due to the persistence of the vascular interchange.
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Mammalian experimentation appears to have established the fact that the neural lobe is not essential to life. The essentiality of the anterior lobe has been questioned, death from its removal being referred by some to injury of the neighboring structures, not to hypophysial deficiency. In this experiment there was no injury to the brain or other neighboring structures, yet the animals promptly died when, in the adult stage, they were deprived of the secretion of the buccal hypophysis. The functional similarity which experimental work has shown to exist between the parts of the amphibian and mammalian hypophyses makes it highly probable that this component is essential for life in the mammal as well.
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81. Does the administration of anterior lobe to the tadpole produce an effect similar to that obtained from thyroid feeding? Philip E. Smith and Garnett Cheney, University of California.
 +
 +
In a recent paper Hoskins and Hoskins have advanced evidence showing that the administration of a commercial anterior-lobe preparation to the normal and thyroidless tadpole gives an effect similar to that which is characteristic for thyroid administration, i.e., causes metamorphosis. This evidence would indicate that the anterior lobe and the thyroid are in this respect functionally similar, and so supports the hypothesis that they may function vicariously. These results are at variance with those obtained by fresh anterior-lobe feeding. We have found that the feeding of the particular commercial preparation used by the Hoskinses gives the results obtained by them. Two other commercial preparations, the dried gland prepared in this laboratory and the fresh gland, failed to give similar effects. Analysis by Doctor Kendall showed that this commercial preparation contained iodine greatly in excess of the norm- 1 amount.
 +
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Iodine as KI was added to the dried gland prepared in this laboratory in a sufficient amount to give an iodine content identical with this commercial product. Tadpoles receiving this substance did not exhibit a decisive acceleration of metamorphosis. In another case iodine as thyroxin iodine was added in identical amounts. Normal and thyroidless tadpoles receiving this substance paralleled in development the animals fed with the commercial preparation in question. The evidence indicates that a similarity of response is not evoked by thyroid and hypophysial administration. The anterior-lobe preparation used by the Hoskinses contained an unusual amount of iodine and displayed an altogether unique activity.
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82. On the presence of longitudinal collector nerves in the tail of the skate and dogfish. Carl Casket Speidel, University of Virginia.
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In the tail of the skate there are present four longitudinal collecting nerve trunks. These extend throughout the tail, but are not present in the body proper. They are located two on each side of the vertebral column, close to the bodies of the vertebrae. The dorsal collector on each side is opposite the junction of the neural arch and centrum of each vertebra. The ventral collector on each side is opposite the junction of the haemal arch and centrum of each vertebra.
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PROCEEDINGS 85
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These collectors are fed regularly by the spinal nerves according to thefollowing system: the ventral root from the spinal cord unites with the dorsal root emerging from the succeeding intervertebral foramen. From this junction emerge two rami, one of which connects with the dorsal collector, the other with the ventral collector. Branches to the muscles and electric organs are given off from these rami. No branches were found from the collectors to the electric organs. Small branches from the collecting trunks to the blood-vessels led to the supposition that they might represent a sort of primitive sympathetic system, a forerunner of the sympathetic system of higher vertebrates. Osmic-acid preparations, however, showed no non-medullated fibers. All the nerve fibers were meduUated. Similar collecting nerve trunks have been found in the tail of the dogfish and shark, although the connections with the spinal nerves w^ere somewhat different.
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83. Comparative study of large irregular cells in the spinal cord of other fishes homologous to the giant glandular cells in the spinal cord of the skates. Carl Caskey Speidel, University of Virginia.
 +
 +
In the caudal portion of the spinal cord of the skate there are present large irregular cells of glandular character. Cells homologous to these have been found in more than thirty genera of fishes. These include both fresh- and saltwater forms, and represent the elasmobranch, teleost, and ganoid fishes. In three genera of fishes the cells were not found. In most of the forms the cells are neither so conspicuous nor so active as in the skate. Granular secretion is usually scanty or lacking. A form of special interest is the summer flounder in which the cells are extraordinarily large and numerous. This unusual type of cell, then, may be said to occur in the great majority of fishes, reaching its greatest degree of development in the skate and flounder. A doubtful homologous cell has been found in the ventral nerve cord of the lobster, but not in the horseshoe crab. In none of the vertebrates higher than fishes have the cells been found.
 +
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84. Experiments on the development of the cranial ganglion and the lateral-line sense organs in Amblystoma. L. S. Stone (introduced by R. G. Harrison), Yale University.
 +
 +
These experiments involve the removal of placodes and neural-crest cells. In normal development the crest cells migrate ventrally over the mesoderm of the visceral arches, around which they w^rap themselves, and finally become situated on their median surfaces, where they form the visceral skeleton. The appearance of a few mesodermal yolk granules among the crest-cell aggregations gives one the impression that there may be a slight mesodermal contribution to the visceral skeleton. When the crest cells are removed, a few cases show an incomplete formation of the visceral skeleton, but no defects in'the ganglionic components are observed due either to the fact that they may take no part in the formation of the ganglia or to the difficulty in eliminating the crest cells on account of their persistent ability to regenerate. All groups of lateral-line organs have separate primordia, except possibly the maxillary group, which may be a branch of the ventral hyomandibular. When sheets of ectoderm, taken anterior and posterior to the position of the ear, are removed at the closure of the neural folds, the body lines, occipital and supra-orbital primordia and their corresponding
 +
 +
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86 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
lateral line ganglia are absent. Removal of the epibranchial placodes of VII, IX, and X produces small ganglia apparently lacking visceral sensory and cutaneous components. Placodes of vagus and facial lateral-line ganglia interchanged produce in their new positions irregular groups of many sense organs innervated by fibers from lateral-line ganglia in the transplanted region.
 +
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85. A icell-preserved human embryo of the presomite period. George L. Streeter, Department of Embryology, Carnegie Institute of Washington.
 +
 +
Lantern slides will be shown of a young human embryo which was found at autopsy by Dr. H. G. Weiskotten, of Syracuse University. The patient, twenty years old, having skipped one menstrual period, died after an extensive pelvic retroperitoneal hemorrhage, presumably originating from an attempt to induce an abortion. The embedded ovum was found in the fundus of the uterus, and, together with the adjacent portion of the uterine wall, was placed in 10 per cent formalin seven and one-quarter hours after the death of the patient. Due to the handling of the specimen during its removal, the ovum and its decidual capsule were partially loosened from the implantation site and apparently flattened, but otherwise the specimen appears to be normal and in an excellent state of preservation. The external diameters of the decidual capsule are 16 X 12 X 5.3 mm. The diameters of the chorionic cavity are 9 X 7.3 X 2 mm. The embryo, i.e., the yolk'-sac and amniotic vesicle combined, measures 2.2 X 2.1 X 1.2 mm. The greatest width of the embryonic shield is slightly less than 1 mm. On account of its being bent upon itself, the length cannot as yet be accurately stated. The general form of the embryo and the character of the chorionic villi will be shown in the slides.
 +
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86. The order, lime, and rate of ossification of the skeleton. II. Mammals. R. M. Strong, Loyola University School of Medicine.
 +
 +
The white rat has been the type used for most of the mammalian portion of this work to date. The results contain too manj' details for the space allowed in an abstract. Some of them are mentioned here: A series of features of the skull, girdles, and long bones have been studied. Stages from the first appearance of ossification to senility (730 days) have been compared.
 +
 +
As in the bird, beginning ossification occurs in several bones at about the same time. The first ossification stages occur fully a week later in rat embryos than in the chick. At seventeen days and fifty-five minutes after insemination, ossification was found well started in the mandible, clavicles, and in the second to eleventh ribs. It had also begun in the maxilla, palatine, premaxilla, orbital portion of the frontal, humerus, radius, and ulna. The scapula showed ossification at seventeen days and eight and one-fourth hours. This had extended to a large portion of the spine several hours later. An ossification center was found in the coracoid process at three days after birth, and fusion with the scapula early in the fourth month. Ossification centers appear in the ilium, femur, tibia, and fibula at eighteen days nine and a half hours. They appear in the ischium and pubis at nineteen days eight and three-fourths hours. In the same embryo, the deltoid crest is well started, and it resembles the adult form a day later. Except for changes in size and general form, the rat skeleton is essentially mature at the end of the first year. Only slight stages take place after the third month.
 +
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PROCEEDINGS 87
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87. Situs hivcrsns in dxmhlc (rout. F. H. Swett, Yale University. Examination has been made of the situs viscerum in fifteen douhie trout embryos and the findings resolve themselves into the following classes : In nine cases the situs viscerum of both components is normal; in one, that of A (the right twin) is reversed; in two, B (the left twin) is reversed, and in three B is normal, A of indeterminate situs. One of the cases which shows situs inversus in component B is of the auto site-parasite type and it is the parasite which is reversed. A definite correlation between the amount of external or internal doubling and the occurrence of situs inversus cannot be demonstrated.
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88. The relation of the pars intermedia of the hypophysis and the pineal gland to pigmentation changes in anuran larvae. W. W. Swingle (introduced by R. G. Harrison), Yale University.
 +
 +
Homoplastic and heteroplastic transplants of the pars intermedia of the hypophysis from adult frogs of the species Rana catesbeiana, Rana climitans, and Rana pipiens were made into bullfrog tadpoles of various ages and sizes. The effect upon growth and metamorphosis of the animals w^as negative, but pigmentation changes following transplantation of the tissue were very marked. Within twenty-four hours after engrafting the pars intermedia either intraperitoneally or into the abdominal lymph spaces the larvae became deeply pigmented, changing color from a light yellow to almost black. The color change is due to marked expansion of the melanophores of the skin, though the deeper-lying pigment cells of the tadpole also expand. The increased pigmentation lasts as long as the engrafted pituitary tissue remains functional and is not resorbed. Following resorption of the graft, the animals resume normal coloration. The environment apparently plays no part in the color change following transplantation of the pars intermedia; the change is due to the stimulating effect of the hormone either directly upon the melanophores or else indirectlj- through the intermediation of the nervous sj^stem.
 +
 +
There is a possible interrelationship of the pars intermedia to the pineal gland in the production of pigmentation changes in anuran larvae. Darklj' pigmented tadpoles engrafted with the pineal gland of reptiles (Chelonia) change color within an hour following transplantation; the expanded melanophores contract and the animals become lightly pigmented. This condition persists for several hours; then slowlj^ normal pigmentation is resumed. Similar changes follow introduction of desiccated mammalian pineal tissue into body cavity.
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89. Mammalian pubic metamorphosis. (Stereo-lantern.) T. Wixgate Todd, Western Reserve University.
 +
 +
In comparing skeletal growth and metamorphosis of man with similar features in other mammals, it is necessary to utilize some standard subdivision of the total life period. In our present work the best subdivision is the following:
 +
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1st life period. Terminates in complete union of the acetabular elements.
 +
 +
2nd life period. Terminates in complete union of epiphj^ses with long bones.
 +
 +
3rd life period. Terminates in complete union of epiphyses with vertebral centra.
 +
 +
4th life period. Between the termination of the 3rd and the commencement of the 5th period.
 +
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88 AMEKICAN ASSOCIATION 'OF ANATOMISTS
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5th life period. Commences with lipping of the glenoid margins of the scapulae.
 +
 +
6th life period. Commencement of senile (quasipathological) erosions and osteophytic growths at joints, and senile textures of bones.
 +
 +
These features, unlike eruption of teeth, closure of cranial sutures and others not here mentioned, present definite relationships to the total life period. Compared with each other they do not represent even approximately equal time relationships. Judged by these standards, it is possible to observe the delay in commencement and still more in completion of pubic metamorphosis as evidenced by higher mammals and by man. At the same time the gradual evolution of the features of this metamorphosis can be studied. Its progressive features are exemplified in members of some orders, other members of which show retrograde conditions. Man falls into the latter group.
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90. The skull as a closed box. Lewis H. Weed and Walter Hughson, Johns
 +
 +
Hopkins Medical School.
 +
 +
The experiments of Weed and McKibben, reported two years ago, demonstrated that the pressure of the cerebrospinal fluid may be markedly lowered and frequently reduced to negative values by appropriate intravenous injections of strongly hypertonic solutions. These findings suggested that the cerebrospinal axis was enclosed within a rigid system, but absolute proof of the 'closed-box' character of the coverings was lacking. Experiments recently performed indicate that if the bony calvarium on one side be removed without opening the dura mater and if the pressure of the cerebrospinal fluid be taken, repeated intravenous injections of strongly hypertonic solutions fail to reduce the pressure to below zero. Likewise, if the bony calvarium on one side be opened and then temporarily sealed, appropriate intravenous injections of the hypertonic solutions will reduce the pressure of the cerebrospinal fluid to negative readings. Under these circumstances, opening the cranial cavity by removal of the sealing device will cause the pressure of the fluid to become immediately positive, the level of the positive pressure being determined by the hydrostatic height of the brain above the needle. These experiments can be explained only upon the hypothesis that within minimal limits the cranium and vertebral canal form a closed system within which lies the central nervous system.
 +
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DEMONSTRATIONS
 +
 +
/. The motor cortex of the brain of the sheep. Charles Bagley, Jr., Johns Hopkins University.
 +
 +
2. The development of connective tissue. George A. Baitsell, Yale University.
 +
 +
3. a — De-electrification of paraffin ribbon, b — Differential bone stains for macroscopic transparent preparations. O. V. Batson, University of Wisconsin.
 +
 +
4. Injection of blood vessels of the lung of the chick during third day of incubation to show the origin of pulmonary veins. Charles E. Buell, Jr. (introduced by Florence R. Sabin), Johns Hopkins Medical School.
 +
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5. Plates of a radiographic atlas of anatomy. H. S. Burr, Yale University, School of Medicine.
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PROCEEDINGS 89
 +
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6. Model of the principal fiber tracts of the central nervous STjstem. J. L. JackowiTZ (introduced by H. S. Burr), Yale University, School of Medicine.
 +
 +
7. Microscopic slides, drawings and graphs illustrating bone, muscle and joint origin in the thigh of the pig (Sus scrofa). Eben J. Carey, Marquette School of Medicine.
 +
 +
8. Sections illustrating the effect of stress and strain upon the healing of bone injuries. Eliot R. Clark and Ralph R. Wilsox, University of Missouri.
 +
 +
9. Digestion of different proteins by the mesenchijme and its derivatives in the tadpole. Vera Danchakoff, Columbia University.
 +
 +
10. Various techniques used in scientiHc illustration. Erwin F. Faber, University of Pennsylvania.
 +
 +
11. Preparations showing the absorption and assimilation of fat. Simon H. Gage, Cornell University.
 +
 +
12. A case of hermaphroditism in the pig. Harley N. Gould, Lake Forest College.
 +
 +
13. a — Thyreo-parathyroidectomised and parathyroidectomised albino rats, b — Effects of removal of the thyroid apparatus on bone growth of albino rate, c — Malformation of the femur and humerus accompanying abdominal tumor in a female albino rat. Frederick S. Ham.mett, The Wistar Institute.
 +
 +
14. Injected pig embryos cleared by the Spalteholz method to show the development of the innominate artery. Chester H. Heuser, Johns Hopkins Medical School.
 +
 +
15. Demonstration of the value of x-ray in anatomical teaching and research. Ebex C. Hill, Johns Hopkins Medical School.
 +
 +
16. Regenerative processes in the spinal cord of frog larvae severed previous to metamorphosis. Davenport Hooker, University of Pittsburgh.
 +
 +
17. Section cutting of the dental tissues by means of the ether-vaporizing microtome. A. Hopewell-Smith, University of Pennsylvania.
 +
 +
18. Stereoscopic photographs of human embryos. N. Williams Ingalls, School of Medicine, Western Reserve University.
 +
 +
19. Sections of chick embrijos showing ganglia of the sijmpathetic trunks derived from cells which advanced peripherally along the fibers of the ventral nerve-roots in segments in which the spinal ganglia and dorsal nerve-roots are absent. Albert KuNTz, St. Louis University.
 +
 +
20. A method for preserving cadavers in the dissecting-room. Frederic P. Lord, Dartmouth Medical School.
 +
 +
21. Histological preparations showing various stages in lactation and subsequent involution of the mammary gland in the albino rat. L. I\L A. ]\L\eder (introduced by C. M. Jackson), University of Minnesota.
 +
 +
22. Microscopic sections showing functional variations in normal human mammary glands. Joseph McFarland, University of Pennsylvania.
 +
 +
23. Cleared preparations illustrating the involution of the mammary gland in the female albino rat. Frank J. Myers (introduced by J. A. Myers), University of Minnesota.
 +
 +
24. a — A graph illustrating simple formulae for correlating crown-heel and crownrump length in fetal life, b— Material illustrating the developmental topography of the thymus with particular reference to the changes at birth and in the neonatal period. Gtjstave J. Noback, University of Minnesota.
 +
 +
25. a — Wax reconstruction of the nuclear masses in the brain stem of a sheep. James W. Papez, Cornell University.
 +
 +
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90 AMERICAN ASSOCIATION OF ANATOMISTS
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 +
^^_ 5 — ]Yax reconstruction of the olivary nuclei of the sheep, rabbit, dog and bear.
 +
 +
James W. Papez. Cornell University.
 +
 +
The inferior olivary nucleus of the rabbit, sheep, dog and bear is divisible into the dorsal, ventral and intermediate olivary nuclei and the olivary sac. The dorsal nucleus is an oval plate that lies dorsal to the sac and is secondarily separated from its dorsal lip. The ventral nucleus is a thick oval plate that extends the entire length and with the intermediate nucleus forms the caudal end of the olivary complex. Orally its medial margin is secondarily separated from the ventral lip of the sac. The intermediate nucleus is formed of three parts; the paramedian plate at the caudal end of the complex united with the ventral nucleus, the intermediate plate extending laterally to the caudal end of the ventral lip of the sac, and the olivary bridge extending from the paramedian plate laterally to join the narrow caudal ends of the dorsal nucleus and sac. The olivary sac is a simple oval sac, compressed dorsoventrally with its opening towards the mid line. The sac is situated in the oral portion of the olivary complex where it intervenes between the dorsal and ventral nuclei. The hypoglossus nerve perforates the dorsal nucleus and lateral end of bridge and in the rabbit also the sac. The larger oral portion of the olivary nucleus appears to have been rotated laterally in the expanded portion of the bulb while the caudal portion has retained a more fixed position oral to the decussation of the cerebrospinal tracts.
 +
 +
27. Materials in a case of multiple atresia of the jejunum of a young child suggesting etiological factors. C. W. M. Poynter, University of Nebraska Medical College.
 +
 +
28. a — Field graphs, curves and charts illustrating the growth of the various external dimensions of the human body in the fetal period. L. A. Calkins (introduced by R. E. Scammon), University of Minnesota.
 +
 +
29. b — Material illustrating the growth of the brain and its parts and of the spinal cord in the fetal period of man. H. L. Dunn (introduced by R. E. Scammon), University of Minnesota.
 +
 +
30. c — Graphs and charts illustrating the growth in weight of the body as a whole and its various parts and organs in the fetal period of man. R. E. Scammon, University of Minnesota.
 +
 +
31. Histological preparations of experimentally doubly-ligated blood vessels, showing the fate of the contained blood and the behavior of the intima. J. Parsons Schaeffer and H. E. Radasch, Jefferson Medical College.
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32. A series of graphs illustrating the changes in the form of the thorax at birth and in the neonatal period. Richard E. Scammon amd William E. Rucker, University of Minnesota.
 +
 +
'These graphs are based upon measurements of the chest in fetuses, full-term children and a series of infants less than two weeks old. The horizontal chest circumference is greatly increased with the first inspiration, but in the course of the first 24 hours enters a period of decrease which continues for three or four days. Following this is a second phase of circumference gain which continues throughout the remainder of the period of observation. The diameters of the thorax undergo changes similar to those of the chest circumference. The thoracic index stands below 90 in the latter part of the fetal period, but it rises to an average of about 106 with the establishment of respiration, and then drops
 +
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PROCEEDINGS 91
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to about 102 in the first 24 hours. Thereafter it declines irregularly to about 100.5 in the middle of the second postnatal week.
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 +
35. Cinematotnicography of serial sections. W. F. Schreiber, Stacy R. Guild, and L. G. Herrmann, Anatomical Laboratory, University of Michigan.
 +
 +
34. Histological preparations showing the effects of inanition upon the development
 +
 +
and structure of the testis in the albino rat. David M. Siperstein (introduced
 +
 +
by C. M. Jackson), University of Minnesota. 85. Model illustrating the effect on the growth of the sacrum following early removal
 +
 +
of the posterior limb-bud in chick embryos. R. G. Spurling (introduced by E.
 +
 +
R. Clark), University of Missouri.
 +
 +
36. Charts showing the weight of the ovaries during the reproductive cycle in albino rats, a — During gestation; b — During normal la<:tation; c — In females deprived of their litter at birth. J. M. Stotsenburg, The Wistar Institute.
 +
 +
37. Unique case of ectopic pregnancy. G. L. Streeter, Carnegie Laboratory of Embryology.
 +
 +
A chorionic sac containing a normal human embryo of about eight weeks development which was obtained by operation from the subcutaneous tissue superficial to the rectus mijscle midway between the umbilicus and the pubis.
 +
 +
38. Cleared embryos and postembryonic stages. R. M. Strong, Loyola University School of Medicine.
 +
 +
39. Free costal bars of the epistropheus of an adult man. Paul K. Webb (introduced by R. J. Terry), Washington University School of [Medicine.
 +
 +
This rare variation is interpreted as further evidence of the tendency to reduction and special modification of the vertebrae at the cranial end of the column.
 +
 +
40. Anomalous right subclavian artery in man. William A. Hudson (introduced by R. J. Terry), Washington University School of Medicine.
 +
 +
The relation of this variant to the oesophagus and the presence of an 'aneurysmal' swelling at its origin have been regarded as possibly causing dysphagia in the subject; it is suggested that the pressure of the anomalous vessel upon the thoracic duct may be a factor in the incidence of slow starvation recorded in connection with this variation. Absence of a right recurrent nerve and origin of the inferior laryngeal directly from the vagus is of practical interest in the operations for goitre.
 +
 +
41. Chondrocranium of Caluromys philander. Wax plate model from a 17 mm. embryo. Walcott Denison and R. J. Terry, Washington University School of ^ledicine.
 +
 +
Of special interest are: the shallow pituitary fossa and rudimentary dorsum sellae; absence of a true optic foramen; high degree of independence of the nasal capsules; presence of paired vomers; an unpaired nasal ossicle (os carunculae).
 +
 +
42. Vitally stained polymorphonuclear leucocytes in the placenta. George B. WiSLOCKi, Johns Hopkins Medical School.
 +
 +
 +
 +
CONSTITUTION Article 1
 +
 +
Section 1. The name of the Society shall be "The American Association of Anatomists."
 +
 +
Sec. 2. The purpose of the Association shall be the advancement of anatomical science.
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Article 11
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 +
Section 1. The officers of the Association shall consist of a President, a Vice-President, and a Secretary, who shall also act as Treasurer. The President and the Vice-President shall be elected for two years, the Secretary for four years. In case of absence of the President and Vice-President, the senior member of the Executive Committee shall preside. The election of all the officers shall be by ballot at the annual meeting of the Association and their official term shall commence with the close of the annual meeting.
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Sec. 2. At the annual meeting next preceding an election, the President shall name a nominating committee of three members. This committee shall make its nominations to the Secretary not less than two months before the annual meeting at which the election is to take place. It shall be the duty of the Secretary to mail the list to all members of the Association at least one month before the annual meeting. Additional names for any office may be made in writing to the Secretary by anv five members at any time previous to balloting.
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Article 111
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 +
The management of the affairs of the Association shall be delegated to an Executive Committee, consisting of eleven members, including the officers. Two members of the Executive Committee shall be elected annually and, so far as possible, election of members of the Executive Committee shall be in proportion to the geographical distribution of members. Five shall constitute a quorum of the Executive Committee.
 +
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Article IV
 +
 +
The Association shall meet at least annually, the time and place to be determined by the Executive Committee. The annual meeting for the election of officers shall be the meeting of convocation week, or in case this is not held, the first meeting after the new year.
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Article V
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 +
Section 1. Candidates for membership must be persons engaged in the investigation of anatomical or cognate sciences, and shall be proposed in writing to the Executive Committee by two members, who shall accompany the recom 93
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94 AMERICAN ASSOCIATION OF ANATOMISTS
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 +
mendation by a list of the candidate's publications, together with references. Their election by the Executive Committee, to be effective, shall be ratified by the Association in open meeting.
 +
 +
Sec. 2. Honorary members may be elected from those who have distinguished themselves in anatomical research. Nominations by the Executive Committee must be unanimous and their proposal with a reason for recommendations shall be presented to the Association at an annual meeting, a three-fourths vote of members present being necessary for an election.
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 +
Article VI
 +
 +
The annual dues shall be seven dollars. A member in arrears for dues for two years shall be dropped by the Secretary at the next meeting of the Association, but may be reinstated at the discretion of the Executive Committee on payment of arrears.
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 +
Article Vll
 +
 +
Section 1. Twenty members shall constitute a quorum for the transaction of business.
 +
 +
Sec. 2. Any change in the constitution of the Association must be presented in writing at one annual meeting in order to receive consideration and be acted upon at the next annual meeting; due notice of the proposed change to be sent to each member at least one month in advance of the meeting at which such action is to be taken.
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 +
Sec. S. The ruling of the Chairman shall be in accordance with "Robert's Rules of Order."
 +
 +
The orders adopted by this Association, which read as follows, have not been altered:
 +
 +
Newly elected members must qualify by payment of dues for one year within thirty days after election.
 +
 +
The maximum limit of time for the reading of papers shall be fifteen niinutes.
 +
 +
The Secretary and Treasurer shall be allowed his tra\eling expenses and the sum of SIO toward the paj-ment of his hotel bill, at each session of the Association.
 +
 +
That the Association discontinue the separate publication of its proceedings and that the Anatomical Record be sent to each member of the Association, on payment of the Annual Dues, this journal to publish the proceedings of the Association.
 +
 +
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AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
OFFICERS AND LIST OF MEMBERS
 +
 +
Officers
 +
 +
President Charles F. W. McClure
 +
 +
Vice-President T. Wingate Todd
 +
 +
Secretary-Treasurer Charles R. Stockard
 +
 +
Executive Committee
 +
 +
For term expiring 1921 George S. Huntington, Harvey E. Jordan
 +
 +
For term expiring 1922 Charles W, M. Poynter, Herbert M. Evans
 +
 +
For term expiring 1923 G. Carl Huber, Lewis H. Weed
 +
 +
For term expiring 1924 S. Walter Ranson, Robert J. Terry
 +
 +
Delegate to the Council of A.A.A.S. Simon Henry Gage
 +
 +
Representative to the National Research Council Charles R. Stockard
 +
 +
Committee on Nominations for 1921 R. G. Harrison, Chairman, H, H. Donaldson and G. Carl Huber
 +
 +
Honorary Members
 +
 +
S. Ram6n y Cajal Madrid, Spain
 +
 +
John Cleland Cretvkerne, Somerset, England
 +
 +
Camillo Golgi Pavia, Italy
 +
 +
Oscar Hertwig Berlin, Germany
 +
 +
A. Nicolas Paris, France
 +
 +
L, Ranvier Paris, France
 +
 +
Wilhelm Roux Halle, Germany
 +
 +
Members
 +
 +
Abbott, Maude E., A.B., CM., M.D., Curator of the Medical Museum, McGill University, Montreal, Canada.
 +
 +
Addison, William Henry Fitzgerald, B.A., M.D., Professor of Normal Histology and Embryology, School of Medicine, University of Pennsylvania, Philadelphia, Pa.
 +
 +
Adelmann, Howard B., B.A., Assistant in Histology and Embryology, Cornell University, Stimson Hall, Ithaca, N. Y. 95
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96 AMEEICAN ASSOCIATION OF ANATOMISTS
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Alford, Leland Barton, A.B., M.D., Associate in Clinical Neurology, Washington University School of Medicine, Hiunboldt Building, St. Louis, Mo.
 +
 +
Allen, Bennet Mills, Ph.D., Professor of Zoology, University of Kansas, 1653 Indiana Street, Lawrence, Kans.
 +
 +
Allen, Edgar, Ph.B., A.M., Instructor in Anatomy, Washington University School of Medicine, 4555 McKinleij Avenue, St. Louis, Mo.
 +
 +
Allen, Ezra, A.M., Ph.D., Professor of Biology, Ursinus College, Collegeville, Pa.
 +
 +
Allen, William F., A.M., Ph.D., Professor of Anatomy, University of Oregon Medical School, Portland, Oregon.
 +
 +
Allis, Edward Phelps, Jr., M.D., LL.D., Palais de Carnoles, Menton (A.M.) France.
 +
 +
Appleby, J. I., A.B., M.D., St. Vincent's Hospital, Toledo, Ohio.
 +
 +
Arai, Hayato, M.D., Chief Gynecologist, Sapporo Hospital, Sapporo, Japan.
 +
 +
Arey, Leslie B., Ph.D., Professor of Microscopic Anatomy, Northwestern University Medical School, 2421 Dearborn Street, Chicago, III.
 +
 +
Atterbury, Ruth Rand, A.M., I40 Broadway, New York City.
 +
 +
Atwell, Wayne Jason, A.M., Ph.D., Professor of Anatomy, University of Buffalo Medical College, 24 High St., Buffalo, N. Y.
 +
 +
Badertscher, J.\cob a., Ph.M., Ph.D., Associate Professor of Anatomy, Indiana University School of Medicine, 312 South Fcss Avenue, Bloomington, Ind.
 +
 +
Bagley, Charles, Jr., M.D., Major M. C, 5 West Chase Street, Baltimore, Md.
 +
 +
Bailey, Percival, M.D., Ph.D., Assistant in Surgery, Peter Bent Brigham Hospital, 721 Huntington Ave., Boston, Mass.
 +
 +
Baitsell, George Alfred, M.A., Ph.D., Assistant Professor of Biology, Yale University, Osborne Zoological Laboratory, New Haven, Conn.
 +
 +
Baker, Wilmer, M.D., Assistant Professor of Anatomy, School of Medicine, Tulane University, New Orleans. La.
 +
 +
Baldwin, Wesley Manning, A.M., M.D., Professor of Anatomy, Albany Medical College, Albany, N . Y .
 +
 +
Bardeen, Charles Russell, A.B., M.D. (Ex. Com. '06-09, Vice-President '18- '20) Professor of Anatomy and Dean of Medical School, University of Wisconsin, Science Hall, Madison, Wis.
 +
 +
Bartelmez, George W., Ph.D., Associate Professor of Anatomy, University of Chicago, Chicago, III.
 +
 +
Bartsch, Paul, M.S., Ph.D., Professor of Zoology, George Washington University, Curator Marine Invertebrates, U. S. National Museum, Washington, B.C.
 +
 +
Bates, George Andrew, M.S., D.M.D., Professor of Histology and Embryology, Tufts College Medical School, 416 Huntington Avenue, Boston, Mass.
 +
 +
Batson, O. v., A.m., M.D., Instructor in Anatomy, University of Wisconsin, 810 N. Bearly St., Madison, Wis.
 +
 +
Bau-mgartner, Edwin A., Ph.D. M.'D.,Halstead Hospital, Halstead, Kansas.
 +
 +
Bau-mgartner, William J., A.M., Associate Professor of Zoology, University of Kansas, Lawrence, Kans.
 +
 +
Bayon, Henry, B.A., M.D. , Professor of Applied Anatomy, Tulane University, 2212 Napoleon Avenue, New Orleans, La.
 +
 +
Bean, Robert Bennett, B.S., M.D., Professor of Anatomy, University of Virginia, Preston Heights, University, Va.
 +
 +
 +
 +
PROCEEDINGS 97
 +
 +
Beck, Claude S., A.B., Medical Student, Johns Hopkins Medical School, Baltimore, Maryland.
 +
 +
Begg, Alexander S., M.D., Instructor in Anatomy, Harvard Medical School, Boston, Mass.
 +
 +
Bensley, Robert Russell. A. B., M.B., Sc.D. (Second Vice-Pres. '06- '07, Ex. Com. '08-'12, President '18-'20), Professor of Anatomy, University of Chicago, Chicago, III.
 +
 +
Bevan, Arthur Dean, M.D. (Ex. Com. '96-98), Professor of Surgery, University of Chicago, 122 South Michigan Blvd., Chicago, III.
 +
 +
Bigelow, Robert P., Ph.D., Associate Professor of Zoology and Parasitology, Massachusetts Institute of Technology, Cambridge 39, Mass.
 +
 +
Black, Davidson, B.A., M.B., Professor of Neurology and Embryology, Peking Union Medical College, Peking, China.
 +
 +
Blair, Vilrat Papin, A.iNI., M.D., Associate in Clinical Surgery, Washington University School of ^Medicine, Metropolitan Building, St. Louis, Mo.
 +
 +
Blaisdell, Frank Ellsworth, Sr., M.D., Associate Professor of Surgery, Medical Department of Stanford University, Sacramento and Webster Sts., San Francisco, Calif.
 +
 +
Blake, J. A., A.B., Ph.B., M.A., M.D., 116 East 53rd Street, Neiv ForA- City.
 +
 +
Bonney, Charles W., A.B., M.D., Associate in Anatomy, Jefferson Medical College, 1117 Spruce Street, Philadelphia, Pa.
 +
 +
BoYDEN, Edward Allen, A.M., Ph.D., Assistant Professor of Comparative Anatomy, Harvard Medical School, Boston, Mass.
 +
 +
Bremer, John Lewis, A.B., M.D., (Ex. Com. '15-'18), Associate Professor of Histology, Harvard Medical School, Boston, Mass.
 +
 +
Broadnax, John W., Ph.G., M.D., Associate Professor of Anatomy, Medical College of Virginia, Richmond, Va.
 +
 +
Brookover, Charles, M.S., Ph.D., Professor of Anatomy, Histology and Embryology, University of Louisville, Medical Department, 101 W. Chestnut Street, Louisville, Ky.
 +
 +
Brooks, Barney, B.S., M.D., Associate in Clinical Surgery, Washington University School of Medicine, ^918 Forest Park Boulevard, St. Louis, Mo.
 +
 +
Brown, A. J., A. B., M.D. , Assistant Professor of Surgery, University of Nebraska Medical College, 402 City Nat'l Bank Bldg., Omaha, Neb.
 +
 +
Browning, William, Ph.B., ^LD., Professor of Nervous and Mental Diseases, Long Island College Hospital, 54 Lefferts Place, Brooklyn, N. Y.
 +
 +
Bryce, Thomas H., M.A., M.D., Professor of Anatomy, University of Glasgow, No. 2, The University, Glasgoiv, Scotland.
 +
 +
Bullard, H. Hays, A.M., Ph.D., M.D., Professor of Pathology, Western University Medical School, London, Canada.
 +
 +
Bunting, Charles Henry, B.S., M.D., Professor of Pathology, University of Wisconsin, Madison, Wis.
 +
 +
Burr, Harold Saxton, Ph.D., Assistant Professor of Anatomy, School of Medicine, Yale University, 150 York Street, Neiv Haven, Conn.
 +
 +
Burrows, Montrose T., A.B., M.D., Associate Professor of Experimental Surgery, Director of Research Laboratories, Barnard Free Skin and Cancer Hospital, Washington University Medical School, St. Louis, Mo.
 +
 +
THE ANWTOMIC.^L- RECORD, VOL. 21, NO. 1
 +
 +
 +
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98 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
Byrnes, Charles M., B.S., M.D., Associate in Clinical Neurology, Johns Hopkins Medical School, 207 East Preston Street, Baltimore, Md.
 +
 +
Cameron, John, M.D., D.Sc, F.R.S.E., Professor of Anatomy, Dalhousie Medical College, Halifax, Nova Scotia.
 +
 +
Campbell, William Francis, A.B., MD , Professor of Anatomy and Histology, Long Island College Hospital, 334- Clinton Avenue, Brookhjn, N. Y.
 +
 +
Cardwell, John C, M.D., Professor of Physiology, Long Island College Hospital, Polhemus Memorial Clinic, Brooklyn, N. Y.
 +
 +
Carey, Eben J., M.S., Sc.D., Professor of Anatomy, Marquette University School of Medicine, Milwaukee, Wisconsin.
 +
 +
Carpenter, Frederick Walton, Ph.D., Professor of Biology, Trinity College, Hartford, Conn.
 +
 +
Carter, James Thornton, D.D.S., Research Assistant, Department of Zoology, University College, 1 Hanover Square, London, W. C. 1, England.
 +
 +
Carver, GailL., A.B., A.M., West Lake. Ga.
 +
 +
Casamajor, Louis, A.M., M.D., Profes.sor of Neurology, Columbia University, J^37 West 59lh Street, New York City.
 +
 +
Cash, James Robert, A.M.,M.D., Instructor in Pathology, Johns Hopkins Medical School, 20 East Ml. Vernon Place, Baltimore, Md.
 +
 +
Chagas, Carlos P., M.D., Professor of Histology and Pathology, Bello Horizonte Medical School, Minas-Geraes, Brazil, South America.
 +
 +
Chambers, Robert, Jr., A.M., Ph.D., Assistant Professor of Anatomy, Cornell University Medical College, New York City.
 +
 +
Chapman, W. B., A.B., M.D., Instructor in Anatomy, Department of Anatomy, Washington University Medical School, St. Louis, Mo.
 +
 +
Charlton, Harry Hayward, A.M., Ph.D., Assistant Professor of Anatomy, Department of Anatomy, University of Missouri, Columbia, Mo.
 +
 +
Cheever, David, A.B., M.D., Assistant Professor of Surgery and Associate in Anatomy, Harvard Medical School, 721 Huntington Avenue, Boston, Mass.
 +
 +
Chidester, Floyd E., A.M., Ph.D., Associate Professor of Zoology, University of West Virginia, Morgantown, West Virginia.
 +
 +
Child, Charles INIanning, M.S., Ph.D., Professor of Zoology, Zoological Laboratory, University of Chicago, Chicago, III.
 +
 +
Chillingworth, Felix P., M.D., Professor of Physiology and Experimental Pharmacology, Tufts Medical College, 416 Huntington Ave., Boston, Mass.
 +
 +
Clark, Elbert, Ph.D., M.D., Associate Professor of Anatomy, University of Chicago, Chicago, HI.
 +
 +
Clark, Eleanor Linton, A.M., Research Worker, Department of Anatomy, University of Missouri, I4O8 Rosemary Lane, Columbia, Mo.
 +
 +
Clark, Eliot R., A.B., M.D., (Ex. Com. '16-'19), Professor of Anatomy, University of Missouri, Columbia, Mo.
 +
 +
CoE, Wesley R., Ph.D., Professor of Biology, Yale University, Osborne Zoological Laboratory, New Haven, Conn.
 +
 +
Coghill, George E., M.S., Ph.D., Professor of Anatomy and Head of Department, University of Kansas Medical School, Department of Anatomy, University of Karisas, Laivrence, Kan.
 +
 +
CoHN, Alfred E., A.B., M.D., Member, Rockefeller Institute for Medical Research, N^ew Y'ork City, N'. Y.
 +
 +
 +
 +
PROCEEDINGS 99
 +
 +
CoxANT, William Merritt, A.B., M.D., Professor of Clinical Surgery, 486
 +
 +
Commonivealth Avenue, Boston, Mass. CoNEL, Jesse LeRoy, A.M., Ph.D., Assistant Professor of Anatomy, New York
 +
 +
University and Bellevue Hospital Medical College, 338 East 26th Street, New
 +
 +
York City. CoxGDON, Edgar Davidson, Ph.D., Assistant Professor of Anatomy, Leland
 +
 +
Stanford University, School of Medicine, 330 Coleridge Avenue, Palo A Ito, Calif. CoNKLiN, EdwIxX Graxt, A.M., Ph.D., Sc.D., Professor of Biology, Princeton
 +
 +
University, 139 Broadmead Avenue, Princeton, N. J. Corner, George W., A.B., M.D., Associate Professor of Anatomy, Anatomical
 +
 +
Laboratory, Johns Hopkins Medical School, Baltimore, Md. Corning, H. K., M.D., Professor of Anatomy, University of Bdle, Anatomische
 +
 +
Anstalt, Bdle, Switzerland. Cowdrt, Edmund V., Ph.D., Professor of Anatomy, Department of Anatomy,
 +
 +
Peking Union Medical College, Peking, China. Craig, Joseph David, A.M., M.D., 12 Ten Broeck Street, Albany, N. Y. Craigie, E. Horxe, Ph.D., Lecturer in Comparative Anatomy, Department of
 +
 +
Biology, University of Toronto, Toronto, Canada. Crile, George W., A.M., M.D., LL.D., F.A.C.S., Professor of Surgery, Western
 +
 +
Reserve University, Cleveland Clinic, 93rd and Euclid, Cleveland, Ohio. Crosbt, Elizabeth Caroline, Ph.D., Superintendent of Schools, Petersburg,
 +
 +
Mich. CtJLLEN, Thomas S., M.B., 20 E. Eager Street, Baltimore, Md. Cummins, Harold, A.B., Assistant Professor of Anatomy, Tulane University
 +
 +
Medical School, Department of Anatomy, Sta. 20, Neiv Orleans, La. Cunningham, Robert S., A.M., M.D., Associate in Anatomy, Johns Hopkins
 +
 +
Medical School, Baltimore, Md. Curtis, George M., A.M., Ph.D., Professor of Anatomy and Director of the
 +
 +
Anatomical Department, Vanderbilt University Medical School, Nashville,
 +
 +
Tenn. Dahlgren, Ulric, A.B., M.S., Professor of Biology, Princeton University, 204
 +
 +
Guyot Hall, Princeton, N. J. Danchakoff, Vera, M.D., Assistant Professor of Anatomy, Columbia University, 437 W. 59th Street, New York City. Danforth, Charles Haskell, A.M., Ph.D., Associate Professor of Anatomy,
 +
 +
Washington University Medical School, St. Louis, Mo. Darrach, William, A.M., M.D., Associate Professor of Surgery and Dean College of Physicians and Surgeons, Columbia University, 437 West 59th Street,
 +
 +
Neio York City. Dart, Raymond A., M.B., Ch.M., M.Sc, Demonstrator in Anatomy, University
 +
 +
College, Gower St., London, W. C. 1, England. Temporary Address: Johns
 +
 +
Hopkins Medical School, Baltimore, Md. Davis, Carl L., M.D, Professor of Anatomy, University of Maryland, Hale thorpe, Md. Davis, David M., B.S., M.D., Associate in Urology and Pathologist, Brady
 +
 +
Urological Institute, Johns Hopkins Hospital, Baltimore, Md. Davis, Warren B., M.D., Instructor in Anatomy, Jefferson Medical College,
 +
 +
135 S. 18th Street, Philadelphia, Pa.
 +
 +
 +
 +
100 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
Dawson, Alden B., Ph.D., Assistant Professor of Microscopical Anatomy,
 +
 +
Loyola University Medical School, 706 S. Lincoln St., Chicago, III. Dean, Bashford, A.M., Ph.D., Professor of Vertebrate Zoology, Columbia
 +
 +
University, Curator of Fishes and Reptiles, American Museum Natural
 +
 +
History, Riverdale-on-Hudson, New York City. De Carlo, John, M.D., Instructor in Topographic and Applied Anatomy, Jefferson Medical College, 1124- Ellsworth St., Philadelphia, Pa. Dendy, Arthur, D.Sc, F.R.S., Professor of Zoology, University of London,
 +
 +
King's College, Strand W. C, London, England. Detwiler, Samuel Randall, A.M., Ph.D., Associate in Anatomy, Anatomicai
 +
 +
Laboratory, Peking Union Medical College, Peking, China. Dixon, A. Francis, M.B., Sc.D., University Professor of Anatomy, Trinity
 +
 +
College, 73 Grosvenor Road, Dvhlin, Ireland. DoDDS, Gideon S., A.M., Ph.D., Associate Professor of Histology and Embryology, West Virginia University Medical School, Morgantown, W. Va. DoDSON, John Milton, A.M., M.D., Dean and Professor of Medicine, Rush
 +
 +
Medical College, University of Chicago, 58.17 Blackston Avenue, Chicago, III. Dolley, D. H., A.m., M.D., Professor of Pathology, University of Missouri,
 +
 +
Columbia, Mo. Donaldson, Henry Herbert, Ph.D., D.Sc. (Ex. Com. '09-'13, Pres. '16-'17),
 +
 +
Professor of Neurology, The Wistar Institute of Anatomy and Biology, Woodland Avenue and 36th Street, Philadelphia, Pa. Donaldson, John C, Ph.B., M.D., Assistant Professor of Anatomy, University
 +
 +
of Cincinnati Medical College, The Maplewood, Clifton, Cincinnati, Ohio. Downey, Hal, A.M., Ph.D., Professor of Histology, Department of Animal
 +
 +
Biology, University of Minnesota, Minneapolis, Minn. DuBREUiL, Georges, M.D., Professor of Anatomy, Faculte de Medicine, Place
 +
 +
de la Victoire, Bordeaux, France. DuESBURG, Jules, M.D., Professor of Anatomy, University of Liege, 22 qusi
 +
 +
Mativa, Liege, Belgium. Dunn, Elizabeth Hopkins, A.M., M.D., Woods Hole, Mass. Eaton. Paul Barnes, A.B., M.D., Instructor Bacteriology, School of Hygiene
 +
 +
and Public Health, Johns Hopkins University, 310 W. Monument Street,
 +
 +
Baltimore, Md. EccLES, Robert G.. M.D., Phar.D., 681 Tenth Street, Brooklyn, N. Y. Elwyn, Adolph, A.m., Assistant Professor of Anatomy, Columbia University,
 +
 +
437' West 59th Street, New York City. Emmel, Victor E., M.S., Ph.D., Associate Professor of Anatomy, Department
 +
 +
of Anatomy, University of California, Berkeley. Calif. Erdmann, C. a., M.D., Associate Professor of Ai)plied Anatomy, Institute of
 +
 +
Anatomy, University of Minnesota, Minneapolis, Minn. EssiCK, Charles Rhein, B.A., M.D., 520 Franklin Street, Reading, Pa. Evans, Herbert McLean, B.S., M.D., (Ex-Com. '19-), Professor of Anatomy,
 +
 +
University of California, Berkeley, Calif. Evans, Thomas Hor.\ce, M.D., Associate Professor of Anatomy, Long Island
 +
 +
College Hospital, Henry and Amity Streets. Brooklyn, N. Y. Eycleshymer, Albert Chauncey, Ph.D., M.D., Professor of Anatomy, Medical
 +
 +
College, University of Illinois, Honore and Congress Streets, Chicago, III.
 +
 +
 +
 +
PROCEEDINGS 101
 +
 +
Fawcett, Edward, INI.D., Professor of Anatomy, University of Bristol, Bristol, England.
 +
 +
Ferris, Harry Burr, A.B., M.D., Hunt Professor of Anatomy, Medical Department, Yale University, 395 St. Ronan Street, Neic Haven, Conn.
 +
 +
Fetterolf, George, A.B., M.D., Sc.D., Assistant Professor of Anatomy, University of Pennsylvania, 2047 Chestnut Street, Philadelphia, Pa.
 +
 +
FixNEY, Theodora Wheeler, A.B., M.D., Mayo Clinic, Rochester, Minn.
 +
 +
Firket, Jean, M.D., Instructor in Anatomy, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
FiscHELis, Philip, M.D., Professor of Histology and General Pathology, Philadelphia Dental College of Temple University, 828 North 5th Street, Philadelphia, Pa.
 +
 +
Ford, Francis C., A.B., M.D., Professor of Anatomy, Hahnemann Medical College and Hospital of Chicago, 2811 Cottage Grove Avenue, Chicago, III.
 +
 +
Formax, Jonathan, A.B., M.D., 394 East Town St., Columbus, Ohio.
 +
 +
Frassetto, Fabio, M.D., Ph.D., Director Anthropological Institute, University of Bologna, Bologna, llnl.y.
 +
 +
Frazer, John Ernest, M.D., F.R.C.S., Professor of Anatomy, University of London, St. Mary's Hospital Medical School, London, W. England.
 +
 +
French, H. E., M.S., M.D., Professor of Anatomy and Dean of the School of Medicine, University of North Dakota, Grand Forks, North Dakota.
 +
 +
Gage, Simon Henry, B.S. (Ex. Com. '06-'ll), Professor of Histology and Embryology, Emeritus, Stimson Hall, Cornell University, Ithaca, N. Y.
 +
 +
Gallaudet, Bern Budd, A.M., M.D., Assistant Professor of Anatomy, Columbia University, Consulting Surgeon Bellevue Hospital, 105 East 19th Street. Neu' York City.
 +
 +
Garcia, Arturo, A.B., M.D., Professor of Anatomy College of Medicine and Surgery, Manila, Philippine Islands.
 +
 +
George, Wesley Critz, A.M., Ph.D., Associate Professor of Histology and Embryology, University of North Carolina Medical School, Chapel Hill, North Carolina.
 +
 +
Gibson, G. H., M.D., Stipendiary Magistrate, ^Vaitangi Chatham Islands, New Zealand.
 +
 +
GiLLASPiE, C, M.D., Professor of Anatomy, University of Colorado, Boulder, Colo.
 +
 +
Globus, J. H., B.S., M.D., Research Fellow in Neuropathology, Mt. Sinai Hospital, 58 East 94th Street, New York City.
 +
 +
Gould, Harley Nathan, A.M., Ph.D., Professor of Biology, Wake Forest College, Wake Forest, N. C.
 +
 +
Grant, J. C. Boileau, M.D., Ch.B., F.R.C.S., Professor of Anatomy, U7iiversity of Manitoba Medical College, Winnipeg, Canada.
 +
 +
Graves, William W., M.D., Professor of Nervous and Mental Diseases, St. Louis University School of Medicine, Metropolitan Building, St. Louis, Mo.
 +
 +
Greene, Charles W., A.M., Ph.D., Professor of Physiology and Pharmacology, Universit}' of Missouri, 8I4 Virginia Avenue, Columbia, Mo.
 +
 +
Greenman, Milton J., Ph.B., M.D., Sc.D., Director of The Wistar Institute of Anatomy and Biology, 36th Street and Woodland Ave7iue, Philadelphia, Pa.
 +
 +
 +
 +
102 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
Gregory, William King, A.M., Ph.D., Curator of Comparative Anatomy, American Museum of Natural History, 77th Street and Central Park West, New York City.
 +
 +
GuDERNATSCH, J. F., Ph.D., 58 East 94th Street, New York City.
 +
 +
Guild, St.\cy R., A.M., Ph.D., Assistant Professor of Anatomy, Medical School, University of Michigan, 562 South Seventh Street, Ann Arbor, Mich.
 +
 +
GuYER, Michael F., Ph.D., Professor of Zoology, University of Wisconsin, Madison, Wis.
 +
 +
Halsted, William Stewart, M.D., Sc.D., LL.D., F.R.C.S., Professor of Surgery, Johns Hopkins University, Surgeon-in-Chief, Johns Hopkins Hospital, 1201 Eutaw Place, Baltimore, Md.
 +
 +
Hamann, Carl A., M.D. (Ex. Com. '02-'04), Professor of Applied Anatomy and Clinical Surgery, Western Reserve University, U6 Osborne Building, Cleveland, Ohio.
 +
 +
HARDESTY,IR^^^•G, Ph.D., Sc.D. (Ex. Com. '10 and '12-15), Professor of Anatomy and Head of Department of Anatomy, School of Medicine, Tulane University, P. 0. Station 20, New Orleans, La.
 +
 +
Hare, Earl R., A.B., M.D., F.A.C.S., 7S0 LaSalle Building, Minneapolis, Minn.
 +
 +
Harrison, Ross Granville, Ph.D., M.D., Sc.D. (Pres. '12-'14), Bronson Professor of Comparative Anatomy, Osborn Zoological Laboratory, Yale University, New Haven, Conn.
 +
 +
Hartman, Carl G., Ph.D., Associate Professor of Zoology, University of Texas, Austin, Texas.
 +
 +
Harvey, Basil Coleman Hyatt, A.B., M.B., Professor of Anatomy, University of Chicago, Department of Anatomy, University of Chicago, Chicago, III.
 +
 +
Hatai, Shinkishi, Ph.D., Associate Professor of Neurology, The Wistar Institute of Anatomy and Biology, 36th Street and Woodland Avenue, Philadelphia, Pa.
 +
 +
Hausman, Loxtis, A.B., M.D., Instructor in Psychiatry, Johns Hopkins Hospital, Baltimore, Md.
 +
 +
Hazen, Charles Morse, A.M., M.D., Professional Building, Fifth and Franklin Streets, Richmond, Va.
 +
 +
Heisler, John C, M.D., Professor of Anatomy, University of Pennsylvania, S829 Walnut Street, Philadelphia, Pa.
 +
 +
Heldt, Thomas Johanes, A.M., M.D., Passed Assistant Surgeon (Reserve) U. S. Public Health Service, 415 E. Broadway, Waukesha, Wis.
 +
 +
Hemler, William Francis, M.D., Professor of Histologj' and Embryology, Georgetown University, 13S0 East Capitol Street, Washington, D. C.
 +
 +
Herrick, Charles Judson, Ph.D. (Ex. Com. '1^'17), Professor of Neurology, University of Chicago, Laboratory of Anatomy, University of Chicago, Chicago, III.
 +
 +
Hertzler, Arthur E., A.M., M.D., Ph.D., F.A.C.S., Professor of Surgery, University of Kansas, Halstead, Kansas.
 +
 +
Heuser, Chester H., A.M., Ph.D., Associate in Anatomy, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Hew-son, Addinell, A.m., M.D., F. A.C.S., Professor of Anatomy, Graduate School of Medicine, University of Pennsylvania, Professor of Anatomy and Histology, Temple University, 2120 Spruce St., Philadelphia, Pa.
 +
 +
 +
 +
PROCEEDINGS 103
 +
 +
Hill, Eben Claytox, A.B., M.D., Instructor in Anatomy, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Hill, Howard, M.D., 1334 Rialto Building, Kansas City, Mo.
 +
 +
Hill, James Peter, D.Sc, F.R.S., Jodrell Professor of Zoology, and Comparative Anatomy, University of London, Ihiiversity College, Gower Street, London, W. C. 1, England.
 +
 +
Hilton, William A., Ph.D., Professor of Zoology, Pomona College, Director Lagiina Marine Laboratory, Claremont, Calif.
 +
 +
Hines, Marion, A.B., Ph.D., Instructor in Anatomy, Department of Anatomy, University of Chicago, Chicago, III.
 +
 +
Hoffman, Clarence, M.D., Demonstrator in Anatomy, Jefferson Medical College, 1621 Pine St., Philadelphia, Pa.
 +
 +
Holt, Caroline M., A.M., Ph.D., Assistant Professor of Biology, Simmons College, 35 Irma Avenue, Watertown, Mass.
 +
 +
Hooker, Davenport, M.A., Ph.D., Professor of Anatomy, School of Medicine, University of Pittsbiirgh, Pittsbtirgh, Pa.
 +
 +
Hopewell-Smith, Arthur, L.R.C.P., M.R.C.S., L.D.S., Professor of Dental Histology and Comparative Odontology, University of Pennsylvania Dental College, Philadelphia, Pa.
 +
 +
Hopkins, Grant Sherman, Sc.D., D.V.M., Professor Comparative Veterinary Anatomy, Cornell University, Ithaca, N. Y.
 +
 +
HosKiNS, Maragert Morris, Ph.D., Instructor in Histology, Richmond College of Medicine, Richmond, Va.
 +
 +
HowDEN, Robert, M.A., M.B., CM., D.Sc, Professor of Anatomy, University of Durham, 14 Burdon Terrace, Newcastle-upon-Tyne, England.
 +
 +
HowLAND, Ruth B., Ph.D., Professor of Biology, Siccet Briar College, Sweet Briar, Va.
 +
 +
HrdliCka, Ales, Ph.D., M.D., Curator, Division of Physical Anthropology, United States National Museum, Washington, D. C.
 +
 +
Huber, G. Carl, M.D. (Second Vice-Pres. 'OO-'Ol, Secretary-Treasurer '02-'14, Pres. '14-'16, Ex. Com. '20), Professor of Anatomy and Director of the Anatomical Laboratories, University of Michigan, 1330 Hill Street, Ann Arbor, Mich.
 +
 +
HuGHSON, Walter, S.B., ]M.D., Assistant in Anatomy, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Hunter, Oscar B., M.D., Professor of Pathology and Bacteriology, George Washington Medical School, 1335 H St., N.W., Washington, D. C.
 +
 +
Huntington, George S., A.M., M.D., D.Sc, LL.D. (Ex. Com. '95-'97, '04-'07, '18-, Pres. '99-'03), Professor of Anatomy, Columbia University, 437 West 59th Street, New York City.
 +
 +
Ingalls, N. William, B.S., M.D., Associate Professor of Anatomy, School of Medicine, Western Reserve University, 1353 East 9th Street, Cleveland, Ohio.
 +
 +
Ingvar, Sven, M.D., Docent in Neurology, University of Lund, Lund, Sweden.
 +
 +
Inouye, Michio, ]\I.D., Professor of Anatomy, Tokyo Imperial University, Tokyo, Japan.
 +
 +
Jackson, Clarence M., M.S., M.D. (Ex. Com. '10-'14, Vice-Pres. '16-'17), Professor and Director of the Department of Anatomy, Institute of Anatomy, University of Minnesota, Minneapolis, Minn.
 +
 +
 +
 +
104 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
Jenkins, George B., M.D., Professor of Anatomy, George Washington University Medical School, Washington, D. C.
 +
 +
Job, Theslb T., M.S., Ph.D., Associate Professor of Anatomy, Loyola University School of Medicine, 706 S. Lincoln St., Chicago, III.
 +
 +
Johnson, Charles Eugene, A.M., Ph.D., Assistant Professor of Zoology, Department of Zoology, University of Kansas, Lawrence, Kansas.
 +
 +
Johnson, Franklin P., A.M., Ph.D., M.D., Associate Professor of Anatouw, University of Missouri, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Johnson, Sydney E., M.S., Ph.D., Associate in Anatomy, Northwestern University Medical School, 24^1 So^lth Dearborn Street, Chicago, III.
 +
 +
Johnston, John B., Ph.D., Professor of Comparative Neurologj^ University of Minnesota, Minneapolis, Minn.
 +
 +
Johnston, Thomas Baillie, M.B., Ch.B., Professor of Anatom}^, University of London, Guy's Hospital Medical School, London, S. E. 1., England.
 +
 +
Jordan, Harvey Ernest, A.M., Ph.D. (Ex. Com. '18-), Professor of Histology and Embryology, University of Virginia, S4 University Place, Charlottesville, Va.
 +
 +
Kampmeier, Otto Frederick, A.B., Ph.D., Associate Professor of Anatomj', College of Medicine, University of Illinois, Chicago, III.
 +
 +
Kappers, Cornelius Urbo Ariexs, M.D., Director of the Central Institute for Brain Research of Holland, Mauritskade 61, Amsterdam, Holland.
 +
 +
Keegan, John J., A.M., M.D., Assistant Professor of Pathology, University of A ebraska. College of Medicine, Omaha, A ebraska.
 +
 +
Keiller, William, L.R.C.P. and F.R.C.S. Ed. (Second Vice-Pres. '9S-'99), Professor of Anatomy, Medical Department University of Te.xas. State .Medical College, Galveston, Texas.
 +
 +
Keith, Arthur, M.D., LL.D., F.R.C.S., F.R.S., Hunterian Professor of Anatomy, Royal College of Surgeons, Lincoln's Inn Fields, London, W.C.2, England.
 +
 +
Kernan, John D. Jr., A.B., M.D., Assistant in Anatomy, Columbia University, 156 East 79th Street, New York City.
 +
 +
Kerr, Abram T., B.S., M.D. (Ex. Com. '10-'14), Professor of Anatomy, Cornell University Medical College. Ithaca, N. Y.
 +
 +
Key, J. Albert, B.S., M.D., 656 Huntington Ave., Boston, Mass.
 +
 +
KiNGERY, Hugh McMillan, A.M., Ph.D., Assistant Professor of Anatomy, School of Medicine, University of Colorado, Boulder, Colo.
 +
 +
Kingsbury, Benjamin F., Ph.D., M.D., Professor of Histology and Embryology, Cornell University, 2 South Avenue, Ithaca, N. Y.
 +
 +
Kingsley, John Sterling, Sc.D., Professor of Zoology, University of Illinois, Urbana, III.
 +
 +
King, Helen Dean, A.M., Ph.D., Assistant Professor of Embrj^ology, The Wislar Institute of Anatomy, 36th Street and Woodland Avenue, Philadelphia, Pa.
 +
 +
Kirkham, William Barui, Ph.D., Research Embrj-ologist, 103 Everit Street, New Haven, Conn.
 +
 +
Knower, Henry McE., A.B., Ph.D., (Ex. Com. '11-'15), Professor of Anatomy, Medical College, University of Cincinnati, Eden Avemie, Cincinnati, Ohio
 +
 +
 +
 +
PROCEEDINGS 105
 +
 +
Kocii, John- C, B.S., M.D., Board of Health, Orthopedic Staff, Harper Hospital, 97 Euclid Avenue, East, Detroit, Mich.
 +
 +
KoFoiu, Charles Atwood, Ph.D., Sc.D., Professor of Zoology, University of California, De-partment of Zoology, University of California, Berkeley, Calif.
 +
 +
Kraxjse, Allen Kramer, A.M., M.D., Associate Professor of Medicine, Johns Hopkins University, Johns Hopkins Hof<pital, Baltimore, Md.
 +
 +
Kudo, Toktjyasu, ^I.D., Professor of Anatomj', Niigata Medical College, hiigata, Japan.
 +
 +
KuxiTOMO, Kanae, M.D , Professor of Anatomy, Anatomical Institute, Nagasaki Medical School, Nagasaki, Japan.
 +
 +
Kunkel, Beverly Waugh, Ph.B., Ph.D., Professor of Biology, Lafayette College, Easion, Pa.
 +
 +
KuNTZ, Albert, Ph.D., M.D., Professor of Anatomy and Biology, St. Louis University Medical School, H02 South Grand Ave., St. Louis, Mo.
 +
 +
KuTCHiN,' Mrs. Harriet Lehmann, A.M., "The MaplewoOd," Green, Lake, Wis.
 +
 +
Lambert, Adriax V. S., A.B., M.D., Associate Professor of Surgery, Columbia University, 168 East 71st Street, New York City.
 +
 +
Landacre, Francis Leroy, Ph.D., Professor of Anatomy, Ohio State University, 2026 Inka Avenue, Columbus, Ohio.
 +
 +
Lane, Michael Andrew, B.S., 122 South California Avenue, Chicago, III.
 +
 +
Laesell, Olaf, Ph.D., Associate Professor of Zoology, Zoological Laboratory, A orthu-estern University, Evanston, III.
 +
 +
Latimer, Homer B., A.M., Professor of Vertebrate Anatomj^ University of Nebraska, 1226 South 26th Street, Lincoln, Neb
 +
 +
Latta, John S., A.B., Ph.D., Instructor in Histology and Embryology, Sti?7ison Hall, Cornell University, Ithaca, N . Y.
 +
 +
Laurens, Henry, A.M., Ph.D., Assistant Professor of Biology, Yale University, Osborne Zoological Laboratory, New Haven, Conn.
 +
 +
Lee, Thomas G., B.S., M.D. (Ex. Com. 'OS-'IO, Vice-Pres. '12-'14), Professor of Comparative Anatomy, Institute of Anatomy, University of Minnesota, Min?ieapolis, Minn.
 +
 +
Leidy, Joseph, Jr., A.M., M.D., 1319 Locust Street, Philadelphia, Pa.
 +
 +
Levi, Giuseppe, M.D., Professor of Anatomy, University of Torino, Torino, Italy.
 +
 +
Lewis, Dean D., M.D., Assistant Professor of Surgery, Rush Medical College, Peoples Gas Building, Chicago, III.
 +
 +
Lewis, Frederic T., A.M., M.D. (Ex. Com. '09-'13, Vice-Pres. '14-'16), Associate Professor of Embryology, Harvard Medical School, Boston, Mass.
 +
 +
Lewis, Margaret Reed, M.A., Collaborator, Department of Embryology, Carnegie Institution of Washington, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Lewis, Warren Harmon, B.S., M.D. (Ex. Com. '09-'ll, '14-'17), Research Associate Department of Embryologj', Carnegie Institution, Professor of Physiological Anatomy, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
LiLLiE, Frank Rathay, Ph.D., Sc.D., Professor of Embryology, Chairman of Department of Zoology, University of Chicago; Director Marine Biological Laboratory, Woods Hole, Mass., University of Chicago, Chicago, III.
 +
 +
LiNEBACK, Paul Eugene, A.B., M.D., Professor of Histology and Embryology, Atlanta Medical College, Emory University, Ga.
 +
 +
 +
 +
106 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
LiPSHtTTZ, Benjamin, M.D., Instructor in Neuro-anatomy, Jefferson Medical
 +
 +
College, 1007 Spruce St., Philadelphia, Pa. LocY, William A., Ph.D., Sc.D., Professor of Zoology and Director of the
 +
 +
Zoological Laboratory, Northwestern University, Evanston, III. LoEB, Hanaxj \Yolf, A.M., M.D., Dean and Professor of the Diseases of the Ear, Nose and Throat, St. Louis University, 537 North Graiid Avenue, St. Louis, Mo. Lord, Frederic P., A.B.,M.D., Professor of Anatomy, Dartmouth Medical School,
 +
 +
Hanover, N. H. LowREY, Lawson Gentry, A.M., M.D., Assistant Professor of Psychiatry; Assistant Director Psychopathic Hospital, University of Iowa, Iowa City, Iowa. Macklin, C. C, M.D., Associate Professor of Anatomy, Johns Hopkins Medical
 +
 +
School, Baltimore, Md. McClung, Clarence E., A.M., Ph D., Professor of Zoology and Director of the Zoological Laboratory (Chairman Division of Biology and Agriculture National Research Council 1919-1920), University of Pennsylvania, Philadelphia, Pa. McClure, Charles Freeman Williams, A.M., Sc.D. (Vice-Pres. 'lO-'ll, Ex. Com. '12-'16, Pres. '20), Professor of Comparative Anatomy, Princeton University, Princeton, N. J. McCoTTER, RoLLO E., M.D., Professor of Anatomy, Medical Department, University of Michigan, 104S Ferdon Road, Ann Arbor, Mich. McFarland, Frank Mace, A.M., Ph.D., Professor of Histology, Leland Stanford Junior University, 2 Cabrillo Avenue, Stanford University, Calif. McGiLL, Caroline, A.M., Ph.D., :\I.D., Physician, 52 W. Quartz, Butte, Mont. McIntosh, William, A.B., A.M., Student of Medicine, Johns Hopkins Medical
 +
 +
School, Baltimore, Maryland. McJuNKiN, F. A., M.A., M.D., Associate Professor of Pathology, Washington
 +
 +
University Medical School, St. Louis, Mo. McKiBBEN, Paul S., Ph.D., Professor of Anatomy, Western University Medical
 +
 +
School, London, Canada
 +
 +
McMuRRicH, James Playfair, A.M., Ph.D., LL.D. (Ex. Com. '06-'07, '17 Pres. '08-'09), Professor of Anatomy, University of Toronto, Toronto, Canada.
 +
 +
Magath, Thomas Byrd, M.S., Ph.D., M.D., Assistant Professor of Clinical
 +
 +
Bacteriology and Parasitologist, University of Minnesota, Mayo Clinic,
 +
 +
Rochester, Minn.
 +
 +
Mangum, Charles S., A.B., M.D., Professor of Anatomy, University of North
 +
 +
Carolina, Chapel Hill, N. C. Malone, Edward F., A.B., M.D., Professor of Histology, University of Cincinnati, College of Medicine, Eden Avenue, Cincinnati, Ohio. Mark, Edward Laurens, Ph.D., LL.D., Hersey Professor of Anatomy and Director of the Zoological Laboratory, Harvard University, 109 Irving Street, Cambridge, Mass. Matas, Rudolph, M.D., LL.D., Professor of Surgery, Tulane University of
 +
 +
Louisiana, 2255 St. Charles Avenue, Neiv Orleans, La. Mavor, James Watt, M.A., Ph.D., Assistant Professor of Zoology, Union College, Schenectady, N. Y.
 +
 +
 +
 +
PROCEEDINGS 107
 +
 +
Maximow, Alexander, M.D , Professor of Histology and Embryology at the Imperial Military Academy of Medicine, Botkinskja 2, Petrograd, Russia.
 +
 +
Mead, Harold Tupper, B.A., M.S., Associate Professor of Zoology, Tulane University, New Orleans, La.
 +
 +
Meaker, Samuel R., A.B., M.D., Teaching Fellow, Department of Anatomy, Harvard Medical School, Boston, Mass.
 +
 +
Mellus, Edward Lindon, M.D., 12 Fuller Street, Brookline, 47, Mass.
 +
 +
Mercer, William F., Ph.M., Ph.D., Professor of Biology, Ohio University, Box S84, Athens, Ohio.
 +
 +
Metheny, D. Gregg, M.D., L.R.C.P., L.R.C.S., Edin., L.F.P.S., Glasg., Dispensary Navy Yard, League Island, Philadelphia, Pa.
 +
 +
Meyer, Adolph, M.D., LL.D., Professor of Psychiatry and Director of the Phipps Psychiatric Clinic, Johns Hopkins Hospital, Baltimore, Md.
 +
 +
Meyer, Arthur W., SB., M.D. (Ex. Com. '12-'16), Professor of Anatomy, Leland Stanford Junior University, 121 Waverly Street, Palo Alto, Calif.
 +
 +
Miller, Adam M., A.M., Professor of Anatomy, Long Island College Hospital, S35 Henry Street, Brooklyn, N. Y.
 +
 +
Miller, William Snow, M.D., Sc.D. (Vice-Pres. '08-'09), Professor of Anatomy University of Wisconsin, 2001 Jefferson Street, Madison, Wis.
 +
 +
MooDiE, Roy L., A.B., Ph.D., Associate Professor of Anatomy, University of Illinois, Medical College, Congress and Honore Streets, Chicago, III.
 +
 +
Moody, Robert Orton, B.S., M.D., Associate Professor of Anatomy, University of California, 2826 Garber Street, Berkeley, Calif
 +
 +
Morrill, Charles V., A.M., Ph.D., Assistant Professor of Anatomy, Cornell University Medical School, 1st Avenue and 28th Street, New York City.
 +
 +
MuLLER, Henry R., A.B., M.D., Assistant in Pathology, Cornell University Medical College, 1st Avenue and 28th Street, New York City.
 +
 +
Munson, John P., M.S., Ph.D., F.R.S.A., Head of the Department of Biology, Washington State Normal School, 706 North Anderson Street, Ellensburg, Washington.
 +
 +
Murphey, Howard S., D.V.M., Professor of Anatomy and Histology, Station A, Veterinary Buildings, Ames, Iowa.
 +
 +
Murray, H. A., Jr., A.M., M.D., 129 East 69th Street, New York City.
 +
 +
Myers, Burton D., A.M., M.D., Professor of Anatomy and Assistant Dean of the Indiana University School of Medicine, 321 A. Washington St., Bloomington, hid.
 +
 +
Myers, Jay A., M.S., Ph.D., M.D., Instructor in Medicine, University of Minnesota, 303 La Salle Bldg., Minneapolis, Minn.
 +
 +
Myers, Mae Lichtenwalner, M.D., Associate Professor of Anatomy and Director of the Laboratories of Histology and Embryology, Women's Medical College of Pennsylvania, North College Avenue and 21st Street, Philadelphia, Pa.
 +
 +
Nachtrieb, Henry Francis, B.S., Professor of Animal Biology and Head of the Department, University of Minnesota, Minneapolis, Minn.
 +
 +
Nanagas, Juan Cancia, M.D., Assistant Professor of Anatomy, College of Medicine and Surgery, Manila, Philippine Islands. (Temporary address — Dept. of Anatomy, Johns Hopkins Medical School, Baltimore.)
 +
 +
 +
 +
108 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
Neal, Herbert Vincent, A.M., Ph.D., Professor of Zoology, Tufts College, Tufts College, 57, Mass.
 +
 +
NiCHOL.\s, John Spangler, B.S., ]M.S., University Fellow in Zoology, Oshorn Zoological Laboratory, Yale University, New Haven, Conn.
 +
 +
NoB.\CK, GcsTAVE J., B.S., M.A., Instructor in Anatomy, Anatomical Institute, University of Minnesota, Minneapolis, Minn.
 +
 +
NoxiDEZ, Jos6 F., Sc.M., Sc.D., Instructor in Anatomy, Cornell University Medical College, 1st Avenue and 28th Street, New York City.
 +
 +
Norris, H. W., A.B., Professor of Zoology, Grinnell College, Grinnell, Iowa.
 +
 +
O'DoNOGHUE, Charles H., D.Sc, F.Z.S., Professor of Zoology, University of Manitoba, Winnipeg, Canada.
 +
 +
Okajima, K., M.D., Professor of Anatomy, Keio University Medical College, Tokio, Japan.
 +
 +
OsTERUi), Hjalmar L., A.B., A.M., Instructor in Anatomy, Institute of Anatomy, University of Minnesota, Minneapolis, Minn.
 +
 +
Ott, Martin D., A.B., Institute of Anatomy, University of Minnesota, Minneapolis, Minn.
 +
 +
Owen, William 0., M.D., Colonel U. S. A. M. C. (Retired), 2719 Ontario Road, Washington, D. C.
 +
 +
Painter, Theophilus S., Ph.D., Adjunct Professor of Zoology, School of Zoology, University of Texa-'i, Austin, Texas.
 +
 +
Papanicolaou, George N., Ph.D., M.D., Instructor in Anatomy, Cornell University Medical College, 28th Street and First Avenue, New York City.
 +
 +
Papez, James Wencelas, B.A., M.D., Assistant Professor of Anatomy and Neurology, Cornell University Medical College, Ithaca, N. Y.
 +
 +
Parker, George Howard, D.Sc, Professor of Zoology, Harvard University, 16 Berkeley Street, Cambridge, Mass.
 +
 +
Paton, Stewart, A.B., M.D., Lecturer in Neurobiology, Princeton University, Princeton, N. J.
 +
 +
Patten, Bradley Merrill, A.M., Ph.D., Assistant Professor of Histology and Embryology, School of ^Medicine, Western Reserve University, 1353 East 9th Street, Cleveland, Ohio.
 +
 +
Patten. William, Ph.D , Professor of Zoology, Dartmouth College, Hanover, N. H.
 +
 +
Patterson, John Thomas, Ph.D., Professor and Chairman of the School of Zoology, University of Texas, University Station, Austin, Texas.
 +
 +
Perkins, Orman C, A.M., Assistant Professor of Anatomy, Long Island College Hospital, 3.35 Henry St., Brooklyn, New York.
 +
 +
Pfeiffer, John A. F., M.A., M.D., Ph.D., Physician and Pathologist, 1421 Edmondson Avenue, Baltimore, Md.
 +
 +
Piersol, George A., M.D., Sc.D. (Vice-Pres. '93-'94, '98-'99, '06-'07, Pres. 'lO-'ll), Professor of Anatomy, University of Pennsylvania, 4724 Chester Avenue, Philadelphia, Pa.
 +
 +
Piersol, William Hunter, A.B., M.B., Associate Professor of Histology and Embryology, University of Toronto, 85 Dunvegan Road, Toronto, Canada.
 +
 +
Ping, Chi, Ph.D., Government Teachers College, Naiiking, China.
 +
 +
PoHLMAN. Augustus G., M.D., Professor of Anatomy, St. Louis University, School of Medicine, 1402 South Grand Avenue, St. Louis, Mo.
 +
 +
 +
 +
PROCEEDINGS 109
 +
 +
Potter, Peter, M.S., M.D., Oculist and Aurist, Murray Ilosijital, Ikitte, Montana, 4II-4IS Hennessy Building, Butte, Montana.
 +
 +
PoYNTER, Charles W. M., B.S. M.D., (Ex. Com. '19-), Profes.sor of Anatomy College of Medicine, University of Nebraska, 42tid and Dewey Avenue, Omaha, Nch.
 +
 +
Pracher, John, M.D., Pathologist, St. Mary's Hospital, Evansville, Ind.
 +
 +
Prentiss, H. J., M.D., M.E., Professor of Anatomy, State University of Iowa, loiva City, loiva.
 +
 +
Pryor, Joseph William, M.D., Professor of Anatomy and Physiology, University of Kentucky, Lexington, Ky.
 +
 +
Radasch, Henry E., M.S., M.D., Assistant Professor of Histology and Embryology, Jefferson Medical College, Daniel Baugh Institute of Anatomy, 11th and Clinton- Streets, Philadelphia, Pa.
 +
 +
Ranson, Stephen W.,M.D., Ph.D., Professor of Anatomy, Northwestern University Medical School, 2431 South Dearborn Street, Chicago, III.
 +
 +
Rasmtjssen, Andrew T., Ph.D., Associate Professor of Neurology, Institute of Anatomy, University of Minnesota, Minneapolis, Minn.
 +
 +
Reagan, Franklin P., Ph.D., Assistant Professor of Zoology, Department of Zoology, University of California, Berkeley, Calif.
 +
 +
Reed, Hugh D., Ph.D., Professor of Zoology, Cornell University, McGraic Hall, Ithaca, N. Y.
 +
 +
Reinke, Edwin E., M.A., Ph.D., Associate Professor of Biology, Vand rbilt University, Nashville, Tenn.
 +
 +
Retzer, Robert, M.D., Medical School, University of Pittsburgh, Pittsburgh, Pa.
 +
 +
Revell, Daniel Graisbbrry, A.B., M.B., Professor of Anatomy, University of Alberta, Edmonton, South, Strathcona, P. O., Alberta, Canada.
 +
 +
Rhinehart. D. A., A.M., M.D., Roentgenologist Little Rock City Hospital, Donaghey Bldg. . Little Rock, Ark.
 +
 +
Rice, Edward Loranus, Ph.D., Professor of Zoology, Ohio Wesleyan University, Delaware, Ohio.
 +
 +
RiNGOEN, Adolph R., A.M., Ph.D., Instructor in Animal Biology, Department of Biology, University of Minnesota. Minneapolis, Minn.
 +
 +
Robertson, Albert Duncan, B.A., Professor of Biology, Western University, London, Ontario, Canada.
 +
 +
Robinson, Arthur, M.D., F.R.C.S. (Edinburgh), Professor of Anatomy, University of Edinburgh, University, Teviot Place, Edinburgh, Scotland
 +
 +
Robinson, Byron L., A.B., M.A., Medical Interne, University Hospital, Minneapolis, Minn.
 +
 +
Rupert, R. R., M.D., Professor of Gross Anatomy, Uriiversity of Utah, Schoot of Medicine, Salt La^-". City, Utah.
 +
 +
Ruth, Edward S., M.D., Associate Surgeon, Children's Ho.spital, 6548i Hollywood Bldg., Los Angeles, Calif.
 +
 +
Sabin, Florence R., B.S., M.D., Sc.D. (Second Vice-Pres. '08- '09), Professor of Histology, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Sachs, Ernest, A.B., M.D., Professor of Clinical and Neurological Surgery, Washington University School of Medicine, 97 Arundel Place, St. Louis, Mo.
 +
 +
 +
 +
110 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
Sansom, George Samuel, B.S., M.C., D.F.C., Honorarj' Research Assistant, Department of Zoology, University College, London, Kennel Moor, Milford, Surrey, England. Santee, Harris E., A.M., Ph.D., INI.D., Professor of Neurology, Jenner ^Medical College, 2806 Warren Avenue, Chicago, III.
 +
 +
ScAMMON, Richard E., Ph.D., Professor of Anatomy, Institute of Anatomy, University of Minnesota, Minneapolis, Minn.
 +
 +
ScHAEFER, Marie Charlotte, M.D., Associate Professor of Biology, Histology and Embryology, Medical Department, University of Texas, 705 North Pine Street, San Antonio, Texas.
 +
 +
ScHAEFFER, Jacob Parsons, A.M., M.D., Ph.D., Professor of Anatomy and Director of the Daniel Baugh Institute of Anatomy, Jefferson Medical College, nth and Clinton Streets, Philadelphia, Pa.
 +
 +
Shoemaker, Daniel M., B.S., M.D., Professor of Anatomy, Medical Department, St. Louis University, 1402 South Grand Avenue, Si. Louis, Mo.
 +
 +
Schulte, Hermaxn vox W., A.B., M.D. (Ex. Com. '15-'18), Professor of Anatomy and Dean, Creighton Medical College, Omaha, Neb.
 +
 +
Schultz, Adolph H., Ph.D., Research Associate, Carnegie Institution, Department of Embryology, Carnegie Laboratory, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Schmitter, Feudin-axd, A.B., M.D., Lt. Col. Med. Corps, U. S. A., 458 Delaware Avenue, Albany, N. Y.
 +
 +
Scott, Johx W., Ph.D., Professor of Zoology and Research Parasitologist, University of Wyoming, Laramie, Wyoming.
 +
 +
Scott, Katherixe Julia, A.B., M.D., Instructor in Anatomy, Department of Anatomy, University of California, Berkeley, Calif.
 +
 +
Selling, Lawrence, A.B., M.D., Selling Building, Portland, Ore.
 +
 +
Senior, H. D., M.D., D.Sc, F.R.C.S., Professor of Anatomy, New York University and Bellevue Hospital Medical College, 338 East 26th Street, New York City.
 +
 +
Shaxer, Ralph Faust, Ph.D., Instructor in Anatomy, Department of Anatomy, Harvard Medical School, Boston, Mass.
 +
 +
Sharp, Claytox, A.B., M.D., Assistant Professor Dental Histology and Embryology, Columbia University, 437 West 59th Street, New York City.
 +
 +
Shellshear, Joseph Lexden, ^T.B., Ch.M., Demonstrator of Anatomy, University College, Gower St., London, W. C. 1, England. (Present address — Dept. of Anatomy, Johns Hopkins Medical School, Baltimore.)
 +
 +
Sheppard, Hubert, M.A., Ph.D., Assistant Professor of Anatomy, University of Kansas, School of Medicine, Lawrence, Kansas.
 +
 +
Shields, Randolph Tucker, A.B., M.D., Professor of Histology and Embryology, School of Medicine, Shantung Christian University, Tsinan, Shantung, China.
 +
 +
Shimidzu, Yoshitaka, M.D., Professor of Gynecology, Nagasaki Medical College, Nagasaki, Japan
 +
 +
Shufeldt, R. W., M.D., Major Medical Corps, U. S. A. (Retired), 3356 Eighteenth Street, Washington, D. C.
 +
 +
Silvester, Charles Frederick, Captain Sanitary Corps, U. S. A., Guyot Hall, Princeton University, Princeton, N. J.
 +
 +
 +
 +
PROCEEDINGS HI
 +
 +
Simpson, Sutherland, M.D., D.Sc, F.R.S.E. (Edin.), Professor of Physiology, Cornell University Medical College, Ithaca, N'. Y.
 +
 +
Sltjder, Greenfield, M.D., Clinical Professor of Laryngology and Rhinology, Washington University Medical School, 354^ Washington A venue, St. Louis, Mo.
 +
 +
Smith, David T., A.B., Medical Student, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Smith, George Milton, A.B., M.D., Attending Surgeon, Waterbury Hospital, 111 Buckingham Street, Waterbury, Conn.
 +
 +
Smith, Grafton Elliot, M.A., M.D., F.R.S., Professor of Anatomy, University College, Gower St., London, W. C. 1, England.
 +
 +
Smith, H. P., A.B., Hooper Research Lab., 1332 Sixth Ave., San Francisco, Calif.
 +
 +
Smith, Philip Edward, M.S., Ph.D., Assistant Professor of Anatomy, University of California, 1513 Scenic Avenue, Berkeley, Calif.
 +
 +
Smith, Wilbur Cleland, M.D., Surgeon, Americus, Ga.
 +
 +
Snow, Perry G., A.B., M.D., Dean and Professor of Anatomy, University of Utah Medical School, Salt Lake City, Utah.
 +
 +
Spaulding, M. H., A.m., Assistant Professor of Zoology, University of Montana, Bozeman, Montana.
 +
 +
Speidel, Carl C, Ph.D., Adjunct Professor of Anatomy, University of Virginia, University, Va.
 +
 +
Stewart, Chester A., A.M., Ph.D., Fellow in Pediatrics, Roorn 121, Millard Hall, University of Minnesota, Minneapolis, Minn.
 +
 +
Stewart, Fred Waldorf, A.B., Ph.D., Instructor in Neurology, Cornell University Medical College, Ithaca, N. Y.
 +
 +
Stiles, Henry Wilson, M.D., Professor of Anatomy, College of Medicine, Syracuse University, 309 Orange Street, Syracuse, N. Y.
 +
 +
Stockard, Charles Rupert, M.S., Ph.D., Sc.D., (Secretarj'-Treasurer '14- ), Professor of Anatomy, Cornell University Medical College, New York City.
 +
 +
Stone, Leon Stansfield, Ph.B., Assistant in Anatomy, Medical College, Yale University, New Haven, Conn.
 +
 +
Stone, Robert S., B.A., Assistant in Anatomy, Peking Uiiion Medical College, Peking, China.
 +
 +
Stopford, John Sebastian B., ]\LD., Professor of Anatomy, University of Manchester, Manchester, England.
 +
 +
Stotsenburg, James M., INLD., Instructor in Anatomy, The Wistar Institute of Anatomy and Biology, Philadelphia, Pa.
 +
 +
Streeter, George L., A.M., M.D., (Ex. Com. 'IS-), Director Department of Embryology, Carnegie Institution of Washington, Johns Hopkins Medical School, Ballimore, Md.
 +
 +
Stromsten, Frank Albert, D.Sc, Associate Professor of Animal Biology, State University of Iowa, 943 Iowa Avenue, Iowa City, Iowa.
 +
 +
Strong, Oliver S., A.M., Ph.D., Associate Professor of Neurology, Columbia University, 437 West 59th Street, New York City.
 +
 +
Strong, Reuben Myron, A.M., Ph.D. (Ex. Com. '16-'19), Professor of Anatomy, Loyola University School of Medicine, 706 South Lincoln Street, Chicago, III.
 +
 +
Sullivan, Walter Edward, A.M., Ph.D., Assistant Professor of Anatomy, University of Wisconsin, Science Hall, Madison, Wis.
 +
 +
 +
 +
112 AMERICAN ASSOCIATION OF ANATOMISTS
 +
 +
SuNDWALL, John, Ph.D., M.D., Professor of Hygiene, Universitij of Minnesota,
 +
 +
Minneapolis, Minn. Sutton, Alan Callender, A.B., M.D., Johns Hopkins Medical School, S129
 +
 +
St. Paul Street, Baltimore, Md. SwETT, Francis Huntington, A.M., Assistant, Osborn Zoological Laboratory,
 +
 +
Yale University, New Haven, Conn. Swift, Charles H., M.D., Ph.D., Assistant Professor of Anatomy, University
 +
 +
of Chicago, 5632 Maryland Avenue, Chicago, III. Swingle, W. W., Ph.D., Instructor in Zoology, Yale University, New Haven,
 +
 +
Conn. Takenouchi, Matsuziro, M.D., Assistant Professor of Bacteriology and
 +
 +
Hygiene, Medical College, Imperial University of Tokio, Tokio, Japan. Terry, Robert James, A.B., M.D. (Ex. Com. '08-'12), Professor of Anatomy,
 +
 +
Washington University Medical School, St. Louis, Mo. Thomson, Arthur, M.A., M.B., LL.D., F.R.C.S., Professor of Anatomy, Uni rersity of Oxford, Department of Human- Anatomy , Oxford, England. Thorkelson, Jacob, M.D., Daly Bank Bldg., Anaconda, Montana. Thro, William C, A.M., M.D., Professor of Clinical Pathology, Cornell University Medical College, 28th Street and 1st Avenue, New York City. Thijringer, Joseph M., M.D., Assistant Professor of Anatomy, Tulane University, P. 0. Station 20, New Orleans, La. Thyng, Frederick Wilbur, Ph.D., Associate Professor of Anatomy, University
 +
 +
and Bellevue Hospital Medical College, 338 East 26th Street, Neio York
 +
 +
City. Tilney, Frederick, M.D., Ph.D., Professor of Neurology, Columbia University,
 +
 +
22 East 63rd Street, New York City. . Todd, T. Wingate, M.B., Ch.B. (Mane), F.R.C.S. (Eng.), (Vice-Pres. '20),
 +
 +
Professor of Anatomy, Medical Department, Western Reserve University,
 +
 +
1353 East 9th Street, Cleveland, Ohio. Tracy, Henry C, A.M., Ph.D., Professor of Anatomy, University of Kansas,
 +
 +
Lawrence, Kansas. TuppER, Paul YoER, M.D., Clinical Professor of Surgery, Washington University
 +
 +
Medical School, Wall Building, St. Louis, Mo. Turner, Clarence L., M.A., Ph.D., Professor of Zoology, Beloit College, Beloit,
 +
 +
Wisconsin. Vance, Harry Wellington, A.B., Medical Student, Johns Hopkins Medical
 +
 +
School, Baltimore, Md. VAN deu Horst, C. J., Ph.D., Zoologi.-ich Labor atorium, PL Muidergracht 34,
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 +
A m.'itcrdam, Holland. Van der Stricht, Omer, M.D., Professor of Histology and Embryology, University of Ghent, 71 March4 au lin, Ghent, Belgium. Waite, Frederick Clayton, A.M., Ph.D., Professor of Histolocv and Embryology, Western Reserve University School of Medicine, 1353 East 9th
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Street, Cleveland, Ohio. VVallin, Ivan E., M.A., D.Sc, Professor of Anatomy, University of Colorado,
 +
 +
College of Medicine, Boulder, Colo. Walmsley, Thomas, M.D., Professor of Anatomy, Queens University of Belfast,
 +
 +
Belfast, Ireland.
 +
 +
 +
 +
PROCEEDINGS 113
 +
 +
Warrex, John, A.B., AI.D., Associate Professor of Anatomy, Harvard Medical School, Boston, Mass.
 +
 +
Waterston, David, M.A., M.D., F.R.C.S. Ed., Butte Professor of Anatomy, University of St. Andrews, St. Andrews, Fife, Scotland.
 +
 +
Watkins, Richard Watkin, B.S., Instructor in Anatomy, Department of Anatomy, University of Chicago, Chicago, III.
 +
 +
Watson, David Meredith Sears, M.Sc, Lecturer in Vertebrate Paleontology, University College, Gower St., London, W . C. 1, England.
 +
 +
Watson, Ernest M., A.M., M.D., Instructor in Applied Anatomy, University of Buffalo, 494 Franklin St., Buffalo, N. Y.
 +
 +
Watt, James Crawford, M.A., M.D., Assistant Professor of Anatomy, University of Toronto, 20 Haivthorne Avenue, Toronto, Canada.
 +
 +
Weed, Lewis Hill, A.M., M.D., (Ex. Com. '20), Professor of Anatomy, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
Wegeforth, Paul, A.B., M.D., Captain M. C, U. S. A., Coronado, Calif.
 +
 +
Weidenreich, Franz, M.D., a.o. Professor and Prosector of Anatomy, formerly 19 Vogesen Street, Strassburg, i Els. France.
 +
 +
West, Randolph, A. M., M.D., College of Physicians and Surgeons, 437 West 59th Street, New York City.
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White, Harry Oscar, M.D., University Club, Los Aiigeles, Calif.
 +
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Whitnall, S. E., M.A., M.D., B.Ch., Professor of Anatomy, McGill University, Montreal, Canada.
 +
 +
Wittenborg, a. H., M.D., Professor of Anatomy, College of Medicine, University of Tennessee, Memphis, Tenn.
 +
 +
Wilder, Harris Hawthorne, Ph.D., Professor of Zoology, Smith College, Northampton, Mass.
 +
 +
Wilhelmj, Charles M., A.B., Teaching Fellow in Anatomy, St. Louis University ^ledical School, I402 South Grand Ave., St. Louis, Mo.
 +
 +
Williams, James Willard, B.A., ]M.A., Professor of Biology, College of Yale in China, Changsha, Chijia.
 +
 +
Williams, Stephen Riggs, A.M., Ph.D., Professor of Zoology and Geology, Miami University, 300 East Church Street, Oxford, Ohio.
 +
 +
Willard, William A., A.]\I., Ph.D., Professor of Anatomy, University of Nebraska, College of Medicine, 42d Street and Dewey Avenue, Omaha, Neb.
 +
 +
Wilson, J. Gorden, M.A., M.B., CM. (Edin.), Professor of Otology, Northwestern University Medical School, 2481 S. Dearborn Street, Chicago, III.
 +
 +
Wilson, James Thomas, M.B., F.R.S., Challis Professor of Anatomy, University, Sydney, Australia.
 +
 +
Wilson, Louis Blanchard, M.D., Director of Pathology Division, Mayo Clinic and Mayo Foundation, Professor of Pathology in the University of Minnesota, Mayo Clinic, 830 W. College Sreet, Rochester, Minn.
 +
 +
Wislocki, George B., A.B., M.D., Associate in Anatomy, Johns Hopkins Medical School, Baltimore, Md.
 +
 +
WiTHERSPOON, Thomas Casey, M.D., Murray Hospital, Butte, Mont.
 +
 +
Woollard, Herbert T., M.D., Demonstrator of Anatomy, University College, Gower St., London, W. C. 1, England.
 +
 +
Worcester, John Locke, M.D., Professor of Anatomy, University of Washington, 5211-21st Avenue, N.E., Seattle, Wash.
 +
 +
 +
 +
r
 +
 +
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\^'^
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BOOKS RECEIVED
 +
 +
THE BLIND : Their coxdition axd the work being done for them in the United States, by Harrj^ Best, Ph. D., 764 pages, The Macmillan Company, New York, 1919.
 +
 +
Foreword. In the present study the field of inquiry in respect to the blind has been limited to the United States, except in so far as an account is necessary of the operations in foreign countries in the way of affording instruction to blind children and of devising a system of raised print, as an introduction to the work in this country. References are accordingly only to American sources, save as to a restricted number of publications in England dealing with the two subjects mentioned, with popular conceptions regarding the blind, and occasionally with other matters.
 +
 +
EMBRYOLOGY OF THE CHICK, by Bradley M. Patten, Western Reserve University, 168 pages, 182 figures, P. Blakiston's Son & Company, Philadelphia, 1920.
 +
 +
Preface. The fact that most courses in vertebrate embryology deal to a greater or lesser extent with the chick seems to warrant the treatment of its development in a book designed primarily for the beginning student. To a student beginning the study of embrj^ology the very abundance of information available in the literature of the subject is confusing and discouraging. He is unable to cull the essentials and fit them together in their proper relationships and is likely to become hopelessly lost in a maze of details. This book was written in an effort to set forth for him in brief and simple form the early embryology of the chick. It does not purport to treat the subject from the comparative view point, nor to be a reference work. If it helps the student to grasp the structure of the embryos, and the sequence and significance of the processes he encounters in his work on the chick, and thereby conserves the time of the instructor for interpretation of the broader principles of embrj^ology it will have served the purpose for which it was written.
 +
 +
THE STORY OF THE .AJMERICAN RED CROSS IN ITALY, by Charles M.
 +
 +
Blakewell, 254 pages, 20 Illustrations, The Macmillan Company, New York,
 +
 +
1920.
 +
 +
Introduction. The purpose of this book is not to give a detailed statistical account of Red Cross activities in Italy, — that may be found in the various Department Reports, — but rather to tell the American people who contributed so generousl}^ to the Red Cross funds the simple tale of what their dollars did in Italy. It is a great and inspiring record and one in which Americans may well take pride.
 +
 +
 +
 +
THE ANATOMICAL RECORD, VOL. 21, NO. 2
 +
 +
 +
 +
Resumen por el autor, George L. Streeter.
 +
 +
La emigraeion de la vesicula auditiva del renacuajo.
 +
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En el curso ordinario del desarroUo la vesicula auditiva del renacuajo experimenta una emigraeion definida, moviendose desde el sitio en el cual se desprende de la piel a una posicion mas medial y dorsal, de tal modo que eventualmente viene a situarse muy cerca de la superficie lateral del cerebro posterior, con el ap6ndice endolinfatico recubriendo el borde del delgado velo medular que forma el techo del cuarto ventriculo.
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Esta particularidad, aparentemente, no es simplemente el resultado de un ajuste producido durante su desarrollo por la interaccion de los procesos mecanicos de las estructuras adyacentes, sino que se debe, al menos parcialmente, a una tendencia autostatica inherente a la vesicula misma, por medio de la cual mantiene y ajusta exactamente su posicion durante al desarrollo con relaci6n al cerebro y las estructuras que le rodean.
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Translation by Jos6 F. Nonidez Cornell Medical College, New York
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AUTHORS ABSTRACT OF TII'S PAPf:R ISSUED BY THE BIBL'-OGHAPHK: SEKVICE, MAT 9
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MIGRATION OF THE EAR VESICLE IN THE TADPOLE DURING NORiMAL DEVELOPMENT
 +
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GEORGE L. STREETER
 +
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Department of Embryology, Carnegie Institution of Washington, Baltimore, Marylayid
 +
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ELEVEN FIGURES
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In 1837 von Baer made the observation that the diaphragm is situated in the neck region in very young embryos, receiving its innervation from the cervical nerves, and that in the course of its development it acquires a more caudal position corresponding to the enlargement of the heart and lungs. This descent of the diaphragm was subsequently described in greater detail by Mall ('97). Uskow ('83) and Mall ('97) pointed out the marked shifting of position which the heart, lungs, liver, intestinal tract, and Wolffian bodies undergo during development in relation to each other and to the vertebral column. The migration of these organs in the embryo has given us the explanation of the peculiar course of their nerves of supply; for example, the inferior laryngeal, the vagus, the phrenic, and the splanchnic nerves. Kolliker ('61) showed that the shifting in position of the spinal cord produces an elongation of the spinal-nerve roots and the formation of the Cauda equina. The influence of this factor in the formamation of the filum terminale has been recently studied by Kunitomo ('18). It has been shown by Lewis ('01, '10) that such muscles as the trapezius and the eye muscles undergo considerable shifting in position between the time of their first appearance and the time when they have acquired their permanent attachments. Among others, Futamura ('06) has described the migration of the facial muscles and the consequent deflected distribution of the branches of the facial nerve. Within the central nervous system there are several instances where the
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115
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116 GEORGE L. STREETER
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component nuclear masses exhibit a distinct migration in the course of their development (Streeter, '08; Kappers, '10). As a result of their disproportionate growth, the primary divisions of the brain shift into new positions relative to each other, and this is accompanied by an interesting adjustment on the part of the vascular drainage of these structures. Kohn ('07) and others have shown that the sympathetic gangUa undergo an extensive peripheral migration. When the places of origin of the thjTQus and thyroid glands were first discovered, it was recognized that these organs exhibit a conspicuous type of migration. Even in the case of the skeleton, it has been maintained (Rosenberg, '76) that the point of vertebral articulation of the pelvic girdle moves along the column into the lumbar territory during development, although this has not been adequately substantiated. There is, however, a very good example of topographical adjustment of bony structures in the case of the teeth.
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To any one occupied with the study of organogenesis, the developmental alteration in topography that is everyAvhere in progress is very striking. In some cases it is obviously a matter of mechanical stress exerted by adjacent organs upon each other, the controlling factors being their relative increase in size and the relative resistance of their tissues; or it may be a matter of traction in connected organs. In other instances we find structures invading new territories by virtue of the direction of their growth, which is dependent on the fact that the proliferation and increase in size of their constituent cells are more active in one direction than in another. In some cases this is associated with a thinning out and disappearance (possibly dedifferentiation) of the opposite pole of the organ, resulting in its complete transposition. Such factors are easily understood and various combinations of them explain most of the instances of developmental topographical alteration in organs which we encounter. There are other cases, however, which are more obscure and in which the movement of the organs or structures during their development cannot be entirely explained by simple mechanical factors; in these the phenomenon resembles a true migration such as is seen in individual cells. For lack of a better explanation, we
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MIGRATION — EAR VESICLE IN TADPOLE 117
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must consider the possibility of the existence of some force, of the nature of a chemotaxis, interacting between these structures and their environment. It is in this group that we must place the ear vesicle which, during the course of normal development, exhibits a considerable change in position. It is to this that I would call attention here.
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From several studies previously reported by the writer (Streeter, '07, '09, '14) and from a recent paper by Ogawa ('21), it is apparent that the determining factors in the posture of the membranous labyrinth involve something more than a passive development of the ear vesicle in the position in which it originally finds itself. It is clearly evident, moreover, that the final position of the labyrinth is not simply the result of an adjustment brought about during its development by the interaction of mechanical processes of the adjacent structures, but that it is due, in part at least, to an autostatic tendency inherent in the vesicle itself, by virtue of which it maintains and accurately adjusts its position during development with reference to the brain and the surrounding structures. When an early ear vesicle is experimentally rotated into an abnormal position, or transplanted in an abnormal position to the opposite side of the same specimen or to another specimen, it subsequently tends to correct its posture, and the final labyrinth, in spite of the previous displacement, is found to possess normal topographical relations.
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It is of interest to record that not only under artificial conditions, but also in the ordinary course of development, the ear vesicle of the tadpole undergoes a definite migration, moving from the point of its detachment from the skin to a more median and dorsal location, so that it eventually lies close against the side of the hindbrain with its endoljonphatic appendage overlapping the margin of the thin medullary velum that forms the roof of the fourth ventricle.
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If one prepares sections through the auditory region in a series of tadpoles covering the period between the premotile stage and the end of the first month, the changing relations of the ear vesicle to the surrounding structures can be readily made out (figs. 1 to 9). These figures are made with the same
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118 GEORGE L. STREETER
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magnification and thus, by comparing them, it is possible to determine the actual increase in size, as well as the differentiation of the walls and the alteration in the position of the individual vesicles. In figures 7 and 8 the length of the specimens is given; in the remaining figures the age given is the length of time the specimen was allowed to develop after reaching the operating stage, i.e., when it has acquired a distinct tail bud and gill eminences, but has not yet exhibited any motor response to stimuli.
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In the first stage shown (fig. 1) the relatively thin lateral wall of the ear vesicle lies tight against the ectoderm. The vesicle is separated from the thick endoderm and the brain tube by a narrow interval filled with mesenchyme which is beginning to show open spaces in the vicinity of the notochord, elsewhere being relatively compact and heavily laden with yolk. As yet there are no blood-vessels in this region and the acoustic nerve and ganglion are not clearly differentiated from the surrounding tissue. It will be noticed that the lateral plate of the brain tube lies in a vertical plane and the point at which the ventral nerve roots are to converge lies opposite the dorsal tip of the ear vesicle.
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In the next stage (fig. 2) the ear vesicle remains in close contact with the ectoderm. The surrounding mesenchyme is assuming a reticular character and in it the primary bloodvessels can be recognized. The acoustic ganglion is distinctly marked off, being attached to the anteromedian surface of the vesicle and connected by a strand with the brain wall. The roof of the latter is thinning out and the lateral walls are undergoing eversion. In the third stage (fig. 3) the conditions are essentially the same, although the vesicle wall has undergone further differentiation, the mesenchyme is distinctly reticular, and there is further eversion of the brain wall. In the sections oral to the one selected for illustration, the acoustic-nerve ganglion is present. It can be seen that the ear vesicle at this time is widely separated from the brain and almost wholly ventral to it. The intervening mesenchyme is loose and would offer slight mechanical obstruction to the migration of the vesicle, and
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Figs. 1 to 9 Sections showing the changes in the topographical relations of the ear vesicle of the tadpole during the period between the premotile stage and the end of the first month. In figures 1 to 6 and figure 9 the age given is the length of time the larva was allowed to develop after reaching the operating stage; i.e., tail bud and gill eminences present, but no motor response to stimuli exhibited. X 50. B.V., primitive blood-vessel ple.xus; Endol., endolymphatic appendage; VIII, acoustic nerve ganglion; IX, glossopharyngeal nerve ganglion.
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119
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120 GEOEGE L. STREETER
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certainly the primary brain blood-vessel cannot be regarded as a serious obstruction, since we find that even a much more mature vascular system can readily accommodate itself to any movement of the surrounding organs. A brilliant example of this is seen in the case of the venous drainage of the fetal cerebrum. Migration, however, cannot occur so long as the vesicle adheres to the ectoderm. Its detachment therefrom becomes complete in the next two stages.
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The stage illustrated in figure 4 is at the critical point where the vesicle is becoming detached coincident with an invasion of mesenchyme between it and the ectoderm. At the same time the brain shows further development of the roof of the fourth ventricle and continued eversion of its walls which tends to thrust it toward the ear vesicle. The vesicle itself is assuming a more dorsal position, as compared with the previous stage. The portion that is to form the endolymphatic appendage can be clearly recognized from five hours on; by the second day it is not only thicker than the rest of the wall of the vesicle, but also shows a beginning evagination and a distinct differentiation of its component cells. A conception of the shifting that is in progress can be obtained by the realization that the endolymphatic appendage of figure 4 will eventually overlap the rhombic lip of the brain wall.
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By the third day (fig. 5) the upper half of the ear vesicle is above the level of the junction of the brain and notochord and is surrounded on all sides by reticular mesenchyme which should favor its migration. Its only attachment is that of the acoustic nerve ganglion which forms a massive strand firmly attached at one end to the brain wall and at the other to the anteromedial wall of the ear vesicle. From the differentiation of the mantle zone -of the brain wall it can be seen that the point of attachment of the nerve corresponds closely to its permanent point of entrance and, tracing it peripherally to the vesicle wall, its fibers can be followed to the macular area. The size and character of the acoustic nerve might lead one to attribute to it a definite influence in any subsequent movement of the vesicle; but we know that the phrenic nerve exhibits no restraining mfluence in
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MIGRATION — EAR VESICLE IN TADPOLE 121
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the descent of the diaphragm and there is no evidence that the facial nerve exercises any guiding force in the migration of the musculature of the face. It is to be noted that there is still a relatively wide interval between the vesicle and the brain wall. As yet the mesenchyme shows no differentiation into skeletal framework, but on each side of the notochord can be seen the oral extension of the spinal musculature.
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Up to the fourth day (fig. 6) there has been a gradual thinning of the main part of the wall of the ear vesicle, accompanied by an increase in the am.ount of the contained otic fluid, and at this time the first steps occur in the formation of the semicircular ducts. A little more than half of the vesicle is now above the level of the junction of the notochord and the brain. The vesicle and brain wall are more closely approximated, which may be explained in part by the further eversion and growth of the latter. On the other hand, there is a beginning differentiation of the subcutaneous tissues and pigment membrane producing an increase in the distance between the ear vesicle and the surface of the larva.
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In larvae 9 mm. long (fig. 7) one finds the formation of the semicircular ducts well under way and at the same time the mesenchyme lateral to the ear vesicle is differentiated into a characteristic subcutaneous tissue, while that median to the vesicle shows a condensation into precartilage tissue. Spreading from the chordal area toward the ear vesicle and surrounding the brain can be seen arachnoidal spaces of a primitive type. Notwithstanding this more permanent type of environment, the dorsal migration of the vesicle is not yet complete, for in older stages almost the entire vesicle lies dorsal to the level of the chorda.
 +
 +
In larvae 12 mm. long the endolymphatic appendage and the dorsal crest of the vesicle have nearly reached the level of the rhombic lip, and at the same time the lowest point of the vesicle lies opposite the level of the center of the notochord. The dorsal extension at this time is due in part to the direction of the growth, associated with the formation of the anterior and posterior semicircular ducts and the increase in the length of the endolymphatic appendage.
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122
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GEORGE L. STREETER
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At one month the ear vesicle is completely differentiated into a membranous labyrinth with three semicircular ducts and a characteristic macular area to which is attached the gangHon and its peripheral nerve terminations. A characteristic endolymphatic appendage is present, consisting of a relatively large sac connected by a slender duct with the vestibular portion of the labyrinth. As can be seen in figure 9, the sac now Ues in close contact with the thin roof of the fourth ventricle. The labyrinth lies wholly dorsal to the midlevel of the notochord and is secured in this position by the mesenchymal otic capsule,
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Fig. 10 Diagram showing the migration of the ear vesicle relative to the brain wall from the position it occupies at the end of the second*,day (ot.) to the position it attains as a differentiated labyrinth at the end of the first month (of), the brain wall being represented as stationary.
 +
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consisting of precartilage tissue, portions of which are already differentiated into typical cartilage cells surrounded by a homogeneous matrix. With this stage the essential relations of the labyrinth may be regarded as established; the subsequent minor changes in its topography are those determined by the mechanical factors of its own further growth and the further growth and differentiation of the surrounding structures.
 +
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From the foregoing comparison of the individual stages it is clear that the ear vesicle shifts its position relative to the brain wall to the extent diagrammatically shown in figure 10. ^Miereas at the end of the second day the vesicle lies ventral to and apart
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MIGRATION^ — EAR VESICLE IN TADPOLE
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123
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from the brain, at the end of the first month it is situated close against the lateral brain wall with its endolymphatic appendage overlapping the rhombic Hp. In the figure there has been no account taken of the lateral movement of the brain wall, and therefore to that extent the path of migration of the ear vesicle is exaggerated. Its dorsal migration relative to the notochord, the ectoderm, and the everted brain wall may be represented as in figure 11, which shows more accurately than figure 10 the extent of its change of position relative to the whole environment. Although the normal migration of the ear vesicle is not so marked
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D. 5emicirc Lot.
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Fig. 11 Superimposed sections of the ear region of a tadpole of the nineteenth hour (dotted) and of another at the end of the first month, enlarged so that the brain is the same size in both cases, the two being fitted so as to exactly coincide.
 +
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as that of the thymus and many other organs, nevertheless that phenomenon unquestionably occurs. To some extent the mechanical forces of growth of the concerned parts can be recognized as influencing the migration; no single one of these factors, however, or no combination of them would appear to adequately explain it.
 +
 +
The detachment of the vesicle from the skin is readily explained by the differentiation of the subcutaneous tissues and the formation of the pigment membrane. This begins to take place about the second day. By the fourth day the elements of the pigment membrane make their appearance, and in tadpoles 12 mm. long there is a relatively complete membrane separating the vesicle
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124 GEORGE L. STREETER
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from the loose tissue underlying the ectoderm. This differentiation releases the vesicle from its firm attachment to the ectoderm, but it does not in any way favor its dorsal migration.
 +
 +
The change in the relative position of the ear vesicle and the brain wall is in part accounted for by the direction of growth of the latter, which undergoes an eversion whereby it is thrust ventralward and lateralward toward the vesicle. The maximum effect of this eversion is reached at the end of the fourth day, but at this time, in addition to the close approximation of the brain wall and the ear vesicle, a dorsal shifting of the latter has occurred relative to the level of the notochord, a fact which can hardly be explained by the change in position of the lateral brain plate.
 +
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As to this dorsal migration of the vesicle as a whole, which takes place gradually throughout the first month, one should consider the possibility of its being due to the direction of growth of the vesicle; i, e., that the dorsal portions of the vesicle may perhaps grow more rapidly than the ventral portions. In the case of the endolymphatic appendage, the direction of growth may very well constitute a factor in the attainment of its final position. The dorsal growth of the sac and the elongation of its duct would favor its dorsal shifting. Aside from the slender endoljTiiphatic duct, however, there appears to be nothing to prevent the sac from occasionally going astray orally or caudally, where the tissues would offer httle obstruction to its extension in these directions. That it never does so forces one to postulate the existence of some form of determinative attraction between the endoljiiiphatic sac and the medullar}^ roof to which it later invariably becomes intimately attached.
 +
 +
There is no evidence that the acoustic nerve gangUon plays any considerable part in the way of a guiding or traction force. The nerve can be recognized at the fifth hour, connecting the vesicle with the brain wall, but when it is experimentally detached, as in the transplantation of a vesicle from one tadpole to another, the severing docs not interfere with a correct adjustment of the posture of the vesicle. This corresponds to our experience with other organs, in which the nerves do not act as a check or show
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MIGILITION — EAE VESICLE IN TADPOLE 125
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any evidence of influencing the migration of the organs in any way. The surrounding mesench>^ne and primitive blood vessels can also be dismissed as factors.
 +
 +
The cartilaginous skull does not make its appearance until the final relations of the labyrinth to its environment are essentially estabhshed, that is, toward the end of the first month, and therefore cannot play a primary part in the migration of the vesicle. However, after the firm otic capsule becomes differentiated the latter must absolutely control those further alterations in the posture of the contained labyrinth which are associated with the final changes in the form of the base of the skull.
 +
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LITERATURE CITED
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V. Baer, K. E. 1S37 Ueber Entwickelungsgeschicht der Thiere. Konigsberg. FuTAMURA, R. 1906 Ueber die Entwicklung der Facialismuskulatur des Men schen. Anat. Hefte, Bd. 30. Kappers, C. U. Ariens 1910 The migrations of the abducens-nucleus and the
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concomitating changes of its root-fibers. Psychiatrische en Neuro logische Bladen.
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1910 The migrations of the motor cells of the bulbar trigeminus,
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abducens and facialis in the series of vertebrates, and the differences
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in the course of their root -fibers. Verh. d. k. Akad. v. Wetenschr. t.
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Amsterdam, Tweede sectie, Deel 16. KoHN, A. 1907 Ueber die Schiedenzellen peripherer Ganglionzellen. Anat.
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Anz., Bd. 30. KoLLiKER, A. 1861 Entwicklungsgeschichte des Menschen und der hoheren
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Thiere. Leipzig. KuNiTOMO, K. 1918 The development and reduction of the tail and of the
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caudal end of the spinal cord. Contributions to Embryology, vol. 8.
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Carnegie Inst. Wash., Pub. 271. Lewis, W. H. 1901 The development of the arm in man. Am. Jour. Anat.,
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vol. 1.
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1910 The development of the muscular system. Manual of Human
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Embryology (Keibel and Mall), vol. 1. Mall, F. P. 1897 Development of the human coelom. Jour. Morph., vol. 12. Ogawa, C. 1921 ExQeriments on the orientation of the ear vesicle in amphibian
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larvae. Jour. Exp. Zool., vol. 32. Rosenberg, E. 1876 Ueber die Entwickelung der Wirbelsaule und das Centrale
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carpi des Menschen. Morph. Jahrb., Bd. 1. Streeter, G. L. 1907 Some factors in the development of the amphibian ear
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vesicle, and further experiments on equilibration. Jour. Exp. Zool.,
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vol. 4.
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1908 The nuclei of origin of the cranial nerves in the 10 mm. human
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embryo. Anat. Rec, vol. 2, p. 115.
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126 GEORGE L. STREETER
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Streeter, G. L. 1909 Experimental observations on the development of the
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amphibian ear vesicle. Anat. Rec, vol. 3.
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1914 Experimental evidence concerning the determination of posture
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of the membranous labyrinth in amphibian embryos. Jour. Exp.
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Zool., vol. 16. UsKOW, N. 1SS3 Ueber die Entwicklung des Zwerchfells, des Pericardiums
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und des Coloms. Arch. f. mikr. Anat., Bd. 22.
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>
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V
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Resumen por los autores, E. L. y E. R. Clark.
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El caracter de los linfaticos en el edema experimental.
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Los autores han producido edema en el renacuajo mediante: (1) Extirpacion del pronefros; (2) extirpacion del esbozo del corazon; (3) impidiendo el desarrollo de la musculatm-a del coraz6n linfatico, y (4) en conexi6n con la inflamacion aseptica. 1. En los individuos sin pronefros, el liquido plasmatico se acumula tan solo en la cavidad abdominal. La circulaci6n sanguinea se hace mds dificil y el desarrollo de los vasos sanguineos se retarda. Los linfaticos se desarrollan, y en apariencia funcionan normalmente. 2. Cuando se extirpa el corazon el edema esta limitado a las cavidades del cuerpo. Los capilares linfaticos de la cola aparecen un poco mas grandes que lo normal. 3. En renacuajos desprovistos de coraz6n linfatico contractu grandes cantidades de liquido se acumulan en los senos cefalicos, y eventualmente en el tejido subcutaneo del cuerpo y cola. 4. En el edema inflamatorio los copilares linfaticos de la regi6n afectada se distienden.
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En embrion^s de polio, los autores impidieron el desarrollo del coraz6n linfatico cortando la cola en los embriones de tres dias. A los siete dias los embriones estan edematosos. La inyecci6n demuestra la presencia de linfaticos distendidos en forma de saco, en vez de aparecer como los conductos mjis pcquefios, presentes en" los embriones normales. Conclusiones :
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1. Los capilares linfaticos se desarrollan normalmente, absorbiendo Unfa, sin circulaci6n sanguinea o con circulaci6n defectuosa.
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2. Cuando se impide la salida del liquido que ocupa los linfaticos estos se distienden. 3. La acumulaci6n de fluido en los espacios de los tejidos esta asociada con una dilataci6n de los capilares linfdticos. Este resultado se opone a la idea generalmente mantenida por los pat61ogos, de que los capilares linfaticos se contraen en el edema.
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Translation by Jos6 F Nonidez Cornell Medical College, New York
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AtrrHOR S ABSTRACT OF THIS PAPER ISSTIED BT THE BIBLIOGRAPHIC SERVICE, MAT 9
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THE CHARACTER OF THE LYMPHATICS IX EXPERIMENTAL EDEMA
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ELEANOR LINTON CLARK and ELIOT R. CLARK
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Anatomical Laboratory, University of Missouri
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FIVE FIGURES
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CONTENTS
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Introduction 127
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Experimental edema in Amphibian larvae 128
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1. Removal of the pronephros 128
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2. Removal of the blood heart • 129
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3. Operation to prevent the development of the lymph-heart musculature 130
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4. Inflammatory edema 131
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5. Experiments with acetic acid 133
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Experimental edema in chick embryos 135
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Discussion and conclusion 138
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Literature cited 141
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INTRODUCTION
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Abnormal collections of fluid in the tissue spaces and serous cavities may be caused by a disturbance in any of the factors concerned with the normal formation transudation and absorption of lymph in the animal organism. The causes are probably different in the different tj'-pes of edema and a number of causes may be involved simultaneously (Wells, '18). Although the lymphatic system is known to be intimately concerned with the normal absorption of fluid, the relation of the l^Tnphatics to edema has never been thoroughly studied. It is well known that edema of a limb ma}^ be caused by blocking of the main IjTiiph channels or l\aTiph glands draining the limb, but this type is of relatively rare occurrence in adult warm-blooded animals, owing to the ability of the veins to take over a large share of the absorptive function of the lymphatics.
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127
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THE ANATOMICAL RECORD, VOL. 21, NO. 2
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128 ELEANOR LIXTOX CLARK AN^D ELIOT R. CLARK
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Smith and Birmingham ('89) have reported a case of edema of the foetus in which they claim that there was a total absence of lymphatic system.
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The reaction of the lymphatic capillaries to the presence of an increased amount of tissue fluid, found in cases of generalized edema of the subcutaneous tissues, is not well understood. According to Adami ('09), the dehcate walls of the l3Tiiphatic capillaries collapse under the increased pressure of the surrounding fluid.
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We have attempted to produce edema experimentally by several methods with the particular object of studying the effect of this condition upon the lymphatic capillaries. Tadpoles were used for these experiments, because of the possibility of watching the Ijonph capillaries in the hving, in the transparent fin expansion. Some experiments were also performed upon chick embryos.
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EXPERIMENTAL EDEMA IN AMPHIBIAN LARVAE
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Two species of frog larvae were used — Rana pipiens and Rana catesbiana. The operations were performed under the binocular microscope, using chloretone anaesthesia. Small glass needles were used for most of the dissections and iridectomy scissors for the removal of the anlage of the blood heart.
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The lymphatic vessels of the edematous specimens and of normal larvae of the same ages were injected with India ink. The capillaries of the transparent fins were studied in the hving in the observation chamber previously described (E. R. Clark, '12).
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The following methods were tried for producing edema in tadpoles: 1) removal of the pronephros; 2) removal of the anlage of the blood heart; 3) removal of somites to prevent the development of the lymph heart; 4) injection of drops of croton oil to produce inflammation (E. R. and E. L. Clark, '20); 5) acetic acid.
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1. Removal of the pronephros
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This experiment was performed upon a number of tadpoles, during the spring and summer of 1915. Since the general re
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LYMPHATICS IN EXPERIMENTAL EDEMA 129
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suits of this operation have been described by Rowland ('16) and Swingle ('19), it is unnecessary to give a detailed description. Edema developed on the day following the operation and was of the type of ascites, fluid collecting only in the abdominal cavity. During the succeeding days, the development of the tadpoles was greatly retarded, the gills remained external for a longer period than in the controls, the coils of the intestine were fewer, the head and eyes smaller, the tail remained much shorter and more pigmented, and the heart beat sluggishly.
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]\Iicroscopic observation of the transparent tails of such larvae showed a more sluggish circulation and fewer blood capillaries than in the normal specimens. However, the lymph hearts of the larvae with pronephros removed beat as strongly as did those of the controls, and even more frequently, and the lymphatic vessels of the tail had extended beyond the blood-vessels and were normal in appearance.
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2. Removal of the blood heart
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The operation for the removal of the heart in tadpoles has been described by Knower ('07) and the effect upon blood-vessels and hanphatics by E. R. Clark ('18). Embryos operated on in this manner soon become edematous — the collection of fluid being confined to the body cavities, the tail remaining small and pigmented.
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Although the development of the blood-vessels is greatly retarded with the heart absent, that of the lymphatics is not. The lymph hearts are larger and beat more strongly than do those of normal larvae of the same age and there is an active movement of fluid inside the lymph-vessels as demonstrated by the occasional presence of blood-cells wdthin the lymphatics, W'hich were observed to move along with the current.
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In studying the lymphatic capillaries of the tail it was found that these vessels develop normally and often extend beyond the blood capillaries, although in normal embryos of the same age and species, the blood-vessels of this region grow out well in advance of the lymphatics. IMoreover, the haiiphatics are w4der than in normal animals (E. R. Clark, '18).
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130 ELEANOR LINTON CLARK AND ELIOT R. CLARK
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This experiment showed that lymph continues to pass into the l3Tnphatic capillaries in the absence of the heartbeat and blood circulation and that the growth and absorptive power of IjTuphatics are not dependent upon the blood pressure.
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3, Operation to prevent the development of the lymph-heart 7niisculature
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For this experiment the somites dorsoposterior to the pronephros were removed on both sides of the larva. In the majority of cases this effectively prevented the development of the pulsating Ijnnph hearts. Such tadpoles developed normally and were practically indistinguishable from the controls for the first four or five days after the operation. On the sixth or seventh day after the operation, edema of the head region of these embryos makes its appearance. This enlargement was noticed invariably on the same day at which the first pulsation of the IjTnph hearts was observed in normal tadpoles of the same age. During the following days the sinuses of the head became still more distended, while those at the sides of the body also enlarged and finally, ten to fourteen days after the operation, the tail became edematous. In contrast to the larvae deprived of their pronephroi or blood hearts, these tadpoles did not contain an excessive amount of fluid in their abdominal cavities.
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The tadpoles without beating Ijanph hearts lived for three weeks after the operation — the longest period of survival being twenty-six days. During the first two weeks after the operation the tadpoles were as large as the controls, and practically normal except for the edema. During the last week of life, however, the blood circulation became impaired and often ceased altogether.
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In the larvae without lymph hearts, the lymph-vessels were studied by injection of india ink into the main dorsal and ventral lymph-vessels of the tail. The dorsal vessel normally empties into the right lymph heart and the ventral vessel into the left. In the case of the operated tadpoles, the dorsal vessel emptied into a large sinus on the right side and the ventral vessel into a
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LYMPHATICS IX EXPEROIEXTAL EDEMA 131
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similar sinus on the left side. These tail vessels together with their branches were found to be wider than those of the controls and the pressure inside them was found to be high, as shown by the effort required to fill them with the injection material.
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^Microscopic examination of the transparent tails of the tadpoles without l>^nph hearts showed no difference from the normal during the first week after operation. At the end of ten or twelve days the tail begins to show evidences of edema particularly at the base. During the next week these changes become visible throughout the whole tail. The actual increase in the thickness of the tail was measured by means of the micrometer screw of the fine adjustment, b}' focusing on a certain point on the surface of the fin and turning the screw until the opposite surface came into focus, and meanwhile counting the divisions on the screw. The edema is further detected by the changed appearance of the tissue in the fin; the whole region becomes clearer and the connective-tissue cells are more widely separated than in the normal tadpoles. The cells themselves do not enlarge.
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Associated with this increase in fluid present in the connectivetissue spaces, we invariably found an enlargement of the Ijniphatic capillaries. The vessels near the base of the tail are first affected and later the more posterior ones enlarge also. Figures 1, 2, and 3 show the difference in size of the hiiiphatic capillaries in these larvae in contrast to that of the blood capillaries of the same specimens and to that of the Ijanph capillaries of normal tadpoles.
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In addition to change in cahber, hmphatics of these tadpoles with generalized edema also show changes in contour — the irregular outhne with abundant fine processes characteristic of the normal hntiiph capillary is lost and the endothehum becomes smoother and thinner.
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4. Inflammatory edema
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The cell reactions which take place after injection of minute globules of croton oil into the tail fins of amphibian larvae, have been described in a recent publication (E. R. and E, L. Clark, '20).
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132
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ELEANOR LINTON CLARK AND ELIOT R. CLARK
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In a number of instances a localized edema was observed at the site of injur^^ The increase in the amount of fluid in the region was easily detected by the increased transparency of the region and by the greater distance between the connective-tissue cells. The increase in the thickness w^as measured by means of the micrometer fine-adjustment screw. The lymphatic capillary sprouts of the edematous region are always wider than similar vessels of neighboring areas; in fact, the simultaneous enlargement of
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Fig. 1 A. Drawing of vessels from the ventral fin of a tadpole ten days after operation for removal of the lymph hearts. Lym., lymphatic; B.V., bloodvessel. Thicknessof the tail at this point, 310m. B. Drawing of the same region in the ventral fin of a normal tadpole of the same age. Thickness of the tail, 180 M. Note difference in the size of the lymphatic in the two specimens. B.V., blood-vessel; Lym., lymphatic. X 175.
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these capillaries was found to coincide precisely with the increase in intercellular fluid (fig. 15, in article by E. R. and E. L. Clark, The American Journal of Anatomy, ^lay, 1920). This enlargement of the Ijmphatics is characterized by a widening of the lumen of the lymphatics, while the endothelial wall becomes thinner and smoother. These lymphatics regain their normal cali}:)er and contour with a return of the region to its normal thickness. The blood capillaries of such regions show no such chaiiiios.
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LYMPHATICS IN EXPERIMENTAL EDEMA 133
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•5. Expeviments with acetic acid
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These experiments were suggested bj^ the work of IVIartin Fischer ('15) which connects the development of edema with the presence of an acidosis in the tissues. Tadpoles were placed in
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Fig. 2 A. Drawing of vessels from the dorsal fin of a tadpole fourteen days after operation for removal of the lymph hearts. Thickness of the tail at this point, 340 M- B. Vessels from the same region of a normal tadpole of the same age. Thickness of the tail, 170 m- This shows still greater enlargement of the IjTnphatic capillary than in figure 1, A. B.V., blood-vessel; Ly7n., Ij'mphatic. X 175.
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varying strengths of acetic acid, with the object of producing edematous tadpoles. The. results of these experiments were as follows :
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All tadpoles in strengths of acetic acid of 1 to 2000 or stronger were dead at the 6nd of an hour and a half.
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134
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ELEANOR LINTON CLARK AND ELIOT R. CLARK
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Tadpoles left overnight in strengths of acetic acid from 1 to 5000 up to 1 to 15,000 were all dead on the following morning.
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Tadpoles in 1 to 20,000 and 1 to 30,000 survived, and at the end of a week they were as large, active and well developed as the controls and showed no signs of edema.
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Tadpoles placed in 1 to 18,000 and 1 to 19,000 died within twenty-four hours.
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Fig. 3 Drawing of the vessels of the posterior portion of the abdominal wall of an edematous tadpole fifteen days after operation for the removal of the lymph hearts. The lymphatics are greatly distended while the blood-vessels are narrower than normal. X 158.
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These experiments were negative in regard to the production of edema in tadpoles by the use of acetic acid in the surrounding fluid, since all specimens died when the acid was stronger than 1 to 20,000, while in this and in weaker strengths of acid no edema developed. Obviously, these results do not necessarily have any bearing whatever on the theory that edema may be caused by acidosis, since the presence of a trace of acid in the surrounding medium may have had no effect on the acidity of the body fluids.
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LYMPHATICS IN ^EXPERIMENTAL EDEMA 135
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EXPERIMENTAL EDEMA IN CHICK EMBRYOS
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We attempted unsuccessfully to produce edematous chick embryos by chemical means— acetic acid was placed in an open dish in the incubator and alcohol also was tried without success. Only one form of edema was produced in chick embryos — that which resulted from the removal of the posterior lymph hearts. The development of the lymph heart is prevented by cutting off the tail rudiment in embryos of two to three days' incubation. This operation and the early development of the lymphatics in such embryos have been described elsewhere (E. R. and E. L. Clark, '19).
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It was shown in a former publication (E. L. Clark, '15) that the lymph flow in the early superficial lymphatics of chick embryos is dependent to a considerable extent upon the pulsation of the posterior lymph hearts. It was shown that the commencement of lymph heart pulsations, in chicks of 6| days, is the factor which instigates the lymph flow in the posterior half of the embryo. The area drained by the lymph heart increases until, in embryos of seven to eight days, the direction of the entire superficial lymph flow is posterior through the lymph hearts into the veins of the tail. Associated with the estabUshment of the lymph flow in the superficial lymphatic plexus, channels develop in the exact places where the movement of lymph had been demonstrated in the living chick by the injection of india ink into the superficial lymph capillaries. In addition to the formation of these ducts, the former investigation showed that the lymphatics in later stages enlarge to form sacs at points where two conflicting pressures occur. In this later stage, eight to nine days, the tissue is very loose — so much so, in fact, that it might almost be called edematous, were it not for the fact of its normal occurrence. At this later stage the lymph hearts are chiefly concerned with the flow of lymph from the allantois.
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In the former publication a case was described in which an embryo of seven days possessed a stunted tail with a small feebly beating lymph heart. This embryo was edematous and the Ijaiiphatics of the pelvis which drained into the Ijnnph heart were
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136
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ELEANOR LINTON CLAEK AND ELIOT R. CLARK
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large and distended, greatly resembling the sacs normally present in this region in chicks of eight and one-half days.
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In the operated tailless chicks of six and one-half days, the stage at which the IjTiiph heart begins to beat in normal chicks, the anterior lymphatics are normal as regards appearance, development of the main duct, and direction of Ijanph flow. The posterior half of the body, however, is markedly edematous in these chicks and the channels normally present over the pelvis
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Fig. 4 Drawing of an embryo chick of seven days, in which the tail containing rudiment of the lymph hearts had been removed at the three-daj-- stage. Compare character of the lymphatic plexus, injected with india ink, with that of a normal chick of the same age (fig. 5). The absence of definite channels in the posterior half of the body and the enlargement of the h-mphatic capillaries over the pelvis are particularly noticeable. X 4.67.
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are absent and in their place is an irregular plexus of the primitive type, the vessels composing which are much larger than usual. In chicks of seven to seven and one-half days, the stage at which the hmjih flow of the entire superficial hanphatic system is normally influenced by the beating of the l^^nph heart, the chicks were always found to be edematous after the operation for the removal of the lymph heart. The edema is noticeable to the naked eye; it is evident from the greater distance necessary to plunge the injecting cannula before reaching the superficial lymphatics, and also from the greater spaces present between the connective-tissue cells in microscopic sections of such embryos.
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LYMPHATICS IN EXPERIMENTAL EDEMA
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137
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In these chicks, channels over the anterior body wall and pelvis are absent and in their place an irregular plexus is present, many of the vessels of which are greatly enlarged and sac-like in appearance (fig. 4). It is evident from the difficulty encountered in
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Fig. 5 Drawing of a normal chick ot six days and twenty-two hours, showing injected superficial lymphatics w^ith newly formed h^mph ducts and Ij-mph heart (L.//.). X 5. (Copied from Clark, E. L., '15, fig. 4.)
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injecting these vessels over the pelvis that the fluid in them is under high pressure.
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In older stages, that is, in chicks of eight and one-half days and older, the tailless embryos are not noticeably more edematous than normal specimens of the same age. Injections of the superficial l3^llphatics show in most cases that the h^nphatics from the two sides have anastomosed over the stump. Otherwise they
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138 ELEANOR LIXTOX CLARK AXD ELIOT R. CLARK
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possess the same channels and superficial sacs as the normal specimens. It will be remembered that in normal chicks of eight and one-half days and over, the lymph heart is only shghtly concerned with the h-mph flow in the superficial Ijiiiphatics, being chiefly concerned with the flow of lymph from the aUantois. It is interesting to find in these operated chicks of eight to nine days that the lymphatics of the allantois are so distended as to render them easily visible to the naked eye without injection.
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These operations on chicks have added more evidence to that already reported with regard to the importance of the hniph heart in instigating and influencing the early flow" of lymph in the superficial lymphatic plexus and in determining the formation of ducts in the posterior part of the body. They also show that when the IjTnph flow is interfered with in these early stages, by removal of the Ijinph heart, embrj^os become edematous, the development of ducts is interfered with, while the vessels of the superficial l^nnphatic plexus enlarge greatly until they become even larger and more distended than the sacs of older chicks.
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DISCUSSION AND CONCLUSION
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The ease with which experimental edema is produced in amphibian larvae by any interference in the flow of fluid in the lymphatics is undoubtedly due to the importance of the lymphatic system of the lower vertebrates in connection with the absorption of water. Maxwell ('13) has found that a relatively enormous quantity of water passes through the frog's skin, and ^Moore ('15) has shown that a large part of this absorbed water is carried off by the lymphatics. In the lower vertebrates in which there is an active absorption of water through the skin, lymph hearts which assist in maintaining the flow of lymph are always present. In birds, the two IjTnph hearts, one on each side of the tail, function during embryonic life, but usually atrophj^ at the time of hatching (exceptions to this rule being water birds and the ostrich and cassowary). In the higher vertebrates — mammals and most adult birds, in which the absorption of water through the skin is practically absent — the importance of the lymphatic system as a drainage system is evidently diminished. ^Nlam
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LYMPHATICS IN EXPEEIMENTAL EDEMA 139
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mals do not possess l>iiiph hearts, but with the appearance of lymph glands the lymphatic system takes on new and important functions not found in lower vertebrates.
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The fact that lymph hearts are present in all birds during development, which takes place in a fluid medium, suggests the possibility that there may be an absorption of fluid through the skin of the higher vertebrates during their embryonic life with a resultant increase in absorption of fluid by the lymphatics. In a former paper (E. L. Clark, '15) it was shown that in the chick embryo lymph sacs develop at a stage in which the pressure inside the lymphatic vessels is high, probably owing to increased absorption and the outlet into the veins interfered with, and that such sacs always develop at points where conflicting pressures occur. It is possible that the early development of lymph sacs in mammalian embryos at points where the lymphatic system communicates with the veins may be due to the fact that this actively functioning drainage system has no pulsating lymph heart to assist in the flow of fluid from the tissues.
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Moreover, the present experiments, which have shown the important effects upon the absorption of fluid from the tissues resulting from an interference with the drainage of fluid by the lymphatics, in tadpoles and in chick embryos, suggest the possibility that edema of the human embryo may also be caused by a blockage of the main l3rmph channels, especially of the thoracic duct.i
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1 Smith and Birmingham ('89) assert that in the edematous foetus which they studied the lymphatic system was entirely absent. However, the illustration which they give (a low-power drawing of a microscopic section) contains certain structures which are unquestionably lymphatics, and not 'spaces' as they are labeled. Microscopic studies of edematous tissues (Marchand, '11; E. R. Clark, '16, and this article) have shown that fluid in subcutaneous tissues does not collect in 'lakelets,' but that it is evenly distributed, separating the cells in a uniform manner. The more probable explanation for this interesting case would appear to be that instead of being absent, the lymphatic system was blocked at some important point — perhaps at the outlet of the thoracic duct — and that there had then occurred a generalized edema of the embryo and a simultaneous distention of the lymphatics including the finest capillaries. It is interesting to see that in this case the 'spaces' in the mesenchyme are much larger than the blood capillaries.
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140 ELEANOR LIXTOX CLARK AND ELIOT R. CLARK
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The experiments reported here have yielded the following results in regard to the relation of the l^^nphatics to experimental edema :
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With the removal of the pronephros or the blood heart in amphibian larvae and the consequent abnormal collection of fluid in the serous cavities, the lymphatics continue to develop and to function in a normal manner. Their development and function are not interfered with even by the absence of circulation in the blood vascular system.
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Generalized edema of the embryo may readily be produced by mechanical interference with the outflow of fluid from the lymphatics (removal of the lymph hearts in tadpoles and in chick embryos).
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In such cases of generahzed edema the l>Tnphatics invariably enlarge and the delicate lymph capillaries do not collapse with the increased pressure outside the vessels, but, on the contrary, they continue to absorb fluid until they become greatly distended.
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In cases of localized edema, in areas where an inflammation has b.een produced, the lymphatic capillaries of the edematous region respond to an increase in the fluid outside by enlarging at the tips, and they resume their normal size with the disappearance of the edema.
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LYMPHATICS IN EXPERIMENTAL EDEMA 141
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LITERATURE CITED
 +
 +
Adami, J. G. 1909 The principles of pathology, vol. 2, chap. 5, p. 103. Lea & Febiger.
 +
 +
Clark, E. L. 1915 Observations of the Ijinph-flow and the associated morphological changes in the early superficial lymphatics of chick embryos. Am. Jour. Anat., vol. IS, p. 399.
 +
 +
Clark, E. R. 1916 A study of the mesenchyme cells in the tadpole's tail toward injected oil globules. Anat. Rec, vol. 2, no. 1, p. 1. 1918 Studies on the growth of blood-vessels in the tail of the frog larva — by observation and experiment on the living animal. Am. Jour. Anat., vol. 23, no. 1, p. 37.
 +
 +
Clark and Clark 1920 The character of the lymphatics in experimental edema. Proc. Amer. Assoc, of Anatomists, Anat. Rec, vol. 18, no. 3, p. 227.
 +
 +
Fischer, ISI. 1915 Oedema and nephritis. John Wiley's Sons, New York.
 +
 +
HowLAND, R. B. 1916 On the effect of removal of the pronephros of the amphibian embryo. Proc. Nat. Acad, of Sciences, vol. 2, p. 231.
 +
 +
Knower, H. McE. 1907 Effects of early removal of the heart and arrest of the circulation on the development of frog embryos. Anat. Rec, no. 7; Am. Jour. Anat., vol. 7, no. 3, p. 161.
 +
 +
Luckhart 1910 Contributions to the physiology of lymph. Comparative electrical conductivity of lymph and serum of the same animal and its bearing on theories of Ijonph formation. Amer. Jour, of Physiol., vol. 25, p. 345.
 +
 +
McClure, C. F. W. 1919 On the experimental production of edema in larval and adult Anura. Jour, of General Physiol., vol. 1, no. 3, p. 261.
 +
 +
Marchand, F. 1911 Das Oedem im Lichte der Kolloid-Chemie. Centr. f. allg. Pathol., Bd. 22, S. 625.
 +
 +
Maxwell 1913 On the absorption of water by the skin of the frog. Amer. Jour, of Physiol., vol. 32, p. 286.
 +
 +
Moore, A. R. 1915 On analysis of experimental edema in frogs. Amer. Jour, of Physiol., vol. 37, p. 228.
 +
 +
Smith and Birmingham 1889 Absent thoracic duct causing oedema of a foetus. Jour, of Anat. and Physiol., vol. 23, p. 532.
 +
 +
Starling, E. H. 1898 The production and absorption of lymph. Text-book of Physiol. E. A. Shafer. Edinburgh. MacMillan.
 +
 +
Swingle, W. W. 1919 On the experimental production of edema by nephrectomy. Proc. Amer. Assoc, of Anatomists, Anat. Rec, vol. 16, p. 165; Journ. of Gen. Physiol., vol. 1, no. 5, p. 509.
 +
 +
Wells, H. Gideon 1918 Chemical pathology, chap. 12. W. B. Saunders Co.
 +
 +
 +
 +
Resumen por el autor, S. E. Whitnall.
 +
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Algunos miisculos anormales de la 6rbita.
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El autor describe un musculo elevador de los parpados superior que presenta dos anomalias comunes de los fasciculos que pasan : (a) A la polea del musculo oblicuo superior (musculo tensor de la troclea, de Budge), y (b) A la glandula lacrimal; y en adici6n, (c) existe una banda transversa y entrecruzada parcialmente (musculo orbitario transverso). El origen del musculo oblicuo inferior del globo ocular fue examinado en cien 6rbitas, hallando el autor un desplazamiento lateral de su posici6n descrita como normal, (inmediatamente adyacente al borde de la incisura lacrimal u orificio superior del canal naso-lacrimal) en muchos casos, y en el 14 por ciento de los casos estaba separado un cuarto de pulgada, proximamente. En un caso, cuando la distancia era 7 mm. la inserci6n ocular fue examinada, hallando el autor que estaba situada mas arriba de lo normal. Otras anormalidades observadas son las de los musculos rectos, mencionadas en la literatura, junto con ejemplos de conexiones entre los musculos, encontradas por el autor en una serie de disecciones.
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Translation by Jos6 F. Nonidez Cornell Medical College, New York
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AUTHOR S ABSTRACT OF THIS PAPER ISSUED BY THE BIBLTOGRAPHIC SERVICE, MAT 9
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SO^^IE ABNORMAL MUSCLES OF THE ORBIT
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S. E. WHITNALL
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Dcj)artment of Anatomy, McGill University
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TWO FIGURES
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The following instances of abnormal muscles were met within a series of dissections of the orbit.
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LEVATOR PALPEBRAE SUPERIORIS
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There are three variations from the normal in this instance which was found in the left orbit of an adult female cadaver, of which the other orbit was not available for dissection.
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1. The most striking feature is the presence of a band of muscle fibers, 2 imii. broad, passing transversely across the anterior part of the orbit and interwoven to a certain extent with the fibers of the levator palpebrae superioris. The extremities of the band curve shghtly backward to be attached to the periosteum of the medial and lateral walls at about the junction of their anterior and middle thirds.
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2. From the medial margin of the levator itself a well-defined slip is separated off and passes in the direction of the trochlea or pulley of the tendon of the superior oblique muscle. This slip loses its fleshy character before it reaches the trochlea, being continued on by connective-tissue strands.
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3. From the lateral margin of the levator a well-marked offshoot passes both to the orbital wall and also to the lacrimal gland. In two other cases I have seen similar fasciculi passing to the lacrimal gland. They are attached to the connective tissue which forms the so-called capsule at the posteromedial region of the gland, and traction upon the levator draws the gland slightly backward. Alicroscopical examination showed all these fibers to be cross-striped.
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14.1
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THE ANATOMICAL RECORD, VOL. 21, NO. 2
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144
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S. E. WHITNALL
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There have been described two abnormalities of the levator of the upper eyelid :
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a. Where the muscle presents an offshoot from its medial border which passes to the pulley of the superior oblique muscle, replacing or reinforcing the normal fascial expansion of its sheath to that point. This muscular slip is the tensor twchleae of Budge ('59), and is identical, according to Macahster, with muscles described by Vesalius, Molinetti, Kolmus, Sandifort, and with
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Fig. 1 Left orbit dissected from above to show an abnormal levator j)alpebrae superioris, showing T., a transversus orbitis; B., a gracillimus or tensor trochlear or comes obliqui superioris, as it is variously termed; G., a slip passing to the lacrimal gland; S.O., is the superior oblique muscle.
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the co77ies oblique superioris of Albinus, and gracillimus orbitis of Bochdalek ('68). According to Budge, it is found in 10 per cent of cases, but in the writer's experience is much more rarely found in a well-defined state. In one preparation there were present two long muscle bundles, arising in common with the levator and ending anteriorly, one upon the fascia bulbi between the superior oblique and the globe, the other on the orbital margin beneath the pulley; the nerve supply came from the fourth nerve; the superior oblique was broader than usual. Ledouble
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SOME ABNORMAL MUSCLES OF THE ORBIT 145
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has found supernumerary fasciculi accompanying the reflected tendon of the superior oblique, and has further recorded a case where the direct or fleshy part of this muscle was absent, the reflected or normally tendinous part being muscular and arising from the site of the pulley, recalling the type found in non-mammalian vertebrates.
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b. The musculus transversus orhitis, described by Bochdalek in 1868 as a muscle passing from the anterior and upper part of the OS planum of the ethmoidal bone across the upper part of the orbit to its, lateral wall. It consists at its origin of small tendinous bands enlarging to fleshy bundles which give off various attachments to neighboring fascia and especially to the levator palpebrae superioris with which it is closely connected; in fact, when the transversus orbitis is small it practically forms part of the levator. Macahster and Ledouble consider it as being a backwardly displaced shp of the orbicularis palpebrarum. This transversus orbitis is sometimes confused with the graciUimus, as, for example, by Howe ('07).
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Perna ('05) described an 'abnormal transverse muscle' of the orbital cavity in man, which appears to be a transversus orbitis. He differs from Macalister as to the real origin of the muscle, considering it to represent the remains of the primitive muscular membrane which surrounds the organ of vision in lower vertebrates and which persists longest in phylogeny where the bony orbit is least complete and of least protection; he considers the levator itself to have the same origin, differentiated later for the special function of palpebral movement. An objection to this view is that the oibital periosteum, the periorbita, with its vestige of involuntary musculature found in the infra-orbital fissure in man and much more largely developed in certain lower animals, may be considered on sounder morphological grounds to be the representative of this primitive orbital cavity (jNIotais, '87; Groyer, '03). It may also be pointed out that the frontal nerve is lying between the planes represented by these two structures — the levator and the periorbita.
 +
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Neither would this anomaly appear to be derived from the peribulbar involuntary musculature described by Landstrom
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146 S. E. WHITXALL
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('07) and recently re-investigated by Hesser ('13), since the fibers are of a different nature and lie on a much more superficial plane.
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As regards the view of .Alacalister that the abnormality is formed by a portion of the orbicularis oculi, it is difficult to see how a portion of the superficial facial muscle sheet comes to be displaced to so deep a plane, posterior to the tarsal plates and septum orbitale, the latter of which is generally regarded as forming the anterior boundary of the orbital cavity, and why such fasciculi are so intimately connected with the levator.
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A third explanation which might be considered is that the transversely disposed muscle fibers replace that thickened part of the superficial fascial sheath of the levator which runs in the same direction across the orbit and presents somewhat similar attachments and, it has been suggested, may act as a check ligament to the action of the muscle ('WTiitnall, '10). This view is supported by the fact that in the present instance the fascial sheath was but little developed and formed no transverse band such as is normally present. The difficulty here is to reconcile the fact that while it is not uncommon to find the reappearance of muscle fibers in connective tissue which has replaced muscle, as, for example, in the case of the panniculus carnosus, yet preexisting connective tissue tends under strain rather to become condensed and developed into a definite ligament than to be replaced by muscle, as instanced by the appearance of definite ligaments in certain portions of the capsules of joints. On these grounds Perna's view is borne out by the numerous offshoots of the levator which may appear — it may be the remains of a much larger muscular sheet, but it is not homologous with the primitive membranous orbit as represented by the periorbita.
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The present instance of an abnormal levator palpebrae superioris muscle is of interest in that it shows, though ])erhaps feebly developed, the two variations commonly described, the tensor trochlea and the transversus orbitis, and in addition an offshoot passing to the lacrimal gland. The latter could have a much more effective action as a retractor glandulae lacrimalis than the medial offshoots as a tensor trochleae, since the gland is fairly movable, the trochlea only slightly so.
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SOME ABNORMAL MUSCLES OF THE ORBIT 147
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MUSCULUS OBLIQUUS INFERIOR
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The inferior oblique muscle of the eyeball is stated to arise from the anteromedial part of the floor of the orbit, just within the margin and immediately adjacent to the opening of the nasolacrimal canal (incisura lacrimalis). The site may be marked by a small oval impression and often the margin of the orbit is slightly lipped in this region. So close is the origin to the edge of the canal that occasionally fibers of the muscle are found to spring from the periosteal covering (lacrimal fascia) of the lacrimal sac at its base (fig. 2).
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Since several cases were found by the writer where the origin was displaced laterally some distance from this normal site, it appeared worth while examining a series of orbits. Out of 100 orbits dissected the distance of the origin from the edge of the nasolacrimal canal was as follows:
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Adjacent (0 to 1 mm. away) in 45 cases
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2 mm. distant in 14 cases
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3 mm. distant in 19 cases
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4 mm. distant in 8 cases
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5 mm. distant in 6 cases
 +
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6 mm. distant in 4 cases
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7 mm. distant in 4 cases
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Total 100
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Approximately, therefore, the origin lay a quarter of an inch (5 to 7 mm.) lateral to the normal site in 14 per cent, the displacement was more commonl}^ found in left orbits.
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In both orbits of one subject (female) the origin of the muscle was found situated 7 mm. away from the orifice of the canal, and the insertion of the muscle onto the right eyeball was specially examined (fig. 3). The breadth of the insertion was 8 mm. (usually 9.9 mm.) and was placed above, instead of below, the horizontal meridian ; its nearest point was 5 mm. from the optic nerve — a httle less than usual; its central point was 9 mm. (usually 11 mm.) distant from a corresponding point on the line of insertion of the superior obhque muscle. The total length of the muscle was 37 mm., which appears normal. In two other cases
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148
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S. E. WHITNALL
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of similar origins examined the most marked differences of insertion were again in a higher position on the eyeball, though it should be added that, according to Howe, the ocular insertions of the inferior oblique are more variable than any of the other muscles. The length of the muscles was normal.
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As regards the possible effect of such a laterally displaced origin on the action of the muscle, it is first to be noted that, since
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Fig. 2 Diagram to show normal position of origin of the inferior oblique muscle and its insertion onto the eyeball.
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the attachment is behind the equator of the globe, contraction of the muscle will tend to draw the latter forward, and the more directly the origin is situated in front of the eyeball, at a greater advantage can the muscle so act. In the second place, the effect of the displacement is to bring the origin nearer the insertion, and so the length of the muscle would be decreased. Since the length of a muscle, in which the fibers are arranged parallel to the long axis, is one of the factors which determine the extent
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SOME ABNORMAL MUSCLES OF THE ORBIT 149
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of movement of its insertion, this shortening would tend to influence the range of action. In these cases, however, the disadvantageous position of the origin is compensated by the higher position of the insertion on the globe and the length of the muscle is not affected. The independent action of the normal inferior oblique is to elevate and abduct the cornea and cause the globe to revolve outward on its anteroposterior axis. The first and las<"
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Fig. 3 Diagram to show an instance of abnormal origin of the inferior oblique muscle and its higher attachment onto the eyeball.
 +
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of these movements are not impaired by the higher position of the insertion; abduction is chiefly effected by the lateral rectus, though shared by the superior rectus, so that the effect on this movement is negligible.
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The superior oblique muscles were examined in the same subjects, especially as in the first case the pulley for the muscle was situated further forward than usual, being almost on the orbital margin (though the position w^as normal in the other cases exam
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150 S. E. WTIITXALL
 +
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ined). Here the angle between the belly of the muscle and its reflected tendon was apparently less than usual, but accurate measurement was impossible, owing to the nobility of the globe in the advanced stage of the dissection. The angle was certainly much less than the normal 54°, and appeared about 31°. The insertion onto the globe in each of two cases was broader than usual (14 mm. and 11 mm., instead of an average width of 9.5 mm.), but the position as regards the vertical meridian was normal and not of the myopic type (i. e., parallel to and wholly on the lateral side of the meridian) ; as in the case of the inferior obUque, however, there is much variation in the 'normal' insertion.
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From comparative anatomy it is seen that this condition resembles that found in certain fishes, w^here the obhque muscles arise from the orbital margin more anteriorh', in front of the globe.
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RECTI MUSCLES
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As regards abnormahties of the recti muscles, it is probable, to judge from the writer's individual experience in finding quite a number of gross anomaUes in a series of dissections, that such are by no means as excessively rare as would appear from the number recorded in the Uterature; in the ordinary dissectingroom conditions do not favor their identification, and in life some may be unrecognizable through compensatory action of the other muscles. They can of course be explained by errors in development by cleavage from the common premuscular mesoblastic mass. In the following notes, mention will be made of such abnormahties as have been recorded in addition to those found by the writer.
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The superior rectus has been found to give off a muscular slip 15 mm. long, which arose from the same origin from the annulus of Zinn and passed do^^•nward and forward across the lateral face of the optic nerve to join the inferior rectus about its midpoint; the nerve supply came from the inferior division of the third nerve (Aubaret, '09).
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The medial rectus has been found absent in some cases of divergent strabismus (Ledouble, '97; Krause). Its posterior third
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SOME ABNORMAL MUSCLES OF THE ORBIT 151
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may be fused with the inferior rectus. A bifid sclerotic insertion by two tendons, 16 mm. in length, is recorded (Wicherkiewicz, '07).
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The lateral rectus has hkewise been found undeveloped in some cases of convergent strabismus (Ledouble, Krause), and a case of atrophy of the muscle has been noted on operating for strabismus in the hving (Bourgeois). A fasciculus may pass from it to the inferior rectus, as is normal in certain ruminants, or to the lateral wall of the orbit (Aloseley, '53). A lateral rectus with two extra fasciculi which passed forward to end on the inferior tarsal plate and lateral wall is recorded (Curnow, '73). In a specimen dissected by the writer there was a well-marked, fleshy bundle 7 mm. long and 2 mm. in diameter, passing from the lateral rectus across the posterior third of the orbit beneath the optic nerve to fuse with the belly of the medial rectus; no nerve could be traced to it.
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The inferior rectus has been found by the writer to give off a large muscular bundle which passed lateral to the optic nerve and joined the superior rectus; it was innervated by the lower division of the third nerve.
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An abnormal muscle bundle (musculus ohliquus accessorius inferior) has been found by Rex ('87) passing from the apex of the orbit to the inferior obhque, but also sending a slip to join the inferior rectus; it was found in both orbits, and was supphed by the third nerve.
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As regards the vestiges of the musculus retractor bulbi which have been found in man, the reader should refer to an article by the writer ('11); to the hterature therein cited may be added a paper by Hopkins ('16).
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152 S. E. WHITNALL
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BIBLIOGRAPHY
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 +
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AuBARET 1909 Sur une anomalie extremement rare des muscles droits de I'oeil.
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Faisceau miisculaire anastomotique reliant le droit superieur au droit
 +
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inferieur. Socicte d'Anatomie de Bordeaux, Seance du 19 juillet. BocHDALEK 1868 Beitrag zu der anomalen Muskeln der Augenhohle. Prager
 +
 +
Vierteljahrsschrift, Bd. 4. Budge 1859 Beschreibung eines neuen Muskels, etc. Zeitschrift fiir Ration elle Medizin, 3, vii, S. 273. CuRNOW 1873 Notes of some irregularities in muscles and nerves. Journal of
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Anatomy and Physiology, vol. 7, p. 304. Groyer 1903 Zur vcrgleichenden Anatomie des Musculus orbitalis und der
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Musculi palpebrales (tarsales). SitzungsberJcht d. k. Akad. d. Wissen schaften in Wien, Bd. 112, iii, S. 50.
 +
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1905 Zur Anatomie des Muse, palbebral. sup. des Menschen. Zeitschrift fur Augenkheilkunde, Bd. 14, S. 365.
 +
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1906 Ueber den Zuzammenhang der Musculi tarsales (palpebrales) mit den geraden Augenmuskeln, etc. Internat. Monatschrift fiir Anatomie und Physiologie, Bd. 23, S. 210.
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Hesser 1913 Der Bindegewebsapparat und die glatte Muskulatur der Orbita
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beim Menschen im normalen Zustande. Anatomische Hefte (Merkel
 +
 +
und Bonnet), Bd. 49, S. 181. Hopkins 1916 The innervation of the muscle retractor oculi. Anat. Rec.,
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ii, vol. 5, p. 199. Howe 1907 The muscles of the eye. Putnam, New York. Landstrom 1908 Ueber Morbus Basedowii. Nord. Med. Ark., Stockholm.
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(Abstract in Nagel's Jahresbericht fiir Ophthalmologie, 1907, p. 472.) Ledouble 1897 Traite des varietes du systememusculaire de I'homme. Paris. Macalister 1875 Additional observations on muscle anomalies in human anatomy. 3rd series (Orbit), Transactions of Royal Irish Academy, vol.
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25, p. 7. MosELEY 1853 On an additional muscle of the eye. Monthly Journal of the
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Medical Sciences, vol. 17, p. 531. MoTAis 1887 L'appareil moteur de I'oeil. Paris. Perna 1905 Un musculo trasverso anomalo della cavita orbitaria neiruomo.
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Anatomischer Anzeiger, Verhandlung, Bd. 20, S. 215. Rex 1887 Ueber einen abnormen Augenmuskel (]\Iusculus obliquus acces sorius inferior). Anatomischer Anzeiger, ii, Bd. 20, S. 625. Whitnall 1910 On a ligament acting as a check to the action of the palpebrae
 +
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superioris muscle. Journal of Anatomy and Physiology, vol. 45, p. 131.
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1911 An instance of the retractor bulbi muscle in man. Journal of
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Anatomy and Physiology, vol. 46, p. 36.
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'i"
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Resumen por el autor, H. E. Radasch.
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La determinacion del tanto por ciento de substancia organica en el hueso.
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El tanto por ciento de substancia organcia en el hueso compacto es 32 a 33 por ciento, segiin los autores. De la inspecci6n de la literatura general no se desprende el metodo empleado en la determinacion de dicha substancia organica. Con el objeto de determinar el tanto por ciento real y hallar, a ser posible, el metodo empleado por los primeros observadores, el autor ha llevado a cabo varios experimentos de diversa naturaleza. Despues de preparar cuidadosamente trozos del femur, tibia y fibula, peso una serie de trozos, que se calcinaron despues, pesando el producto de esta operacion. La perdida de peso indica la cantidad de substancia organica incinerable que forma parte del hueso compacto.
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Entre los veinte a sesenta aiios de edad, el tanto por ciento medio hallado es 40.75. En el gato adulto el tanto por ciento de peso en del hueso joven es 38.32, mientras que en el conejo (dos tercios del crecimiento total) el tanto por ciento medio es 38.90. Mediante otros metodos, la humedad y las substancias solubles en el alcohol y el eter fueron eliminadas, fijando la cantidad de contenido organico fijo. La cantidad media de humedad durante el periodo comprendido entre los veinte y sesenta afios es 8.42%, y la relacion 7 de la substancia organica fija y el hueso seco es solamente 34.92%. La cantidad media de substancia soluble en el eter es 9.27 por ciento; la relaci6n media de la substancia organica fija y el hueso extractable es 3L34%. Parece sin embargo que el peso tipo debe ser el del hueso j6ven, y si se acepta esto, la cantidad media, de substancia organica contenida en el es 40.75 por ciento.
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Translation by J036 F. Xonidcz Cornell Medical College, New York
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AUTHOR S ABSTRACT OF THIS PAPER ISSUED BY THE BIBLIOGRAPHIC SERVICE, MAT 9
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THE deter:viixatiox of the percentage of the
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ORGANIC CONTENT OF CO^^IPACT BONE
 +
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H. E. RADASCH
 +
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Laboratories of the Daniel Baiigh Institute of Anatomy of the Jefferson Medical
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College
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In considering the chemical composition of bone we are told that it consists of two main substances intimately commingled, viz., earthy and animal substances. The former comprises the following substances, according to Cunningham's Anatomy ('14):
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per cent
 +
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Calcium phosphate 53 .23
 +
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Calcium carbonate 7 .32
 +
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Calcium fluoride 1 .41
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Magnesium phosphate 1 .32
 +
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Sodium chlorid . 69
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68.97 Organic material 31.03
 +
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100.00
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The organic substances comprise fats and ossein.
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According to Piersol, who quotes Berzelius, the inorganic material comprises 67.3 per cent, while the organic material consisting of gelatin and blood-vessels constitutes 33.3 per cent. Schaefer, Prudden (Ref. Handbook of Medical Sciences), Sobotta, all give the same as Piersol, apparently having accepted the same source as their guide. Gra^^'s Anatomy ('18) gives the organic content as from 67 to 68 per cent and so the inorganic constitutes 33 to 32 per cent.
 +
 +
We are further told by Schaefer that the animal material, improperly called cartilage of bone, differs from cartilage phj'sically and chemically. It is much more flexible and softer and upon boiling the bone yields mainly gelatin. He concludes that
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153
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154 H. E. RADASCH
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the animal material closely resembles white fibrous and areolar tissues in that it consists mainly of collagen.
 +
 +
Normal bone is hard, rigid (to a certain extent), tenacious, and also elastic. The earthy materials contribute to its hardness and rigidity, while the organic material gives bone its tenacity and elasticity. With the last characters in mind, we can readily understand some of the results of fractures. Although we are not told so, we naturally conclude that the foregoing percentages and characteristics apply to compact bone and to the adult type. This being agreed, we naturally would consider that the bones of the young and adolescent would contain a greater percentage of organic material and, therefore, a lower percentage of inorganic substance. This chemical difference, therefore, makes a physical difference to the effect that the bones of the young should, theoretically, be more elastic and tend less to fracture under the same proportionate strain than that of the adult; that the writer beUeves the surgeon will admit. In the case of ultimate fracture, however, we might expect a different result than in the adult, and consequently we find the green-stick fracture pertains to youth entirely and does not occur in the adult. This is due to the higher percentage of organic substance in the bones of the young. This will be shown actually in the succeeding data.
 +
 +
We are told that by subjecting the bone to an open fire (calcining) the organic substance is burned out, leaving a white, brittle, chalk-Uke substance that preserves its original shape, but with the loss of about one-third of its weight. This porous cast is easily broken, so apparently the substance which gives tenacity has been removed. We might naturally infer from this that in old age there is a reduction of organic substance, for it is known that in old individuals fractures occur more easily than in those in the prime of hfe; also repair is less rapid and less satisfactory in old age. We would believe, then, in the elderly, that there is a reduction of organic substance that causes the bone to yield more quickly to strains. Yet Rusby (Ref. Handbook of the ^Medical Sciences) tells us that as age advances there is a diminution in the mineral constituent of bone and the
 +
 +
 +
 +
ORGANIC CONTENT OF COMPACT BONE 155
 +
 +
organic element is slightly increased. This should make the bone somewhat more tenacious and less prone to fracture — just the reverse of actual experience. He states that this increase is due to the replacement of bone by enlarged blood-vessels and marrow, so that there is, in reaUty, a reduction of fixed organic material. Yet in those bones examined in this work no reduction was noted, but rather an increase, so that theoretically the bone should not be weakened in old age as it naturally is. There is apparently a thinning or diminution of the actual bony layer of the long bone, and this accounts partly for the readiness of the fracture.
 +
 +
Hoppe-Sejder is quoted (Ref. Handbook of the Medical Sciences) as giving the following composition of dried bone without the removal of the marrow or blood. Water, 50 per cent; fat, 15.75 per cent; ossein, 12.40 per cent; bone earths, 21.85 per cent. Wliy the bone-marrow^ and blood should be considered and included in the determination of the organic composition of bone seems strange. These two substances are not a direct part of the bone and they should be got rid of entirely in the determination of the organic constituency. Again, these substances will give some ash and will contain some elements that are concerned in bone formation, so that the effect of calcination of fresh bone with its blood and marrow would be to add to the inorganic constituents the amount of ash of the organic parts. As a result, the percentage of inorganic would be somewhat higher than it should.
 +
 +
For the same reason there is no way in which the organic structure of cancellous bone can be determined, as the marrow contained cannot be got rid of in any waj^ that would not tend to remove some of the soluble organic constituent of the bone. The percentage of organic material would be quite high in such a case.
 +
 +
It would seem that to get the real percentage of organic substance of compact bone, it would be necessary to remove as thoroughly as possible all traces of fat, marrow, and bloodvessels and external, or surface moisture. In that waj- the organic material remaining would practically belong to the bone and be a part thereof.
 +
 +
 +
 +
156 H. E. RADASCH
 +
 +
Primarily, the reason for the following determination was to find out, if possible, a definite relation, or variation, of the organic constituents of bone at the various ages. Just what methods of procedure were used by those who made the early determinations was not known, so some fresh bone was cleaned, weighed, calcined, and the contents determined. By this method the percentage of inherent, fixed, or component organic substance was so far above that given in the text-books that it caused surprise. There was no reason to believe that it could be an accidental variation, so that the writer immediately wondered how Berzelius, et al., made their determinations. If, according to Hoppe-Seyler, the marrow and blood-vessels were included with the bone, then we can see readily that there would be a variation, but this would make the organic content still higher than the author's determination.
 +
 +
In order to attempt to find out the method used by the older chemists, the determination of the organic content was carried on in a number of different ways.
 +
 +
So as to try to reach as near as possible the true percentage of organic substance in compact bone, five different sets of determinations were carried out. Four of these were applied to every sample of green bone and the fifth applied to the bones used for study by the students. The determinations were made on the bones of adults, varying the ages as much as possible, and stillbirths and even fetuses. In addition, in order to have a comparative anatomy relationship, determinations were also made in rabbits and cats.
 +
 +
The same method of preparation was used in all, except the bones used by the students for study. Certain bones only were used in all ages and in all of the animals, viz., femur, tibia, and fibula. In order to get as fair a sample of compact bone, i.e., where it would be most compact, the middle (from end to end) of each was chosen, and a section cut out and handled in a certain routine manner in all instances. The material was chosen chiefly from postriiortem subjects, and not from the remains of the subjects from the dissecting-room for several reasons: 1) To avoid involving thie chemicals of the embalming fluid. 2) In
 +
 +
 +
 +
ORGANIC CONTENT OF COMPACT BONE 157
 +
 +
order to determine the normal inherent moisture of the bone as just removed from the body. Determinations were also made in bodies that had been refrigerated for some time, and a difference was noted in the results here also.
 +
 +
After removal of a section of the femur, tibia, and fibula from the same sources, the flesh was allowed to remain on the others until one had been prepared for all four methods, as follows: First, the flesh of one piece of bone is all carefully cleaned off and the periosteum completely stripped, say off the femur. This caused no trouble except along the Unea aspera of the femur and at all of the borders of the tibia and the fibula. Here the membrane adheres most tenaciously, as many processes extend into the bones at these lines and serve to anchor the membrane firmly in position. Here care must be exercised to get out all traces of Sharpey's fibers, else they might naturally add their mite to the organic constituent of compact bone, and erroneously so.
 +
 +
The next step is to strip out all of the marrow and then cut out all of the cancellous spicules along the inner surface of the bones. In cutting these away considerable fatty matter is thus exposed and removed, thereby getting rid of another errorproducing element. ^^Tien as much of this cancellous bone as possible has been removed, one can feel reasonably sure that the remainder is a real sample of compact bone. Then the bone is carefully wiped externally and internally and a section (ring) about 1 cm. in height is cut; this is then cut into quarters. Each quarter is then carefully wiped again, especially the narrowcavity side, in order to remove all superficial moisture and fat; it is then weighed and this is the green weight. This is done with all four pieces, so that this green weight serves as an excellent check in the three other determinations.
 +
 +
Next the tibia is treated in the same way and then the fibula. The reason why all are not cleaned at once and then cut and weighed is because, if cleaned and left exposed to the room air, some of the moisture would escape and cause a variation in the determination. For that reason each specimen is treated in this routine manner. This may seem far-fetched, but it is of
 +
 +
THE ANATOMICAL RECORD, VOL. 21, NO. 2
 +
 +
 +
 +
158 H. E. RADASCH
 +
 +
the greatest importance, especially in the handling of fetal bones and bones of the child at birth. Here the parts must be cleaned, wiped, and weighed as rapidly as possible, or there is a marked variation, as these young bones have a greater percentage of inherent moisture. If the weighing process is slow, this variation will be noticed right on the balance pans.
 +
 +
By this method pieces of adult bone weighing from 1.1 grams up to over 3 grams were prepared. In fetal bones and those of the cat and rabbit, however, the weight of green bone was about 0.5 gram, as they are very bulky for their weight.
 +
 +
To procure and prepare four pieces of femur, tibia, and fibula and get the green weight of each requires about two hours of tedious and patient labor, but this is not the end.
 +
 +
The importance of the removal of all of the cancellous tissue and contained marrow will be shown in determinations A, B, C, and D. It will also show why cancellous bone proper should not be used, as the true organic constituency of osseous tissue cannot be correctly determined therefrom. This is due to the inability to get at and to remove the marrow from the canceUi.
 +
 +
Each of the four pieces of sample was treated as follows:
 +
 +
1. Green. The first piece of each bone was immediately calcined until the weight was constant and then the percentage of organic material determined, as will be shown later.
 +
 +
2. Oven-dried. The second piece of each bone after preliminary weighing was placed in an oven at 56°C. for twenty-four to forty-eight hours, allowed to cool, and then weighed. The loss in weight indicated the amount of moisture and the volatile organic substance present. It was then calcined until the weight was constant. By this method the percentage of moisture and volatile matter was found and also the amount of what might be termed real, or fixed organic material was obtained. In addition the green (original) weight permitted a determination of the organic material in green bone before the drying process was undertaken, giving a green-check determination.
 +
 +
3. Alcoholic-extracted and oven-dried. The third piece of each bone (after preliminary weighing) was placed in a 95 per cent
 +
 +
 +
 +
ORGANIC CONTENT OF COMPACT BONE 159
 +
 +
alcohol for twenty-four to forty-eight hours and then transferred to an oven at 56°C. for twenty-four to forty-eight hours, and then weighed when cooled. The weight lost indicated the moisture and volatile material and alcohol-soluble material. After calcining then the percentage of organic material in green bone, the percentage of moisture, volatile material and alcohol substance was next determined, and lastly the amount of remaining (fixed) organic substance.
 +
 +
4. Ether-extracted and oven-dried. In this determination a fresh piece from each bone (after preliminary weighing) was placed in ether from twenty-four to forty-eight hours, then oven-dried at 56°C. for twenty-four to forty-eight hours, and then weighed when cool. After calcination the percentage of organic material in green bone, the percentage of moisture, ether-soluble and volatile materials was next computed and then the amount of (fixed) organic substance remaining was computed.
 +
 +
The calcination was carried out by the use of two Bunsen burners. The porcelain crucible containing the green or extracted bone was placed on a triangle at an angle of about 45° and just high enough so that the Hght blue cone was close to the crucible. The crucible and contents were warmed gently and then the burner put in a position with some air cut off so that for the first half hour the heat would not be so intense, but sufficient to volatiUze and drive off most of the carbon and volatile substances. These would ignite and burn at the mouth of the crucible. Following this, the air was turned on full to get the greatest heat and another Bunsen with all of the air turned on was held so that the blue cone was directed upon the piece of bone at the mouth of the crucible. Between these two flames the calcining was completed; the bone being turned from time to time. In this way the bone is rendered incandescent and all carbon is burned out. The time varies for different thicknesses from five minutes to half an hour. This is repeated until the weight is constant.- The heat should be carefully appUed at first.
 +
 +
In order to comprehend the following tables the method of determining these various percentages will be first given by an example :
 +
 +
 +
 +
160
 +
 +
 +
H. E. RADASCH
 +
 +
 +
Body 89—1920
 +
 +
 +
Negro Frozen About 35 years of age
 +
 +
 +
 +
 +
Ether — Oven-dried
 +
 +
 +
 +
 +
Bone No.
 +
 +
 +
 +
 +
 +
 +
Femur 90
 +
 +
 +
31.6305 31.6305
 +
 +
 +
4.0670 a 4.0670 a
 +
 +
 +
 +
 +
27.5635 27.9450
 +
 +
 +
3.6845 b 2.4029 d
 +
 +
 +
 +
 +
4.0670 a 3.6845 b
 +
 +
 +
0.3825 c 1.6641 f
 +
 +
 +
 +
 +
31.6305 3.6&15b
 +
 +
 +
f /a = 40.90 per cent organic ma
 +
 +
 +
 +
29.2276 2.4029 d
 +
 +
 +
terial in green bone.
 +
 +
 +
 +
 +
2.4029 d 1.2816 e
 +
 +
 +
c/a = 9.55 per cent moisture, ether-soluble substance, etc.
 +
 +
e/b = 34.78 per cent fixed organic material in the extracted bone.
 +
 +
e/a = 31.51 per cent of fixed organic material in reference to green bone.
 +
 +
 +
 +
In all of the weighings a constant weight (50 grams) was used on the left pan and the right one contained the watch-glass, bone, and weights required to balance the 50 grams.
 +
 +
The various letters indicate the following:
 +
 +
a = The weight of the green bone.
 +
 +
b = The weight of the bone after (1) oven-drying or (2) alcohol-extracting and oven-drying or (3) ether-extracting and oven-drying, c = The weight of the moisture and volatile material alone or (1) -H the
 +
 +
alcohol-soluble or ether-soluble material. d = The weight of the calcined bone. e = The weight of the organic material after (1) oven-drying, or (2)
 +
 +
after extracting and oven-drying, f = Organic material in green bone, f/a = The percentage of organic material and water, volatile and extracted
 +
 +
material in green bone. c/a = The percentage of water, volatile and extractablc material in green
 +
 +
bone, e/b = The percentage of fixed organic material in the dried or extracted
 +
 +
and dried bone. e/a = The percentage of fixed organic in the green bone.
 +
 +
These last two percentages exclude the water and volatile material, and while one percentage is in relation to the weight of the extracted bone, the other percentage is in relation to the weight of the green bone.
 +
 +
The results obtained will be tabulated with reference to age and method employed. Fresh indicates simple postmortem, not embalmed and not preserved in any way ; frozen indicates storage
 +
 +
 +
 +
ORGANIC CONTENT OF COMPACT BONE
 +
 +
 +
 +
161
 +
 +
 +
 +
in the cadaver refrigerator and unembalmed; dissection refers to material taken from cadaver after the dissection was completed.
 +
 +
 +
 +
Green hone Four and one-half months (fresh)
 +
 +
 +
 +
NUMBER
 +
 +
 +
BONE
 +
 +
 +
f/a
 +
 +
 +
REMARKS
 +
 +
 +
7 8
 +
 +
 +
Fe Tib
 +
 +
 +
63.35 66.05
 +
 +
 +
Fresh
 +
 +
 +
At birth (fresh)
 +
 +
 +
 +
Fe
 +
 +
 +
49.61
 +
 +
 +
Tib
 +
 +
 +
50.44
 +
 +
 +
Fe
 +
 +
 +
50.79
 +
 +
 +
Tib
 +
 +
 +
53.07
 +
 +
 +
 +
 +
65.95
 +
 +
 +
 +
Extremit}' of femur consisted mostly of cancellous bone and contained marrow and blood
 +
 +
 +
 +
20 to 60 years
 +
 +
 +
 +
84
 +
 +
 +
Fem
 +
 +
 +
41.15
 +
 +
 +
Negro
 +
 +
 +
85
 +
 +
 +
Tib
 +
 +
 +
41.95
 +
 +
 +
47 years
 +
 +
 +
S4a
 +
 +
 +
Fib
 +
 +
 +
39.85
 +
 +
 +
Frozen
 +
 +
 +
112
 +
 +
 +
Fem
 +
 +
 +
40.61
 +
 +
 +
 +
 +
113
 +
 +
 +
Tib
 +
 +
 +
41.32
 +
 +
 +
Dissection
 +
 +
 +
113a
 +
 +
 +
Fib
 +
 +
 +
40.98
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
 +
61 to 90 years
 +
 +
 +
 +
 +
11
 +
 +
 +
Fe
 +
 +
 +
40.88
 +
 +
 +
71 years
 +
 +
 +
 +
 +
15
 +
 +
 +
Tib
 +
 +
 +
42.46
 +
 +
 +
Frozen
 +
 +
 +
 +
 +
19
 +
 +
 +
Fem
 +
 +
 +
41.57
 +
 +
 +
Very greasy
 +
 +
 +
 +
 +
23
 +
 +
 +
Feb
 +
 +
 +
44.18
 +
 +
 +
Fresh
 +
 +
 +
 +
 +
24
 +
 +
 +
Tib
 +
 +
 +
44.68
 +
 +
 +
Bones thin, 87 years
 +
 +
 +
 +
 +
31
 +
 +
 +
Fem
 +
 +
 +
43.75
 +
 +
 +
 +
 +
 +
 +
35
 +
 +
 +
Tib
 +
 +
 +
45.25
 +
 +
 +
Frozen
 +
 +
 +
 +
 +
39
 +
 +
 +
Fib
 +
 +
 +
41.56
 +
 +
 +
87 years
 +
 +
 +
 +
 +
43
 +
 +
 +
Fe
 +
 +
 +
42.28
 +
 +
 +
 +
 +
 +
 +
44
 +
 +
 +
Tib
 +
 +
 +
41.40
 +
 +
 +
Fresh. 76 years
 +
 +
 +
 +
 +
45
 +
 +
 +
Fib
 +
 +
 +
41.00
 +
 +
 +
 +
 +
 +
 +
63
 +
 +
 +
Fe
 +
 +
 +
48.62
 +
 +
 +
80 years
 +
 +
 +
 +
 +
64
 +
 +
 +
Tib
 +
 +
 +
45.77
 +
 +
 +
Fresh. Bones thin and buckled
 +
 +
 +
in calcining
 +
 +
 +
66
 +
 +
 +
Fib
 +
 +
 +
41.48
 +
 +
 +
 +
 +
 +
 +
 +
Green Bone— Continued 61 to 90 years
 +
 +
 +
 +
NUMBER
 +
 +
 +
BONE
 +
 +
 +
f/a
 +
 +
 +
REM.4RKS
 +
 +
 +
76
 +
 +
 +
Fe
 +
 +
 +
39.81
 +
 +
 +
 +
 +
 +
 +
77
 +
 +
 +
Tib
 +
 +
 +
41.68
 +
 +
 +
Frozen. 87 years
 +
 +
 +
 +
 +
77a
 +
 +
 +
Fib
 +
 +
 +
40.71
 +
 +
 +
 +
 +
 +
 +
92
 +
 +
 +
Fe
 +
 +
 +
39.44
 +
 +
 +
65 years
 +
 +
 +
 +
 +
93
 +
 +
 +
Tib
 +
 +
 +
41.78
 +
 +
 +
Negro. Frozen
 +
 +
 +
 +
 +
100
 +
 +
 +
Fe
 +
 +
 +
43.39
 +
 +
 +
 +
 +
 +
 +
101
 +
 +
 +
Tib
 +
 +
 +
39.86
 +
 +
 +
Fresh. 89 years
 +
 +
 +
 +
 +
101a
 +
 +
 +
Fib
 +
 +
 +
40.80
 +
 +
 +
 +
 +
 +