Talk:Paper - The morphology of the seminiferous tubules of Mammalia (1913)
The Morphology Of The Seminiferous Tubules Of Mammalia
G. Carl Huber And George Morris Curtis
Department of Histology and Embryology, University of Michigan FIVE FIGURES At the Cleveland meeting of the American Association of Anatomists, (1912-1913), Curtis 1 reported on wax plate reconstructions of the seminiferous tubules of the white mouse, presenting figures of a model of an entire tubule having an actual length of somewhat over 13 cm. The tubule completely reconstructed presents the form of an arch, the two ends of the arch lying in close proximity, each terminating 'n a tubulus rectus attached to the rete testis. In the course of the very thorough study which must of necessity be given to the series of sections in the preparation of drawings on which the reconstruction is based, it became evident that the testis in question contained no seminiferous tubules terminating in blind ends, and that anastomosis between tubules was very limited. Only one branching tubule was disclosed and on graphic reconstruction of this tubule it was found that each of the three branches terminated at the rete testis in tubuli recti. In the entire series of sections of the testis in question there were found but thirty-three tubuli recti, from which it appears that this testis contains but sixteen tubules, one of which is branched and terminates, as above stated, in three tubuli recti. These results, which are so at variance with the usual conception of the form and course of the mammalian seminiferous tubule, made it desirable to extend these observations to other forms, to determine whether the findings in the mouse testis would admit 1 George M. Curtis, Reconstruction of a seminiferous tubule of the albino mouse. 207 208 G. CARL HUBER AND GEORGE MORRIS CURTIS of generalization or pertained only to the form studied. The time involved in making the necessary drawings and wax reconstructions of the very long and coiled seminiferous tubules of adult mammalia is so great that it occurred to us that it might be possible to ascertain the main facts concerning the form and length of the mammalian seminiferous tubules by the less time consuming though perhaps more difficult process of maceration and teasing. For nearly all the known facts pertaining to the form, length and course of the mammalian seminiferous tubule we are indebted to the observations of the earlier investigators made on macerated and teased material. Successful teasing is dependent on the thoroughness and the uniformity of maceration of the tissue to be teased. Huber 2 has shown that by injecting a concentrated solution of hydrochloric acid into fresh tissues and then placing the injected tissue in a similar acid solution, a much more thorough and uniform maceration could be obtained than is the case when the tissues are placed directly into the macerating fluid as is the usual procedure. The method as applied to the study of the testis tubules is as follows: A cannula was inserted into the lower abdonimal aorta and the femoral vessels clamped just beneath the inguinal ligament. A 75 per cent solution of hydrochloric acid was then injected as rapidly as possible and under a pressure of about twenty to twenty-five pounds, the pressure being maintained until the parts appeared well injected, or until there is a rupture, which is not unusual. A few moments after the injection is completed the testes were removed and placed in a seventy-five per cent solution of hydrochloric acid in which they remain for from three to four hours. It is advisable to inject several animals at the same sitting and remove portions of the material from the macerating fluid at different intervals. The optimum degree of maceration can only be approximated, the extent of injection and other factors not readily controlled influencing the time required for thorough and uniform maceration. When the desired degree of maceration is thought to have been reached, the tissues 2 G. Carl Huber, A method for isolating the renal tubules of mammalia. AnatRec, vol. 5, 1911. SEMINIFEROUS TUBULES OF MAMMALIA 209 are transferred to distilled water, in which they remain for from twenty-four to forty-eight hours. It is best to transfer the tissues from the acid to distilled water gradually and slowly, this by pouring off in part the acid and then filling the dish with distilled water and repeating the process until all of the acid has been removed. The distilled water is changed at frequent intervals during the first few hours. After a thorough washing in the distilled water the tissues are transferred to Mayer's hemalum solution in which they remain from twenty-four to forty-eight hours and are then transferred to tap water. The hemalum solution not only stains the tubules so that they may be followed the more readily while teasing but also hardens the tissue. Before the final teasing is undertaken the stained tissue pieces are transferred for several hours to a 0.5 per cent solution of ammonium hydrate. This develops the stain to a rich purple blue, clears the tissue and slightly softens the tubules so that they become quite pliable. The final teasing is carried on under the stereoscopic binocular. With thoroughly macerated, well stained and sufficiently ammoniated tissue pieces at one's disposal it is not so difficult to tease out complete seminiferous tubules if the teasing is carried out in shallow Petri dishes with sufficient quantity of distilled water to enable the teased portions of the tubule to float about freely. We have experienced, however, great difficulty in attempting to make permanent mounts of such preparation. The method which has given us the best results, after many others were discarded as unsatisfactory, is the following: The larger pieces of testis tissue are separated in relatively large quantities of distilled water into masses comprising single tubules or tubule complexes (see below) . The smaller pieces thus obtained are then transferred to a large slide, the edges of which have been built up by means of melted soft paraffin until a well is formed holding a layer of distilled water having a depth of from 3 mm. to 5 mm. The tubule may now be teased out completely, all of the coils separated so as to admit of moderate extension. The teased tubule or tubule complex is now arranged as desired in the final mount. The water in the paraffin well is then very carefully drawn off by means of a fine pipette or strips of filter 210 G. CARL HUBER AND GEORGE MORRIS CURTIS paper until the teased tubule rests upon the slide. The paraffin case is then removed, the slide cleaned and placed on the warm oven to hasten the evaporation of the water adhering to the tubule. It care be taken a stage is reached in which the tubule will adhere to the slide sufficient to admit of mounting, without showing distortions consequent to complete drying. The tubule may now be mounted under a cover glass coated with a layer of glycerine, lowered very slowly from one edge. The method is not simple, requires time and patience, but with it results may be obtained, as here reported. In macerated material details of cell structure cannot be made out, the method is, therefore, not applicable for ascertaining the length of the spermatogenetic wave. The space relations of the coils of a given tubule are of necessity destroyed after complete teasing. The length, general course and relations of tubules, their relation to the rete testis, branching and anastomosis are factors which can be determined in teased preparations. In this preliminary note we shall deal with observations made on isolated seminiferous tubules of adult rabbits. In a more complete publication, in which the literature bearing on this subject will be given consideration, one of us (Curtis) will report on reconstructions and teased preparations of the seminiferous tubules of several mammals. This work so far as completed, it may here be stated, confirm the results here recorded. The seminiferous tubules of the rabbit appear to be arranged in the form of lobules having irregular pyramidal shapes, their bases bordering the tunica albuginea. These lobules may readily be seen in cross or sagittal sections of fixed material. The lobules are separated by more or less well defined strands of connective tissue, continuous with the mediastinum on the one side and the tunical albuginea on the other. On attempting to separate these lobules in the preliminary teasing of the larger masses of macerated testis tissue, it became evident that what appeared as a lobule could not be completely separated without tearing tubular structures, that apparent lobules were connected with adjacent lobules by tubules which passed from one to another. In well macerated tissue it is relatively easy to separate these so called lobules in the region of the mediastinum, especially if SEMINIFEROUS TUBULES OF MAMMALIA 211 care be taken to break the tubuli recti, which form the apices of the lobules, at their point of connection with the rete testis. If the lobules be now separated from the region of the mediastinum toward the periphery of the testis it will be found that certain ones do not reach the periphery but become connected through a bridge of coiled tubules to an adjacent lobule which in turn may be traced toward the rete testis, ending in a tubulus rectus; others with similar general course may extend toward the periphery of the gland and reach the region of the tunica albuginea It is possible to separate from tissue masses taken from any portion of the testis such coiled tubule masses arranged in the form of an arch or inverted U, the ends of the pillars of the arch terminating in tubuli recti attached to the rete testis. Such arch shaped coils of tubules, consisting apparently of two lobules united at the periphery, when completely teased out show a single tubule, both ends of which terminate in a tubulus rectus attached to the rete testis. They vary greatly in length and in the degree of coiling and folding of the constituent tubules. Numerous such tubules, completely teased and mounted, and taken from the testes of several rabbits, have been observed. They form the simplest type of the seminiferous tubule of the rabbit and are in every way comparable to the tubule of the mouse testis reconstructed in full by Curtis. In figures 1 and 2 are shown two seminiferous tubules of this simpler and more prevalent type, completely teased and mounted. These and the other tubules figured were sketched with the aid of the camera lucida at a magnification of 25 diameters, reduced to the present size in the reproduction. Each tubule, as may be observed, begins and ends in a tubulus rectus. The tubule shown in figure 1, one of the shortest teased, presents an actual length of 9.1 cm., while the tubule shown in figure 2, one of the longest simple tubules teased out completely, presents an actual length of 30.2 cm. The measurements here given were obtained by measuring the length of the tubule as presented in the enlarged drawing by means of a map-measurer, the length thus obtained being then divided by 25, the magnification used in making the drawing. 212 G. CARL HTJBER AND GEORGE MORRIS CURTIS Figs. 1 and 2 Seminiferous tubules of adult rabbit, arranged in the form of an arch, with ends attached to rete testis. X 2.5. SEMINIFEROUS TUBULES OF MAMMALIA 213 In presenting these measurements we are aware of slight sources of error, due largely to the fact that it is difficult to portray accurately the exact length of a coil which has its direction up and down in the field of vision. Furthermore, there is evidence of slight shrinkage when the tissues are injected and placed in hydrochloric acid, perhaps compensated during washing in distilled water. The ammoniated water causes a slight swelling of the tissue, and this we are forced to disregard in making the measurement. The measurements given appear to us approximately accurate, we believe more so than those given by earlier observers. Our observations on teased preparations show that the seminiferous tubules of the adult rabbit do not present blind ends nor do they show longer or shorter diverticuli nor nodular enlargements. In stained tissue the observer is able to trace the course and outline of a given tubule much more clearly than is the case in unstained tissue. We have often noted what we are inclined to believe might readily be regarded as diverticuli or nodular enlargements were our observations confined to unstained tissue. The tubules often present very sharp turns, the two arms being parallel and in close relation. Such a sharp turn presented to view in such a way that one arm overlaps the other, may in unstained tissue readily simulate a diverticulum. When such a sharp turn is extended, the convex border appears to project as a nodular enlargement, which disappears when the parts are allowed to approximate their normal relations. A study of the numerous teased preparations has led to the conclusion that no seminiferous tubules of the adult rabbit, whether of the type of a simple arch, figures 1 and 2, or of a more complex type with branchings and anastomoses as in figures 3, 4 and 5, can be regarded as teased completely unless all of the free tubular ends can be traced to a termination in a tubulus rectus. This has been our criterion in determining whether the more extensive tubular complexes about to be described are to be regarded as teased completely. In the preliminary teasing of the larger masses one frequently meets with tubular complexes in which more than two so called lobules are joined together. On complete teasing of such portions one meets here and there, and practically at all 214 G. CARL HUBER AND GEORGE MORRIS CURTIS Fig. 3 Seminiferous tubule complex of adult rabbit, showing junction of three tubules, each attached to rete testis. X 2.5. Fig. 4 Seminiferous tubule complex of adult rabbit showing junction of two arched tubules. X 2.5. SEMINIFEROUS TUBULES OF MAMMALIA 215 levels, though most frequently toward the periphery, distinct Y-shaped or T-shaped branching, through which several arch systems are linked together. The extent to which this branching and anastomosis may take place is difficult to determine since the connections between the lobules are very readily broken and loops which reach the tunica albuginea are very easily torn during the manipulation necessary for the removal of the tunica and the teasing required to separate the so-called lobules. Many broken ends are encountered in attempting to isolate completely tubule complexes with a number of anastomoses, broken ends very often not evident until the teasing is practically complete. We present here a number of types of tubule complexes with anastomoses of tubules regarded as teased completely, in that in each case each tubule was traced to its termination in a tubulus rectus, ending in the rete testis. The figures are so clear that only a brief word of explanation is deemed necessary. In figure 3 is shown a tubule complex in which three so-called lobules are joined by means of a T-shaped division. The region of the division presents no structural peculiarity, each of the three tubules show functional activity in the region of joining. This statement, however, is based on observations made on sections, rather than on teased preparations, though even in the latter the structure presented in the immediate vicinity of the division is very similar to the other parts of the tubules. As may be seen in the figure, each of the three tubules ends in a tubulus rectus, which in the unteased mass was in close proximity with the other two, and joined the rete testis. The actual length of the tubule complex, measured as above described, we find to be 26.7 cm. In figure 4, are shown two arched tubules, in general arrangement very similar to those shown in figures 1 and 2, but linked by means of a short transverse bridge. Configurations of this type are not frequently met with owing perhaps to the fact that the narrow transverse bridge is readily broken during manipulations necessary to separating the mass from the testis tissue. The mass from which this tubule complex was teased presented four so-called lobules folded together like a closed book, the transverse bridge being hidden and embedded in one of the lobules THE ANATOMICAL RECORD, VOL. 7, NO. 6 216 G. CARL HUBER AND GEORGE MORRIS CURTIS and not evident until the teasing was practically completed. Each of the four tubular ends terminates in a tubulus rectus, which join the rete testis in close proximity. At the right of the figure the junction of three tubules is favorably placed, at the left of the figure a like junction is obscured. While still floating freely in the water it was possible to move this tubule complex about, cause tension here and there and determine with certainty the existence of the anastomoses. So with other tubule complexes completely teased. After the water has been withdrawn, so that the tubule complex rests upon the slide, the slightest tension usualy results in a tear. Experience, therefore, leads one to be content with the position assumed by the tubule complex after the withdrawal of the water, even though the resulting figure may not be as clear as is desired. The actual length of this tubule complex, which was removed from the middle third of the testis, in which region are found the largest tubules, proves to be 38.5 cm. In figure 5, is shown a prevalent type of tubule complex, a type, however, which is very difficult to tease out completely. Many masses recognized as presenting similar tubule complexes have been teased, only to find here and there a broken tubular ending, indicating that only a portion of the complex had been separated from the testis tissue. As stated above, the evidence seems conclusive that only tubules ending in tubuli recti can be regarded as completely teased. A tubule broken at a sharp turn often simulates very closely one terminating in a blind end, especially if the basement membrane seems to pass around the broken end. Closer study, and especially turning over the supposed blind end, reveals a broken surface, admitting of a correct interpretation. In figure 5 are shown seven tubules linked together. The mass from which this complex was teased, when partly separated and unrolled, presented seven slender so-called lobules united at the periphery. After complete teasing it could be readily determined that all of the seven tubules were linked together through Y-shaped divisions of the tubule. In making a permanent mount of this tubule complex a slight shifting of tubule segments from the position originally given them SEMINIFEROUS TUBULES OF MAMMALIA - 217 Fig. 5 Seminiferous tubule complex showing junction of seven tubules, each ending in a tubulus rectus and attached to the rete testis. X 2.5. has led to the obscuring of certain of the junctions. In an attempt to straighten somewhat the second tubule from the left in this figure, this was torn from its attachment at the T-shaped division. This tear was disregarded in making the figure. The last tubule to the right does not show in the mounted preparation its termination in a tubulus rectus, which is folded under the tubule, yet was clearly evident after the completion of teasing. The other six tubules show clearly their termination in tubuli recti. This tubule complex was removed from the lower third of the testis and presents an actual length of 30.4 cm. We are convinced that the tubule complex shown in figure 5, does not show the extent of linking of tubules which may take place in the adult rabbit testis. In one preparation at least twelve tubules seemed joined together, although in this preparation certain of the tubules could be traced only for a short distance before a broken end was reached; others which could be completely teased terminated in tubuli recti. The difficulty met in separating the parts belonging to a single tubule complex, during the preliminary teasing of the larger masses of testis tissue, masses which are not sufficiently transparent to admit of transmitting even strong artificial light, leaves it largely to chance 218 G. CARL HUBER AND GEORGE MORRIS CURTIS as to whether one obtains a complete tubule complex for the final teasing. Three of the six testes prepared for teasing proved to be well macerated. Preparations made of each of these presented the same general features. One was over macerated, teasing very readily, but the tubules were too soft to admit of the manipulation necessary for complete isolation. One rabbit, as was noted after completion of the hydrochloric acid injection, presented a very small cryptorchid on the left side, with the right testis slightly larger than one-half the size of a normal testis of rabbit of similar weight. The left testis was disregarded as it was found to be infantile, with very small tightly coiled tubules. The right testis was not very successfully macerated. From it, however, there was isolated a tubule complex, which though not complete, in that it was not possible to trace all of the constituent tubules to their termination in the rete testis through tubuli recti, presents clearly an extended anastomosis, such as has not been seen in what we regard as normal testes. In two regions of this tubule complex, toward the periphery, tubules were joined together so as to form two folded rings, to different segments of which were attached tubules extending to the rete testis. This tubule complex will be considered more fully by Curtis in a later publication. The question arises as to whether this somewhat unique arrangement may be regarded as characteristic of the incompletely developed state of the gland or merely a chance finding. It is regretted that the maceration of this gland was such that a more extended observation was not permitted. Judging from the teased preparation the gland in question seemed functional. Concerning the life history of this rabbit we have no data. The observations of Bremer 3 on the human seminiferous tubule, based largely on reconstructions of embryonic material, will be considered in the light of our work in a later publication. 3 John Lewis Bremer, Morphology of the tubules of the human testis and epididymis. Amer. Jour. Anat., vol. 11, 1910-1911. SEMINIFEROUS TUBULES OF MAMMALIA 219 As a result of our observations on the seminiferous tubules of the adult rabbit we feel warranted in presenting the following conclusions : 1. The seminiferous tubules of the adult rabbit present no blind ends, diverticula or nodular enlargements. 2. In their simpler form they are arranged in the form of an arch, the tubule beginning and ending in a tubulus rectus, each attached to the rete testis, both ends of the tubule having thus a functional connection with the rete. 3.. The more extensive tubular complexes may be regarded as composed of a series of linked arches, joined through Y-shaped or T-shaped divisions of the tubules, the regions of the divisions showing no structural peculiarity, all the tubules ending in tubuli recti attached to the rete testis. 4. The extent of the linking of the tubules is difficult to determine. Observations show that from three to twelve tubules may thus be linked in one tubule complex. 5. The lobules evident in sections of the rabbit testis, or on macroscopic inspection, do not represent each a complete tubule, if a tubule be regarded as one beginning and ending in the rete testis, but represent a coil complex of a portion of a tubule as it passes from the mediastinum toward the periphery or from the periphery toward the mediastinum. 220 BOOKS RECEIVED BOOKS RECEIVED. DIE BIOLOGLSCHEN GRUNDLAGEN DER SEKUND&REN GESCHLECHTSCHARAKTERE, Dr. Julius Tandler, Professor der Anatomie an der Wiener Universitat und Dr. Siegfried Grosz, Privatdozent fur Dermatologie und Syphilidologie an der Wiener Universitat, Mit 23 Textfiguren, 169 pages including index, 1913. M. 8. Julius Springer, Berlin. THE POSTURE OF SCHOOL CHILDREN, with its home hygiene and new efficiency methods for school training, Jesie H. Bancroft, assistant director physical training, public schools, New York City, illustrated, 327 pages including index, 1913, $1.50. The Macmillan Company, New York. THE NARCOTIC DRUG DISEASES AND ALLIED AILMENTS, pathology, pathogenesis and treatment, Geo. E. Pettey, M.D., member, Memphis and Shelby County Medical Society, Tennessee State, illustrated, 516 pages including index, 1913, $5.00. F. A. Davis Company, Philadelphia. THE CEPHALIC NERVES: SUGGESTIONS ROBERT BENNETT BEAN The Anatomical Laboratory, Tulane University THREE FIGURES The BNA term 'cerebral' as applied to the nerves of the head is a misnomer. There are only four cerebral nerves proper, although the nerve of taste may have cerebral terminals. Hardesty, in the anatomy of Morris, returned to the use of the old term 'cranial' in preference to 'cerebral' and rightly so, because the nerves distributed in the head do pass through openings in the base of the skull, and but four of them are attached to the cerebrum. Furthermore, the cranial nerves need a reclassification. No author or publisher of a text-book of anatomy has yet been brave enough to replace the twelve pairs of cranial nerves with the nerves as they really exist. The time is propitious for some alteration because of the gross errors and apparent complexity that exist in an attempt to conform recent discoveries with old fashioned notions. For instance, there are not two olfactory nerves but about forty, the olfactory bulb and tract being not a nerve but an outgrowth of the brain. Likewise, the optic nerve is not a nerve but another outgrowth of the brain: There is a retina which is a modified cerebral cortex, an association tract and a decussation, but no nerve proper. The first and second pairs of cranial nerves should therefore be described with the olfactory apparatus and the optic apparatus. The tenth and eleventh cranial nerves should not be considered with the nerves of the head, because they are distributed to the neck, shoulder and trunk, and form an intermediate stage between the cervical spinal nerves and cranial (why not cephalic?) nerves. Omitting these four pairs 221 THE ANATOMICAL RECORD, VOL. 7, NO. 7 JULY, 1913 222 KOBERT BENNETT BEAN of nerves there remain but eight of the usually so-named cranial nerves. However, if only one cranial nerve be lost the classic twelve is broken and all indication by numerals may as well be discarded. I therefore propose an alteration in the terminology of the present so-called cranial nerves in the following manner : 1. Call the nerves distributed in the head the cephalic instead of the cranial or cerebral nerves. The head includes the cranium and face, with the orbital, nasal and buccal cavities as a part of the latter. 2. Omit the olfactory and optic nerves and describe them under their proper apparatuses. 3. Omit the pneumogastric and spinal accessory nerves from the cephalic group because they belong to the spinal cord type, or may be considered as transitory nerves between the spinal cord and brain, and they are not distributed to the head but to the neck, shoulders and trunk. 4. Add three nerves to the cephalic group. a. Add the motor root of the trigeminals, which is as much a separate nerve as the facial, the two supplying motion to the mandible and face, as motor reciprocal to the trigeminal which supplies sensation to the teeth and face. The name of the motor root of the trigeminal should be the masticator nerve (n. masticatorius), as given in the BNA, because it supplies the muscles of mastication. b. Add the sensory part of the facial, including the intermediate nerve of Wrisberg, the geniculate ganglion containing the cells of origin of this nerve, and the chorda tympani, with its distribution in the tongue and palate. Call this nerve the glossopalatine nerve (n. glossopalatinus), as suggested by Hardesty. The work of Streeter, Cushing, Sheldon and others demonstrates that this nerve is only a segregated portion of the glosso-pharyngeal nerve in its ontogeny and phylogeny, as well as in its central and peripheral terminations, but its roundabout course necessitates a separate name. c. Add the nerve of the semicircular canals, separating it from the nerve of the cochlea. Retain the name acoustic or auditory CEPHALIC NERVES 223 for the latter and give the former separately the name it bears at present, vestibular nerve. 5. Finally, omit the sympathetic ganglia of the head, especialty the ciliary, sphenopalatine, otic and'submaxillary, from the description of the cephalic nerves, and constitute them as a ganglionated cephalic plexus, including the sympathetic part of the geniculate, petrous and jugular ganglia, the prolongation upward of the cervical sympathetic system. This will be considered separately at the end of. this study. The nerves as rearranged may be enumerated as the cephalic nerves : NAME Oculo-motor Trochlear or pathetic Abducens Trigeminal or trifacial. Masticator Facial Auditory or acoustic. . . Vestibular Glossopharyngeal Glossopalatine Hypoglossal DISTRIBUTION" NATURE 1 1 } eye muscle J ' l !> face ( internal ear \ tongue, palate, etc. motor sensory motor sensory sensory sensory (mixed) sensory (mixed) This is a more rational arrangement than that of the twelve cranial nerves, if only the grouping of the nerves of like distribution is considered and when it is kept in mind that the origin and central connections, course and distribution of each nerve is distinct, their individuality is apparent. It may be well to give descriptions of the newly constituted nerves, the masticator nerve, the vestibular nerve and the glossopalatine nerve, although the masticator and vestibular nerves are so well known under the names of the motor root of the trigeminal, and the vestibular part of the acoustic, respectively, that onlj- the glossopalatine nerve will be described in detail. Diagrams are given to illustrate the course and distribution of the masticator and glossopalatine nerves, and the ganglionated cephalic plexus and its connections, (figs. 1, 2 and 3). 224 ROBERT BENNETT BEAN The glossopalatine nerve This nerve consists of four parts which have been recognized as parts of one nerve -but not so described in the text-books. The four parts are the pars intermedia or intermediate nerve of Wrisberg, the geniculate ganglion, the chorda tympani and the palatine portion of the nerve. The nerve is apparently an aberrant part of the glossopharyngeal nerve. Its cells of origin are located in the geniculate ganglion, the peripheral processes ABBREVIATIONS a.d.t.n., anterior deep temporal nerve a.t.n., auricular temporal nerve b.n., buccinator nerve c.p., carotid plexus c.a., carotid artery c.t., chorda tympani c.b., communicating branch to middle cervical sympathetic ganglion e.g., ciliary ganglion c.t.n., caroticotympanic nerve (small deep petrosal) c.c.p., carotid and cavernous plexuses c.n., carotid nerve e.p.n., external pterygoid nerve e.c.a., external carotid artery e.s.p.n., external superficial petrosal nerve f.n., facial nerve f.a., facial artery f.n.f., facial nerve fibers G.g., Gasserian ganglion g.n., glossopharyngeal nerve g.p. of g.g., glossopalatine portion of geniculate ganglion gen.g., geniculate ganglion g.s.p.n., great superficial petrosal nerve g.d.p.n., great deep petrosal nerve g.p.n., glossopalatine nerve g.r., geniculotympanic ramus i. c.t.n., inferior carotico tympanic nerve i .c.n., internal carotid nerve i.p.n., internal pterygoid nerve i.m.a., internal maxillary artery i.a.n., inferior alveolar nerve j.n., jugular nerve j.g., jugular ganglion l.n., lingual nerve mas.n., masseter nerve my.n., mylohyoid nerve m.m.a., middle meningeal artery max.n., maxillary nerve m.m., mandibular nerve mas.n., masticator nerve n. of p.c, nerve of the pterygoid canal (Vidian) n.p., nodosal plexus o.g., otic ganglion oc.n., oculomotor nerve op.n., ophthalmic nerve p.i., pars intermedia p.d.t.n., posterior deep temporal nerve p.n., petrosal nerve p.g., petrous ganglion p.p., of g.n., palatine portion of glossopalatine nerve s.g., sphenopalatine ganglion sub.g., submaxillary. ganglion s.c.s.g., superior cervical sympathetic ganglion s.s.p.n., small superficial petrosal nerve s.g., sphenopalatine ganglion t.n., tympanopetrosal nerve t.p., tympanic plexus tym.n., tympanic nerve (Jacobson's) tri.n., trigeminal nerve v.n., vagus nerve CEPHALIC NERVES 225 of which end in the anterior two-thirds of the tongue and the soft palate, and the central processes of which terminate about cells superior to the nucleus of termination of the glossopharyngeal nerve in the medulla. Fig. 1 Diagram showing the glossopalatine nerve and the ganglionated cephalic plexus. Each ganglion has three roots; the motor root is in broken lines, the sensory is in dotted lines and the sympathetic is in solid lines. Mesial view, left side. The geniculate ganglion is embedded in the anterior border of the great bend of the facial nerve behind the hiatus Fallopii. It is somewhat triangular in form and at its three angles three nerves are found. Its external angle has the chorda tympani attached, its anterior angle is connected with the great superficial petrosal nerve, and its superior angle has the root of the inter 226 ROBERT BENNETT BEAN e.s.p.n. Fig. 2 Scheme to represent the continuity of the sympathetic connections of the cephalic ganglia (ganglionated cephalic plexus). mediate nerve proper. A part of the geniculate ganglion belongs to the sympathetic system and will be described below with the ganglionated cephalic plexus. The fibers of the intermediate nerve concerned in the glossopalatine nerve pass from the geniculate ganglion in the facial CEPHALIC NERVES 227 canal (aqueduct of Fallopius) inside the sheath of the facial nerve, which it leaves as it passes inward through the internal auditory meatus to turn slightly downward in the posterior fossa of the cranium. It enters the medulla immediately below the pons between the facial and auditory nerves, passes through the reticular formation inward and backward to terminate in the group of cells superior to the nucleus of termination of the glosso Fig. 3 Schematic representation of the masticator nerve (in black); modified from Spalteholz. Lateral view, right side. pharyngeal nerve. In the internal auditory meatus the nerve gives two delicate filaments to the vestibular nerve. The intermediate nerve contains a few motor fibers probably acquired while it is in the sheath of the facial nerve. It also may contain secretory fibers from the medulla whose impulses reach via sympathetic neurones the glands and mucous membrane of the salivary apparatus. 228 ROBERT BENNETT BEAN The chorda tympani is so well known it need not be described. Other sensory fibers of the glosso-palatine nerve besides those of the chorda tympani rise in the geniculate ganglion and pass through the great superficial petrosal nerve and the sphenopalatine ganglion to the soft palate where they are probably connected with the peripheral taste organs found there, as well as serving as fibers of general sensibility for the palate. Enough has been said to indicate the most essential changes to bring the nerves of the head up to date. There is one other change, a change in the hypoglossal nerve. The ansa hypoglossi or loop of the hypoglossal is not a part of this nerve and should not be included with it but instead should be described with the cervical plexus of which it is a part. The name ansa hypoglossi should be discarded and in its place the name ansa cervicalis substituted. Likewise the descendens hypoglossi and the communicans hypglossi should be altered to the descendens cervicalis and the communicans cervicalis. Whether the suggestions here given be followed or not there can be no doubt that such changes would clarify and simplify the cephalic nerves. The removal of the ganglia and their connections from the facial, trigeminal and glosso-pharyngeal nerves, and so forth, simplifies these nerves, and the segregation of the masticator, vestibular and glosso-palatine nerves further simplifies the nerves with which they are usually described. The ganglionated cephalic plexus (figs. 1-2) The ganglia of the head receive and distribute three classes of fibers, motor, sensory and sympathetic. They do not belong to any one nerve or set of nerves, although they all have sympathetic connections and may be considered as the prolongation upward of the cervical sympathetic ganglia. They correspond both structurally and developmentally with the sympathetic ganglia, except those parts of the geniculate, petrous, and jugular ganglia which represent the dorsal root ganglia, or ganglia of origin of the sensory portions of the glossopalatine, glossopharyngeal, and pneumogastric nerves respectively. Some of these ganglia of the head are vagrant ganglia which separated from the CEPHALIC NERVES 229 embryonal semilunar or Gasserian ganglion at an early period of development — just as the sympathetic ganglia of the neck and trunk separated from the embryonal spinal ganglia. These ganglia of the head with their connections may be conveniently grouped together as the ganglionated cephalic plexus, and may be said to consist of the ciliary, the sphenopalatine or Meckel's ganglion, the otic, the submaxillary, and a part of the geniculate, of the petrous and of the jugular ganglion. Each ganglion may be said to possess a motor root, a sensory root, and a sympahetic root, and the ganglia act as relays and points of dispersal for these three sets of fibers. Motor impulses go to the eyeball, the palate, the middle ear and the pharynx; sensory impulses come from the same regions and from the lining of the mouth ; and secretory fibers are distributed to the lachrymal glands, to the mucous membrane of the nose and mouth, pharynx and palate, to the parotid glands, and to the submaxillary and sublingual glands. The superior cervical sympathetic ganglion gives off two large branches which pass upward to communicate with the ganglionated cephalic plexus. One of these, the carotid nerve, is the direct continuation upward of the gangliated cord, and through its branches, the caroticotympanic and the deep petrosal nerves, as well as through the plexuses derived from it, this nerve communicates with practically all the ganglia of the head. Another nerve from the superior cervical sympathetic ganglion, the jugular nerve, passes directly to the ganglia of the pneumogastric and glossopharyngeal nerves, through the nodosal plexus to the jugular ganglion, and directly to the petrous ganglion. It may be well to describe each ganglion with its roots of origin, and its branches of distribution, in order to obtain a clear insight into the composition of the ganglionated cephalic plexus. Whereas the three roots will be described in the terminology of gross anatomy, it is realized that in their microscopic construction the roots of the sympathetic portions of the jugular, petrous and geniculate ganglia especially, may be of varying significance. Very few fibers of the sensory root of a sympathetic ganglion actually terminate within the ganglion, about its cells, 230 ROBERT BENNETT BEAN and probably none except the few which terminate in its capsule, and in which arise general sensations from the ganglion to the central system. A motor root of a sympathetic ganglion may consist of two varieties of fibers ; those which arise in the motor nuclei (of origin) in the central system and terminate about cells within the sympathetic ganglion (splanchnic efferent fibers) and, second, those which have the same origin and pass through the ganglion uninterrupted to their termination upon striated muscle (somatic efferent fibers), or pass through and go as splanchnic efferent fibers to other sympathetic ganglia. A sympathetic root of a ganglion may consist of two or even three varieties of fibers : (1) those which arise from cells in other sympathetic ganglia and terminate about cells in the ganglion in question, which cells in turn contribute fibers to its branches of distribution; (2) fibers arising in other sympathetic ganglia which pass through the ganglion uninterrupted, and out with its branches of distribution; and (3), in case of the mixed ganglia of cephalic and spinal nerves especially, fibers arising in sympathetic ganglia which enter the ganglion in question and terminate about cell bodies of the dorsal root ganglion type, that is, cell bodies giving origin to ordinary cerebro-spinal sensory fibers, which are thus enabled to carry into the central system sensory impulses arising in the sympathetic distribution, as well as sensations arising in the cerebro-spinal peripheral terminations. The present knowledge of the minute construction of the ganglia of the ganglionated cephalic plexus and the origin of the fibers related to them in the plexus renders it impossible to use a terminology in describing them based upon their construction. The jugular ganglion This ganglion lies on the trunk of the vagus nerve in the jugular foramen. It receives its motor and sensory roots from the vagus nerve and its sympathetic root from the superior cervical sympathetic ganglion through the nodosal plexus immediately inferior to it. Its chief nerve of distribution is the auricular branch of the vagus, or nerve of Arnold, which leaves the jugular ganglion in CEPHALIC NERVES 231 the jugular foramen. It receives a branch from the petrous ganglion, enters the mastoid canaliculus in which it receives a communication from the facial nerve or merely lies in contact with it as far as the stylomastoid foramen, where it leaves the temporal bone. It- may pass through the tympanomastoid fissure, after which it divides behind the pinna into two branches, one of which joins the posterior auricular branch of the facial, and the other ramifies in the posterior inferior part of the cartilaginous portion of the ear, and to the skin of the dorsal part of the pinna. It also supplies twigs to the bony part of the external auditory meatus, and to the lower part of the outer surface of the tympanic membrane. The petrous ganglion This ganglion lies around the glossopharyngeal nerve in the lower part of the jugular foramen. The motor and sensory roots are derived from the vagus and probably also from the facial and glossopharyngeal nerves. The sympathetic root is a fine filament derived from the superior cervical sympathetic ganglion. The branches of distribution of the petrous ganglion are mainly through the tympanic branch, or nerve of Jacobson, to the tympanic plexus where communication is established with the facial nerve, and with two branches of the carotid nerve, the superior and inferior caroticotympanic nerves which enter the tympanic cavity through channels of the same name. From this plexus arises the small superficial petrosal nerve which goes to the otic ganglion. Other branches are distributed to the middle ear, and many filaments pass to the carotid plexus, while still others go to the pharyngeal plexus. Fibers also pass by way of the glossopharyngeal nerve to the tonsils. The tympanic plexus serves as a common point of distribution of fibers from the carotid plexus, the cavernous plexus, and the superior cervical sympathetic ganglion, by way of the caroticotympanic nerves, and the jugular and tympanic nerves. The tympanic plexus communicates with the petrous, jugular, geniculate, otic and sphenopalatine ganglia, and the only cephalic ganglia of the sympathetic that it does not communicate with 232 ROBERT BENNETT BEAN are the ciliary and submaxillary ganglia, which are supplied from the carotid plexus direct, or from plexuses derived from the carotid. The tympanic plexus is formed by nerves derived indirectly from the superior cervical sympathetic ganglion, the inferior caroticotympanic from the carotid plexus, the superior caroticotympanic from the cavernous plexus, and the tympanic nerve derived from the petrous and jugular ganglia which it has entered as the jugular nerve. The tympanic plexus communicates with the geniculate ganglion through a small branch which may be called the geniculo tympanic ramus; it communicates with the sphenopalatine ganglion through the great superficial petrosal nerve by way of a branch that may be called the tympanopetrosal ramus; and it communicates with the otic ganglion by way of the small superficial petrosal nerve. It will be seen that the tympanic plexus with the carotid and derivitive plexuses and the cephalic ganglia enumerated above represent broken up cephalic portions of the gangliated sympathetic cord whose ganglia have fused more or less in the neck and have become scattered in the head. The tympanic plexus is the communicating plexus of the ganglia, and represents not only the rami communicantes, but the sympathetic trunks connecting the sympathetic ganglia. The ganglia of the glossopalatine, glossopharyngeal and pneumogastric nerves, that is, the geniculate, petrous and jugular ganglia, are different from the other cephalic sympathetic ganglia, in that the central and sympathetic portions have not become separated by the wandering off of the sympathetic portions. The ciliary, sphenopalatine, otic and submaxillary ganglia wandered off from the Gasserian ganglion at an early embryonic period, in a manner similar to the wandering of the sympathetic ganglia of the gangliated cord from the spinal root ganglia, and the four ganglia are true sympathetic ganglia. The sympathetic portions of the ganglia of the glossopalatine, glossopharyngeal and pneumogastric nerves remain fused with the spinal portions of the same ganglia, but the tympanic plexus forms a common ground of communication, and affords a ready means of understanding the relationship between all the cephalic sympathetic ganglia. CEPHALIC NERVES 233 The geniculate ganglion This ganglion lies embedded in the anterior border of the geniculum of the facial nerve dorsal to the hiatus Failopii. Its motor root is of fibers from the facial nerve joining it at the great bend of the latter. The sensory root is derived from the dorsal root portion or the ganglion of the glossopalatine nerve, either in the ganglion or adjacent to it. The sympathetic root is the external superficial petrosal which passes through the hiatus Failopii and connects the ganglion with the sympathetic plexus on the middle meningeal artery or through the great superficial petrosal nerve from the sphenopalatine ganglion. The branches of distribution of this ganglion pass through other ganglia, or other nerves. The great superficial petrosal nerve passes directly from the geniculate ganglion to the sphenopalatine ganglion. A communicating branch passes from the geniculate ganglion to the small superficial petrosal nerve which afterwards enters the otic ganglion. The sphenopalatine or Meckel's ganglion This ganglion and the three following may be described as in the anatomy of Morris, remembering to dissociate them from the trigeminal nerve. The important facts concerning these ganglia are to determine their motor, sensory and sympathetic roots of origin, and to establish their fibers of distribution. The three roots of origin, motor, sensory and sympathetic, of the sphenopalatine ganglion are from the facial, trigeminal, and great deep petrosal nerves respectively. The fibers are distributed to the mucous membranes lining the ethmoidal and sphenoidal sinuses, and that of the nasal, buccal and pharyngeal cavities. Fibers of taste belonging to the glossopalatine nerve, arising from the geniculate ganglion, pass through the sphenopalatine ganglion from the great superficial petrosal nerve, and are distributed to the soft palate. Some of the small palatal muscles may be supplied by motor branches passing through this ganglion without interruption. 234 ROBERT BENNETT BEAN The position of the sphenopalatine ganglion is determined by the size and shape of the sphenoid sinus. In many recent dissections I have found it medial, lateral or inferior to this sinus and in five subjects the Vidian nerve passed through the sphenoid sinus in a tube of bone covered with mucous membrane. The otic ganglion The motor root of the otic ganglion is derived from the motor nucleus of the facial and some fibers probably also from the masticator nerve. Its sensory root passes through it from the glossopharyngeal nerve, and its sympathetic root from the middle meningeal plexus and from the tympanic plexus through the continuation of the tympanic nerve in the small superficial petrosal nerve. The sympathetic fibers from the otic ganglion are distributed to the parotid gland, the glands and vessels of the tongue, and uninterrupted motor cranial fibers to the tensor tympani and tensor veli palatini muscles. The submaxillary ganglion The motor root of this ganglion is derived from the motor nucleus of the glossopalatine, the sensory root from the lingual (Gasserian ganglion) and the sympathetic root from the plexus on the facial artery, or from the sympathetic portion of the geniculate ganglion through the chorda tympani. The fibers arising from this ganglion are distributed to the submaxillar}' and sublingual glands and to the floor of the mouth. The ciliary ganglion The motor root of this ganglion is derived from the oculomotor nerve, fibers which terminate in it, the sensory from the trigeminal, and the sympathetic root from the cavernous plexus. The fibers from this ganglion are distributed to the ciliary body, the iris, the cornea, and probably to the lachrymal gland. CEPHALIC NERVES 235 The parotid ganglion A small plexiform mass containing ganglion cells, and located beneath the parotid gland on the auriculotemporal nerve, connecting with the vagus, facial and trigeminal nerves, has been dissected repeatedly by students in the laboratory at Tulane University under my direction. At present investigations are under way to determine if this is the ganglion of the parotid gland. I realize that the term sympathetic needs restriction in its use, therefore, I propose that it be reserved for use in gross description, the sympathetic nervous system as a whole, in the same way that the terms central and peripheral nervous systems are used. In any presentation of the functional differences of neurones the terms somatic motor, somatic sensory, visceral motor, and visceral sensory should be used insofar as present knowledge of the subject will permit. From the standpoint of gross anatomy there can be no question as to the propriety of assembling the ganglia of the head and their connections as the ganglionated cephalic plexus, and from the standpoint of their sympathetic connections they are one, although it is desirable to determine exactly what fibers are motor, sensory or secretory, where they have their origin and where they are distributed. ANATOMY IN THE FAR EAST ELBERT CLARK College of Medicine and Surgery, University of the Philippines THREE FIGURES CHINA Of all branches of western education which are striving to enter China modern anatomy and pathology will be among the last to gain admission. Dissection and autopsy on the human subject are directly opposed to all the ancient culture of China, and for this culture, which has endured for so many centuries, China has decidedly more respect than for that of the West. Western education although admitted to be more practical is scarcely considered culture by the Chinese. However, should the present form of government obtain,, the outlook for anatomy may rapidly improve, for the medical missionaries and the Chinese educated abroad, many of them in medicine in America, have been most directly responsible for the "awakening of China," the recent revolution, and the growing popularity of western education. Up to the present time a religious respect for custom and tradition, the worship of ancestry, and the great fear of arousing public disapproval have made the teaching of anatomy and pathology in the medical schools of China all but impossible. Autopsies on natives are not permitted in China and the dissection of a Chinaman, particularly by a foreigner, would be sufficient grounds for a riot. These, among many others, are the difficulties, more or less variable, which each medical school of China encounters ; for as yet medical education is tolerated rather than encouraged. Several of the medical schools, however, are making a commendable effort to overcome this deficiency of the 237 THE ANATOMICAL RECORD, VOL. 7, NO. 7 238 ELBERT CLARK field of anatomy, either by a liberal use of models and manikins and dissection on dogs, as at the Union Medical College in Peking or by a more extensive course in comparative anatomy followed by a study room course in human anatomy with models and lectures as at Nanking University. Other schools have tried to obtain human dissection material from the Philippines, but we were unable to supply them. The medical schools of China, of which there are now some seventeen, are comparable to the smaller proprietary medical schools of the United States of a generation or two ago. All but one have been established to forward missionary work. Some teach in English, some in Mandarin, some in Chinese, and one in German. Microscopic anatomy fares better than dissection. Several schools have fair laboratories and equipment for histology and embryology. In China where there is so much superstition concerning the human body — a superstition many of the Chinese physicians seem never thoroughly to overcome for themselves — the teaching of dissection should be a most desirable and practical measure in medical education. A glimpse of what is inside the natural human being would, no dpubt, tend to allay much of this superstition and give the student more confidence in the foreigner's later instruction. The Chinese being a practical people — they learned centuries ago by experience that it is not safe tp drink unboiled water in their country — they will probably eventually countenance, then approve, dissection and autopsies. Yet this time is, no doubt, a long way off. The physician, at least in North China, does not enjoy a good social standing, and the medical students as a rule are recruited from the lower levels. Why should the Chinaman throw his sacred traditions to the wind and permit the mutilation of a Celestial's body by a foreigner all because the foreigner (as yet a not altogether popular person) tells him such will make it easier to apply the western art, in which the Chinaman himself has little confidence? The attitude of the more enlightened public is, as a rule, such as this and frequently one of a pronounced suspicion. ANATOMY IN THE FAR EAST 239 Hongkong The British colony of Hongkong, although essentially a Chinese city, has succeeded in making dissection and autopsies on the human subject available to her Chinese students. The Medical School here is a part of the Hongkong University. Dissection and autopsies form a conspicuous part of the five-year curriculum of this school. It is here also that we get the best idea of the Chinese student as a student of anatomy. During the short time these courses have been open to him, he has shown himself, up to a certain point, a good student, a good dissector and neat with his drawings. I am told further that, as might be expected from the old system of education so long in vogue in China, he shows a great tendency to drift into learning anatomy from the book by memory. As to his interest in the subject, it seems difficult to gage the Chinese student. The whole thing, methods as well as subjects, is so new to his countrymen that we would expect him to take much of it on faith, some by curiosity and perhaps more by discipline. INDO-CHINA In French Indo-China there is one Medical School with a hospital in which the natives are given courses in medicine. This is the "Medical School of French Indo-China" at Hanoi. It was established by the French and is a government-supported school. The faculty consists of army surgeons and sanitary physicians of the colonial government. France's colonies in the Far East are considered by her as permanent dependencies and thus little effort is made to place higher education within reach of the native. The primary object of the school is, I was told, to train high class hospital assistants, quarantine assistants, sanitary inspectors, and the like, to fill minor positions in the government service, which would be too expensive to have filled by Europeans. It is rare to find a native graduate in practice for himself. Anatomy being of little direct practical value, the courses here, although modelled after those of the universities in France, are much more abbreviated than the course of the latter schools. Anatomy is a means to an end and as such is likely to remain, and, indeed, there seems little reason for change. 240 ELBERT CLARK JAPAN The medical schools of Japan are departments of her universities. The College of Medicine of the universities of Tokyo and Kyoto are the best examples. Both of these institutions possess rather well equipped laboratories of anatomy, pathology and bacteriology, physiology and chemistry, and a medical faculty nearly all of whom have received training in the universities of Europe or America. The instruction is in Japanese, but a reading knowledge of German is required of all matriculates. The medical schools were established about twenty-five years ago along with the organization of the universities. At this time the faculty consisted almost entirely of foreigners, as was the case with the other branches of the university. The Japanese, however, have shown a remarkable adaptability to western medical education and have been rapidly replacing the foreign professors by Japanese. The latter are trained entirely abroad, or, having taken the M.D. degree in Japan, are later sent abroad for specialization. This is especially true of the anatomy faculty, for as yet little attempt seems to be made to train anatomists at home. The courses in anatomy, so far as I could gather, are conducted after modern ideas and rather according to the German method. The department, however, is not an institute of the university but rather a preparatory school for clinical medicine. There also exists in Japan a prejudice against the too free use of the human subject by the anatomist or the pathologist. THE PHILIPPINES Modern anatomy in the Philippines, or we might say in the Orient, dates only from the opening of the Philippine Medical School (now College of Medicine and Surgery, University of the Philippines) some six years ago. Fostered by the Bureau of Science of Manila and by a "Board of Control" acquainted with and in sympathy with research work and in a city where health problems were being worked out almost weekly, it is easy to understand the high ideals and ANATOMY IN THE FAR EAST 241 liberal financial backing with which this school began its work. Modelled after the better American medical schools and supported by a liberal appropriation from the Philippine government, the school has always been able to maintain in the biologic branches teachers giving their entire time to the separate departments. Time, funds, technical assistants and opportunity have been and are afforded each man in each department for scientific investigation. Anatomy has enjoyed these luxuries almost equally with the other branches. The Department of Anatomy of the College of Medicine and Surgery, University of the Philippines, gives courses in gross human anatomy, elementary neurology, histology and embryology. The Laboratory for Histology and Embryology occupies the second floor of the east wing (50 x 80 feet) of the new Medical School building. Here are located two offices for members of the staff, a private laboratory and preparation room and the class laboratory. The floors are of concrete. Each room is fitted with built-in hardwood tables and side desks, fully equipped with lockers and supplied with running water, gas, sinks and electric lights. Nearly the whole north side of this wing is window space. With the exception of a few rainy days, any part of the laboratory is light enough for high-power observation with the microscope. Each student is supplied from the central store room with a microscope, instruments, and so forth, for the course, and is given individual desk and locker space. The entire third floor of this building is also given over to anatomy. Here are located two dissecting rooms, a study room with models, a laboratory for elementary neurology and the study of cross sections, an instructor's room, a preparator's and specimen store-room, a lavatory and a large corridor with student's lockers. On the ground floor in the city morgue are located the cadaver vats. Here the subjects are kept in the refrigerator boxes till embalmed. The morgue is connected with the dissecting room through the medium of a hand power lift upon which cadavers are hoisted to the laboratory. For dissecting tables plain heavy wood tables covered with a sheet of galvanized iron or tin are employed. The building being of reinforced 242 ELBERT CLARK concrete, everything can be washed easily. Figure 2 gives an interior view of the dissection laboratory. The Department is in charge of myself and Ruskin M. Lhamon. For additional assistance in microscopic anatomy we have been favored by the loan of an officer from the medical corps of the United States Army. During the past year we have been fortunate in securing the services of Dr. Ernest R. Gentry in this capacity. The Department of Zoology of this university has rendered us valuable assistance in the laboratory course in embryology. While during the past two years the Department has had demonstrators in gross anatomy, there are as yet no permanent occupants for these positions. Student demonstrators have not proven desirable. With this arrangement, Dr. Lhamon and I have enjoyed a fair amount of time for investigation. Filipino 'boys,' after a long and tedious period of training, make excellent and faithful technical assistants. Courses of instruction The courses of instruction follow the same general plan as that of the more advanced medical schools of America. Special effort is, moreover, made to place the subject in hand in a more simple form before the students. The proximity of the morgue makes it possible to secure at practically all times fresh tissue for the class in microscopic anatomy. The rainy season compels us to postpone practical instruction in section cutting, staining, and so forth, till the latter part of the first year. The relative uniformity of the seasons' temperature places continuously much ready embryologic laboratory material near our doors. In the laboratory courses in elementary neurology dissection of the human brain follows laboratory instruction in comparative neurology and the development of the central nervous system, and is succeeded by first hand study of the fiber tracts and of the microscopic structure of the central nervous system and organs of special sense. In gross human anatomy we have made one departure which can be recommended to those laboratories with a limited teach Fig. 1 Interior view of fche class Laboratory of microscopic anatomy. Fig. 2 The dissection laboratory. Fig. 3 Laboratory for elementary neurology and study room for cross sections and special dissections. 243 244 ELBERT CLARK ing staff and an abundance of material, as is the case here. All of the first year class are put to work upon the same dissection (two separate dissections in large classes) and continued in such sections so nearly as possible throughout the course. During the first dissection they are working upon the same cadavers as the second year students or with such of the latter as have failed to finish their dissection in the first year. Study room specimens of the lower extremity are available for comparison when they are wwking upon the upper extremity and vice versa. The more brilliant students are encouraged to do special dissections, such as that of the lymphatics, variations, and so forth. Lectures in gross anatomy are quite unsuited for our students and we are beginning to be a little skeptical of the laboratory manual. Where, as here, it is all-important to develop in the students individual initiative (a quality forcibly discouraged here for the past three hundred years) for a practice in later life under the most trying conditions, anatomy can be made of the highest practical value if the student can be led to approach it with the attitude of a well guided explorer rather than that of a well booked tourist on the beaten path. We, however, have found that this method entails more time and personal instruction on the part of the instructor. The Filipino student A profound respect for western civilization and American educational methods is responsible for a keen desire upon the part of the student to catch every word of instruction and to remember it literally. The students are practically all conscientious, hard workers and make good use of their text-books and are clever at dissection. They will undertake any amount of work assigned to them but will not volunteer for any work not required and will not remain during vacation for work in the laboratories or the hospital without pay. They prefer American instructors and will submit without murmur to any schedule or discipline arranged by these, but often resent the same from the junior men of their own nation ANATOMY IN THE FAR EAST 245 ality. It is very common to find in the first year class, students who can give a complete description (sounding very much like the text-books or one's own lecture) of the structure of the kidney and the next moment pronounce a section of the kidney to be tongue. The dissections of the right side are better than those of the left, the illustrations in the atlases being from the right side. A student in anatomy made a dissection of the peripheral lymphatics which was worthy of a text-book figure, but when examinations came on, a few days before the work could have been finished, he lost interest in the dissection and left it lying upon the table in our tropical heat to perish. Yet some surprises in originality are in store for the instructor who has found the Filipino lacking in this quality. To my first class in gross anatomy in Manila I was demonstrating the elasticity of the arteries and explaining the change during old age, not troubling them with any pathological names, when one of the students called my attention to a calcified radial artery in an eighty-year-old subject. On showing this to our one Igorote student (from a mountain tribe which do not wear trousers) who had never been inside of a hospital, he immediately exclaimed, "Ah! Arteriosclerosis, my father died of that." Manila, February 28, 1913. CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF THE MUSEUM OF COMPARATIVE ZOSLOGY AT HARVARD COLLEGE, NO. 237. NOTES ON RONTGEN-RAY INJECTION MASSES G. H. PARKER In studying variations in the circulatory systems of animals, it is often convenient to be able to make a rapid preliminary inspection of the preserved material on the basis of which a selection of specimens for detailed dissection can be made. Such an end can be accomplished by using an injection mass which is so compounded as to be opaque enough to admit of the preliminary inspection by Rontgen rays and firm enough to make subsequent dissection easy. The following four masses have been found to meet these requirements for small animals. No. 1. This mass is a simple gelatin mass containing in suspension a sufficient quantity of bismuth subnitrate to make it opaque to the Rontgen rays. The proportions of the ingredients are as follows : Dry gelatin 2.5 grams Water 100.0 cc. Bismuth subnitrate 25 . grams The gelatin is to be dissolved in the water, which should be warm, and to this solution the bismuth subnitrate is to be added. It is well to strain the mass through cheese cloth. If the mass is to be kept in stock for any length of time, a small amount of thymol or other bactericide should be added. The mass should be injected warm enough to be fluid. It flows with great freedom and yields a very complete injection. Its whiteness is usually sufficiently distinctive, but it may be colored, like ordinary white starch-mass, with carmine, Prussian blue, etc. Its chief deficiency is its tendency to separate, the heavy bismuth subnitrate settling on the lower inner surfaces of the vessels. It must, therefore, be thoroughly agitated before it is injected and radiographs are usually more successful if taken shortly after the injec 247 248 G. H. PARKER tion has been made than after the specimen is a week or so old. The mass yields very sharp radiographs and is satisfactory for subsequent dissection. The specimens should be preserved in alcohol. No. 2. A second bismuth mass was made from vaseline or petrolatum to which was added enough bismuth subnitrate to render it reasonably stiff. The proportions were as follows : Bismuth subnitrate 20 grams Vaseline 130 grams The two ingredients are to be mixed with a spatula on a glass plate. It is well to strain the mass by pressing it through cheese cloth. It can be injected cold, though the injections are fuller if the specimen is slightly warmed previous to the introduction of the mass. The bismuth does not tend to separate in this mass as in the gelatin mass. The radiographs are sharp. This mass, like No. 1, may be variously colored. No. 3. The third mass was compounded on the same plan as No. 2 except that lead chromate was used in place of bismuth subnitrate. The proportions of the ingredients were as follows: Lead chromate 20 grams Vaseline 100 grams This mass is, of course, yellow in color; otherwise it is much the same as No. 2. In many respects it resembles the red-lead mass described by Descomps, de Falletans, et de Lalaubie ('10). No. 4- Mercury was naturally among the first substances to be used for Rontgen-ray injections. Haschek und Lindenthal in 1896 published a radiograph of the human hand injected with Teichmann's mass the opacity of which depended in part on the contained chalk but chiefly on the cinnabar. In the matter of opaqueness the great advantage of metallic mercury over its salts was clearly shown by Braus ('96). Anyone, however, who has used fluid mercury for injection must have been impressed with its many inconveniences: on handling the preparation, the mercury is very likely to shift about in the vessels and spaces, and, if a slight rupture is made, the whole injection may be lost. RONTGEN-RAY INJECTION MASSES 249 To obviate these difficulties and yet retain the advantages of the metallic mercury, the suggestion of Fredet ('00) to use mercurial ointment was adopted. An injection mass compounded of mercurial ointment and vaseline proved most satisfactory. For a freely flowing mass the following proportions were used : Mercurial ointment 50 grams Vaseline 50 grams The mercurial ointment, composed of one part by weight of metallic mercury and one part by weight of lard, is thoroughly mixed with an equal weight of vaseline, strained, and injected cold or slightly warmed. The mass itself is dark gray in tone but may be colored by any of the ordinary means. It flows freely, especially if the part to be injected is previously warmed, gives a very sharp radiograph, and from its oily nature, can be easily wiped from the specimen, if, by accident, it overflows. On the whole, it is a most satisfactory injection mass for Rontgenray work. BIBLIOGRAPHY Bratts, H. 1896 Ueber Photogramme von Metallinjectionen mittelst Rontgen Strahlen. Anat. Anz., Bd. 11, pp. 625-629, Taf. 1. Descomps, P., de Falletans, G., et de Lalaubie, G. 1910 Technique pratique pour injections et radiographics de pieces anatomiques. Bull, et Mem. Soc. anat., Paris, ann. 85, pp. 493-496. Fredet, P. 1900 Les arteres de l'uterus etudiees au moyen de la radiographic Compt. rend. 13 Congres internat. med., Paris, sect, anat., pp. 103-108Haschek, E., tjnd Lindenthal, O. T. 1896 Ein Beitrag zur praktischen Ver wertung der Photographie nach Rontgen. Wiener klin. Wochenschr., Jahrg. 9, pp. 63-64. 250 BOOKS RECEIVED BOOKS RECEIVED THE FIRST SIGNS OF INSANITY, Their prevention and treatment, Bernard Hollander, M.D., 346 pages including index, 1913. $3.25, net. Funk and Wagnalls Company, New York and London. COLLECTED PAPERS FROM THE RESEARCH LABORATORY PARKE, DAVIS AND COMPANY, DETROIT, MICHIGAN, illustrated, 287 pages including index, 1913, reprints, volume 1.
A METHOD OF ELECTROPLATING WAX RECONSTRUCTIONS 1 IVAN E. WALLIN The temporary nature of wax models has been a matter of some concern to investigators using the Born method of reconstruction. From a casual examination of the literature I have not found any methods described for making wax models permanent. Paints and varnish have been used with a certain degree of success. Small models when coated with French varnish will not wilt as readily as an uncoated one, the fragility however, is not altered by this process. In technical literature I found a method for electroplating on wax and other non-metals with the use of graphite. This method was tried but the results were far from satisfactory. I experimented with graphite and bronze powder and finally devised a method which gives good results. ' Electric current. In larger cities laboratories are often supplied with the direct current. This is generally a 110-volt current and appears to be just the proper current for this kind of electroplating. An Edison storage cell may be used if the direct current is not at hand. To get the proper amperage a lamp rheostat which is easily made (see any text book on electricity) is very convenient. The lamps are arranged in parallel. One 16-candle-power lamp gives approximately one-half ampere, two lamps one ampere, and so forth. The number of amperes to be used will depend upon the size of the object to be plated. A model the size of an ordinary drinking glass will be plated satisfactorily with one-half ampere. Bath. The copper sulphate solution which I have used has the following composition: CuS0 4 150 grams H2SO4 ; 50 ct;. Distilled water 1 liter Dissolve the copper sulphate in the water, then add the sulphuric acid. The size of the bath will depend upon the size of the object to be plated. There should be a space of at least six inches between the model and the sides, bottom, and top of the vessel containing the fluid to obtain the best results. For the' anode a copper plate may be used. This should be large enough to form a lining to the inside of the vessel. 1 From the Anatomical Laboratory, University and Bellevue Hospital Medical College, New York City. 251 252 IVAN E. WALLIN Preparation of model. First coat the model with graphite (Dixon's flake graphite. No. 2). This may be applied with the fingers. In places which can not be reached with the fingers use a small bristle brush. Next make a paint or suspension mixture of bronze or copper powder in chloroform. With a camel's hair brush paint the graphite coated model with the bronze paint. One should not rub over a spot more than once or twice as the chloroform dissolves the wax. It will require a couple of hours or more for this coat to dry. When it is thoroughly dry the bronze will not rub off and the model should again be coated with graphite, using the same method as in the first coat. If the bronze coat is not even it may be touched up with the bronze paint before the last coat of graphite is put on. Heat a copper wire (preferably an insulated wire, removing about an inch-and-a-half of the insulation from the two ends) and plunge it into the wax, holding it in position until it has cooled and remains firm. For a large model it is advantageous to use a number of wires distributed over the model. At the point where the wire comes into contact with the model the wax should be scraped from the wire. With the point of a knife pack graphite around the wire to insure a good contact between the wire and the coating on the model. Wax being lighter than the fluid of the bath it is necessary to anchor the model. This may be done in two ways, either by attaching a weight to the wiring or plunge a hot wire hook into the model and attach the weight to the hook. If the weight is metal it should be coated with paraffin. To determine the polarity of the electric current attach one of the wires to the copper plate and hold the other in the fluid of the bath for a few moments. Copper will deposit on the cathode which is to be connected with the model. When the model is ready to be plated it should be placed in the bath and if it contains cavities it should be turned so that all the air will escape. The current should not be on when the model is being lowered into the bath for the heat generated will melt the wax and insulate the wire attachments from the coating. After the model is fairly plated over there may be a few spots Avhich have not received a deposit of the copper. Apply the bronze paint to these spots and then graphite and immerse in the bath again. The thickness of the plating will depend upon the length of time in the bath. To render a model durable it should have a fairly thick coat of copper (from 0.3 mm. to 0.8 mm.). The necessary time required for this thickness will depend upon the size of the model and the amperage and can only be determined by experience. After the plating is completed, the model should be washed thoroughly in water, then in alcohol, and dried rapidly by fanning. When drying slowly from a washing in water the color of the copper may not be constant. I wish to take this opportunity to thank Prof. S. A. Tucker of Columbia University, who so kindly gave me the use of his laboratory and apparatus when I first began this work and also, for valuable information in connection with electroplating.