MARINE BIOLOGICAL LABORATORY,

Received

Accession No.

Given by

Place,

*,* No book or pamphlet is to be removed from the Lab- oratory without the permission of the Trustees,

ANATOMISCHER ANZEIGER

CENTRALBLATT GESAMTE WISSENSCHAFTLICHE ANATOMIE. AMTLICHES ORGAN DER ANATOMISCHEN GESELLSCHAFT.

HERAUSGEGEBEN

VON

D KARL von BARDELEBEN,

PROFESSOR AN DER UNIVERSITAT JENA,

SECHZEHNTER BAND,

MIT 4 TAFELN UND 282 ABBILDUNGEN IM TEXT,

JENA VERLAG VON GUSTAV FISCHER 1899.

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Inhaltsverzeichnis zum XVI. Band, Nr. 124,

I, Aufsätze.

Allis, Edward Phelps jr., On Certain Homologies of the Squamosal, Intercalar, Exoccipitale and Extrascapular Bones of Amia calva. p- 49—72.

— — An Abnormal Musculus obliquus superior in Carcharias. With 1 Fig. p. 605—607.

Arnold, Julius, Weitere Beobachtungen über ,vitale“ Granula- färbung. p. 568—572.

— — W. Fremming und die „Mitomlehre“. p. 607-615.

Atheston, Lewis, The Epidermis of Tubifex rivulorum Lamarck, with Especial Reference to its Nervous Structures. With 5 Fig. p. 497—509.

Ballowitz, E., Ueber polytome Nervenfaserteilung. Mit 2 Abb. p. 541 — 546.

Bühler, A., Das Verhalten der Carpalknochen bei den Seitenbewe- gungen der Hand. Mit 3 Abb. p. 223—229.

Cole, F. J., On the cranial Nerves and Sense Organs of Fishes. p. 40 —48.

Diamare, Vincenzo, Sul valore anatomico e morfologico delle isole di LAngERHANs. p. 481—487.

Doering, H. Beitrag zur Streitfrage über die Bildung des Corpus luteum. Mit 1 Taf. p. 299—301.

Eisler, P., Ueberzählige Carpalia. Mit 1 Abb. p. 487—489.

Ellermann, W., Ueber die Structur der Darmepithelzellen von Helix. Mit 6 Abb. p. 590—593.

Eschweiler, R. Die Fenestra cochleae bei Echidna hystrix. Mit 3 Abb. p. 584-590.

Eternod, A.C.F., Il y a un canal notochordal dans l’embryon humain. Avec 17 fig. p. 131—143.

Eycleshymer, Albert C., The Cleavage of the Egg of Lepidosteus osseus. With 5 Fig. p. 529—536.

IV

Fischer, Eugen, Seltener Verlauf der Vena azygos (Abspaltung eines Lungenlappens). (Nachtrag.) p. 91—92.

Flint, Joseph Marshall, Reticulium of the Adrenal. With 8 Fig. p. 1—13.

Hansen, Fr. C. C. Ueber die Genese einiger Bindegewebsgrundsub- stanzen. Mit 13 Abb. p. 417—438.

Havet, J., Note préliminaire sur le systeme nerveux des Limax (mé- thode de Gouer). Avec 10 fig. p. 241—248.

Hazen, Annah Putnam, The Regeneration of a Head instead of a Tail in an Earthworm. With 6 Fig. p. 536—541.

Heidenhain, Martin, Beiträge zur Aufklärung des wahren Wesens der faserförmigen Differenzirungen. Mit 15 Abb. p. 97—131.

Herfort, Karl, Die Conjugation der Vorkerne und die erste Furchungs- spindel im Ei von Petromyzon fluviatilis. Mit 5 Abb. p. 369—376.

Hertwig, Oscar, Ueber die Stellung der Anatomie und Physiologie in den medicinischen Prüfungen. p. 594 — 600.

Hill, Charles, Primary Segments of the Vertebrate Head. With 22 Figures. p. 353—369.

His, W., und Fick, R., X-Photogramme von Konrap Wiest in Aarau. p. 239— 240.

Holmgren, Emil, Zur Kenntnis der Spinalganglienzellen des Kanin- chens und des Frosches. Mit 11 Abb. p. 161—171.

— — Weitere Mitteilungen über den Bau der Nervenzellen. Mit 13 Abb. p- 388—397. '

Johnston, William B., A Reconstruction of a Glomerulus of the Human Kidney. With 6 Fig. p. 260—266.

Keibel, F., Ueber die Entwickelung des Labyrinthanhanges (Recessus labyrinthi oder Ductus endolymphaticus). Mit 1 Abb. p. 490—492.

Koltzoff, N. K., Metamerie des Kopfes von Petromyzon Planeri. Mit 3 Abb. p. 510-523.

v. Lenhossek, M., Das Mikrocentrum der glatten Muskelzellen. Mit 2 Abb. p. 334—342.

Lenssen, Anatomie de la Neritina fluviatilis. p. 401—404.

Locy, William A. New Facts Regarding the Development of the Olfactory Nerve. With 14 Fig. p. 273—290.

Maas, Otto, Ueber Reifung und Befruchtung bei Spongien. Mit 12 Abb. p. 290 —298.

Mall, Franklin P., Supplementary Note on the Development of the Human Intestine. With 1 Fig. p. 492—495.

Martinotti, Carlo, Sur la réaction des fibres élastiques avec l’emploi du nitrate d’argent, et sur les rapports entre le tissu élastique et le tissu musculaire. p. 201—207.

Matiegka, H., Ueber das ,Os malare bipartitum“. Mit 11 Abb. p. 546—557.

Mayer, Sigmund, Bemerkungen iiber die sog. Sternzellen der Leber und die Structur der capillaren Blutgefäße. p. 180—192.

Mehnert, Ernst, Kainogenesis, Cenogenesis, Kenogenesis, Cenegenie, Caenogenese oder Cänogenese? p. 29—31.

5

ee

de Meijere, J. C. H., Ist die Gruppenstellung der Säugetierhaare eine Stütze für die Maurer’sche Hypothese von der Ableitung des Haares von Hautsinnesorganen niederer Vertebraten? Mit 2 Abb. p. 249 — 256.

Metcalf, Maynard M., An Answer to a Suggestion by DELAGE and H£ROUARD that the Accessory Eyes in Salpidae may be Otocysts. p. 301—302.

Morpurgo, B., Ueber die Verhältnisse der Kernwucherung zum Längen- wachstum an den quergestreiften Muskelfasern der weißen Ratten. p- 88—91.

— — Ueber die Regeneration des quergestreiften Muskelgewebes bei neugeborenen weißen Ratten. p. 152—156.

Nageotte, J., Note sur un nouveau microtome a cerveau. p. 38—40.

Negri, A., Ueber die Persistenz des Kernes in den roten Blutkörper- chen erwachsener Säugetiere. Mit 9 Abb. p. 33—38.

Nusbaum, Jözef, Die Entstehung des Spermatozoon aus der Sperma- tide bei Helix lutescens Zıesz. Mit 7 Abb. p. 171—180.

— — und Sidoriak, Szymon, Das anatomische Verhältnis zwischen dem Gehörorgane und der Schwimmblase bei dem Schleimbeißer (Cobitis fossilis). Mit 7 Abb. p. 209—223.

Paulcke, Wilhelm, Zur Frage der parthenogenetischen Entstehung der Drohnen (Apis mellif. ¢). Mit 2 Abb. p. 474—476.

Prenant, A., Rectification au sujet de la communication de M. MAurkr: „Die Schlundspalten-Derivate von Echidna“. p. 572—575. |

Rauber, A. Ein Wort der Entgegnung an Epuarp Van Benepen. p. 523-- 524.

Ruffini, Angelo, Una rivendicazione di prioritä a S. Ramon CAJaL nel considerare come Organi di senso i Fusi neuro-muscolari, con qualche considerazione sui recenti studi dell’ argomento. p. 13—26.

— — Di una singolarissima anomalia in un osso temporale dell’ uomo. Con 3 fig. p. 381—388.

RtzZiéka, Vladislav, Zur Geschichte und Kenntnis der feineren Structur der Nucleolen centraler Nervenzellen. Mit 1 Abb. p. 557 563.

Sala, Guido, Untersuchungen über die Structur der Pacrni’schen Körperchen. Mit 1 lithogr. Taf. p. 193—196.

Schaper, Alfred, Noch einmal zur Structur der Kerne der Stäbchen- Sehzellen der Retina. p. 342—349.

— — Zur Histologie des Kleinhirns der Petromyzonten. Mit 4 Abb. p. 439 — 446.

Schimkewitsch, W. Ueber die Entwickelung der Cephalopoden unter künstlichen Bedingungen. p. 564—568.

Schneider, Guido, Einiges über Resorption und Excretion bei Amphioxus lanceolatus YAarker. Mit 2 Abb. p. 601—605.

Schultze, Oskar, Ueber die Einwirkung niederer Temperatur auf die Entwickelung des Frosches. p. 144—152.

Schüller, M, Epithelien auf der Innenfläche der Schalenhaut des Hühnereies. Mit 7 Abb. p. 460-467.

u ie

Sclavunos, G., Ueber Keimzellen in der weifen Substanz des Riicken- marks von älteren Embryonen und Neugeborenen. Mit 5 Abb. p. 467

— 473. Smidt, H., Die Sinneszellen der Mundhöhle von Helix. Mit 6 Abb. p- 567 —584.

Sokolow, A. Zur Frage über die Endigungen der Nerven in den Varer-Pacını’schen Körperchen. Mit 2 Abb. p. 452—455.

Stahr, Hermann, Bemerkungen über die Verbindungen der Lymph- gefäße der Prostata mit denen der Blase. p. 27—29.

Sterzi, Giuseppe N., Die Rückenmarkshüllen der schwanzlosen Am- phibien. p. 230—239.

Stéhr, Philipp, Ueber die Querschichtung in den Kernen der mensch- lichen Stäbchensehzellen. Mit 3 Abb. p. 197—201.

Strahl, H., Die Verarbeitung von Blutextravasaten durch Uterindrüsen. p- 266— 269.

Studnitka, F. K. Ueber das Vorkommen von Kanälchen und Al- veolen im Körper der Ganglienzellen und in dem Axencylinder einiger Nervenfasern der Wirbeltiere. p. 397—401.

Tandler, Julius, Zur Frage der Tyson’schen Drüsen. p. 207—208.

Thilo, Otto, Die Entstehung der Luftsäcke bei den Kugelfischen. Mit 2 Taf. p. 73—87.

Tonkoff, W., Ueber die vielkernigen Zellen des Plattenepithels. Mit 2 Abb. p. 256—260.

— — Zur Entwickelung der Milz bei Vögeln. p. 405—406.

— — Zur Kenntnis der Nerven der Lymphdrüsen. p. 456—459.

Van Beneden, Edouard, Recherches sur les premiers stades du developpement du Murin (Vespertilio murinus). Avec 16 fig. p. 305 — 334.

— — Réponse a la reclamation de M. Rauser. p. 524—526.

Vincenzi, Livio, Ueber eigentümliche Faserendigungen im Trapez- kern. Mit 6 Abb. p. 376—880.

Vosmaer, G. C. J., Eine einfache Modification zur Herstellung von Platten-Diagrammen. p. 269—271.

Wallenberg, Adolf, Notiz über einen Schleifenursprung des Pedun- culus corporis mamillaris beim Kaninchen. p. 156—158.

Ziehen, Th. Zur vergleichenden Anatomie der Pyramidenbahn. Mit 2 Abb. p. 446—452.

II. Litteratur.

Nr. 2 p. 1-16. No. 8 p. 17—32. No. 10 u. 11 p. 33—48. No. 13 u. 14 p. 49—64. No. 19 p. 65-80. No. 23 p. 81112.

III. Anatomische Gesellschaft. Neue Mitglieder p. 32, 48, 96, 600. ' Quittungen p. 32, 96, 616. Versammlung in Tübingen p. 31—32, 93—96.

Vit

IV. Personalia.

Bertelli, p. 48. — Victor von Mihalkovics, p. 240. — G. Sclavunos, p. 416. — J. B. Carnoy, p. 480. — Th. Thilenius, p. 528. — K. Tel- lyesniczky, p. 496. — M. Heidenhain, Sobotta, H. Braus, p. 576. — Elliot Smith, M. v. Lenhossék, p. 600.

V. Nekrologe.

Victor von Mihalkovies — Mihalkovics Geza, p. 349—352. — W. H. Flower, p. 4935 —496.

VI. Sonstiges.

Auszug aus der Geschäftsordnung für die k. k. zoologische Station in Triest. p. 526—528.

Berichtigungen, p. 48, 304.

Bitte, p. 160.

Bücherbesprechungen, p. 158—160, 271—272, 302—-304, 407—416, 477—480, 496, 616.

Referat, p. 92.

71. Versammlung deutscher Naturforscher und Aerzte in München. p. 272.

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ANATOMISCHER ANZEIGER

Centralblatt

für die gesamte wissenschaftliche Anatomie.

Amtliches Organ der Anatomischen Gesellschaft.

Herausgegeben von Prof. Dr. Karl von Bardeleben in Jena.

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Der ,,Anatomische Anzeiger‘* erscheint in Nummern von etwa 2 Druckbogen. Um ein rasches Erscheinen der eingesandten Beiträge zu ermöglichen, werden die Nummern ausgegeben, sobald der vorhandene Stoff es wünschenswert macht und event. erscheinen Doppelnummern. Der Umfang eines Bandes beträgt etwa 50 Druckbogen und der Preis desselben 16 Mark. Das Erscheinen der Bände ist unabhängig vom

Kalenderjahr.

XVI. Band. +3 5. Mai 1899. & No. I.

INHALT. Aufsätze. Joseph Marshall Flint, Reticulum of the Adrenal. With 8 Figures. p. 1- 13. — Angelo Ruffini, Una rivendicazione di priorita a S. RAMON CAJAL nel considerare come Organi di senso i Fusi neuro-muscolari, con qualche considerazione sui recenti studi dell’argomento. p. 13—26. — Hermann Stahr, Bemerkungen über die Verbindungen der Lymphgefäße der Prostata mit denen der Blase. p. 27—29. — Ernst Mehnert, Kainogenesis, Cenogenesis, Kenogenesis, Cene- genie, Caenogenese oder Cänogenese? p. 29—31. — Anatomische Gesellschaft.

p. 31—32

Aufsätze.

Nachdruck verboten.

Retieulum of the Adrenal.

By JoseprH MARSHALL FLinv.

(From the Anatomical Laboratory of the Johns Hopkins University, Baltimore.)

With 8 Figures.

RANVIER !) and BIZZOZERO ?) showed almost simultaneously that the framework of lymphatic glands was not made up of the processes of multipolar cells, but consisted of a meshwork of fibrils with the cells resting upon them. These fibrils are shown not to be elastic

1) Ranvier, Société de biologie, 1871. 2) Bızzozero, Reale Istituto Lombardo, 1872. Anat, Anz. XVI. Aufsätze, 1

2

fibres by Ewatp and Kttune') who found that they resisted pan- creatic digestion and, accordingly, it was assumed that they consisted of white fibrous tissue. More recently, however, MALL ?) has emphasized the fact that the interstitial tissue of many glands and organs consists of a network of branching and interlacing fibrils that have no definite connection with the connective tissue cells. He found, moreover, that these fibrils are neither white fibrous nor yellow elastic tissue, and owing to differences of a chemical nature and to reactions distinct from either of them, he formed of them a new interstitial tissue which he designated as Reticulum. Reticulum has a wide distribution throughout the body especially in the splanchnic area and is easily differentiated from yellow elastic tissue by the fact that it resists pancreatic digestion. It is characterized in a general way by being more resistant than white fibrous tissue and yields on manipulation a characteristic residue, Reticulin?). If boiled in !/, °/, HCl tendon is dissolved in one minute, while it takes about eighteen minutes for reticulum to go into solution; and, similarly, when a !/, °/, solution of KOH is used, the reticulum is dissolved in thirty: five, while tendon is destroyed in two minutes. It appears, however, that the resistance of reticulum in different situations is liable to vary for in a later paper Mat‘) states that he finds in the spleen two types of reticu- lum, the most resistant and the least resistant. In dilute acids tendon and reticulum swell but the sharp contour of the fibrils is brought back when they are stretched by pressing on the cover glass. These reticulated tissues have been studied by methods of maceration, di- gestion, staining, and precipitation (OPPEL’s modified GoLGI method) and the different procedures have yielded apparently quite different results. But recent work, however, seems to indicate that these results will be brought more or less into harmony, inasmuch as apparent differences in structure and arrangement seem to result simply from differences in manipulation. In this connection it is interesting to note that OppreL®) has accepted Maur’s observations and has ac- knowledged that the “Gitterfasern” which he found in the liver with his silver method are identical with the reticulum fibrils which

1) Ewaup und Künne, Verhandl. d. Naturhist.-med. Vereins Heidel- berg, Bd. 1.

2) Marz, Abhandl. d. Kgl. Sachs. Ges. d. Wiss., 1890, and the Johns Hopkins Hospital Reports, Vol. 1.

3) SIEGFRIED, Habilitationsschrift, Leipzig 1892.

4) Marz, The Johns Hopkins Hospital Bulletin, 1898.

5) Orrer, Verdauungsapparat. MERrKEL-Bonner’s Ergebnisse, 1898.

3

Mat had previously described after a study of the organ by means of digested frozen sections. In studying the framework of the ad- renal I have used principally the methods of digestion and find that the interstitial tissue is similar to the reticulum which Mau has found in the liver, kidney, spleen, lymphatic glands, intestine ete. Inasmuch as the connective tissue of the adrenal has never been studied by any of the destructive methods there is no literature on the framework per se, but much has, however, been written con- cerning the arrangement of the connective tissue as it is seen in sections. According to Ecker!) the connective tissue of the cortex is formed of homogeneous membranes that surround the gland tubules (Drüsenschläuche) which make up the cortical portion of the gland, while the medulla consists of a network of fibres containing in its meshes a quantity of “molecular material with nuclei and nucleated globules”. KOELLIKER ?) believed that the capsule gave off fibrous laminae which divide the cortex into oblong spaces containing the cells and from these laminae the stroma of the medulla is derived which, however, he does not describe. Lrypic*) thought that the connective tissue of the cortex is derived from the capsule and runs in parallel strands at right angles to it; these strands with numerous transverse septa divide the cortex into small spaces which contain the cells. The medulla, according to this investigator, functions as a nerve centre and its interstitial tissue forms a fine network of fibrils which supports the ganglion cells. According to HArLEY *), who was the first to study stained sections of the adrenal, the cortex is not composed of tubules, but of columns of cells surrounded by connective tissue. In the medulla he was unable to find a basement membrane surrounding the cell groups. Morrs®) described smooth muscle and elastic fibres in the capsule and holds that the cells of the cortex are not supported by basement membranes or by thicker processes of connective tissue, but rest in the meshes of a fine fibrillar network. The medulla, likewise, shows only slight differences in structure from the cortex and its stroma is also in the form of a meshwork. Re- garding the framework of the cortex, JOESTEN ®) is in accord with

1) Ecker, Der feinere Bau der Nebennieren beim Menschen und den vier Wirbeltierklassen. Braunschweig 1846.

2) KoELLIKER, Mikroskopische Anatomie, 1854.

3) Leypie, Lehrbuch der Histologie des Menschen, 1857.

4) Harıey, Lancet, June 5th and 12th, 1858.

5) Moers, Vircnow’s Arch., 1864.

6) Joesten, Arch. f. Heilkunde, 1864.

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4

Moers except that he describes an outer layer of cells surrounded by thicker septa from the capsule. These cell groups he calls capsules and each cell occupies a mesh of the stroma network. In the medulla, however, JOESTEN believes that the cells are arranged in tubules embraced by a membrane.

ARNOLD!) who named the layers of the cortex studied the con- nective tissue of the adrenal in sections from which some of the cells had been brushed out. From preparations thus formed he describes the arrangement of the stroma as follows:

“In der Zona glomerulosa bildet das interstitielle Gewebe rund- liche Räume, welche in ihrem Innern von einem Reticulum durchsetzt werden, in dessen Maschen rundliche, kernhaltige und membranlose Parenchymkörper liegen.

“Der säulenartige Bau der Zona fasciculata ist durch die vor- wiegende Längsrichtung der Bindegewebspfeiler, zwischen denen das Reticulum mit dem Parenchymkörper liegt, bedingt. Die Zona reti- cularis besteht aus einem gleichmäßig ausgespannten Bindegewebsnetz, das in seinen Maschen die Parenchymkörper einschließt.

“Die Marksubstanz besteht aus interstitiellem Gewebe und Par- enchymkörpern. Das erstere begrenzt in den peripherischen Teilen des Markes längsovale Räume, welche mit ihrem Längsdurchmesser perpendicular gegen die Centralvene und meistens in zwei Reihen über einander aufgestellt sind. Diese zerfallen durch ein zartes Reti- culum in kleinere Räume, in denen große Kerne mit den ihnen zuge- hörigen Protoplasmateilen liegen. In den centralen Teilen des Marks bildet das interstitielle Gewebe ein Netz, in dessen engen Maschen die Parenchymkörper liegen.’

According to GRANDRY ?) the cortex is made up of closed vesicles and long cylinders or tubes limited by the connective tissue of the blood vessels. In the cow, GRANDRY states that the cylinders have no membrane but he believes one to be present in the dog and cat. The medulla of the cow is composed of numerous closed vesicles, round, tubular, curved, pressed together in a multiplicity of forms. von BrunNn?), on the other hand, thinks that with the exception of the outer cortical layer the connective tissue forms a delicate net- work. In the spaces of the zona glomerulosa, however, there is no fine reticulum, but the long processes of the spindle cells pass into

1) ArnoLp, VircHow’s Arch., 1866. 2) Granpry, Journ. de l’Anat. et de la Physiol., 1867. 3) von Brunn, Arch. f. mikr. Anat., 1872.

5

and intertwine with the fibrils of the connective tissue septa that embrace the cell groups. According to HEnLE!) the cortex is com- posed of “Säulen” and “Schläuche”. The columns correspond to the Zona glomerulosa of ARNOLD and are separated by thick processes from the capsule, the tubes, on the other hand, are only separated by the blood vessels and the homogeneous membrane which encloses the cells. In the medulla HENLE found tubes with a membrane and a considerable amount of interstitial tissue between them. STILLING ?) described stellate pigment cells in the capsule and large septa of the sheep’s adrenal which give the surface of the organ a mottled appear- ance, but somewhat earlier, however, similar cells had been found in the capsule of the cow’s suprarenal by GRANDRY.

Methods.

For the study of the reticulum I have used principally the di- gestion method of Mau and that of SPALTEHOLZ?). In Maur’s method frozen sections of the fresh gland from 40—80 u thick are digested for 24 hours in pancreatin *) and then carefully washed in distilled water. The sections are then placed in a test-tube half full of water and thoroughly shaken in order to remove all of the cellular debris, after which they can be coaxed up on a slide and allowed to dry. A few drops of the following solution are then allowed to dry on the preparation:

Picric acid 10 gms. Absolute alcohol 33 ccm. Water 300 ccm.

The sections are then stained for about half an hour in a solution of acid fuchsin which is made as follows:

Acid fuchsin 10 gms. Absolute alcohol 33 ccm. Water 66 ccm.

The section is washed in the picric acid solution, dehydrated and cleared in absolute alcohol and xylol and mounted in balsam.

1) Hexte, Anatomie des Menschen, Bd. 2, 1873. 2) STILLING, VircHow’s Arch., 1887. 3) Horst, Arch. f. Anat. u. Physiol., Anat. Abt., 1897, and SpALTE- HOLZ, ibid., Suppl.-Bd., 1897. 4) Parke Davis and Co.’s Pancreatin 5 gms. Bicarbonate of soda 10 gms. Water 100 ccm.

6

In addition to MAut’s reticulum stain, I have found that splendid results can be obtained with the following mixture:

Nigrosin 4 gms. Water 100 ccm.

A few drops of this solution is allowed to remain in the section for 15 to 20 minutes. It is then washed in 70°/, alcohol, transferred to absolute alcohol, cleared in xylol, and mounted in balsam. The picture afforded by this stain is very sharp and it does not fade as quickly as the fuchsin.

The tissue for the SPALTEHOLZ method is fixed in 1°/, solution of mercuric chloride in 33°/, alcohol for 24 hours. The strength of the alcohol is then increased about 10°/, every 24 hours until the tissue reaches absolute alcohol when it can be transferred to creosote, xylol and embedded in paraffin in the usual way. Serial sections about 6 w thick are cut and the alternate sections arranged in two series, the one for digestion and the other for control staining. The sections to be digested are firmly fixed on the slide by the water method and after the paraffin has been dissolved, they are allowed to remain in benzine for 24 hours. The slides with the sections are then submitted to the action of an artificial pancreatic juice for 6 to 12 hours when they are removed, washed and stained.

When digested, frozen sections of the adrenal are treated with dilute acids, the reticulum swells and becomes transparent but the transparency of the fibrils, however, is not as marked as that obtained when white fibres are submitted to the same treatment. If the pro- cess is allowed to go on under the microscope the former sharp contour of the fibrils is brought back by the exertion of a slight pressure on the cover glass. In making the following tests frozen sections of tendon, adrenal, and lymph gland were taken from the same dog, my object being to compare the behavior of the framework of the adrenal with the white fibrous tissue of the tendo Achillis, on the one hand, and the reticulum of the lymph gland on the other. The sections were kept under precisely the same conditions throughout the experiment. They were digested in pancreatin 24 hours, washed and shaken in distilled water and then allowed to remain in the acid or in the alkali solutions 2 hours before boiling. The figures repre- sent the average of two experiments and the time was not taken until the temperature had reached 99,5° C.

Solution | Time required to dissolve | Tendon | Adrenal reticulum | Lymph gland reticulum HCL 05 %, | 3'/, min. 10 min. 11'/, min. KOH 0,13%, | 33 min. 148/, min 22 min.

In both HCL and KOH the tendon was completely dissolved in the time specified and the solutions remained clear. The framework of the adrenal and lymph gland, on the other hand, did not dissolve entirely, but remained as a finely granular detritus which persisted, even after boiling for 35 minutes.

While the figures in the above table show extreme differences in the time required for the tendon and adrenal framework to dissolve, the figures in the case of the reticulum are considerably less than those obtained by Mau. This may be partly explained by the fact that the tissue was allowed to remain in the solutions 2 hours be- fore boiling, while MALL only permitted his to remain one hour, and, partly, because MALL used in his experiments frozen sections of the spleen which contains the most resistant type of reticulum. Other experiments were made to test the reaction of the adrenal framework with cold solutions of HCL and KOH of varying strengths and these gave results similar to those obtained by MALL.

That most of the periglandular tissue and a considerable portion of the outer layer of the capsule is made up of white fibrous tissue can be shown by placing the gland with its surrounding tissue in strong KOH (8—10°,). All of the periglandular connective tissue and much of the outer part of the capsule soon dissolves leaving the smooth inner layer of reticulum which begins to disintegrate at a much later period. This white fibrous portion of the capsule can be readily seen in SPALTEHOLZ preparations (Fig. 2, C). Although no effort was made to obtain reticulin from the adrenal framework, it is, nevertheless, undoubtedly true reticulum, but viewed from the stand- point of resistance, it occupies a position midway between the most and least resistant types which Mau found in the spleen.

The description of the microscopic anatomy of the adrenal ret- iculum is based on a careful study of sections prepared by the methods of MALL and SPALTEHOLZ. At first sight it appeared that the pictures obtained in this way were quite different but more careful observation showed that essentially the same structures were preserved in each instance and that apparent differences were due simply to the

Fig. 1. Fig. 2.

Figs. 1 and 2. Semidiagrammatie figure of the reticulum of the Zona glomerulosa of the dog’s adrenal. Fig, 1 prepared by SPALTEHOLZ’ method. Fig. 2 by MaAur’s method. Magnified about 120 diameters.

C capsule. Z. @. Zona glomerulosa. Z, F. Zona fasciculata. c small process limiting cell column of Zona glomerulosa. S large septum from the capsule to the Zona reticularis. 5 septum cell spaces of the Zona glomerulosa.

different methods of manipulation. For example, the sections in MALL’s method are thick and one is thus able to obtain a suggestion of the third dimension so that the reticulum fibres can be traced throughout their entire course, although the violent shaking which is necessary to remove all of the cellular debris is liable to displace many of them. The relations of the fibrils; on the other hand, in the SPALTEHOLZ preparations’ are admirably preserved inasmuch as they are fixed in situ and can be compared with stained controls but owing to the fact that the sections are so thin and the fibrils cut in such small seg- ments it is impossible to trace them for any distance. The larger septa in the SPALTEHOLZ sections often appear black and homogeneous, while by Marr’s method the individual fibrils comprising them are clearly stained. I have found, however, that the fibrillar structure of the septa in sections prepared by SPALTEHOLZ’ method can often be seen when they are studied with an immersion lens. Accordingly, I believe that these two methods are mutually explanatory and in the study of the reticulated tissues, in general, should always to be used together inasmuch as neither method, in itself, is sufficient to explain all of the relations of the fibrils in an organ.

ee

The fibrous envelope of the adrenal contains connective tissue cells, smooth muscle fibres and some nerves and ganglion cells be- longing to the adjacent solar plexus which are found principally in the dorsal and mesial surfaces of the gland. In addition there is a plexus of superficial lymphatics, described first by StirLıne !). In digested sections of the dog’s adrenal, the capsule is separated more or less into two layers, the outer denser zone consisting of white fibrous tissue and an inner zone made up principally of reticulum. From the capsule there are two sorts of processes which pass into the gland, the large septa (Figs. 1 and 2, s), which extend through the greater part of the cortex almost or entirely to the Zona reticularis and the smaller septa (Figs. 1, 2, 6), which divide the peripheral part of the cortex into irregular oblong or ovoid spaces containing the coiled columns of columnar cells that make up the Zona glomerulosa (Fig. 1, Z. G.). These spaces average about 0,15—0,2 mm in width and 0,25 —0,3 mm in depth and are subdivided again, not by a fine fibrillar network as ARNOLD and others describe, but by smaller processes of reticulum (Figs. 1 and 2, c) which separate the coiled columns of cells. When these septa are viewed in the third dimension they might be looked upon as membranes running between the cell columns of the Zona glomerulosa but if this view is held, they must not be considered to be homogeneous membranes, surrounding the “Säulen” and “Schläuche” as described by the earlier investigators but as septa formed by the intertwining of fibrils of reticulum. The course of these fibrils is roughly shown in Fig. 2, while they are seen cut in short parallel segments in Fig. 1. It is not improbable that some of the larger septa which pass from the capsule through the cortex may be contaminated with white fibres from the outer layer of that structure.

The reticulum of the Zona fasciculata in the dog is derived from the inner septa of the Zona glomerulosa and the fibrils run towards the medulla in wavy parallel lines passing in and out between the cells composing it (Figs. 1—4, Z. F.). Besides the isolated fibrils there are smal processes running at right angles to the capsule which sup- port and maintain the arrangement of the cell colums of the Zona fasciculata. From these processes as well as from the larger capsular septa, fibrils are constantly given off which run in and out between the cells. Preparations made by SPALTEHOLZ’ method, Figs. 1 and 3, indicate that there must be a network of reticulum in this layer. The

1) STILLING, loc. ‘cit.

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Fig. 3. Fig. 4.

Figs. 3 and 4. Reticulum of the Zona fasciculata. Fig. 3, by SPALTEHOLZ’ me- thod. Fig. 4, by MArr’s method. Magnified about 120 diameters,

earlier view held by Ecker, GERLACH, HENLE and others, that the cell columns of the Zona fasciculata are composed of “Schläuche” surrounded by a homogeneous membrane was finally disproved by ARNOLD who showed that structures which these investigators had mistaken for the membranes are in reality the walls of the capillaries which define so sharply the cell columns of the middle cortical zone. While ArnoLp’s view of the arrangement of the interstitial tissue of the Zona fasciculata is, in general, correct, he has, nevertheless, mistaken the wavy fibrils of reticulum for a meshwork between the parallel processes.

The fibres of the Zona reticularis (Figs. 5 and 6, Z. R.) are con- tinuous with those of the stratum above which on reaching the inner cortical layer branch and anastomose to form a dense meshwork of reticulum. All of those capsular processes (Fig. 6, d) which have not

Fig. 5. , Fig. 6.

Figs. 5 and 6. Reticulum of the Zona reticularis. Fig. 5, by SPALTEHOLZ’ method. Fig. 6, by Maxu’s method. d septum reaching from the capsule to the Zona reticularis. Magnified about 120 diameters.

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been lost in the Zona fasciculata, break up immediately when the Zona reticularis is reached and assist in forming its meshwork. While many of the fibrils run singly there are, however, irregular fibrillar processes which embrace groups of cells in this layer. But as ARNOLD points out, the meshwork here is so dense that practically every cell has a space in the reticulum for itself. As the fibrils pass from the Zona fasciculata into the Zona reticularis they become irregular in direction and their subsequent course is so variable and intricate that it is difficult to follow them (Figs. 5 and 6, Z. R.). The network of fibrils in the Zona reticularis forms a sharp line of demarcation between the cortex and medulla and where there are invaginations of the cortex into the medulla the junction between the two tissues is still separated by this thick network.

In the dog the line of demarcation between the cortex and me- dulla is fairly regular, although it is not uncommon to find either projections of the medulla into the cortex or invaginations of the cortex into the medulla, but in these instances the definition of the two {tissues is still sharp inasmuch as the dense framework of the cortex is easily distinguished from the loose septa of the medulla. From the Zona glomerulosa strands of reticulum run into the medulla and unite to form irregular spaces which contain the groups of medul- lary cells (Figs. 7 and 8, m). These spaces are not subdivided by a fine reticulum although in preparations made by Marr’s method dis- placed fibrils are frequently seen stretching across them. They are,

Fig. 7. Fig. 8.

Figs, 7 and 8. Reticulum from the medulla. Fig. 7, by SPALTEHOLZ’ method Fig. 8, by MALL’s method. Magnified about 120 diameters.

m space for the groups of cells of the medulla. » vein. e horizontal section of septum,

ss

however, simply displaced fibrils which result from the agitation of the section in washing out the debris. Like the septa of the Zona glomerulosa, those of the medulla often appear as homogeneous pro- cesses but can be shown, in frozen sections or sometimes by the higher powers of the microscope, to consist of aggregations of fibrils, cut in parallel segments or as a delicate crosshatch when the fibrils interlaced. These septa embrace the medullary cell groups entirely and are considered by the earlier investigators to be the membranae propriae of the medullary “Schläuche”. Sometimes the septa in digested paraffin sections are cut horizontally (Fig. 7, e) and show the fibrillar structure of the septa.

ARNOLD described two layers in the medulla which showed dif- ferences in the arrangement of the interstitial tissue and cell groups. This apparent stratification is due, however, to the distribution of the smaller veins in the peripheral portion of the medulla which renders the cell groups in that region more distinct. The medulla, as a whole, is arranged on a uniform plan and excepting for the distribution of the veins the groups in the central have relations similar to those in the peripheral portions.

The veins of the medulla are provided with a sheath of reticulum (Fig. 7, v), to which the septa surrounding the cell groups are at- tached. Thus, in thick sections prepared by Matu’s method the course of the veins is clearly marked out in the reticulum to that beautiful negative pictures of the venous tree are obtained. Clear spaces in the reticulum bounded by definite walls indicate the course of the veins and circular strands of reticulum traversing these spaces show where branches of the venous tree leave the plane of section and turn down into the depths.

Resumé.

1) The framework of the adrenal is made up of reticulum.

2) The reticulum of the Zona glomerulosa in the dog is composed of septa derived from the capsule which divide the outer layer of the cortex into oval or oblong spaces that contain the coiled columns of cells forming that zone. Smaller processes of reticulum pass in and separate the columns from each other.

3) The reticulum of the Zona fasciculata consists of processes and fibrils running at right angles to the capsule from the Zona glomerulosa to the Zona reticularis. The fibrils pass in and out between the cells of this layer and are frequently gathered into small processes that sustain the relations of the cell columns of this zone.

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4) The reticulum of the Zona reticularis is in the form of a dense meshwork composed of branching fibrils derived from the fibrils of the Zona fasciculata and the larger septa from the capsule. In this layer the fibrils may be gathered into strands which embrace small groups of cells.

5) The framework of the medulla is made up of strands or septa composed of reticulum fibrils which form round, oval, or irregularly crescentic spaces and contain the medullary cell groups. These spaces are not subdivided by a fine reticulum and the arrangement of the reticulum in the central and peripheral portions of the medulla is practically alike.

Nachdruck verboten.

Una rivendicazione di priorité a S. RAM6N CAJAL nel considerare come Organi di senso i Fusi neuro-museolari, con qualche con- siderazione sui recenti studi dell’ argomento.

Pel Dott. AngetLo RUFFINI, Libero docente d’Istologia normale nella R. Universita di Siena.

(Dal laboratorio d’Istologia ed Embriologia dell’ Ospedale di Lucignano [Arezzo].)

S’era scritto, ed anch’ io fra gli altri, che primo a considerare come Organi di senso i Fusi neuro-muscolari fosse stato il KERSCHNER fin dal 1888. Ed io ho gia da tempo portata una critica, severa se vuolsi, ma vera e serena intorno a questa idea del KERSCHNER, perche non mi parve e non mi pare tuttora che i fatti da lui allora addotti a corroborare questa idea fossero tali e di tal forza da autorizzarlo © sostenere cosi recisamente che si poteva senz’ altro considerare i Fusi neuro-muscolari come Organi di senso; e tanto pill mi parve un po’ azzardata la sua proposta in quanto che il KERSCHNER non aveva portata neppure una figura a dimostrazione ed a prova della sua convinzione. Ma ad ogni modo questa ipotesi ebbe piu tardi il sug- gello di una verita indiscutibile per le belle e dimostrative ricerche di SHERRINGTON.

Né io sapevo, ne da altri vidi citate osservazioni che dopo o contemporaneamente a quelle di KERSCHNER e prima delle mie (1892) avessero contribuito a chiarire la funzione fisiologica dei Fusi neuro- _ muscolari. Quando, e con mia grande sorpresa ed anche con un poco di dispiacere, pochi giorni or sono mi vidi giungere il Vol. II, Fasc. 3 e 4 (1897) della Revista trimestral micrografica, la quale

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conteneva un articolo di Santraco Ramon CAJAL sulle terminazioni nervose dei Fusi muscolari della rana; sulla copertiva [del quale Fascicolo, RamMoén CAJAL s’ era compiaciuto di scrivere poche parole onde darmi una tiratina d’ orecchi per non aver io mai citato questo suo lavoro. A dir vero io non meritavo il rimprovero, com’ egli non meritava che fossero dimenticate le sue poche ma belle e dimostra- tivissime osservazioni.

Ed ecco la ragione perché io oggi mi sento il dovere di prendere la penna e parlare di questo lavoro cosi generalmente sconosciuto.

Fu pubblicato la prima volta sulla: Revista trim. de Histol. nor. y patol., No. 1, Mayo, 1°, 1888, contemporaneamente quindi al primo lavoro di KERSCHNER, e portava per titolo: ,,Terminaciones en los husos muscolares de la rana“. Vedendo poi che questo lavoro „pas6 completamente desapercibido de los sabios“, lA. si decise a nuovamente pubblicarlo sulla: Revista trimestral mierogräfica, Vol. II, Fasc. 3 y 4, 1897, col titolo: ‚„‚Terminaciones nerviosas en los husos muscolares de la rana“.

Lo riassumo ed in parte anche lo traduco nella breve parte che concerne lo studio della terminazione nervosa nel Fuso neuro-muscolare.

Il metodo impiegato per queste ricerche fu quello di Eariicn col bleu di metilene e fra i muscoli della rana fu scelto il pettorale cutaneo. Ogni Fuso neuro-muscolare riceve due arborizzazioni terminali. Una che giace ad una certa distanza dal rigonfiamento fusiforme, ha tutti i caratteri di una terminazione motrice comune, da cui si distingue unicamente per essere un poco pitt piccola ed offrire minor copia di ramificazioni pallide terminali. L’altra situata nella regione fusiforme o capsulata del Fuso, € un po’ pit’ complicata. La fibra o le fibre nervose che la originano sono grosse e flessuose ; dopo aver attraver- sate le capsule e perduta la mielina si decompongono immediatamente in una grande quantita di sottilissimi fili variocosi quasi tutti paralleli all’ asse muscolare, di cui abbracciano una grandissima estensione. Le varicosita di questi filamenti sono tali che a prima vista mettono in dubbio sulla loro natura nervosa, parendo che il bleu di metilene abbia colorato solo i grossi granuli cosi abbondanti negli interstizi di certe fibre muscolari.

Ed ecco le interpretazioni che S. RAmön CAJAL da a queste due specie di 'terminazioni nervose. N

Riguardo alla prima forma di terminazione cosi si esprime: „Por razön de esta analogia puede considerarse dicha arborizaciön como una terminaciön motriz destinada 4 exitar las contracciones de la parte no granulosa, es decir, estriada del huso muscolar.“

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Riguardo alla seconda forma da quest’ altra interpretazione: ,,La analogia que, tanto en delicateza como en varicosidades, ofrecen estas arborizaciones con las intra-epiteliales de la piel y de la cörnea, in- clinan el änimo 4 estimarlas como de naturaleza sensitiva.“

L’A. termina questa nota aggiungendo il risultato delle sue osservazioni portate su altri animali ed a tal proposito cosi scrive: Nei muscoli della lucertola i Fusi muscolari rivelano ancora le due specie di terminazioni menzionate. Di queste la ordinaria € una vera piastra motrice con tutti i suoi caratteri e l’altra si dispone come nella rana, offrendo perö granuli e varicosita molto pil grosse nei rami dell’ arborizzazione. Nel coniglio, nella cavia e nel ratto appare, con poca differenza, la medesima disposizione fondamentale, studiando i muscoli di questi animali col cloruro d’oro e col bleu di metilene.

Dopo aver riportata testualmente questa prima Nota, TA. si diffonde in qualche commento sulle ragioni per le quali egli & indotto a considerare i Fusi neuro-muscolari di natura sensitiva. Da ultimo aggiunge poche righe per riferire nuove osservazioni sui Fusi della rana. Dalle quali osservazioni € risultato come le terminazioni possono essere tre o pil, ma solo una é di carattere sensitivo; le altre sono motrici e si trovano sempre discoste dalla regione fusiforme del Fuso e di queste ne ha osservate non raramente due, una nella regione distale e l’altra in quella prossimale del Fuso. Di pit A. avrebbe potuto vedere anche nella terminazione sensitiva del Fuso della rana come le ramificazioni terminali qualche volta prendano un andamento arciforme o spirale, come Craccto ha visto accadere per i rami terminali dell’ Organo muscolo-tendineo di GOLGI.

L’A. riporta anche in questa ristampa la figura della prima memoria del 1888; figura che io trovo molto chiara e dimostrativa; ma non potrei dire se e quanto corrispondente al vero, perché non ho mai estese le mie ricerche ai Fusi neuro-muscolari della rana.

Ed ora mi sia lecito di fare alcune considerazioni in merito a questo lavoro di Ramon CAJAL e, giacché sono ritornato sull’ argo- mento, qualche considerazione anche sui risultati che alcuni osservatori hanno pubblicato in questi ultimi anni sulla distribuzione dei nervi nei Fusi neuro-muscolari e sulla interpretazione che dobbiamo dare ad al- cune delle terminazioni nervose intrafusali.

L’ osservazione di Ramon CAJAL €, senza dubbio, di un interesse grandissimo tanto per i fatti osservati con molta precisione e rettitudine, quanto per la castigata interpretazione che doveva necessariamente scaturire da quella diligente osservazione. Io non credo ci possano essere discrepanze su questo giudizio. Altro merito pure incontestabile

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del lavoro sta in cid che TA. riproduce una immagine delle osser- vazioni fatte, di cui a niuno pud sfuggire la chiarezza e la dimostra- tivitä. Queste adunque sono le ragioni che oggi m’ inducono a dichiarare eccellenti le osservazioni di RAmön CAJAL € giustamente apprezzato il significato da lui fin da quel momento attribuito ai Fusi neuro-musco- lari, mentre mi dispiace non poter dire altrettanto di quelle osser- vazioni da KERSCHNER pubblicate antecedentemente al mio primo articolo (1892).

Di quanti osservatori, compreso lo scrivente, si sono bene o male occupati di questo argomento dal 1888 ad oggi, nessuno ha ricordata mai l’osservazione di Ramon Cagau. Cid probabilmente accadde per la pochissima diffusione del periodico sul quale venne quella osser- vazione pubblicata. Che questa ragione sia probabile stia a provarlo il fatto che il detto periodico non ebbe che un anno di vita e non trovd abbonati all’ estero. Fatalita pur volle che io non ricevessi né il numero della Revista del 1888, né quello del 1897 che lo stesso Ramon CAJAL assicura di avermi spediti, uno dopo la mia prima comunicazione del 1892 e l’altro appena pubblicato; per cui io mi trovai nella assoluta impossibilita di poterlo citare. Ed ho anche piacere che queste ragioni sieno apparse buone allo stesso RAMON CAJAL, il quale forse mi rimproverd credendo che io avessi ricevute le sue comunicazioni e che le avessi ad arte taciute. E purtroppo vero, confessiamolo francamente, che taluni hanno di queste deplorevoli abitudini! Ma mi & grato sperare che nessuno voglia attribuire un atto simile a me, che restai profondamente addolorato sol perche fosse stata trascurata l’interessante osservazione di un sapiente, del quale non c’& nel mondo scientifico chi disconosca l’alto intelletto ed i meriti incomparabili.

Dovrei ora per debito d’imparzialita, entrare a discutere del valore e dell’ apprezzamento di alcuni fatti di cui € parola in questo lavoro di RAmön CAJAL, ma siccome mi son deciso di estendere maggior- mente questa discussione, cosi io ne parlerö qui in modo generico, riferendomi anche ai recenti risultati di altri osservatori, che pure portarono il loro contributo allo studio di questo stesso argomento.

Discorrerd solo dei Fusi neuro-muscolari dei mammiferi, come quelli che furono oggetto delle mie speciali ricerche, riferendomi per qualche momento anche a quelli dei vertebrati inferiori ma solo in via di confronto e quando i fatti osservati in essi possono portare qualche luce nell’ interpretazione di alcuni ‘fatti strutturali che si pos- sono osservare nei Fusi dei mammiferi medesimi. Metterd a confronto

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i risultati miei con quelli di CıPoLLONE, Huser e DE Wirt e Gta- COMINI, per ciö che riguarda lo studio della terminazione dei nervi nei Fusi, ed alcune mie interpretazioni di fatto coi risultati sperimen- tali ed anatomo-patologiei di CIPOLLONE, MORPURGO, BATTEN, SPILLER, HORSLEY e GRÜNBAUM.

Non uscirö che incidentalmente da questa cerchia di osservatori, perche € specialmente l’opera loro che a me preme discutere e con- frontare colle mie proprie osservazioni.

E da premettere, a scanso di possibili questioni di prioritä, che il mio ultimo lavoro sulla struttura dei Fusi neuro-muscolari, compiuto fin dal Dicembre 1895 e comunicato all’ Accad. medico-fisica di Firenze nella tornata del 24 Febbraio 1896, fu potuto pubblicare, Journal of Physiology, Vol. XXIII, No. 3, July 26, solo nel 1898, non per colpa mia, ma delle mie condizioni. Ciö per la storia.

Si deve a questo grande ritardo nella pubblicazione se le mie osservazioni furono 0 non conosciute o male apprezzate nel breve reso- conto, senza figure, che ne pubblicai sul Monit. Zool. Ital., Anno VII, Fasc. 3, Marzo 1896.

A buon diritto quindi tanto le due osservazioni di CIPOLLONE !) quanto quella di Huser e De Wırr?) si devono ritenere di molto posteriori al mio ultimo lavoro.

Mentre questi osservatori sono d’accordo con me nel riconoscere la struttura morfologica della terminazione primaria od a nastri anulo- spirali, come io la descrissi fin dal 1892, non sono riusciti a vedere come la terminazione secondaria od a fiorami sia una terminazione a sé e da quella distinta per caratteri morfologici e per individualita di fibra nervosa.

Che CIPOLLONE non abbia saputo degnamente apprezzare e distin- guere dalle altre la terminazione secondaria, appare chiaramente a pag. 3 del suo secondo lavoro. Dopo aver ricordate le tre qualita di terminazioni che io ho viste e distinte nel Fuso del gatto, cosi prosegue: „Come si vede, con questa distinzione si trova abbastanza in accordo

1) L. T. Creottonn, Ricerche sull’ anatomia normale e patologica delle terminazioni nervose nei muscoli striati. Suppl. agli Annali d. Med. nav., Anno 3, Agosto, 1897, Edit. Rosenberg e Sellier, Torino. — Nuove ricerche sul Fuso neuro-muscolare. Ricerche fatte nel Lab. d. Anat. norm. d. R. Univ. di Roma ecc., Vol. 6, 1898, Fasc. 2 e 3.

2) C. Huser and Lypia M. A. De Wirt, A Contribution on the. motor Nerve-endings and on the Nerve-endings in the Muscle-spindles. The Journal of Comparative Neurology, Vol. 7, No. 3 and 4.

Anat, Anz. XVI. Aufsätze. 2

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quella fatta da me nella precedente nota; la differenza é solo nel non aver io fatta una specie distinta delle cosi dette terminazioni a fio- rami, che pure ho riscontrate e descritte. Ne trovo di dovermi correggere, perché molto pit importante d’ogni altra ritengo ancora la distinzione fra le terminazioni a spirale ed a forme varie che deri- vano sempre da fibre midollate grosse e cingono le fibre muscolari nel rigonfiamento fusiforme, e le piccole terminazioni a placca, che deri- vano invece da fibre midollate sottili e sono nei tratti laterali del fascetto di WEISMAnN.“ Che il CrpoLLONE voglia dare un altro nome a questa forma di terminazione e non voglia quindi accettare la mia denominazione sta benissimo, ma non mi pare possa essere autorizzato a non riconoscere l’esattezza della mia osservazione nel distinguere questa terminazione dalle altre, perché non ha con esse di comune ne la fibra nervosa, ne i caratteri morfologici.

Riguardo alla terminazione primaria od a nastri anulo-spirali, CIPOLLONE non ha aggiunto nulla di nuovo alle descrizioni da me date nel ’92 nel ’96.

Dissente da me solo nella descrizione e nella interpretazione delle terminazioni a forma di piastra, ma di cid parleremo pit tardi.

I] lavoro di Huser e DE Wirt non meriterebbe la pena di essere ricordato se le inesattezze che questi osservatori mi hanno voJuto far dire non mi costringessero a correggerle, onde qualche studioso, poco addentro nella conoscenza di questo argomento, non sia tratto in in- ganno riguardo alle mie osservazioni coscienziose e, fino a prova con- traria, esatte.

Huser e DE Wirt mentre riconoscono l’esattezza della mia descri- zione riguardo alla terminazione primaria, non hanno esattamente riferita la distinzione da me fatta delle terminazioni del Fuso. Perocché dicono averle io cosi distinte: terminazione a spirale, ad anella ed a fiorami, mentre a tutti 6 noto come le dividessi per contro in: terminazione a nastri anulo-spirali, terminazione a fiorami e terminazione a forma di piastra.

Descrivendo la terminazine secondaria od a fiorami, cosi si espri- mono: ,,Le terminazioni a fiorami menzionate da RUFFINI sono senza dubbio, come suggerisce KERSCHNER, le terminazioni finali delle spirali e di branche delle spirali.“ Evidentemente Huser e DE Wirt igno- rano lo svolgimento delle osservazioni a questo riguardo. Che la terminazione a fiorami si credeva fosse una dipendenza di quella a nastri anulo-spirali lo dissi, erroneamente, io primo nel ’92 e K=rscHNui lo ripeté nel 93; ma nel ’96 io corressi questo errore di osservazione,

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riconoscendo che se pur talvolta accade che i nastri anulo-spirali della terminazione primaria finiscano, agli estremi di questa, con dei rigonfia- menti multiformi a guisa di fiorami, tuttavia la caratteristica termi- nazione a fiorami & indipendente da quella a nastri anulo-spirali e proviene da una fibra tutt’ affatto propria. Cosi e non altrimenti stando le cose, ognuno puö comprendere qual valore possa avere l’affermazione, ribadita con quel senza dubbio, di questi osservatori.

Con ogni probabilita HUBER e DE WITT essendo venuti a cognizione del mio ultimo lavoro solo quando avevano finito di scrivere il loro articolo e senza essersi preoccupati di prenderne una esatta conoscenza, se la cavano con queste asserzioni gratuite: ,,Rispetto all’ ultima nota di Rurrinı (si referiscono al sunto pubblicato sul Monit. Zool. Ital.) noi vogliamo dire, per quel che ci & dato determinare dal breve sunto da lui dato, che egli non ha materialmente nulla aggiunto alla sua prima nota (quella dell ’92) ...... inoltre noi crediamo che le nostre figure dimostrino le varie forme di terminazioni da lui menzionate con eccezione forse delle terminazioni a forma di piastra. Riguardo a queste & piuttosto difficile, dovendo stare al breve sunto dato, for- marsi un’ idea definita della maniera di terminazione che Rurrint ha in mente quando formula la sua descrizione.“

Mi é grato sperare che Huser e De Wirrt leggendo il mio lavoro per esteso, tanto pitt che & stato pubblicato in inglese, riescano a materialmente convincersi che ho aggiunto qualche cosa alla mia prima nota e che possano formarsi un’ idea definitiva (cosa che io auguro loro di tutto cuore!) della maniera di terminazione a forma di piastra che io ho in mente.

Posso adunque concludere dicendo che riguardo ai fatti anatomici concernenti la struttura e la disposizione delle terminazioni nervose nei Fusi dei mammiferi, gli studi posteriori alle mie osservazioni non solo non hanno sostanzialmente nulla aggiunto a quanto io dissi e figurai nel 92 e nel 96, ma eziandio non giunsero a far vedere cid che io con ogni chiarezza e precisione riuscii a dimostrare. Questo fatto perö non deve, secondo il mio giudizio, essere ascritto ad im- perizia nell’ osservare, ma deve trovare piuttosto la sua ragione nei risultati poco completi e poco netti delle reazioni auriche impiegate.

Veniamo ora a portare il nostro giudizio imparziale e spassionato, come sempre, sopra un’ altra questione intorno alla quale si & tanto discusso e si discute tuttora. Voglio alludere alla natura e funzione da attribuirsi alle terminazioni a forma di piastra. Su questo punto abbiamo oggi osservazioni anatomiche, risultati sperimentali ed

D*

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anatomo-patologici. Noi li passeremo in rassegna, premettendo qualche dato storico.

KERSCHNER (Febbraio 1888) e S. Ramon Casau (Maggio 1888) si esprimono in modo netto e preciso sull’ esistenza di piastre motrici terminanti nelle fibre muscolari intrafusali. Le descrivono nella rana, nei rettili e nei mammiferi.

Io nel 1892 non parlai di piastre motrici, ma solo di piccoli in- trecci terminali aventi presso a poco la grandezza, ma non la strut- tura, delle piastre motrici; non seppi decidermi sul loro significato e sulla loro natura e perciö mi limitai solo a descriverli ed a figurarli. Nel 18931) pero io ammisi l’esistenza di un apparato motore, tratto in inganno da uno dei miei allora scarsi preparati, nel quale pareva appunto che alcuni tra i rami nervosi terminantisi sulle fibre musco- lari circostanti, andassero a posarsi sulle fibre intrafusali; ma pit tardi riconobbi che quei ramoscelli nervosi, invece che sulle fibre muscolari intrafusali, si terminavano per contro su alcune fibre muscolari circo- stanti, le quali, per lo schiacciamento subito dal preparato, pareva fossero sullo stesso piano ottico del Fuso e sembravano quindi le stesse fibre muscolari intrafusali. E tanto & vero quello che asserisco che nella stessa nota critica del ’93 io dissi che aveva ragione KERSCHNER nell’ ammettere un apparato motore nel Fuso, ma che oltre a questo esistevano indubiamente sulle fibre intrafusali certe piastrine ter- minali che mi sembravano alquanto diverse dalle piastre motrici tipiche (p. 86). Nelle osservazioni posteriori (1896) ba- sandomi sui caratteri morfologici di queste che chiamai terminazioni a forma di piastra, negai che potessero essere considerate vere piastre motrici delle fibre muscolari intrafusali e mi parve di poter loro attri- buire il significato di terminazioni sensitive. Cosi venni a stabilire, sempre pero colla debita riserva, che il Fuso neuro-muscolare fosse privo di terminazioni nervose motrici.

CIPOLLONE nei suoi due lavori ha sempre riconosciuto in queste terminazioni a forma di piastra delle vere e proprie piastre motrici, basandosi sui loro caratteri morfologici e sui propri risultati speri- mentali.

Anche Huser e Dre Wirr ammettono positivamente che le fibre muscolari intrafusali sieno fornite di piastre motrici.

1) Considerazioni critiche sui recenti studi dell’ apparato nervoso nei fusi muscolari. Anat. Anz., Bd. 9, 1893, No. 3.

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Gracomin1!) nelle sue diligenti osservazioni comparate sui Fus; dei Sauropsidi ha potuto chiaramente dimostrare, contrariamente ai risultati di altri osservatori, che le terminazioni a forma di piastra dei Fusi neuro-muscolari di questi vertebrati non sono vere e proprie piastre motrici, come quelle che si osservano sulle fibre del muscolo, ma sono per contro le cosi dette terminazioni a grappolo oda ciocca (TScHIRIEW), le quali, secondo BREMER e GIACOMINI, avrebbero pitt i caratteri di terminazioni di senso che di moto. I preparati di GIACOMINI, da me visti e studiati, sono di una tale chiarezza da non lasciare alcun dubbio riguardo all’ esattezza di questa osservazione, per noi cosi preziosa.

E gli studi sperimentali ed anatomo-patologici che cosa ci dicono ?

SHERRINGTON mette in dubbio l’esistenza di una innervazione motrice intrafusale.

CIPOLLONE mediante la prova di STENSON, che gli riusci completa una sola volta in una coniglia adulta, asservö che le fibre e ter- minazioni di senso fossero normali e quelle di moto in- vece alterate.

HORSLEY, in cani e gatti ai quali furono tagliati i nervi sciatici ed uccisi a periodi diversi, da 3 giorni ad un anno, non trovö mai le fibre muscolari del Fuso apparentemente alterate.

Morpurgo, in un bellissimo lavoro sulla ipertrofia funzionale dei muscoli volontari, cosi conclude: „I Fusi neuro-muscolari di Künne non cooperano in alcun modo all’ ingrossamento dei muscoli; le loro fibre non partecipano al processo Wipertrofia.“

SPILLER studiö i Fusi neuro-muscolari in un caso d’intensa atrofia muscolare e li trovö sempre normali.

BaTTEN ha osservato che nella paralisi infantile il Fuso neuro- muscolare rimane assolutamente normale, mentre il tessuto circostante soggiace a completa atrofia; nella atrofia muscolare progressiva il Fuso rimane inalterato; nella tabe hanno luogo certi speciali cambia- menti nella terminazione del nervo, ma resta normale la struttura generale del Fuso.

A. S. GRÜNBAUM, in un caso di paralisi pseudo-ipertrofica, trovö la massima parte delle fibre muscolari dei Fusi inalterate; soli in pochi Fusi vi era diminuzione in grandezza di una fibra intrafusale con attorno un deposito di materiale jalino.

1) ErcoLE Gracomrnt, Sui fusi neuro-muscolari dei Sauropsidi. Atti d. R. Accad. dei Fisiocritici di Siena, Ser. IV, Vol. 9, 1898.

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Dunque, concludendo, l’osservazione anatomica avrebbe condotto a degli apprezzamenti contradittori, perché mentre KERSCHNER, S. RAMON CAJAL, CIPOLLONE, HUBER e Dr Wirt stabiliscono recisamente che le terminazioni a forma di piastra siano di natura motrice, le osser- vazioni mie e quelle di GrACoMINI ci porterebbero per converso alla conclusione opposta: cioé che queste terminazioni, con ogni probabi- lita, debbano considerarsi di natura sensitiva, venendo cosi a negare una innervazione motoria alle fibre muscolari del Fuso.

Gli studi sperimentali ed anatomo-patologici starebbero a deporre in favore della opinione mia e di quella di GIACOMINI, se si eccettuano i risultati di CIPOLLONE, i quali parlerebbero non solo contro alla nostra interpretazione anatomica, ma anche contro ai risultati di tutte le altre osservazioni sperimentali ed anatomo-patologiche gia ricordate.

Cerchiamo di vagliare tutti questi risultati e di vedere possibil- mente da che parte stanno le maggiori probabilita del vero, pur ri- conoscendo che altre indagini sono ancora necessarie per risolvere completamente il problema che ci occupa.

Per sciogliere la questione dal punto di vista anatomico era ne- cessario stabilire con tutto rigore quali fossero i caratteri morfologici delle terminazioni a forma di piastra e vedere con ogni esattezza se questi caratteri corrispondessero o no a quelli delle comuni piastre mo- trici. Ad ottemperare alle predette condizioni indispensabili, io di- segnai scrupolosamente (servendomi della camera lucida ABBE- ZEISS) sei piastre motrici scegliendone di forma e grandezza diversa, per quanto queste variazioni nello stesso animale oscillino entro limiti molto ristretti. Cid fatto, e sempre colla medesima diligenza, disegnai dieci terminazioni a forma di piastra dei Fusi neuro-muscolari, diverse fra loro per forma e grandezza. E da notare che tanto le piastre motrici quanto le terminazioni a forma di piastra appartenevano allo stesso animale ed a preparati ottenuti colla medesima reazione; con- dizione questa indispensabile per salvaguardarsi da ogni possibile eve- nienza di differenze individuali o da variazioni possibilissime tra re- azione e reazione. La grande differenza che corre fra queste due serie di immagini, che io cosi ottenni, ognuno pud apprezzarla osser- vando la seconda tavola del mio ultimo lavoro. Dunque il giudizio da me espresso intorno alla struttura delle terminazioni a forma di piastra, mi parve e mi pare ancora giustificata dalla chiara dimo- strazione dei fatti. ;

KERSCHNER, CIPOLLONE, HUBER e DE WITT che vedono in queste specie di terminazioni delle vere e proprie piastre motrici, non ci

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hanno fornita la testimonianza della loro convinzione con figure che ci autorizzino di convenire colle loro idee e ci lasciano sempre un dubbio fortissimo intorno alla chiarezza e dimostrativita dei loro pre- parati. Per abbattere la nostra dimostrazione anatomica, ci vuole una prova altrettanto chiara e dimostrativa; ma fino a tanto che detta prova non si fara manifesta, la nostra dimostrazione starä& sempre come torre ferma che non crolla.

Le osservazioni di GIACOMINI sui Fusi neuro-muscolari dei Sau- ‚ropsidi portano un valido appoggio alla mia dimostrazione, perche, come dissi, anche in questi vertebrati la differenza di struttura tra le piastre motrici e quella delle terminazioni a forma di piastra & evidentissima.

Le sole prove che potrebbero portare un forte argomento contro la nostra interpretazione sono quelle di S. Ramon Cagau e di CIPOL- LONE Sui Fusi della rana. Infatti nelle figure riportate da questi osser- vatori si vede come la terminazione posta ad uno degli estremi del Fuso abbia veramente tutte le apparenze delle comuni piastre mo- trici della rana.

Si pud oggi di queste osservazioni sulla rana farne una regola generale ed abbattere cosi i fatti da me posti in evidenza nel gatto e da Giacomini nei Sauropsidi? Assolutamente no. Eccone le ragioni di fatto.

GIACOMINI in una serie di interessantissime comunicazioni!) ha potuto mettere in evidenza: che nei muscoli dei pesci (Teleostei e Selaci), degli Anfibi urodeli e degli anuri non esistono ne Fusi neuro- muscolari, ne Organi muscolo-tendinei; che in luogo di questi organi terminali si trovano, sulle estremita delle fibre muscolari, delle speciali espansioni nervose ch’ egli chiamö: terminazioni a paniere; che un primo accenno alla formazione di Fusi e di Organi muscolo- tendinei si ritrova nei muscoli degli arti degli Anfibi urodeli nei quali pero persistono sempre le terminazioni a paniere; che nelle larve degli

1) Gracomrnt, Sulla maniera onde i nervi si terminano nei tendini e nelle estremita delle fibre muscolari degli arti negli Anfibi urodeli. Monit. Zool. Ital, Anno 9, No. 5, 1898. — Sulla maniera onde i nervi si terminano nei miocommi e nelle estremitä delle fibre muscolari dei miomeri nei Teleostei. Atti d. R. Accademia dei Fisiocritici, Ser. IV,

Vol. 10, No. 4, 1898. — Sulla maniera onde i nervi si terminano nei miocommi e nelle estremita delle fibre muscolari dei miomeri nella larve degli Anfibi. Ibid. — Sulla maniera onde i nervi si terminano nei

miocommi e nelle estremita delle fibre muscolari dei miomeri nei Selaci. Ibid, Ser. IV, Vol. 10, No. 5, 1898.

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Anfibi urodeli ed anuri si osservano pure le terminazioni a paniere, ma mentre nei primi queste perdurano anche nella vita adulta, negli anuri per contro spariscono e vengono sostituite da Fusi neuro-musco- lari e da terminazioni tendinee; che nei rettili (Ofidi, Sauri e Cheloni) e negli uccelli si trova il Fuso ancora maggiormente perfezionato ed individualizzato e fornito di terminazioni a forma di piastra, le quali nulla hanno a che vedere, riguardo alla loro forma, colle comuni piastre motrici.

Adunque le belle e geniali ricerche di GIACOMINI ci pongono sotto lo sguardo tutta la storia dello sviluppo degli organi terminali sensitivi del muscolo, che egli ha potuto cosi felicemente ricostruire studiandola nelle svariate famiglie dei vertebrati inferiori.

Questa storia di fatti non deve avere solo una grande importanza dal punto di vista della morfologia, ma non pud non parlare anche alle nostre menti, avide di quelle prudenti e rette leggi che dai fatti conquistati con diligenza ed oculatezza devono costantemente emanare.

Noi vediamo dunque che le terminazioni sensitive del muscolo hanno come primo punto di partenza Ja terminazione a paniere di GIACOMINI; questa terminazione incomincia, con dei leggerissimi cam- biamenti, ad estendersi in ampiezza sulla superficie delle fibre musco- lari da un lato e sulle fibre tendinee dall’ altro, venendo cosi a formare un primo abbozzo e dei Fusi neuro-muscolari e delle termi- nazioni tendinee. Questa prima preparazione, diciamo cosi, alla costi- tuzioni dei due organi terminali, raggiunge una differenziazione mani- festa nei muscoli della rana, dove distinguiamo gia nettamente i Fusi neuro-muscolari e le terminazioni sul tendine. Ma sebbene nella rana troviamo gid questa differenziazione ben manifesta, non é da credere che tanto i Fusi quanto le terminazioni sul tendine abbiano qui raggiunto Tl’ ultimo gradino del loro perfezionamento. Man mano che si va salendo verso i vertebrati superiori, noi osserviamo dei continui e forti cambiamenti nella forma di questi organi non che nella quantita delle loro fibre nervose e pitt che altro nel modo onde questi nervi vi si distribuiscono.

E un perfezionamento lento e graduale al quale noi assistiamo attraverso le diverse famiglie dei vertebrati; perfezionamento che trova con ogni probabilita la sua ragione d’essere nella legge della divisione del lavoro. Infatti mentre nei pesci, negli anfibi urodeli e nelle larve degli anfibi anuri osserviamo una sola terminazione di senso — la terminazione a paniere di GIACOMINI — nei vertebrati superiori troviamo

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x

che questa unica terminazione si & divisa in tre distinti organi ter-

minali — Organi muscolo-tendinei, Fusi neuro-muscolari, Corpuscoli di Pacint — diversi fra loro per forma, struttura e rapporti topo- grafici.

Per dato e fatto che nella rana non si possono assolutamente considerare come definitivamente evoluti i Fusi neuro-muscolari, cosi non é giusto che i fatti in essi osservati si prendano come norma per la struttura in genere dei Fusi delle altre classi di vertebrati e special- mente dei vertebrati superiori.

Per cui se anche si potesse dimostrare con ogni sicurezza, il che non é stato ancora fatto, che nei Fusi della rana quelle terminazioni nervose da RAmön CagaL e da CIPOLLONE interpretate come vere e proprie piastre motrici, fossero veramente tali, non si potrebbe logi- camente inferire che nei Fusi neuro-muscolari di tutte le altre classi di vertebrati esistano delle vere e proprie piastre motrici.

I risultati sperimentali, eccettuati quelli di CIPOLLONE, ed ana- tomo-patologici, stanno, come gid dicemmo, ad appoggiare la tesi da noi sostenuta.

HORSLEY non trovö mai le fibre intrafusali alterate dopo il taglio del nervo sciatico, mentre le fibre muscolari proprie del muscolo erano profondamente alterate. Se il Fuso possedesse piastre motrici, evidente- mente anche le fibre intrafusali avrebbero dovuto subire le stesse alte- razioni di quelle del muscolo.

Ma assai pit probativi mi sembrano i risultati delle diligenti osservazioni di MORPURGO. Difatti mi pare ovvio che se le fibre del Fuso possedessero nervi di moto dovrebbero necessariamente prendere parte attiva e sinergica colla contrazione delle fibre del muscolo e quindi come queste diventare ipertrofiche. Non diventando ipertro- fiche vuol dire che non si contraggono e non contraendosi significa che non posseggono fibre di moto. Questa mi pare la consequenza diretta e logica che scaturisce dalle esperienze di Morpurco. Ma CIPOLLONE che ha voluto, a mio parere, sostenere con troppo ardore la tesi opposta, ha dovuto ricorrere ad una interpretazione, ingegnosa si, ma poco verosimile, per volgere in suo favore i risultati della ipertrofia funzionale. CiPoLLONE sostiene che le fibre muscolari intra- fusali non s’ipertrofizzano perche dotate d’un ricambio meno attivo di quello che hanno le comuni fibre muscolari. Io non dico che non possa accadere anche a questo modo, ma non v’ & neppure una prova lontana che possa autorizzarci ad accettare questa spiegazione.

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I risultati di CIPOLLONE, ottenuti mediante la prova di STENSON e la reazione al cloruro d’oro, lasciano qualche cosa a desiderare. Anzitutto la prova di STENSON non puod certo annoverarsi fra i mezzi sperimentali pit sicuri per ottenere con rigorosa certezza l’atrofia delle sole fibre di moto, perché questa prova contiene in sé la presunzione di contare con soverchia sicurezza sulla stabilita di vascolarizzazione del midollo spinale; vascolarizzazione sottoposta alle molteplici varia- zioni individuali di tutti gli altri organi del corpo animale. Secondaria- mente sarebbe stato pit probativo il fatto della osservazione diretta se CIPOLLONE avesse potuto usufruire di un materiale un po’ piü ab- bondante e confortare i risultati ottenuti col cloruro d’oro con qualche altro metodo diretto al medesimo scopo. Perché io conosco, per espe- rienza personale, il valore assoluto e sicuro di questo metodo nelle indagini di istologia fisiologica e le cautele non mai abbastanza racco- mandabili nell’ apprezzare le alterazioni patologiche che col mezzo di questo stesso metodo ci prefiggiamo d’indagare. Per tutte queste ragioni adunque crediamo che gli argomenti portati in campo da CIPOLLONE contro l’ipotesi da noi sostenuta abbiano ancora bisogno di una nuova e pit completa serie di ricerche.

I risultati anatomo-patologici di SPILLER, BATTEN e GRUNBAUM mi sembrano cosi eloquenti e tanto d’accordo coi risultati sperimentali ottenuti da MORPURGO, che io crederei di far cosa superflua ferman- domi a commendarli dettagliatamente. La conclusione a cui possiamo giungere dopo questi risultati € che nei processi patologici che colpi- scono le cellule delle corna grigie anteriori ed in cui si ha una pro- fonda e completa alterazione delle fibre muscolari, le fibre dei Fusi neuro-muscolari restano costantemente inalterate. Si pud anche in questi casi ricorrere al concetto di un ricambio meno attivo delle fibre muscolari del Fuso?

Noi quindi possiamo concludere dicendo: che le terminazioni a forma di piastra del Fuso neuro-muscolare, con ogni probalilita sono di natura sensitiva, come le altre due specie di terminazioni del me- desimo e che l’opinione da noi primi sostenuta fin dal 1895 é stata fino ad oggi dimostrata probabile dalle ricerche comparative, dai risul- tati sperimentali ed anatomo-patologici.

Se poi le indagini future ci potranno dimostrare con chiare ed inoppugnabili prove che la tesi da noi sostenuta era veramente erronea, noi ossequenti, come sempre, all’ autorita non delle persone ma dei fatti, saremo felici di poter chinare il capo‘alla verita che si fa strada.

Lucignano, 10 Marzo 1899.

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Nachdruck verboten. Bemerkungen über die Verbindungen der Lymphgetäße der Prostata mit denen der Blase.

Von Dr. Hermann Sranr, Breslau.

Bei unseren Untersuchungen über die Anatomie der Lymph- sefäße und ihren Verlauf müssen vor allem die großen Kenner des Lymphsystems, die französischen Forscher BRESCHET, CRUVEILHIER und Sappry, besonders aber der Altmeister Sappey zu Rate gezogen werden. Wir finden bei ihnen eine Fülle von Kenntnissen, welche vielfach, gerade eben bei SAPPEY, auf gediegensten, selbst unter- nommenen Injectionsversuchen beruhen. Deshalb ziehen denn auch alle neueren Arbeiter auf diesem Gebiete Sappry’s Abbildungen und Beschreibungen nicht nur zur ersten Orientirung heran, sondern hören nicht auf, die Resultate eigener Bemühungen mit den seinen zu ver- gleichen.

Eine der Arbeiten, deren Erscheinen ich bereits im Arch. f. Anat. u. Physiol.) angezeigt hatte, liegt nunmehr vor: Dr. G. WALKER, Ueber die Lymphgefäße der Prostata beim Kinde. W. giebt darin die Resultate zahlreicher, mühevoller Untersuchungen, welche in der ana- tomischen Anstalt in Breslau ausgeführt wurden, in knapper, aber präciser Uebersicht, und widmet dementsprechend auch der Litteratur nur einen engen Raum. Die Arbeit ist übrigens in Leipzig mit ganz vorzüglichen, künstlerisch-schönen Abbildungen versehen worden, welche wir dem Verfasser hier leider nicht bieten konnten.

Bei der Litteratur nun, welche Herrn W. nicht vollständig vorlag, muß aber gerade in dieser Frage genauer an SAPPEY angeknüpft werden, zumal noch ein abweichender Befund, den auch W. nicht versäumt hat als wichtig hervorzuheben — aber ohne Beziehung zu SAPPpEY’s Arbeiten — geradezu auf Untersuchungen des französischen Autors, die beim Menschen angestellt wurden, hinweist.

SAPPEY ist der Erste gewesen, welcher die Prostata-Lymphgefäße injicirt hat, und er ist bis zu W.’s Arbeit der Letzte geblieben, wenn

1) Arch. f. Anat. u. Physiol. (Anat. Abt.), 1898, Heft 6. (Die Arbeit ist am 17. Febr. im 1. Heft 1899 erschienen und nicht in einem Supplement 1898.)

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man nicht beiläufige Bemerkungen GEROoTA’s, welche dieser uns in seiner Arbeit über die Lymphgefäße der Blasenwand giebt, hinzu- rechnen will. GEROTA bildet hier!) die Lymphgefäße der Blasen- muscularis von je drei vorzüglich vollständig injicirten Präparaten von der Vorder- und Hinterfläche ab. Aus dem Texte der Arbeit (p. 439) geht hervor, daß G. auch beiläufig die Nachbarorgane beim weiblichen und männlichen Neugeborenen injieirt hat. Hier heißt es nun: „Beim Manne communiciren dieLymphgefäße des Blasenfundus mit denen der Prostata und der Samenblasen“ u.s. w. (Fig. 4, Taf. VIII, 7 Samenblasen).

Auf die Prostata geht GEROTA also bei seinen eigenen Unter- suchungen nicht weiter ein; anders in seinen Litteraturangaben: p. 430 eitirt er Sappry’s Traité d’anatomie descriptive?). Danach hat S. beim Hunde und Kaninchen die Lymphgefäße der Blasen- muskelhaut auf der hinteren Fläche derselben gesehen und sagt vom Menschen folgendes: „Chez l’homme on apercoit sur la sur- face externe de cet organe [la vessie] deux ou trois troncs absorbants de chaque cété; ce sont ces troncs qui ont été vus par CRUIKSHANK et par Mascaeni. Mais ils ne partent pas des parvois vésicales, ils viennent de la prostate.

In Sappey’s Originalarbeit*) heißt es:

„Les vaisseaux lymphatiques de la prostate sont tres-nombreux. Nés de chacune des granulations de la glande, ils se dirigent vers sa périphérie qu’ils couvrent de leurs anastomoses. Quatre troncs princi- paux partent de ce plexus périphérique, deux droits et deux gauches. Ils se rendent dans les ganglions intra-pelviens les plus antérieurs, en cheminant sur les parties postéro-latérales de la vessie. Ces vaisseaux sont faciles a injecter chez le foetus et Venfant.“ etc.

Unter dem Eindrucke dieser Citate gewinnt der in Fig. 4, Taf. II von WALKER dargestellte besondere Verlauf denn doch erst seine rechte Bedeutung, denn die einzige Wiedergabe SAPpEY’scher Untersuchungen, nämlich die von TestuT, bringt nichts, was sich auf die Blase bezieht. Es kann somit auch nicht dieser einzig dastehende Verlauf eines ein- zelnen Gefäßes von der Prostata zu den lumbalen Drüsen auf weitem

1) Ueber die Anatomie und Physiologie der Harnblase. Arch. f. Anat. u. Physiol. (Phys. Abt.), Heft 5/6, 1897.

2) p. 802, II. edit, Tome 2, Paris 1888.

3) Recherch. sur la conformation de l’urethre, Paris 1854. Citirt im T. 2 des Traité d’anatomie descript.

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Umwege mit Netzbildung durch die Musculatur der Blase als ein ab- weichender angesehen werden, sondern es bestehen eben Communicationen der Lymphgefäße der Prostata und Blase auch beim Hunde; Verhält- nisse, die SApPpEY — dem die Injection von der Blasenwand nicht ge- lang — beim Menschen offenbar so häufig vorfand, daß er daran zweifelt, MASCAGNI und CRUIKSHANK hätten es mit Lymphgefäßen, die in der Blase ihr eigenes Capillarnetz haben, zu thun gehabt.

Mit diesen kurzen litterarischen Bemerkungen möchte ich die Fachgenossen auf WALKER’s Arbeit im Uebrigen verweisen; neue Unter- suchungen an menschlichem Material, welche uns W. aus Leipzig an- meldet, werden sich mit diesen Dingen zu beschäftigen haben und wohl weitere Aufklärung bringen.

Breslau, 7. März 1899.

Nachdruck verboten.

Kainogenesis, Cenogenesis, Kenogenesis, Cenegenie!), Caenogenese oder Cänogenese? Von Ernst Meunert, Halle a. S.

Alle die vorstehenden Namen haben im Laufe der Jahre An- wendung gefunden zur Bezeichnung der von der „Palingenese“ ab- weichenden Erscheinungsformen in der individuellen Entwickelung.

In meinen ersten Publicationen schrieb ich nach althergebrachter Weise mit HAECKEL — Cenogenese. Später kam es mir aber besonders darauf an, gerade die Recenz solcher Erscheinungen zu kennzeichnen, ich accepirte darauf mit Freuden die von GEGENBAUR in Anwendung gebrachte Schreibweise Caenogenese mit der Ableitung von xavdg = neu. In meinen beiden letzten Publicationen „Kainogenesis“ und „Biomechanik“ habe ich nur Kainogenesis und kaino genetisch geschrieben. In der letzteren Arbeit habe ich auf der ersten Seite in einer Anmerkung die von mir begangene Wandlung begründet und mitgeteilt, daß ich die griechische — nicht latinisirte — Schreib- weise nur deshalb vorgezogen habe, um unliebsame Nebenbedeutungen zu vermeiden.

Nichtsdestoweniger hat mein Verfahren neuerdings von Seiten FRANZ KEIBEL’S eine absprechende Beurteilung erfahren. KEIBEL

1) Von KEIBEL promiscue gebraucht, siehe Ergebnisse p. 731.

30

sagt in den Ergebnissen 1897 auf p. 731: „Ich muß bekennen, daß mir hier eine nicht wiinschenswerte Laxheit in der Namengebung vor- zuliegen scheint“, und auf p. 788 ist zu lesen unter ausdrücklicher Bezugnahme auf mich: ,,Sehr ungliicklich finde ich weiter die Wahl des Ausdruckes Kainogenese. Von xouvdc abgeleitet, kann Kainogenese nichts anderes heißen als Caenogenese, und Mehnert*) verkennt doch wohl den Einfluß, welchen seine Definition einem seit Jahrzehnten geübten Gebrauch gegenüber haben kann und wird!). Vermutlich wird wesent- lich eins erreicht werden, es wird nämlich die schon heute herrschende Unklarheit im Gebrauch?) von Cenogenese, Caenogenese durch das Hinzukommen von Kainogenese noch um ein beträchtliches vermehrt werden.“

Ich kann mein Befremden nicht verhehlen, daß KEIBEL gerade mir Vorwürfe macht, obgleich ich in der Etymologie mich nur GEGEN- BAUR angeschlossen habe. Außerdem schreibt auch Kauuıus bekannt- lich — ganz unabhängig von mir — kainogenetisch, dem lang- jährigen Colleggebrauche Bonnet’s folgend. Es wäre daher wohl an- gebracht, wenn KEIBEL seine scharfen Angriffe nicht nur gegen meine Person, sondern auch nach Heidelberg, Greifswald und Göt- tingen richten würde Auch Straßburg käme in Berücksichtigung, da auch SCHWALBE sich des von KEIBEL gerügten Vergehens schuldig gemacht hat.

Zur Begründung will ich jetzt berichten, auf welche Weise ich zu der Schreibweise Kainogenese gedrängt worden bin, und hiermit überhaupt die ganze Frage nach derselben dem Richterspruche der Fachcollegen unterbreiten.

Es war mitten in den Herbstferien, als ich einem mir begegnenden Nichtfachcollegen auf seine Anfrage erzählte, daß ich am nächsten Morgen eine Arbeit) unter dem Titel Caenogenese an den Verleger absenden wolle. Diese Mitteilung erregte heftigstes Staunen. Meine diesbezüglichen historischen und etymologischen Explicationen wurden mit der Aufforderung beantwortet, ich möge doch nur dem bisherigen Gebrauche der ,,Mediciner“ folgen.

*) Im Originale nicht gesperrt.

1) Auf diese Weissagung werde ich an anderer Stelle antworten.

2) Der scharfe persönliche Vorwurf der „Unklarheit im Gebrauch“, den Krisen auch gegen seine Fach- und Zeitgenossen erhebt, dürfte wohl einigermaßen ungewöhnlich — und soweit er sich auf die Zukan ft bezieht — auch erstaunlich sein.

3) Kainogenesis als Ausdruck differenter phylogenetischer Energien, Gustav Fischer, 1897, p. 1— 165.

dl

Am anderen Morgen wurden mir in aller Frühe zwei Lexica mit Lesezeichen zugestellt.

Im griechischen Lexicon war folgende Stelle angemerkt:

xevög .... leer. Gegensatz von zAEwg. 1) leer, 2) ver- gebens, 3) eitel, 4) müßig, 5) ausgeleert!).

Im lateinischen Lexicon aber las ich:

Coenum (auch caenum geschrieben) .. . Schmutz, Koth, Unflath (stets mit dem Begriffe des Ekelhaften)?).

Nach dieser Kenntnisnahme verzichtete ich darauf, meine Arbeit Kenogenesis oder Caenogenesis zu nennen, insbesondere schien mir letz- tere Bezeichnung, zumal als Titel, doch etwas bedenklich, und ich hielt es für geboten, im Manuscripte auch das Wort caenogenetisch — ent- sprechend dem Worte zaıvog = neu — in kainogenetisch umzuändern.

Ich werde auch weiterhin unentwegt an dieser Schreibweise fest- halten trotz KEIBEL’s Protest. KeıBEr’s Vorwurf der „Laxheit in der Namengebung“ und sein Bedauern über „meine unglückliche Wahl“ werde ich ruhig über mich ergehen lassen, weiß ich doch, daß ich in der Etymologie GEGENBAUR gefolgt bin und auch andere Forscher, näm- lich Bonner und KaArLıus, und neuerdings auch SCHWALBE?) mir zur Seite stehen.

Halle a. S., den 6. April 189.

1) Passow, Scunemer’sches Handwörterbuch der griechischen Sprache, Leipzig 1826, Bd. 1.

2) W. Freunn, Wörterbuch d. lateinischen Sprache, Leipzig 1834, Bd.1.

3) Zeitschrift für Morphologie und Anthropologie, Bd. 1, Heft 1, p. 102, 103.

Anatomische Gesellschaft.

Für die 13. Versammlung in Tübingen (21.—24. Mai d. J.) haben angemeldet:

12) Herr A. v. KoELLIKER: Ueber das Chiasma des Opticus. Nach- weis an WEIGERT’schen und Gousr’schen Präparaten von Em- bryonen des Menschen, Schafes, Rindes, der Katze, des Hundes 1) daß die überwiegende Mehrzahl der Opticusfasern sich kreuzt; 2) daß an GorGI-Präparaten eine gewisse geringe Zahl unilateraler,

sich nicht kreuzender Fasern bei der Katze und dem Schafe demonstrirbar ist; 3) daß einzelne wenige Teilungen von Opticusfasern vorkommen.

13) Herr CL. Regaup de Lyon: Origine, renouvellement et structure des spermatogenies chez le Rat. (Avec démonstration.)

14) Herr A. Van GEHUCHTEN: Contribution 4 étude de la structure interne des cellules nerveuses.

32

15) Herr J. Disse: Demonstration einer Serie von Diapositiven über die Entwickelung des Riechnerven.

16) Herr F. KEIBEL: a) Beobachtungen an einem menschlichen Ei bryo von 6,8 mm größter Länge.

b) Mitteilungen über die Entwickelungsgeschichte des Rehes.

c) Demonstration von Zeichnungen f. Normentafeln v. Huhn u. Ente.

d) Demonstration von Plattenmodellen menschlicher Embryonen (hergestellt von den Herren Dr. Hernrica Scumirr und Cand. med. Hans PIPER.

17) Herr W. His: Demonstration anatomischer Diapositive.

18) Herr E. BAaLLowItz: Demonstration mikroskopischer Präparate (elektrisches Organ des Zitterwelses, Malopterurus).

19) Herr HEIDENHAIN: Demonstration neuer Muskelmodelle mit Er- lauterungen.

20) Herr Lesoucg: Ueber die Entwickelung der Fingerphalangen.

21) Herr Mrnaukovics: Das neue anatomische Institut der K. Uni- versität zu Budapest.

22) BARDELEBEN: Feinerer Bau der Spermien bei Wirbellosen und niederen Wirbeltieren. (Mit Demonstration.)

23) Herr R. Fick: 1) Mitteilungen über die Eireifung bei Amphibien. 2) Bemerkung zur Mechanik der Wirbelsäule.

24) Herr H. Vırcnow: Ueber die Bänder und Gelenke der Hand auf Grund von Bänderpräparaten, RÖNTGEn-Aufnahmen und Gefrier- präparaten.

25) Herr J. Syminaron: a) Photographs illustrating cranio-cerebral topography.

b) Stereoscopic photographs of the heart hardened in situ.

26) Herr O. VAN DER STRICHT: Sur la fixation de l’oeuf a ’intérieur de la matrice.

27) Herr K. W. ZımMERMANN: Demonstrat. mikroskopischer Präparate.

28) Herr Fr. MAURER: Die Schlundspaltenderivate von Echidna.

29) Herr ALFRED SCHAPER (Boston): Zur Morphologie des Kleinhirns. (Mit Demonstrationen.)

Herr SosoTTA wird die Demonstration durch Vortrag erläutern.

In die Gesellschaft ist eingetreten: Dr. CLAUDIUS REGAUD, Chef des travaux histologiques a l'Université de Lyon — Faculté de médecine. Beiträge zahlten (s. No. 19 u. 20, Bd. 15 d. Z.) die Herren: KERSCHNER 7—0, GROBBEN 9, Rawırz 7—9, BRACHET 9. LAHOUSSE 7—9, Sir WıLLıam TURNER 7—9, REINKE 8. 9, R. He.Twiıe 8. 9, ScHAPER 8. 9, von GENERSICH 8. 9, LacHı 7—9, TUCKERMAN 9, E. Scumipt 8. 9, Martin 7—9, Junin 7—9, Antipa 7—9, GRIES- BACH 9, BÜHLER 7—9, Stross 7—9, HULTKRANTZ 9, Hamann 7—9. Ablösung bewirkten die Herren SPALTEHOLZ und SALA y Pons. Der Schriftführer: BARDELEBEN.

Abgeschlossen am 2. Mai 1899.

Frommannsche Buchdruckerei (Hermann Pohle) in Jena.

ANATOMISCHER ANZEIGER

Centralblatt

fiir die gesamte wissenschaftliche Anatomie,

Amtliches Organ der Anatomischen Gesellschaft.

Herausgegeben von Prof. Dr. Karl von Bardeleben in Jena.

Verlag von Gustav Fischer.in Jena.

Der ,,Anatomische Anzeiger‘“ erscheint in Nummern von etwa 2 Druckbogen. Um ein rasches Erscheinen der eingesandten Beiträge zu ermöglichen, werden die Nummern ausgegeben, sobald der vorhandene Stoff es wünschenswert macht und event. erscheinen Doppelnummern. Der Umfang eines Bandes beträgt etwa 50 Druckbogen und der Preis desselben 16 Mark. Das Erscheinen der Bände ist unabhängig vom Kalenderjahr.

XVI. Band. 432. Mai 1899. No. 2.

INHALT. Aufsätze. A. Negri, Ueber die Persistenz des Kernes in den roten Blutkörperchen erwachsener Säugetiere. Mit 9 Abbildungen. p. 33—38. — J. Nageotte. Note sur un nouveau microtome 4 cerveau. p. 33—40. — F.J. Cole, On the cranial Nerves and Sense Organs of Fishes. p. 40—48, — Personalia. p. 48. — Ana- tomische Gesellschaft. p. 48. — Berichtigung. p. 48. — Litteratur. p. 1-16.

Aufsätze.

Nachdruck verboten. Ueber die Persistenz des Kernes in den roten Blutkörperchen erwachsener Säugetiere. Vorläufige Mitteilung von A. NEGRI, stud. med.

(Aus dem Laboratorium für allgemeine Pathologie und Histologie der Kgl. Universität zu Pavia unter der Leitung des Prof. C. Gorcı.)

Mit 9 Abbildungen.

Als in diesen letzten Jahren die Anschauungen HENLE’s, NASSE’s, JONES’, BOETTCHER’S u. A., die da behauptet hatten, durch besondere Hülfsmittel zur Beobachtung des Kernes in den roten Blutkörperchen erwachsener Säugetiere gelangt zu sein, von allen Forschern aufge- geben worden, stimmten diese darin überein, daß sie besagte Blut- körperchen für kernlos hielten. Die Bestrebungen der Fachmänner - zielten lediglich dahin, zu erklären, auf welche Art und Weise aus den im circulirenden Blute des Embryos und in den blutbildenden Organen des erwachsenen Individuums befindlichen kernhaltigen roten Blutkörperchen später kernlose hervorgehen.

Anat, Anz. XVI. Aufsätze. 3

a

Gegen die Annahme, es seien die roten Blutkörperchen der Säuge- tiere kernlos, ist PETRONE!) mit aller Entschiedenheit aufgetreten. Nach ihm soll der Kern keineswegs verschwinden, sondern sich ein- fach der Beobachtung entziehen, und zwar infolge Verdichtung der ihn umgebenden Protoplasmapartie, wobei das Blutkörperchen an Hämoglobin reicher werde. Sobald aber durch passende Mittel das Protoplasma gelichtet wird, so trete der Kern wieder deutlich hervor; solcher Methoden erwähnt PETRONE mehrere; hierzu empfiehlt er be- sondere Färbungsmittel, deren Formeln er auch zuerst angiebt.

Die große Bedeutung der von PETRONE nach dieser Richtung hin erzielten Resultate ist wohl leicht einzusehen: die bezüglich der Structur des roten Blutkörperchens gegenwärtig herrschende An- schauung würde dadurch eine wesentliche Aenderung erfahren. Verf. fügt noch hinzu, daß seine Befunde ‚eine Anzahl klinischer An- wendungen von unschätzbarem Werte in Aussicht stellen und seine Untersuchungsmethoden vielleicht die Frage in Betreff des angeb- lichen Malaria-Parasiten lösen werden“.

Um nun die Versuche PETRONE’s zu wiederholen, habe ich im hiesigen Laboratorium für Histologie methodisch geordnete Unter- suchungen über diese Frage angestellt. Ich erlaube mir, hier die meiner Meinung nach nicht ganz uninteressanten Ergebnisse derselben in aller Kürze mitzuteilen.

Was zunächst die Technik anlangt, so bin ich — sowohl für die Extraction des Blutes, als auch für die darauf folgende Fixirung bezw. Färbung desselben — streng nach den verschiedenen von PETRONE empfohlenen Methoden vorgegangen. Die besten Resultate wurden mit in Osmiumsäure 1: 4000 extrahirten, sodann in Pikrinsäure — ebenfalls 1 : 4000 — gebrachten und mit dem von PETRONE empfohlenen in Ameisensäurekarmin gefärbten Blute erzielt.

Meine Aufmerksamkeit hat sich zunächst dem Blute erwachsener Tiere zugewandt.

Die mit dem Blute verschiedener Säugetiere, speciell des Menschen und des Kaninchens, angestellten Untersuchungen haben mir die Möglichkeit verschafft, das von PETRONE zuerst Beobachtete leicht und schnell festzustellen.

1) Perrone, L’esistenza del nucleo nell’ emasia adulta dei mammi- feri. Catania, Galatola, 1897. — Sull’azione degli acidi, specialmente del formico, nella tecnica della colorazione nucleare, ed un nuovo liquido, il formio-carmino. Contributo speciale alla colorazione del nucleo delle emasie. Ibid. 1898. — Altri metodi per la ricerca del nucleo dell’ emasia.

Ibid. 1898. — Bollettino dell’ Academia Gioenia di Scienze naturali in Catania, 1897—98.

35

In den mit passenden Mitteln behandelten roten Blutkérperchen des Menschen bezw. Kaninchens gewahrt man denn auch richtig jenes Körperchen, das vom Entdecker als Kern gedeutet wird. Dasselbe stellt ein kleines, excentrisch gelegenes Gebilde dar, so daß man es bei den meisten roten Blutkörperchen an der Peripherie des Elementes antrifft; zuweilen — um hier die Worte PETRONE’s zu gebrauchen — „ist es derart gegen die Membran hingedrängt, daß es wie mit der- selben verwachsen aussieht“. Hie und da zeigt es eine centrale Lage, was jedoch — wie P. selbst hervorhebt — nur eine auf der Lage des Elementes beruhende Täuschung ist. Davon kann man sich durch entsprechende Verstellungen der Mikrometerschraube leicht überzeugen, besonders in solchen Fällen, wo es gelingt, ein auf dem Gesichtsfelde dahinrollendes Blutkörperchen zu überraschen; mit anderen Worten: man bekommt den Eindruck einer centralen Lage des kleinen Ge- bildes, sobald dasselbe gegen die mittlere Partie der oberen bezw. unteren Fläche des Blutkörperchens — vom Beobachter aus — zu liegen kommt. Die Contouren des fraglichen Gebildes sind manchmal scharf, bisweilen sind dessen Ränder unregelmäßig ausgezackt, was besonders dann der Fall ist, wenn solche Gebilde so weit nach außen zu gedrängt sind, daß sie wie aus dem Blutkörperchen herausgetreten erscheinen. Die mit Ameisensäure versetzten Farben, insbesondere das Ameisensäurekarmin, färben dasselbe rasch und electiv.

Besser und leichter als jede Beschreibung dürfte eine Vergleichung der von mir nach Möglichkeit abgebildeten Formen mit den von PETRONE angefertigten Zeichnungen die Identität meiner Resultate mit denen, die er zuerst erzielt hat, ins Licht stellen.

Nachdem ich mich von dem thatsächlichen Vorhandensein der von diesem fleißigen Forscher angegebenen Erscheinungen, sowie von der Richtigkeit seiner Beschreibungen überzeugt hatte, habe ich an mich noch die Frage gestellt, ob es denn gestattet sei, dieses Ge- bilde als den Kern des roten Blutkörperchens aufzufassen.

PETRONE spricht. von einer körnigen Structur und erwähnt hier- bei mitotische Scheingebilde. Anstatt nun auf solche Vorkomm- nisse, die dem individuellen Ermessen so großen Spielraum gewähren, ohne dabei die Frage zu lösen, hier näher einzugehen, halte ich es für zweckmäßiger, die Sache von einer anderen Seite zu betrachten. Ich habe mich nämlich bemüht, festzustellen, welche Beziehungen zwischen dem Körperchen Perrone’s und dem Kern der kernhaltigen Blutkörperchen bestehen mögen, eventuell von diesem Gesichtspunkte aus die Umgestaltungen zu studiren, die der Kern während der Ent-

wickelung des Blutkörperchens durchmacht. 3*

36

Zu diesem Zwecke habe ich mich des embryonalen Blutes, und zwar insbesondere jenes des Kaninchenfoetus bedient. Ein vorzügliches Material haben mir die gegen die Mitte der intrauterinen Entwickelung entnommenen Embryonen dieser Tiere geliefert.

Bei den nach Perrone behandelten Präparaten von fötalem Blut ist es mir gelungen, in den durch die bisher gebräuchlichen Methoden kernlos erscheinenden roten Blutkörperchen dasselbe kleine Gebilde wahrzunehmen, das auch in den roten Blutkörperchen erwachsener Säugetiere anzutrefien ist und diesem bezüglich der Gestalt und Größe — letztere im Verhältnis zum Blutkörperchen — sowie der Lage und der mikrochemischen Eigenschaften ganz genau entspricht.

Bei den nämlichen Präparaten habe ich jedoch ein derartiges Gebilde auch in den kernhaltigen roten Blutkörperchen als eine neben dem Kern vorkommende, aber von diesem sich ganz unterscheidende Bildung wahrnehmen können, Mit besonderer Deutlichkeit tritt der Unterschied vermittelst einer Contrastfärbung hervor, so z. B., wenn

Fig. 1.

Fig. 3. Fig. 4.

37

Fig. 7. Fig. 8.

Fig. 1—2. Rote Blutkörperchen des er- wachsenen Menschen. Färbung mit Bleu fin en grains (MeisteR-Lucrus et BRUNING) in Ameisensäurelösung — nach PETRONE —.

Fig. 3—9. Rote Blutkörperchen des Kaninchenfoetus, gegen die Mitte des intra- uterinen Lebens. Doppelfärbung mit Ameisen- säurekarmin und Hämatoxylin.

Alle diese Blutkörperchen wurden in Osmiumsäure 1 :4000 extrahirt und sodann mit Pikrinsäure 1 :4000 behandelt — nach PETRONE —. :

man zuerst das fragliche Gebilde mit _Ameisensiurekarmin färbt und so- dann den Kern durch eine Hämato- Fig. 9.

‚xylinfarbe hervortreten läßt. Man

- gewinnt dadurch die Bilder, die ich zu photographiren versucht habe ‚amd auf beifolgenden Abbildungen zur Anschauung bringe.

BE:

In kernhaltigen roten Blutkörperchen ist das in Rede stehende Gebilde nur dann wahrnehmbar, wenn jene Bedingungen erfüllt sind, welche sein Erscheinen in den kernlosen roten Blutkörperchen ermög- lichen; die Modification aber tritt sowohl bei den einen als auch bei den anderen gleichzeitig ein und — wie man sich durch Prüfung des nämlichen Präparats überzeugen kann — sind in beiden Kategorien ‘yon roten Blutkörperchen die Form, das Volumen, die Lage, sowie die Electivität für die mit Ac. form. versetzten Farben stets die gleichen. Daß dies aber das von PETRONE in den vollständig ent- wickelten Blutkörperchen entdeckte Gebilde ist, kann meiner Ansicht nach wohl kaum einem Zweifel unterliegen. Mit dem Blute der Eier legenden Wirbeltiere hingegen ist es mir bisher niemals gelungen, in den roten Blutkörperchen etwas dem Gebilde Perrone’s Aehnliches zur Wahrnehmung zu bringen.

Mit Rücksicht auf das im embryonalen Blute der Säugetiere Be- obachtete erscheint wohl die Annahme berechtigt, es könne das in den roten Blutkörperchen sich zeigende Gebilde — wenn erstere der Ein- wirkung besonderer Reagentien ausgesetzt werden — nicht als der Kern dieser Elemente gedeutet werden, da es ja auch in solchen Blutkörperchen anzutreffen ist, die bereits einen eigentlichen Kern besitzen.

Unerklärt bleibt freilich noch, warum unter solchen Verhältnissen die Erscheinung in den roten Blutkörperchen auftritt; auch muß noch Wesen und Herkunft, des fraglichen Gebildes ins Klare gebracht werden. Vorläufig fühle ich mich außer Stande, diese Fragen zu be- antworten; meine Untersuchungen in dieser Richtung werden jedoch noch gegenwärtig fortgesetzt. Jedenfalls habe ich es für nicht un- passend gehalten, meine ersten Resultate in dieser Frage mitzuteilen, da, wie ich glaube, sich aus derselben die Notwendigkeit ergiebt, die Auffassung Perrone’s bezüglich seiner sonst sehr interessanten und der Aufmerksamkeit der Fachmänner würdigen Befunde in eingreifender Weise zu modificiren.

Nachdruck verboten. Note sur un nouveau microtome a cerveau.

Par le Dr. J. NaGEorte, médecin-adjoint de l’Hospice de Bicétre.

Tous les histologistes qui ont eu a pratiquer de grandes coupes du cerveau ont pu remarquer que les microtomes actuels présentent de graves inconyénients. Le microtome de GUDDEN est assez simple, mais il ne permet pas de faire des coupes tres régulieres parce que le rasoir, méme manié avec une grande habilite, ne peut pas passer a

39

chaque coupe exactement par les mémes points; il en résulte forcément des inégalités car le tranchant du rasoir n’est jamais absolument recti- ligne. De plus le rasoir est trainé sur la surface de coupe, ce qui n’est pas une circonstance favorable; il est reconnu que les coupes se font mieux lorsque le rasoir présente une certaine obliquité par rapport a cette surface. Enfin le rasoir s’&mousse assez vite au contact du plan résistant sur lequel il glisse, ce qui nécessite de fréquents repassages.

Le microtome de REICHERT que j’ai eu entre les mains, malgré un bloc lourd et un systéme destiné a éviter les flexions du rasoir, n’evite pas les trépidations; les coupes sont toujours striées et parfois méme fragmentées par les vibrations de la lame.

Pour obtenir une stabilité suffisante du rasoir, en conservant les dispositions usuelles, il faut employer un bloc et un appareil de con- tention d’un volume et d'un poids énormes, comme dans le micro- tome de JUNG, qui parait donner de bons résultats. Mais cet appareil est encombrant, lourd et trés cher; de plus son maniement est in- commode parce que l’operateur ne peut pas faire mouvoir le rasoir et surveiller en méme temps la coupe pendant qu'elle se fait.

J’ai cherché a établir un systéme simple, solide, peu volumineux et d’un prix relativement modique, qui n’ait aucun des inconvénients ci-dessus mentionnés. J’y suis arrivé avec l’aide de M' Dumaige!) qui a construit l’appareil pour le laboratoire de M' le Dr. Bagınskı a ’höpital de la Pitié, ot on l’emploie avec succes.

L’innovation consiste essentiellement dans le mode de fixation du rasoir. Cette piece est prise par ses deux extrémités et fixée sous un chariot qui glisse sur deux rails entre lesquels se trouve la piece & couper. Cette disposition supprime absolument les flexions et les vibrations de la lame. Le chariot est carré et percé en son centre d’un grand trou rond qui découvre complétement le rasoir; celui- ci plonge dans une cuve a eau; un dispositif spécial permet de lui donner Vobliquité utile. Des deux rails ’un sert de conducteur et a une forme prismatique; l’autre est plan. Sur le premier le chariot prend deux points d’appui; sur le second un seul point d’appui, ce qui fait que le chariot repose sur trois points d’appui. Ces trois points d’appui se trouvent dans le méme plan horizontal que le tranchant du rasoir. Le mouvement de va et vient est communiqué au chariot par une corde sans fin qui est tendue entre deux poulies et actionnée par une troi- sieme poulie portant une manivelle. En revenant A son point de dé- part le chariot agit sur un mécanisme qui fait monter la piece & couper de l’epaisseur que l’on a préalablement fixée (de !/,, 41/,, de mm).

1) Dumaige, constructeur-opticien, 3 rue des Poitevins, Paris

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Le systeme de contention de la piece est le méme que dans le microtome de GUDDEN. C’est en réalité un grand microtome de Ran- VIER dont les dimensions sont calculées de maniére a permettre de débiter en coupes sériées un hémisphére entier dans une direction quelconque, et au besoin les deux hémisphéres ensemble. Un dispositif special permet de faire tourner la piece ä couper sur son axe vertical, de maniére a l’attaquer par le point le plus favorable, eu égard ä la direction des fibres dans la région. 3

Avec cet instrument, dont le volume est moindre que celui du microtome de GUDDEN, et dont le prix n’est pas sensiblement supérieur, on obtient tres facilement des coupes absolument réguliéres, ce qui pré- sente un grand avantage au point de vue de la décoloration lorsqu’ on emploie les méthodes colorantes électives de la myéline. Les pieces friables se coupent moins mal qu’avec le microtome de GUDDEN. On peut pratiquer au moins 100 coupes de suite sans affüter le rasoir. Enfin la coupe se fait sous les yeux de l’opérateur qui peut régler la vitesse de son rasoir suivant les circonstances et se servir de sa main gauche pour éviter les enroulements.

Nachdruck verboten.

On the cranial Nerves and Sense Organs of Fishes. A Reply. By F. J. Core, University College, Liverpool.

I hasten to reply to Mr. Aruıs’ criticism of my recent work on Gadus (just received), and in order to facilitate a more harmonious dis- cussion of the points at issue, let it at once be understood that I regret Mr. Auuis should have taken exception to the tone of the criticism I passed on his work. It seems that I have failed in the difficult task of disagreeing amicably with a distinguished fellow-worker, and trust that what was perhaps an excess of zeal may not be taken as a dis- courtesy towards an older observer than myself, and one the author of two such important, not to say beautiful, memoirs on the subject as his works on Amia. At the same time I think I may claim, without being accused of ill-humour, that the tone of his reply at least equal- ises matters in this respect.

1) Regarding the definition of the infra-orbital canal I have read Auuts’ reply carefully twice, and whilst I should be happy to adapt the terms of the objection to the susceptibilities of my opponent, the passage in substance represents what I still think. The alleged incon- sistency in my Chimaera work is more apparent than real. The upper scheme on page 635 is a very general statement, and as such is cer- tainly ambiguous, but the lower scheme on the very same page is quite consistent, and I must further protest strongly against the passage in my Cod paper on page 122 being lifted out of its context. The question at issue now is the value of the nerves in classifying the canals. The bulk of the reply on this point is to my mind irrelevant to that issue, and whether the supra-temporal canal is what Aurıs claims it to be

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does not in the least affect my contention that canals must be defined according to the nerves supplying them and not by any structural peculiarities of their own. My opponent is stating his own view of the case, which may or may not be right, but is not meeting mine. ALLIS is disposed to deny that he defines the canals by their innervation (although omitting the case of the infra-orbital that is what he practically has done in Amia), and says that their names are “based on purely topographical considerations”. In the latter case one is dis- posed to ask how the canal in Amia containing sense organs 15 to 21, situated above and altogether behind the eye, is termed infra-orbital. Axnuis is therefore inconsistent in both respects — first as regards innervation, and second as regards topographical relations. I shall now be interested to learn how the sensory canals are to be classified. From my own point of view no classification can have any importance, since the whole system is itself a unit and cannot there- fore be classified in any but a purely convenient manner. But certain facts are stated as opposed to the innervation classification of the sensory canals, and these are as follows: 1) A branch of the buccal in Scomber is said (for the first time here) to innervate one organ of the supra- orbital canal. To quote Atuis’ own words, as I had no access to his notes, my failure to take this fact into account is perhaps excusable. 2) A branch of the profundus in Chimaera is stated on my authority to innervate twc organs of the same canal. Here again I must object to this observation being quoted apart from its context, and I accord- ingly refer those interested to the original paper, where the bearings of this apparent anomaly are discussed. 3) Ewarr is quoted as follows: “In Selachians in general, according to Ewarr’s schema, that section of canal that is defined by him as temporal, is innervated by the branches of three nerves, the oticus facialis, the glossopharyngeus, and the lateralis vagi.’ I must express surprise, that this quotation should have been made. In the schema in question the temporal canal is well defined by the lettering 7. T., and is innervated only by the IXth nerve. It was inserted solely on the authority of Aruıs’ own work, since Ewart himself did not find any branches of the IXth supplying lateral sense organs +), nor does he describe a temporal canal in the types investigated by him, but distinctly denies being able to delimit one. On p. 70 Ewart refers to a temporal canal, but the passage relates to Amia, and toa distinct canal innervated, as it was then supposed, by a distinct nerve, and not as stated by Auuis by branches of 3 nerves. On the other hand as the only statement on which the temporal canal was founded has since been dissipated, the canal must also go with it. Finally Ewart himself is perfectly logical and consistent in defining the canals according to their innervation, his “temporal canal” was a necessary result of this consistency, and in my opinion to quote his work in support of the opposite view was not permissible. The peculiar views of Auuis there-

1) This has since been described by Ewart and the writer, but a comparison of Ewart’s figure with that given in our joint description ‘at once suggests that the latter is an anomalous case, whilst also the IXth nerve there does not supply a part of Arrıs “temporal canal”. Arrıs by the way misquotes this paper in his list of literature.

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fore on the classification of the sensory canals, as far as his criticism enlightens us, are based on an unpublished fact in Scomber’, on a doubtful condition in Chimaera, and on a misinterpretation of Ewarr.

2) Here Arııs has somewhat failed to grasp my meaning, and the passage in question is, as it stands, too condensed. The point was that whilst the independence of the primitive cord of cells was a significant fact (but one in which Amia is so far peculiar), the later independence of the two canals is involved by the fact of there being a pore at their junction — whether this pore be formed by the fusion of half or primary pores notwithstanding. The latter quotations from my Chimaera paper are of course quite correct, but do not apply to the exceptional case of Amia.

3) As I made no claim to have homologised the bones of the Cod fishes skull!), it is difficult to see that I can be blamed for not having done so. To accuse me, however, of ambiguity in connection with the Post-frontal is not just, since the alleged ambiguity is fully ex- plained, and was in fact entirely introduced, by the circumstances de- tailed in the post-script to my paper — added as it was passing through the press. I referred to a bone as the post-frontal or sphenotic purely and simply because that bone actually has received those names in Gadus and closely allied forms, and I was anxious to give the full synonymy. Further on ALLIS arguing on the basis of the position of the dermal tubules and sense organs (in my opinion a dangerous line of argument) is led to conclude that the post-frontal +- sphenotic of Gadus are homologous with the post-orbital of Amia. Whilst I do not pre- tend to the special knowledge of the piscine skull that I freely accord to my critic, it seems to me that he is here certainly in error. Firstly because the bone in Gadus is, contrary to the bone in Amia, at least largely an ossification of the auditory capsule (sphenotic), with however I believe a superadded dermal lateral line element (post-frontal), and its precise homologue in the Salmon is identified as the sphenotic by W. K. Parker, whose opinion demands the fullest respect, and secondly because the bone lodging the infra-orbital canal in front of the squamosal would then be the post-frontal in both our types. Auuis on the other hand homologises my post-frontal + sphenotic with his post-orbital, and my sub-orbital 6 with his post-frontal. To my mind these comparisons are from his own point of view quite inadmissible, since the two bones would then occupy exactly reverse positions in the two forms, and if, as he claims, the topographical relations of dermal tubules and sense organs have any value, I should expect the same relations of the cranial bones to have a still greater value. I contend however that these homologies can only be maintained on developmental evidence, and not on the position of a variable series of characters.

4) I have already dealt with my alleged ambiguity in the use of the terms post-frontal and sphenotic, and pointed out that the charge cannot justifiably be preferred against me. With regard to the re- mainder of the paragraph, it contains its own answer and I do not therefore propose to discuss it.

5) In the preceding paragraph, be it noted, my critic expresses sur-

1) This is emphasized in a footnote to my paper.

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prise that I should homologise a sense organ situated in one ossicle with a sense organ found in another. It is indeed difficult to be con- sistent, and I note with surprise that in the very next paragraph he homologises (“probably”) a sense organ in Scomber situated in the hind end of the squamosal with one in Gadus situated between the supratemporal ossicles 2 and 3.

6) I have read the passage in question over again (p. 627—628) and still affirm that it is not a consistent view of the case. It is true the word “probably” occurs, but the comparison with A mia which follows is in some detail, so that the value of the “probable” is somewhat dis- counted. If however I modify my statement so as to assert that ALLIs provisionally rejects the canal as a lateral line structure in Polypterus, but provisionally accepts it as such in Clarias and Auchenaspis, I should be more correctly conveying his meaning, but the inconsistency would still be there. With regard to my statement that the canals in question are “exactly the same”, and the quotation from me re Poly- pterus, I must re-affirm that as far as the meagre descriptions of POLLARD go any other conclusion is out of the question, and as to the Poly- pterus quotation, it is still another instance of a remark divorced from its context. I may affirm that the canal A is the same as the canal B, without being able to determine the precise relation of both to another system of canals of another nature, Auris concludes by remarking that it is a “pure supposition” to homologise the “lateralis” nerve of Petromyzon with the ramus lateralis accessorius. It is something more than a supposition — it is probable. It rests upon a very fair basis of fact, and is moreover a conclusion, as Professor Jupson HERRICK remarked to me in a letter, that most workers on the subject have ar- rived at quite independently. This alone, apart from the facts in sup- port of it that Srrone and myself have elsewhere adduced, raises it above the level of a “pure supposition”. I shall be interested to learn how these same facts are met by Arrıs. In the meantime I must protest against a carefully argued homology being summarily rejected without any discussion.

7) As counts 1 and 2 of my criticism are admitted by ALLIs I need make no further reference to them. When I stated in the foot- note quoted by him that I omitted reference to text bookst), it simply meant that I assumed my readers, as professional zoologists, would be at least as well acquainted with them as myself. I do not yet see how this simple reference can be manipulated by my opponent into a justi- fication of his ignorance of these works. His quotation from p. 173 of my work is intended to convey the impression that I was quietly claim- ing a homology as my own which was in fact stated by my opponent himself. It will I think surprise most readers when I point out that the last sentence of the same paragraph containes an admission that Aırıs had recognised these homologies. —- Count 3 probably holds good but it should not, I admit, have been allowed to rank with

1) It must not be forgotten that the branches to the pelvic fin were described by Srannius, so that here again Arııs’ explanation fails to meet the case. I did not however mention Srannius, because I was referring to an older author — Swan.

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the others, although the nerve in question is figured, but apparently not described, by Ewarr. — Count 4, to quote Aris, “states that I have made a marked error in my work”. The adjective “marked” is by the way not mine, as I consider the point to be one of very small detail. As however Arrıs enters somewhat fully into it his reply must be considered. The facts are that Srannius affirms, and I fully confir- med his statement in many dissections, that the accessory lateral passes externally to the lateralis. As Anuis stated that it passed internally to this nerve, I felt justified in denying the accuracy of his assertion. He now adduces the following statements in his own support. On one side of the first specimen, the nerve, excepting a small bundle, bears out his statement. On one side of another specimen the course of the nerve is against him and as I stated, but on the other side of the same specimen the nerve is partly external and partly internal to the lateralis. The facts therefore, as far as ALLIs now states them, are perfectly equally balanced, and no one, I think, on this evidence, could possibly say which was the normal condition. Nevertheless, surprising as it may seem, Arnis concludes his passage as follows: “I think, however, that I can safely maintain the accuracy of the statement made by me, notwithstanding the fact that I am in evident opposition to so careful a worker as Srannius.” He is further apparently aggrieved that I should have accused him of error. Now if anyone were to assert that the left carotid of the rabbit arose from the aorta, I should cer- tainly reply that he was in error. And if he adduced that small per- centage of variation in the position of the artery that undoubtedly occurs in support of his assertion, I should accuse him of instituting a controversial distinction between a downright error and a statement cal- culated to seriously mislead his readers. As matters now stand Arnıs’ facts must be regarded as variations, and his statement is therefore erroneous for the normal condition, whatever term he chooses to apply to his action. — As to count 5 I regret that Arrıs does not frankly acknowledge his error and thus obviate a distasteful discussion. That he overlooked a very obvious root of considerable morphological import- ance in a professedly original description must, I insist, be admitted. In extenuation of this he says: “I am also wholly unable to see why, in a memoir relating) to Amia, a particular passage should be con- sidered faulty simply because I had failed, in it, to fully note or de- scribe certain conditions in Gadus that had no direct relation whatever to a relatively simple comparison I was seeking to make.” May I ask my opponent whether it is his practice in his discussions to introduce matter of an inaccurate description and having “no direct relation whatever” to those discussions? And is his summary supposed to in- clude “relatively simple comparisons”, for this one monopolises a para- graph in that portion of his work. But as the homology of the nerves in Amia is left obscure, and as that obscurity I venture to think would have been cleared up by a recognition of the vagal root of Gadus, it appears that the comparison is not so “relatively simple” after all, nor has the fact in question “no direct relation whatever” to the subject.

8) Here I am accused of a “most excellent bit of that special pleading that can be traced in other parts of Core’s work”. If this

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expression gave any Satisfaction to the writer thereof, it has certainly afforded me some amusement. The facts are as follows: On p. 628 of Aruıs’ last work, the last paragraph relates to the “great recurrent branch of the facialis”!). Throughout that paragraph, in order to avoid repetition, this branch is referred as “the nerve”. Towards the end of the paragraph the following expression occurs: “The nerve in Gadus has, contrary to the arrangement of the branches in Amia, an intra-cranial course.” My procedure here is quite obvious. The ex- pression “the nerve” I interpreted in the meaning it had conveyed all through the paragraph, overlooking for the moment the fact that as Auuis had missed the posterior root of Gadus, it could only possibly refer to the anterior root of that nerve. AurLıs’ passage is necessarily ambiguous owing to this oversight, and I consequently misunderstood it. Substitute in the above sentence the expression “anterior root” for ‘nerve” and the ambiguity due to imperfect observation on Aurıs’ part at once disappears. I make the amende honorable with great pleasure, and trust that at least one “bit of special pleading” has now been removed from my work. — With regard to the last paragraph of this section I do not, like Arrıs, formulate an homology on the geography of a nerve, nor do I consider it permissible to reject one on such grounds; but this question cannot be discussed here. I cannot under- take to discuss Hatter without his work to refer to, but as my remarks were only of the nature of a “provisional interpretation” and as I point- ed out that Harrer’s nerve A was anomalous on that interpretation, I am not inclined, as far as my own work goes, to attach much import- ance to the passage. If the quotation from Harrer refers to the anterior root, which however is difficult to comprehend, it cannot be sympathetic any more than it can be a part of the lateralis accessorius.

9) Here I have to acknowledge, with due expressions of regret, having made a bibliographical error of some importance. That is to say I was not entitled to assert that the terms internal mandibular and hyoideus were synonyms. Without wishing in any way to palliate this offence, I may be permitted to point out that as this part of my work is done during short visits to London, and as there is a con- siderable quantity of it to be got through, it is not possible to do it as thoroughly as I could wish. This is, as far as I am aware, the only noteworthy blunder in this portion of my work that has been committed, it had already been pointed out to me by Prof. Jupson Herrick, and I had taken the necessary steps to acknowledge it. Whilst therefore I would prefer not to discuss the details of this section of Aurıs’ criticism without independently going over the ground again, I am free to admit the justice of several of the points he has made against me. I may however in the meantime point out that I did not, as he charges me, overlook his r. mand. int. trigemini, and indeed the very passages of his work he refers me to are in my copy strongly marked with pencil. As however the chorda tympani is essentially a. component of the facial, and as the nerve he identifies as the chorda is a branch of the trigeminus, the facts of its sensory nature and topo-

1) This of course has an anterior and posterior root according to PoLLArD.

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graphical position, though important, are by no means sufficient to establish the homology claimed. It was for this reason that I did not mention it.

10) No comment necessary.

11) With regard to the “prophecy” incident I have read the two passages over again, and am so confident that the unprejudiced reader will detect no essential difference between them, that I leave the matter in this position. As to the lateral line branch of the IXth in Amia it would perhaps be better that I should briefly recapitulate the facts. In his first Amia paper Aruıs states that the lateral line branch of the IXth has in the larva a separate root, a separate foramen in the skull (often), and a separate ganglion. On what substantial grounds, therefore, this nerve was associated with the glossopharyngeus, except for the purpose of pure convenience, it is difficult to imagine. In his second Amia paper these facts are restated, but without mention of the separate root, with the additional information however that the nerve in the adult is derived from the root of the lateralis, and that after its origin it accompanied the IXth and entered its ganglion. If any additional evidence had been necessary to establish the independ- ence of this nerve from the glossopharyngeus the latter fact surely supplies it, and I confidently believe that the morphologists are few who would, like Anis, have still described this nerve as a branch of the TXth, How is this procedure justified? Passing over the first statement on p. 376, in which my critic conveniently refuses to recognise the obvious sense of the passage quoted from me, the first reason given is that he does not see why the fact that the nerve arises from the lateralis should cause it to be disassociated from the IXth. If this is intended to be an obscure blow at the discrete nature of the cranial nerves, I am heartily in accord with my critic. So long however as the independence of the cranial nerves is maintained, and this I take it is the view adopted by Aruıs, so long for example must a nerve issuing from the brain in company with the trigeminus be kept distinct from the facialis. The second reason is sufficiently important to be quoted in extenso. “Whether its association with the glosso- pharyngeus is primary or secondary I do not pretend to judge, but that the branch in Amia has the same relation to that nerve, be it segmental or not, that the so-called facial and vagal branches of the lateral system have to the facialis and vagus I consider as unquestion- able.” This passage is the truth but not the whole trath. The lateral line nerves have peripheral relations with the VIIth and Xth it is true, but, as Annis describes and figures himself, they also enter into the same relations with the trigeminus. We hence have the interesting anomaly of our critic disagreeing with CorLinGe in the latter’s association of the buccal nerve with the trigeminus, whilst he himself associates a nerve with the glossopharyngeus on precisely the very same grounds 1). — Regarding the concluding portion of this paragraph it is either ir- relevant, or is (by implication) based ‘on a misunderstanding of my position

1) Of course the most rational explanation of the lateral line nerves, and one now held by several workers in the subject, is that they are not branches of any cranial nerve. The condition of the lateral nerve of the IXth of Amia fits in admirably with this view.

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on this question. It is sufficient to refer readers to p. 154 ete. of my Gadus paper. Inote that Aruıs does not endeavour to meet the objection that I urged against his view of the matter. — As to Arcock’s work on Ammocoetes Auuis says: “I consider [it] a valuable contribution to our knowledge of the lateral sensory system, differing radically, in this, with Core.” This is hardly correct. I did not doubt that the work in question had been carefully and ably conducted, and only strongly criticised the primature conclusions based on that work. It will be remembered that my principal objection was that we knew nothing of the status of the so- called lateral line organs of Arcock, and they could not hence be used as a basis for discussion. The very same objection was emphasized by another worker on cranial nerves in a letter received before my criti- eism was published. Further my criticism was accompanied by at least some evidence, whereas the only point Aurıs urges for his opinion is as follows: “The ventral line of epidermal pits in Ammocoetes, for example, a part of which is said to be innervated by a branch of the ventral branch of the glossopharyngeus, explains, in all probability the gular line of pit-organs im Amia, a line of organs doubtless overlooked by Core in his statement that ‘the ventral line from the IXth backwards is not represented in other recent or fossil Fishes’.” I beg to say I did not overlook the organs in question, but as their innervation was not “fully determined” (see fig. and text) in Auuis’ first Amia paper, and as I did not find any branch of the IXth described as supplying them in his second Amia paper, I considered their nature of too doubtful a character to have any value in the discussion. — With regard to the nerve I identified as the otic branch of Ammocoetes, such identification may be wrong, but it is based on a comparison with Selachians, and therefore has more a priori probability than the sug- gestion of Aruıs. It is a common practice on the part of the latter to interprete all fishes in terms of Amia — a specialised fish it must be remembered of a family going no further back than at most the Jurassic. — The last paragraph of the criticism is easily met. It is in my opinion gratuitous to doubt Jounsronn’s work in this particular connection, as lateral line fibres are easy to identify, and Jounsrone& actually did not err in his identification of the roots of the IXth, which are in fact, omitting the olfactory and optic nerves, the easiest roots to identify in a fish. Moreover the peripheral distribution of the nerves of Acipenser has been carefully described. Omitting the well-known work of GORONOWITSCH, it is sufficient to mention the admirable account of Stannius published in 1839. That he considered this work to hold good is obvious from the preface to his 1849 memoir, and the latter Aruıs, like the rest of us, holds in great admiration. The 1839 work is however not quoted either by JOHNSTONE or ALLis, but as the main results figure in the general memoir well known to both, I hold that Jonnsronn’s data were fully sufficient for this particular purpose (i. e. the IXth nerve), and see no reason to doubt his statements — except a controversial one. As to Kınasgury it is idle to doubt that I overlooked the statement in question (which was in fact consulted before writing the passage now criticised), I did not further include him amongst the older writers, nor do I be- lieve that careful and philosophic writer to have been guilty of error. Until Jomsstoxe’s full memoir appears it would be premature to com-

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pare the two accounts in detail, but it is quite easy to conceive how they may be harmonised. In the meantime Jonnsronx fails to describe in Acipenser a lateral line branch belonging definitely and morpho- logically to the IXth, and Kiyessury says: “it [the lateral line nerve] also receives a small contingent of fine fibres from the IXth and in turn gives to it a small bundle of its coarse [i. e. lateral line] fibres.” In a footnote it is pointed out that the fibres thus contributed to the IXth are distributed as they should be to lateral line organs!). How this simple statement (also quoted by Arııs) can be converted into the assertion that according to Kinessury “lateral fibres are sent, in Aci- penser, from the linea lateralis to the glossopharyngeus” is still con- tinuing to excite my curiosity, unless indeed “linea lateralis” is a clerical error for lateralis vagi. The statement as it stands conveys the im- pression that Kixaspury describes a true lateral line branch of the IX th, Such a statement is directly contrary to the whole tenor of Kinespury’s work, the tendency of which in fact is against the discrete nature of the cranial nerves and against the association of the lateral line nerves with the cranial nerves sensu stricto, My interpretation of the passage on the other hand is precisely the opposite of that given by Auris, and it is the one moreover which I am confident Kinespury would place on it himself.

To sum up generally: Whilst I am as far as Auuis could wish from presuming to be the parent of unassailable views, and whilst those views must I suppose go the way of most in being either modified or entirely rejected with advancing knowledge, it still seems to me that, apart from the bibliographical error admitted in section 9, my work remains in the same position as it did before Aruıs’ criticism was published. As to matters of fact there is, it is satisfactory to note, but little disagreement.

Liverpool, March 20, 1899.

1) On reading the footnote over again it seems to me uncertain whether Kinessury’s conclusion in it refers to Acipenser or to Amia, but of course it does not affect my point; and this was probably the reason why I did not refer to Kinesspury’s statements re Acipenser in my criticism of ALCOCK.

Personalia.

Pisa. Dr. BERTELLI ist zum Professor der Anatomie in Padua, an VLACOVICH’s Stelle, ernannt worden.

Anatomische Gesellschaft.

Dr. med. W. Tonxorr, Volontär-Assistent des Anat. Instituts der Kaiserl. Militär-Akademie zu St. Petersburg (z. Z. Freiburg im Breis- gau) ist in die Gesellschaft eingetreten.

Berichtigung. In No. 1, Band XVI des Anatom, Anzeigers, S. 27, Absatz 2, Zeile 3 (STAHR’s Artikel „Bemerkungen etc.“) muß es heißen „beim Hunde‘ statt „beim Kinde“.

Abgeschlossen am 18. Mai 1899.

Frommannsche Buchdruckerei (Hermann Pohle) in Jena.

ANATOMISCHER ANZEIGEK

Centralblatt

fir die gesamte wissenschaftliche Anatomie. Amtliches Organ der Anatomischen Gesellschaft.

Herausgegeben yon Prof. Dr. Karl von Bardeleben in Jena.

+

Verlag von Gustav Fischer in Jena.

Der „Anatomische Anzeiger‘‘ erscheint in Nummern von etwa 2 Druckbogen. Um ein rasches Erscheinen der eingesandten Beiträge zu ermöglichen, werden die Nummern ausgegeben, sobald der vorhandene Stoff es wünschenswert macht und event, erscheinen Doppelnummern. Der Umfang eines Bandes beträgt etwa 50 Druckbogen und der Preis desselben 16 Mark. Das Erscheinen der Bände ist unabhängig vom

Kalenderjahr.

XVI. Band. 5 6. Juni 1899. & No. 3 und 4.

InHALTt. Aufsätze. Edward Phelps Allis jr., On Certain Homologies of the Squamosal, Intercalar, Exoccipitale and Extrascapular Bones of Amia calva. p. 49 bis 72. — Otto Thilo, Die Entstehung der Luftsäcke bei den Kugelfischen. Mit 2 Tafeln. p. 73—87. — B. Morpurgo, Ueber die Verhältnisse der Kernwucherung zum Längenwachstum an den quergestreiften Muskelfasern der weißen Ratten. p 88—91. — Eugen Fischer, Seltener Verlauf der Vena azygos (Abspaltung eines

ungenlappens. (Nachtrag) p. 91—92. — J. Havet, Referat. p. 92. — Ana- tomisehe Gesellschaft. Bericht über die 13. Versammlung. p. 93—96.

Aufsätze.

Nachdruck verboten.

On Certain Homologies of the Squamosal, Interealar, Exoceipitale and Extrascapular Bones of Amia calva.

By Epwarp PHeırs ALLIs jr,

Of the squamosal of Vertebrates Gaupp says (No. 16, p. 89): “So können wir das ‘Squamosum’ definiren als einen Belegknochen des äußeren Umfanges der Ohrkapsel, als ein ‘Paroticum’ — eine Bezeich- nung, die ich freilich vorerst, um die Verwirrung unter den ‘Otica’ nicht zu vermehren, nicht anwenden will. Durch die Befestigung des Quadratums an der Ohrkapsel wird die Anlagestelle des Squamosums noch genauer localisirt. Diese bei den höheren Wirbeltieren sich deutlich aussprechende Natur des Knochens macht es dann ziemlich zur Gewißheit, daß auch das ‘Squamosum’ der Fische diese Bezeich- nung ganz mit Recht führt und mit seinem Deckknochenanteil dem

Anat. Anz. XVI. Aufsätze, 4

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Squamosum der Reptilien, Vögel und Säuger complet homolog ist. Dagegen ist bei den jetzt lebenden Amphibien kein Deckknochen vor- handen, der die Bezeichnung ‘Squamosum’ verdiente.”

Of the squamosal of Teleosts VROLIK says (No. 33, p. 283), that it “constant den Can. semic. ext. einschließt”. He furthermore says (p. 229): “Mit dem Postfrontale zusammen bildet das Squamosum gewöhnlich das Gelenk für das Hyomandibulare. Den Namen Squa- mosum hat schon Sprx gebraucht. Dagegen deutet Cuvier diesen Knochen als Mastoideum der Schildkröten und Krokodile, das mit dem Frontale posterius die Gelenkfläche bildet für das Hyomandibulare, dem CuvIER den Namen Squamosum zuteilte. MECKEL nannte das Frontale posterius Squamosum; darum deutet er unser Squamosum als mastoideum. HALLMANN giebt als Function des Squamosum an, daß es die Gelenkfläche des Hyomandibulare bildet; auch erwähnt er, daß es den Canalis semicircularis externus birgt. KÖSTLIN stützt seinen Namen Squamosum auf Vergleichung mit der Begrenzung und Lage bei Reptilien und Vögeln. Acassız nennt diesen Knochen Temporal, weil er ihn, seiner Begrenzung wegen, nicht für ein Mastoideum halten kann.”

Huxtey, or perhaps first PARKER, proposed for the squamosal of fishes the name pterotic, and of it HuxLey says (No. 19, p. 26): “It lies on the upper and outer part of the ear-capsule between the proötic and the epiotic.” Of the bone in Esox he says (loc. cit. p. 133): “The postero-external [process of the primordial cranium] closely cor- responds with the squamosal of the higher Vertebrata in position; but, as a cartilage bone, it corresponds with an ossification of the capsule of the ear, called pterotic in the higher Vertebrata.” PARKER says of it (No. 24, p. 96), that it is an ossifying tract that “begins. over the ampulla and arch of the horizontal canal”.

In Amia the squamosal was described by BrIDGE (No. 7) as a parietal. The true parietals of the fish, which, in the specimen BRIDGE. examined, were found fused with each other in the middle line of the head to form a single median bone, were considered by him as a dermo-supraoccipital. The outer margin of each so-called parietal was said by him to fulfil “the function of a supratemporal in trans- mitting the cephalic continuation of the main lateral slime-canal”. Two separate and independent, so-called supratemporals, one on each side of the head, were however described by him. They are the extrascapulars of SAGEMEHL’s descriptions (No. 27) and my own.

The squamosal of Amia, as both Brincge and SAGEMEHL have stated, rests upon the primordial cranium only along its lateral edge,

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the remainder of the bone being separated from the underlying cartilage by the temporal hole of SAGEMEHL, that hole lodging an anterior extension of the dorsal muscles of the trunk. Along the under surface of the lateral edge of the bone two short lamellae are said to project downward and somewhat mesially, and to firmly embrace the sharpened, dorso-lateral edge of the chondrocranium. One of the two lamellae lies along the lateral surface of the skull, extending downward approximately to the dorsal edge of the articular facet for the hyomandibular. The other lies along the lateral edge of the floor of the temporal hole. These lamellae, although closely applied to the surface of the cartilage they embrace, are said by SAGEMEHL (No. 28, p. 59) to be everywhere separated from it by a layer of perichondrium. The entire bone is, accordingly, considered by him as of purely dermal origin.

In Teleosts, SAGEMEHL says (No. 29, p. 507) that the squamosal consists of two parts, one of them being of dermal origin while the other presents all the characteristics of a primary ossification. In the Characinidae the dermal part of the bone is said by him (No. 28, p. 59) to be a bony plate that lies in the same level as the other dermal bones that cover the top of the skull. Along its lateral edge it is said to be connected with the primary portion, which is described as a bony plate directed medianly and forming a part of the floor and lateral boundary of the temporal hole and a part of the lateral surface of the skull. The dermal part of the bone is traversed by the main infraorbital lateral canal, and lies dorsal to the muscles that fill the temporal hole. The primary part of the bone lies lateral or ventral to those muscles, and is traversed by the external semicircular canal of the ear. It, extends downward along the lateral surface of the skull beyond the dorsal articular end of the hyomandibular, and the posterior part of the articular facet for that bone lies on its external surface, and, according to the figures, is lined with cartilage. The median wall of the temporal hole is said to be partly of cartilage and partly of membrane, a fascia closing a large round opening which is always found leading through the cartilage, from the hole, directly into the labyrinth recess of the cranial cavity (No, 28, p. 81.)

In the Cyprinidae the mesial edge of the dorsal, dermal part of the squamosal is said by SAGEmEHL (No. 29, p. 550) not to reach the exoccipitale, as it does in all the Characinidae, a certain space, covered by the parietal, being left between the two bones. In certain of the Cyprinidae this space is said to be so greatly enlarged that

the temporal hole becomes in part uncovered; and in still others the 4*

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lateral edge of the parietal becomes “so weit verkürzt” that practically no roof whatever is left to the hole. The same conditions are said to be found in many of the Physostomi, and in nearly all of the Acanthopterygii and Anacanthini. In Sclerognathus the hole is said to be reduced to “eine tiefe, von medial und hinten von scharfen Rändern begrenzte Grube”. Sclerognathus thus seems to present ex- actly the conditions found in Scomber, and to which I have already referred in an earlier work (No. 4, p. 92). I there said: “This seems to indicate that Amia and Scomber represent separate lines of descent from some fish in which the trunk muscles had not as yet invaded the temporal part of the skull to the extent they have in these two fishes.” A similar conclusion is perhaps indicated in SAGEMEHL’s statement (No. 29, p. 551): “Selbstverständlich sind die bei diesen Formen (Cyprinidae) und bei Sclerognathus so ähnlichen Bildungs- verhältnisse ganz unabhängig von einander entstanden zu denken.” That the condition found in Scomber is not due simply to the dis- appearance of the plate of bone that forms the dorsal, dermal part of the squamosal of the Characinidae and Cyprinidae, and the whole of the bone in Amia, seems shown conclusively by the fact that the hind end of the supraorbital canal lateral, which, in all these fishes, lies in the frontal bone, lies, in Scomber, internal to the trunk muscles that fill the temporal groove, while, in all the others, it lies morpho- logically external to those muscles.

From the hind end of the squamosal, both in the Characinidae and Cyprinidae, a process, usually long, is said to project down- ward and backward and to serve for the attachment of the supra- clavicular.

According to SCHMID-MONNARD (No. 30) the squamosal of Tele- osts is always formed of at least two different components, and there may be even three or four such components, all fused together to form the single bone of the adult fish. One of the two components that are said to be always present is partly of subperichondrial origin and partly of endochondrial origin. It is said to first appear as two thin layers of bone, called by ScHhmip-MonnArD the primary bony lamellae, both lying internal to the perichondrial membranes, one on the outside and the other on the inside of the cartilage that encloses the summit of the external semicircular canal. These two layers of bone are thus of exochondrial origin although subperichondrial in position, Internal to them the cartilage ossifies directly, true endochondrial bone thus arising, continuous with the two primary exochondrial lamellae The second component always found is, in young embryos, wholly

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separate from the subperichondrial one, and it encloses and adjoins that section of the lateral sensory canals that, in the adult, traverses the compound bone. It lies external to the perichondrial membrane of the adjacent part of the chondrocranium, and it is said to be of osteoblastic origin, or partly of osteoblastic and partly of fibrous origin. These two, originally distinct components soon fuse, but a distinct limit exists between them, throughout the life of the fish, “sofern nicht Re- sorption der gesamten Knochensubstanz eintritt”. The other com- ponents that may be found in the bone of the adult may be called a fibrous component, formed in, or in connection with, the tendons or fascia that have their attachment on the bone; and a fibro-cartila- ginous component, that may be formed in relation to the articular facet for the hyomandibular. These latter components seem, from the descriptions, to form additions to the extra-perichondrial com- ponent, above referred to, rather than to the subperichondrial one, and they are never, even in larvae, sharply limited and defined in relation to it.

VROLIK, in his work (No. 33), did not notice, in the bones of Teleosts, the several components described by Scumrp-Monnarp. He, however, describes, in the adult Esox and in embryos of Salmo, “perichondrostotisch” and “enchondrostotisch” bones, the former being approximately the two primary bony lamellae of the subperichondrial bone of Scuomrp-Monnarp’s descriptions, and the latter the more or less fully developed subperichondrial and endochondrial bone, fused with the one or more other extra-perichondrial components that may become associated with it.

In the adult Salmo VROLIK says the bones are all wholly enchon- drosteal. In the sections he gives of the adult of this fish he shows no lateral canal traversing the squamosal, nor does he allude to it. In one of the two sections that he gives of the embryos of the fish he shows a lateral canal, but not in the other. While I should hesitate to accept these figures as a confirmation of CoLLINGE’s statement (No. 13) that the lateral canals in the young of Salmo traverse the bones of the skull, but, in the adult, have left those canals to become lodged in drainpipe-like canal-bones, that lie superficial to them, the coincidence is nevertheless singular. VROLIK’s figures seem simply to have been carelessly drawn, or carelessly reproduced, for no canals whatever are shown in the frontal bones, either of the adult or of larvae, and in none of his sections of Esox are the parietal bones shown, although sections 2 and 3 should certainly, one or both, have hit them.

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In Amia the squamosal lodges three lateral sense organs, or sensory patches (No. 1). Two of these organs are innervated by branches of the ramus oticus facialis, and the third one by a branch of that lateral nerve that issues from the skull with the nervus glosso- pharyngeus. The two organs that are innervated by the facialis lie anterior to the point where the main infraorbital canal is joined by the dorsal end of the preoperculo-mandibular canal. The third organ lies posterior to that point.

In Scomber, as in Amia, there are, in the squamosal, three lateral sense organs. Two of these organs are innervated by branches of the oticus facialis, and the third by a branch that has its apparent origin from the first vagus nerve. This latter branch is, almost unquestion- ably, the homologue of that branch of the nervus lineae lateralis of Scyllium or Salmo, described by HALLER, to which I made reference in my latest publication (No. 5, p. 377), and which I there considered as the probable homologue of the so-called dorsal branch of the glossopharyngeus of Amia. The two organs that are innervated by the facialis lie, in Scomber, as in Amia, in front of the point where the main infraorbital canal is joined by the preoperculo-mandibular canal, the third organ lying posterior to that point.

That part of the squamosal of Scomber that lodges the lateral canal by which the bone is traversed, is a tall thin ridge or process of bone that looks like a separate plate or piece applied by its edge to the dorso-lateral surface of the rest of the bone. It pro- jects dorso-laterally, and lies between the muscles that fill the tem- poral groove of the fish and the dilatator operculi muscle, which fills the dilatator groove. The bone does not cover any portion of the dorsal surface of either of the muscle-masses between which it lies, there being absolutely no superficial plate-like extension to this part of the bone. The primary part of the bone forms part of the floor of the temporal groove, part of the floor of the dilatator groove, part of the posterior surface of the skull, and a part of its lateral surface, this last surface of the bone containing the facet that receives the posterior articular head of the hyomandibular. The bone is traversed by the external semicircular canal of the ear, and, partly from its hind edge and partly from the corresponding edge of the dorsal, dermal part of the bone, a long pointed process projects backward and laterally, and gives insertion to a fascia that covers the external surface of the adjacent segment of the muscles of the trunk. The entire bone thus has three distinct components, the dorsal, ridge-like portion, arising in connection with the lateral canal by

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which it is traversed; the body of the bone, of perichondrial or endo- chondrial origin, and lodging the external semicircular canal; and the posterior process, formed in connection with the fibrous structures to which it gives insertion. The body of the bone has the same relations to the skull of the fish that Sagement found in the corresponding part of the bones of the Teleosts he examined, and it is certainly their equivalent; while the dorsal ridge, or process, of the bone is the equivalent of the dorsal, horizontal, dermal portion of the bones in those other Teleosts. This dorsal ridge in Scomber is also the equi- valent of the entire bone of Amia, as SAGEMEHL describes that bone, but it would seem as if the V-shaped process along the ventral sur- face of the lateral edge of the bone in Amia might, contrary to SAGEMEHL’S determination, represent of the perichondrial body of the bone of Scomber and other Teleosts, and not a part of the dermal component.

In Polypterus the so-called parietal of Traquatr’s (No. 32) de- scriptions is said by him to be traversed by the main lateral canal small of each side of the head. Because of this relation to the canal VAN WHE (No. 36, p. 259) concluded that the bone could not be a true parietal, and that it must be formed by the fusion of the squamosal and parietal elements of the skull of the fish. He accordingly proposed for it the name squamoso-parietal, a proposition to which PoLLARD later gave his adhesion (No. 26, p. 407). It is to be noted, however, that the so-called squamosal part of this bone takes little, if any, part in the formation of the articular facet for the hyoman- dibular. According to TRAQUAIR the anterior part of the lateral edge of the bone lies mesial to the spiracular canal, the posterior part forming the dorsal portion of the hyomandibular facet. According to POLLARD’s figures, where the bones are shown in section, the dorsal end of the hyomandibular is capped by what he calls the third spira- cular ossicle, and it is that ossicle and not the hyomandibular itself that articulates with the lateral edge of the squamoso-parietal. Both the ossicle and the anterior portion of the dorsal end of the hyoman- dibular are said to lie internal to the spiracular canal. The squamoso- parietal also comes into no relation whatever with the external semi- circular canal of the ear, that canal traversing the so-called opisthotic of the fish. Of this latter bone TRAQUAIR says (No. 32, p. 168): “This bone, the ‘mastoid’ of Acassız and MÜLLER, I must identify as the opisthotic of HuxLeyv, but it is evident that it also includes his epiotic element”. It seems to me that it must include not only those two elements, which are, respectively, the intercalar and exoccipitale

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of my descriptions of Amia, but also the so-called primary part of the squamosal of Teleosts. The dorsal, dermal part of the squamosal of Teleosts has simply retained that primary independence from the underlying primary part of the ossification that is ascribed to it by Scumip-Monnarp, and has fused with the lateral edge of the parietal. It has also fused with, and wholly appropriated to itself, that fibrous component of the bone of Teleosts that forms, in those fishes, the posterior process of the bone, this process being described, in Polypterus, by TRAQUAIR, and more fully by POLLARD, as a posterior process of the squamoso-parietal. In old specimens this process, called by POLLARD the squamosal process, is said by him to become completely anchylosed with the so-called opisthotic (No. 26, p. 407), the primary and secondary parts of the squamosal thus finally acqui- ring, in Polypterus, the connection usually found in Teleosts, and the squamoso-parietal and opisthotic necessarily forming a single bone.

Assuming that: I am correct in the assumptions made above, the general relations, in Amia, Scomber and Polypterus, of the several parts of the several bones here concerned, to each other and te associated structures, would closely resemble each other. Thus, in Polypterus, the so-called opisthotie is said by TRAQUAIR to be “drilled by both the external and posterior semicircular canals of the ear”. In Scomber these two canals traverse, respectively, the primary part of the squamosal and the exoccipitale; and in Amia the posterior canal “kommt fast in unmittelbare Beriihrung mit dem Exoccipitale” (No. 27, p. 206), the external canal lying in the cartilage of the side wall of the skull and having no direct relation whatever to the squamosal. In Polypterus the squamosal process of the squamoso-parietal is said by POLLArD to give attachment to one of the stoutest tendons of the neck muscles. In Amia and Scomber the corresponding process of the squamosal gives attachment to fascia connected with the muscles. of the trunk. In Polypterus the opisthotic, or cranio-spinal, process of PoLLARD’s descriptions is said by him to be connected by ligament with the posttemporal scale, and this ligament is said to become, in older animals, completely ossified. In Amia and Scomber the posterior process of the intercalar gives attachment, by ligament, to the so- called leg or pedicle of the suprascapular. In Polypterus the nervus glossopharyngeus is said by POLLARD (No. 26, p. 397) to give “off a fine branch which passes dorsally and vertically upward and penetrates the process of the Petrosum”. Then in a foot-note he adds: “It doubt- less supplies one of the mucous canal organs”. In his Fig. 13, Pl. 28, he shows this nerve piercing the posterior process of the so-called

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opisthotic, which is thus undoubtedly the bone miscalled in his text the petrosal. In Amia this same nerve pierces the intercalar, to reach and supply a lateral organ in the squamosal and the pit organs of the middle head line of my descriptions, while in Scomber its prob- able homologue, the nerve already referred to that has its appar- ent origin from the first vagus nerve, runs upward and mesially, postero-ventral to the hind end of the intercalar, to supply a lateral organ in the squamosal. In Polypterus the vagus foramen lies be- tween the so-called opisthotic and occipital bones. In Amia it lies between the intercalar and the occipitale laterale, almost completely enclosed in the anterior edge of the latter bone, in which it is enti- rely enclosed in Scomber.

In Alepocephalus rostratus, so far as can be judged from GEGEN- BAUR’S descriptions and figures (No. 17), the primary and secondary components of the squamosal, if they both exist, must be entirely separate and distinct from each other, as they are in Polypterus, and there is apparently no fibrous component. The bone is said to enclose the summit of the external semicircular canal; and between that part of the bone that is formed on the external surface of the cartilage and the thin layer that lines its inner surface and directly encloses the space traversed by the semicircular canal, there is a thin persistent layer of cartilage. The bone thus represents a stage of development similar to that described by Scumrp-Monnarp in the young of Esox, excepting that no indication whatever is given of a lateral canal in any way related to it. The shape, alone, of the bone, as shown in the figures, seems to preclude the possibility of its being traversed by such a canal, and yet no separate canal element can be recognised in the descriptions, unless it be described in the bone of which GEGENBAUR says: “Ein einzelnes kleines Knochenstückchen ist endlich noch vom Schädeldach zu erwähnen, wo es auf dem Parietale und dem Occipitale externum aufliegt. Es gehört gleichfalls dem Hautröhrensysteme an und trägt die Mündungen von 2—3 Röhrchen.” This little bone would seem, however, from its position, to be an extrascapular. If it be such, and if the squamosal is not traversed by a canal, then either the otic and more posterior portions of the main infraorbital canal of Alepocephalus must be entirely wanting, must be represented, in part, in that highly developed posterior exten- sion of the supraorbital canal that is shown in the frontal bone, or they must be, as often happens for certain portions of the sensory system, enclosed in thin bony tubes or scales attached to the integ- ument, and so easily removed unnoticed. This latter supposition

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seems much the more probable one, the dermal component of the squamosal, in that case, being represented in certain of the little scales that lodged or protected the canal, and that are not described by GEGENBAUR.

In Polyodon, CoLLInGE (No. 12) shows no squamosal bone, the region where that bone is usually found being occupied by what he calls a posttemporal and a dermosphenotic. The dermosphenotic is said to be almost hidden by the development, upon its surface, of a “series of much expanded canal bones”. Later, these canal bones are said to lie upon the “dorsal surface” of the dermosphenotic. Whether, in these statements, the canal bones are to be considered as entirely separate from the underlying bone, or as partly or entirely fused with it, it is difficult to judge. The name dermo-sphenotic is said to have been given to the underlying bone by BRIDGE, in a work that I have not at my disposal, and superficial to the bone the main lateral canal is said by CoLLINGE to divide into supraorbital, suborbital and hyoman- dibular branches. The bone thus occupies a position, relative to the lateral canals, that would correspond to the united dermal postfrontal and squamosal bones of Amia and Teleosts.

In Accipenser the squamosal is said by Huxuey (No. 19) to be a “membrane bone”, and it is traversed, according to VAN WIJHE (No. 36), by the main lateral canal of the head.

In the Stegocephali a squamosal, properly so-called according to Gaupp (No. 16, p. 105), is found, and it is said to be traversed, in certain species, by a lateral canal (No. 15). This canal, in Tremato- saurus, forms one section of a nearly circular canal which begins and ends at the external opening of the ear, having traversed successively the so-called squamosal, postorbital, jugal, and supratemporal bones. Whether it traverses also the epiotic, or simply lies along its lateral edge, I can not judge from the figures. These bones are all said to be dermal bones, and the canal that is said to traverse them is de- scribed by Frirscu (No. 15, Bd. I, p. 35) as a half cylindrical gutter on the external surface of the bone. The membranous sensory canal thus probably lay superficial to the bones it is said to traverse, but whether it was enclosed in separate and independent bony scales, as in Polyodon and certain Teleosts, or not, can not be judged from the descriptions, and I shall have occasion to refer to it again.

In Gymnarchus niloticus, and in Mormyrus, conditions are found that seem to approach, somewhat, the conditions described in the Stegocephali. In these fishes, according to ERDL (No. 14), the squa- mosal is a semicircular bone bounding the “äußere Gehöröffnung”, the open part of the semicircle directed upward and backward, and

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its lower arm containing “einen Kochenkanal, der an der inneren Fläche des breiten Mittelstückes frei und nach oben gerichtet sich öffnet”. A wholly separate and apparently purely dermal bone is found asso- ciated with it, in both Gymnarchus and Mormyrus. It is called by ErpL the “Gehördeckel, den man vielleicht mit den äußeren Gehör- gangknochen mancher Säugetiere, z. B. des Bibers, vergleichen könnte”. This semicircular bone, traversed in part by a canal, and covered by a separate bone, thus strongly recalls the circular canal of the Stego- cephali, the “Gehördeckel” of Gymnarchus occupying, approximately, the place of the supratemporal bone of the Stegocephali. With other Teleosts the conditions described in Gymnarchus seem to offer no basis whatever for a direct comparison.

In Protopterus, the squamosal of WIEDERSHEIM’s descriptions (No. 34) seems to be the homologue of Gaupp’s paraquadratum, and hence, if it be such, it can not, according to Gaupp’s conclusions, be the homologue of the squamosal of Ganoids and Teleosts. In Cera- todus, and in fossil Dipnoids, a bone is found (No. 15, Bd. II) that seems to more closely resemble the squamosal of other fishes. As, in both Protopterus and Ceratodus, lateral canals exist, and are said to traverse the squamosal region of the skull, bony substance strictly homologous with the canal component of the bones of Teleosts and Ganoids must exist in these fishes also. The canals, however, are nowhere sufficiently described or figured to allow of any definite opinion regarding the bones that are related to them. A separate, bony, otic capsule is described by FRITSCH in Ctenodus.

We thus see that the squamosal of fishes is composed of a canal component and a deeper-lying component which may be either a so- called membrane bone, or such a bone fused with a so-called primary ossification. The primary ossification may be wholly wanting, and perhaps the canal component also. Furthermore the canal component may be found entirely separate from the underlying bone, may be found fused simply with an underlying membrane component, or may be found fused with such a component and with a so-called primary ossification, which latter ossification, alone, is traversed by the external semi- circular canal. The canal component, apparently always united with the underlying membrane bone, may, as a so-called dermal bone, be found fused with other, adjoining, dermal bones; while the primary ossification may be {fused with other adjoining primary ossifications (Ctenodus), or with such ossifications and the intercalar (Polypterus). It is the primary part of the bone, and not its “Deckknochenanteil“, that gives articulation to the hyomandibular.

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The intercalar of fishes was considered by HuxLery as the homo- logue of the opisthotic of higher animals, and most writers have since accepted this interpretation of it. As already stated in an earlier publication (No. 3, p. 21), my work leads me to doubt the correctness. of this interpretation and to accept VROLIK’s statement that the bone does not belong to what he calls “integrirende Teile des Schadels” ; that is that it is not a true otic bone. The intercalar of Amia is. said by SAGEMEHL to be of primary origin, but I have already had occasion to express my opinion that he was wrong in this conclusion,. and that the bone in this fish is wholly of membranous origin (No. 2, p. 688). In the Characinidae SAGEMEHL says (No. 29, p. 557) that the central part of the bone is, in all probability, of primary origin, but that the posterior point or process of the bone is of membranous (“metaplastische”) origin. This membranous point or process of the bone is said to be always present, and to give attachment to a liga- ment connected with the pedicle of the suprascapular. The bone is said to be in process of reduction, and in certain of the Cyprinidae it is said to have finally wholly disappeared. In his work on the Characinidae this reduction of the bone is said by SAGEMEHL to be due to the reduction of the pedicle of the suprascapular, to which the process of the intercalar gives attachment, and the bone, as it dis- appears, is said to be replaced by the squamosal. In his work on the Cyprinidae he concludes that the cartilaginous part of the intercalar is first displaced and replaced by the encroaching squamosal, and that the dermal part of the intercalar, although unaffected by this encroach- ment of the squamosal, later diminishes, independently, in size, and finally disappears, with the reduction of the pedicle of the supra- scapular. The bone is then specially referred to as an example of a bone, originally of unquestionably primary origin (Amia), which becomes, by gradual reduction (certain Teleosts), a purely dermal one, and then finally disappears. The bone in Amia was considered by SAGEMEHL as the homologue of the opisthotic of higher animals (No. 27, p. 188).

The exoccipitale of SAGEMEHL’s descriptions and my own, is, like many other bones of the skull of fishes, known under several different names. It was called by HuxLry the epiotic, and was said by him to be developed in relation to the posterior vertical semicircular canal. As the occipitale externum it is said by VROLIK to be of “perichondro- stotische” origin, to be developed in relation to the insertion of muscles, and not to belong to the “intergrirende Theile des Schädels”. Of it, and of the supraoccipital and the squamosal also, he says (No. 33, p. 276), they form “fünf für das Hinterhaupt der Teleostier charakte-

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ristische Vorsprünge, zwischen welchen sich vier von Muskeln erfüllte Gruben befinden; das Verhältnis dieser Vorsprünge zu den Gruben bietet einen unendlichen Wechsel dar”.

In Amia the exoccipitale is not traversed by any part of the lateral sensory canals. It lies, however, directly internal to the extra- scapular, which bone lodges the supratemporal crosscommissure of the lateral system. In Teleosts, also, the bone is never, so far as I can find, traversed by a lateral canal, and, although not always lying directly internal to the extrascapular, as in Amia, it seems to lie internal to the mesial end of that bone, or internal to the mesial end of the lateral canal that traverses the bone, the canal naturally ex- tending slightly beyond the end of the bone that lodges it. The ex- occipitale of Amia and Teleosts thus seems to have much the same relations to the extrascapular and to the supratemporal commissure of the lateral canals, that the primary part of the squamosal has to the dermal part of that bone and to that section of the main infra- orbital canal by which it is traversed, and that the postorbital ossi- fication of my descriptions of Amia has to the dermal postfrontal and to the section of canal it lodges. The dermal postfrontal, it is also to be noted, often does not directly overlie the primary ossification to which it is considered to be related.

According to VROLIK, the exoceipitale of Teleosts is usually tra- versed by, or partly encloses, a part of the posterior semicircular canal of the ear; but in certain Teleosts it simply lies, as it does in Amia, external to the summit of that canal, but wholly separated from it by cartilage. As the squamosal and postorbital ossifications are similarly related, respectively, to the external, and anterior semicircular canals, the relations of dermal canal components to primary ones, in the three otic regions, may be something more than a simple coin- cidence.

The extrascapular of Amia is a large dermal plate that lies in a transverse position superficial to the exoccipitale, and meets, in the middle line of the head, its fellow of the opposite side. The lateral part of the bone is traversed by the main infraorbital canal of the lateral sensory system, and it lodges one sense organ of that line. From this section of canal the supratemporal crosscommissure arises, and, traversing the bone, unites with its fellow of the opposite side of the head. The commissure contains three sensory organs on each side.

In Teleosts, the extrascapular is, according to SAGEMEHL (No. 27, p. 181), almost always found as a superficial dermal bone, usually but little developed, lying between the arms (“Zinken”) of the supra-

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scapular. It is usually called the supratemporal by English writers, and Srtannıus is said to have first given the name extrascapular to it. to distinguish it from a bone that lies lateral to the squamosal and is also called a supratemporal. This latter supratemporal bone is. shown by PARKER in Salmo (No. 24, Pl. VI, Fig. 1), and is unquestion- ably traversed by, and developed in relation to, the dorsal end of the preoperculo-mandibular lateral canal. The extrascapular of Tele- osts may be found as a series of bones, as in the Cod, Plaice, and Turbot (No. 31), and it or they probably always lodge, as in Amia, not only a part of the main infraorbital lateral canal, but also a supra- temporal branch of that canal which is the homologue of one half of the crosscommissure of Amia. A part of the bone, or of the series of bones, or a part of the canal by which it or they are traversed, seems, as stated above, to always lie superficial to the exoccipitale.

In Polypterus there are, on each side of the supratemporal region of the head, three bones called by Traquarr (No. 32) the supra- temporals; andthese three bones combined are usually considered as the: homologue of the single extrascapular of Amia. The lateral one of the three bones of Polyterus is said by TRAQUAIR to lodge a section of the main infraorbital canal, and from this section a branch canal arises, which, traversing the other two bones, forms the supratemporal crosscommissure of the fish. This commissure is usually considered as, and in all probability is, the homologue of the one in Amia, but its innervation is not yet definitely known, POLLARD simply indicating, in a table (No. 26, p. 398), that it is innervated by a branch of the vagus. According to COLLINGE (No. 10) the main infraorbital canal of Polypterus traverses two of the supratemporal bones, instead of only one of them, the crosscommissure lying, however, partly in each of the three bones, as TRAQUAIR states. The commissure, and one, at least, of the three bones that lodge it, lie superficial to the epiotic: portion of the so-called opisthotic bone of the fish. By Hux ey (No. 18) the most lateral bone of the series was considered as an epiotic, the mesial one being called a supraoccipital, these two bones thus being homologised with the correspondingly named bones in the Stegocephali, but the middle one of the three being left unaccounted for.

In Lepidosteus, CoLLınGE (No. 11) states that the supratemporal: commissure traverses, on each side, a supratemporal and a dermo- occipital bone. The dermo-occipital is not shown as a separate bone in PArker’s figure of the fish (No. 25, Pl. 37), the space between the: supratemporals, that should apparently be occupied by the dermo- occipitals, being occupied by the hind ends of the parietals. Accord-

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ing to PARKER there are, in Lepidosteus, distinct, primary, opisthotic and epiotic centers of ossification. The dermal canal bones of the region are thus wholly separate and distinct from the otic bones, as they are in Polypterus and in Amia, and must be the homologues of the extrascapulars of the latter fishes.

In Polyodon there is, according to CoLLINGE (No. 12, p. 506, 512 und 519) no complete supratemporal commissure, the commissure being represented, on each side of the head, by a short branch of the main lateral canal which traverses a so-called occipital series of canal bones lying “upon the surface” of the so-called posttemporal bone. This posttemporal bone adjoins, in front, the so-called dermo-sphenotic, which latter bone occupies, as I have already stated, a position corre- sponding, in its relations to the lateral canals, to the squamosal and dermo-postfrontal combined of Amia and Teleosts. The posttemporal bone of CoLLınge’s descriptions would thus seem to be the extra- scapular of my nomenclature, and not the suprascapular, which latter bone is the posttemporal of ordinary English terminology. The com- missure of Polyodon, under this supposition, would be the homologue of the supratemporal crosscommissures of Amia and Polypterus, but it is to be noted that the mesial end of the commissure is shown lying superficial to the hind end of the parietal; that is, in the posi- tion of the middle head line of pit organs in Amia. The sense organs of the canal in Polyodon are said to be innervated, so far as I can understand the descriptions, by a branch of the lateralis vagi, given off close to its base, and which is, apparently, the ramus supratem- poralis vagi of van W1jHE’s descriptions.

In Acipenser, according to VAN WIJHE (No. 36, p. 228), the supra- temporal commissure leaves the main infraorbital canal in a lateral supratemporal bone, and traverses that bone and then a median supra- occipital. The lateral supratemporal is said to have been called the occipitale externum by GEGENBAUR and the epiotic by HuxLey. As the bone is said to be a purely dermal one, and as the sensory canal is said to lie in it, and not superficial to it, it must be the homologue of one or both of the lateral supratemporal bones of Polypterus, the median supraoccipital of Acipenser being the homologue of the mesial supratemporals of opposite sides of the head of Polypterus, fused with each other in the middle line. CoLLInGE differs somewhat from VAN WIJHE in saying, in one place, that the commissure is given off by the main canal as it traverses the “posttemporal” bone of the fish, - and, in another, that it leaves that canal near the anterior end of the “epiotic” (No. 12, p. 522 and 523). He also says that the suborbital

64 branch of the main canal traverses first the prefrontal bone, and then the postorbital and following bones of the circumorbital series, thus having a somewhat peculiar course.

In Psepherus gladius, CoLLInGE (No. 12, p. 519) finds much the same conditions as in Acipenser, the supratemporal commissure leav- ing the main canal in the epiotic and traversing a median dermo- occipital. In very large specimens he says that it traverses also the hind end of the parietal, a statement that certainly needs confirmation and explanation.

All these Ganoids thus agree in that the so-called supratemporal crosscommissure of the lateral canal system traverses bones that are of purely dermal origin; and in that these bones in no way enclose or protect, or have any direct relation whatever to, the semicircular canals of the ear. They are accordingly not true otic bones in any sense of the word, and this is further indicated by the separate and independent development of true otic bones in all three of the bony Ganoids described. In Teleosts, also, the commissure traverses dermal bones that are wholly unconnected with true, primary, otic components. In Teleosts and the three bony Ganoids, the commissure traverses no median bone. In the cartilaginous Ganoids it is said to traverse such a bone. There is thus a difference here that may be important, and the development of the bones concerned, and of the canal they lodge, deserves careful investigation, more especially as the vexed question of the supraoccipital bone is here apparently directly concerned.

According to SAGEMEHL (No. 29, p. 519) a supraoccipital bone is found in all Teleosts, but is wanting in all Dipnoids, and in all Ganoids. The bone, according to him, was never possessed by the Ganoids, and is, in Teleosts, a recent acquisition to the skull. In Acipenser and Polyodon, he says no trace of it is found, the most anterior, median, dorsal “Hautschild” lying, according to him, posterior to the cross- commissure of the lateral canal system. The bone can not, accordingly, be derived, according to him, from a dermal ossification, and he looks for the cause of its origin in the assimilation of certain vertebrae in the occipital region of the skull. His own words are: “Nach meiner Ansicht giebt der Processus spinosus, indem er sich an die knorpelige Spina occipitis anlegt, die Veranlassung zur Entstehung einer zuerst periostalen Ossification an dieser Stelle, die jedoch bald Beziehungen zur knorpeligen Unterlage gewinnt und, sich der Gestaltung der letzteren anpassend, das Occipitale superius hervorgehen läßt.” The assimil- ation of the oceipital vertebrae is then said to be indicated by the occipital nerves of the animal. These nerves are said to be wholly wanting in Amphibia, and a supraoccipital bone is accordingly wanting,

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as it should be, in those animals. “Umgekehrt kommt denjenigen Wirbeltieren, die noch einen oder mehrere hinter dem Vagus das Cranium verlassende Nerven besitzen, auch ganz constant ein Occipitale superius zu; in diese Kategorie gehören die Amnioten und die größte Mehrzahl der Knochenfische.” If I was right in my conclusion (No. 4) that the two posterior, partly assimilated occipital vetebrae of Amia are re- presented in the first two free vertebrae of Scomber, it is evident that SAGEMEHL’S proposition can not be wholly correct, a supraoccipital not being found in amia. It is also to be recalled that both van WIsHE and CoLLINGE have stated that the supratemporal commissure of Aci- penser traverses a median, dermal supraoccipital, instead of lying, as SAGEMEHL states, anterior to the most anterior, median, dorsal “Haut- schild”; that WIEDERSHEIM and Huxtey both call one of the bones of Lepidosiren a supraoccipital; and that Fritsch says (No. 15, Bd. II, p. 68) that in fossil Dipnoi there is a median dermo-occipital. According to VROLIK (No. 33) the supraoccipital of Teleosts is a bone developed on or in the cartilage of the chondrocranium, in relation to the point of attachment of muscles or ligaments, and that, in its origin, it is in no way related to the lateral sensory canals. It is however to be noted that it seems to be associated with, if not related to, a but slightly developed extrascapular; and that, with the reduc- tion of this latter bone, and naturally also of the canal that traverses it, the middle head line of pit organs may be found relatively much more strongly developed than it is in Amia. Thus, in both the Characinidae and Cyprinidae the extrascapular is said by SAGEMEHL (Nos. 28 and 29) to be reduced to a little bony scale lying at the hind edge of the squamosal, and in all these fishes there is, in the parietals, that is, in the position of middle head line of pit organs, a canal, called by SAGEMEHL the supratemporal commissure but said by him not to be the homologue of the one so-named in Amia. In Scomber, on the contrary, although the extrascapular is an exceedingly delicate scale-like bone lying in the integument posterior to the bones of the skull proper, the middle head line of pit organs is not especially important. The same relations between bone and pit line exist in Gadus, according to CoLe’s descriptions (No 9), and there are said to be, in this fish, four supratemporal bones. The same relations will probably be found to exist in Salmo, where PARKER says (No. 24, p. 99) there are no conspicuous supratemporals; in Alepo- cephalus where GEGENBAUR probably describes that bone in the little superficial bone already once referred to; and in Amiurus where I

can not find that McMurricu (No 23) even describes the bone. Anat, Anz. XVI. Aufsätze. 5

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In Esox I find the extrascapular as a delicate Y-shaped bone, to which CoLLinGE (No. 13) has already referred, and the related con- ditions of the sensory canals deserve especial attention. The parietals in this fish are, as is well known, relatively small bones lying on either side of a median supraoccipital. They largely cover the dorsal surface of the epiotics (exoccipitalia), which lie immediately beneath and behind them, and these latter bones adjoin the supraoccipital an- tero-mesially, and laterally form the mesial wall of the supratemporal hole. What seems unquestionably the homologue of the middle head line of pit organs of Amia lies, on each side of the head, immediately superficial to the parietal, and the line is so strongly developed that. it forms a marked groove on the outer surface of the dermis. The line begins, laterally, directly dorsal to the dorsal end of the pre- operculo-mandibular canal, and its mesial end almost meets the corre- sponding end of its fellow of the opposite side. The ends of both lines here slightly overlap the antero-lateral edges of a large round median scale which lies directly superficial to the supraoccipital bone. Elsewhere the two lines lie anterior to the scales of the trunk. The innervation of this line I have not yet determined, but it must be the middle head line of pit organs of the animal, not only its position indicating this but also the fact that there is a short supratemporal commissure lying in the extrascapular bone of the fish. This latter canal lies posterior to several rows of scales. On the dorsal surface of the parietal, beneath the line of pit organs, there is a well marked, depressed line, or groove, which indicates its course and position.

There thus seem to be, in Teleosts, two groups differing consi- derably from each other in the relative importance of the middle head line of pit organs and the supratemporal canal line. The bony and cartilaginous Ganoids may also be found to differ from each other in this same respect; and it is the cartilaginous Ganoids, and the Teleosts represented by Esox, that seem to present the conditions that most resemble those found in the Stegocephali, the only animals above fishes, so far as I can find, in which lateral sensory canals are de- scribed. The so-called canals in these latter animals may, however, be simply pit lines, similar to the supratemporal line in Esox, for, as already once stated above, Frirscu says of them that they are found as half cylindrical gutters on the external surface of the bones to which they are related, and that they increase in depth and distinct- ness with the age of the fish. If they be simply highly developed pit lines, as thus seems possible, the Stegocephali would not differ so radically, in this respect, from all other known Amphibia.

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In the Stegocephali, there are usually, as I understand FrirscH (No. 15), the only extensive work on the subject that I have at my disposal, two dermo-occipitals, or supraoccipitals, one on each side of the head; but these two bones may, according to Macer (No. 22), be found fused with each other to form a single median bone, or they may be fused with the epiotic bones, or with the parietals, or in still other combinations. In Tremotosaurus both the supraoccipitals and the epiotics are said by Baur (No. 6) to be traversed by a lateral canal which he considers as the homologue of the supra- temporal crosscommissures of both Amia and Polypterus. The main lateral canal on each side, in the Stegocephali, does not, however, seem to traverse the epiotic, as it does the assumed homologue of that bone im Amia and Polypterus, being interrupted by the external opening of the ear. Because of their relations to the commissural canal, the epiotic and supraoccipital bones of each side of the head of the Stegocephali are considered by Baur as the undoubted homologues of the three so-called supratemporal bones of Polypterus and of the single so-called extrascapular of Amia. The commissure in the Stegocephali may, however, as stated above, be the homologue of the commissural canals of the Characinidae and certain other Teleosts, and hence of the middle head line of pit organs of Esox, in which case the supposed homologies of the related bones would necessarily be greatly changed. All speculation regarding it is certainly useless until the complete distribution of the sensory lines, and their innervation, in the cartilaginous Ganoids and the Dipnoids, and perhaps also in living Amphibia, is definitely known.

Mager has recently attempted to establish the homologies of the bones here concerned by comparison with embryological conditions that he finds in man. In his preliminary communication (No. 20) and in his own résumé of his final work (No. 21), he refers to the supra- occipitals and epiotics of the Stegocephali as the retroparietals, and he says that they are represented in human embryos by four centres of ossification, from which may develop, in the adult, four distinct bones, the interparietals. In Polypterus the homologues of these so- called interparietal bones are said to be “les quatre plaques osseuses postérieures, en série transversale, de ce qu’on appelle bouclier osseux sus-occipital”, and these osseous plates are said to be shown by WIEDERSHEIM in what must be Figure 77, page 108, in the 1893 edition of his Grundriß. They there form a transverse series immediately posterior to the six supratemporal bones of TraqQuarr’s descriptions

of the fish, and are said by that author to be simply “proper scales 5*

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of the trunk”. Between the mesial bones of these two transverse series, there is a median rhomboidal plate, also considered by Tra- QUAIR as a proper scale of the trunk, but said by Macacı to be the homologue of the “préinterpariétal unique rhombique de VYhomme”. This latter bone in man is said by Maaai to arise by the fusion of four separate and distinct preinterparietal centres of ossification, which may, however, not fuse to form a single bone, but be found, in the adult man, fused with each other or with the neighbouring bones in various combinations. The single median bone of Polypterus can accordingly be assumed, according to Maaai, to be formed by the fusion of four ‘‘petites plaques osseuses correspondant aux préinter- paritaux de l’homme”. Between it and the four interparietals, behind, and the so-called parietals of the fish, in front, there are four bony plates in transverse line which Maccı calls the retroparietals or post- parietals, and of which he says, “c’est une série qui doit étre mor- phologiquement unie aux plaques parietales”. These four bony plates are the four mesial supratemporal bones of TRAQUATR’s descriptions, and they are said by Maaear to be represented in man by two centres of ossification found by him in the posterior part of each parietal; the anterior part of each parietal of man being represented, in Poly- pterus, by the so-called parietal bone of the fish. As the parietal of WIEDERSHEIM’S figure of Polypterus, to which alone Maaat refers, is the squamoso-parietal of VAN WIJHE, we thus have the parietal of man formed by the fusion of the true parietal, the dermo-squamosal, and two of the three supratemporal elements on each side of the skull of Polypterus. Still another bone, “l’os de l’obelion”, may also be fused with these several elements. The third supratemporal element of Polypterus, which, in WIEDERSHEIM’S figure, lies between the lateral halves of the lateral plates of the two transverse series, I can not definitely trace in the discussion. It may, however, be the fourth centre of ossification of the parietal, said by Macar to be sometimes found in man, and to be found in Rhinosaurus as an anterior epiotic bone. The homologue of the squamous part of the temporal bone of higher animals is found by him, in Polypterus, in the operculum, and in the Stegocephali in the so-called supratemporal bone of those animals. The “lamelles triangulaires ou lamelles latérales de Pozzi’, in man and certain other mammals, are said to be represented in Polypterus in scales that lie posterior to the interparietals of his descriptions; that is in the second row of scales posterior to the supratemporal bones.

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The supratemporal bones of Polypterus are thus not, according to Mager, the homologues of the epiotics and supraoccipitals of the Stegocephali, and the related sensory canals can not, accordingly, be homologous. As the canal in Polypterus lies, according to Maget’s determinations, morphologically anterior to the one in the Stegocephali, it would seem necessarily to become the homologue of the middle head line of pit organs in Amia, and not of the supratemporal cross- commissure of that fish. While this may be found to be the case, it certainly seems most improbable.

In very young sturgeons the interpanjetals of 1 man and of Poly- pterus are said by Maaer to be found as “quatre plaques osseuses rétropariétales également en série transversale, dont, chez les adultes, les médianes se fondent entre elles, tandis que les latérales restent distinctes”. The median plates are then said also to fuse with a median rhomboidal plate that lies anterior to them, and that is said to be formed by the fusion of two triangular plates found one on each side of the head of young larvae. Each of these two latter tri- angular plates is said to represent two of the four preinterparietal centers of ossification of man, and, hence, also a lateral half of the single, median, rhomboidal, preinterparietal plate of Polypterus. The fusion of these four distinct bones, or six centers of ossification, of the young sturgeon are said to give origin to the bone called by Hux ey in the adult fish, the supraoccipital. The lateral retroparietal plate, on each side of the head of the young sturgeon, becomes, so far as I can understand Maaat, the epiotic of HuxLey’s descriptions of the adult, and it and bone I of HuxLey are together the homologues of the lateral interparietals of man.

In the Stegocephali the interparietals of Maaai’s discussion are, as already stated, the four bones usually called the supraoccipitals and epiotics, and these bones are, accordingly, the homologues, not of the median four supratemporal bones of Polypterus, but of the four osseous plates that, lie transversely, posterior to those bones. The preinterparietals are said to be rarely found distinct in the Stego- cephali, the two anterior ones being almost always fused, each with that so-called parietal of the animal that lies immediately in front of it, and the two posterior ones fused with the interparietals. The so- called parietal of the animal is not, according to Maaat, the homologue of the parietal of Polypterus, but is the homologue of that bone of Polypterus fused with the mesial retroparietal or postparietal (supra- temporal) of the fish. The parietal of the Stegocephali is thus the

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homologue of two, and only two of the centres of ossification of the bone in man. The third centre of the bone of man, that is the lateral postparietal of Polypterus, is said to be found in the Stegocephali as a separate bone, the squamosal of ordinary terminology. The lateral one of the three posttemporal bones of TRAQuarR’s description of Polypterus would seem to be considered by Maccı as the homologue of the so-called posterior squamosal of the Stegocephali, when such a bone is found , as sometimes occurs. The so-called supratemporal bone of the Stegocephali is considered as the homologue of the squamous part of the temporal bone of man, and is hence, according to Maaai’s determination, the homologue of the operculum of Poly- pterus.

While my work certainly leads me to strongly doubt the correct- ness of many of the homologies here proposed by MAccı, I may perhaps state that it is not because of his pronounced belief that the cranial bones fuse and interfuse with each other in numerous com- binations. Gaupp thinks such fusions are much too lightly, and usually erroneously, assumed, and he says (No. 16, p. 84) that when- ever a particular bone seems missing in any particular anatomical region it should not be assumed that it has fused with neighbouring bones, unless that assumption is based on positive embryological evid- ence; when of course it is no longer an assumption. So far as the skull of fishes is concerned, with which I am alone familiar, anatomical evidence alone seems to me unquestionably often a good and sufficient basis for the assumption.

As to the incorporation of the extrascapular and suprascapular bones of fishes in the skull of mammals, I have always accepted, with- out personal investigation or consideration, SAGEMEHL’s several state- ments that they form part of the secondary shoulder girdle of the animal, and hence that they could not enter into the skull of higher animals.

Palais Carnoles, Menton, 12 April 1889.

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1) Auris, Epwarp Preres jr, The Anatomy and Development of the Lateral Line System in Amia calva. Journ. Morph., Vol. 2, No. 3, April 1889.

2) — — The Cranial Muscles and Cranial and First Spinal Nerves in Amia calva. Ibid., Vol. 12, No. 3, March 1897.

3) — —, The Morphology of the Petrosal Bone and of the Sphenoidal

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Region of the Skull of Amia calva. Zoöl. Bull, Vol. 1, No. 1, August 1897, p. 1—26. 4) Anus, Epwarp Puexps jr., The Homologies of the Occipital and First Spinal Nerves of Amia and Teleosts. Ibid., Vol. 2, No. 2, October 1898, p. 83—97.

5) — — A Reply to Certain of Cour’s Criticisms of my Work on Amia calva. Anat. Anz, Bd. 15, No. 19 u. 20, 24. Febr. 1899, p. 364—379.

6) Baur, G., The Stegocephali. Anat. Anz. Bd. 11, No. 22, 20, Marz 1896, p. 657—673.

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8) Coz, Frank J., On the Cranial Nerves of Chimaera monstrosa (Linn.) with a Discussion of the Lateral Line System and of the Morphology of the Chorda Tympani. Trans. Royal Soc. Edinburgh, Vol. 38, 1896, Part 3. (No. 19.)

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‘ October 1898.

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Proc. Birm. Phil. Soc., Vol. 8, Part 2, March 16, 1893, p. 255—262.

11) — — The Lateral Canal System of Lepidosteus osseus. Ibid., May 24, 1893, p. 263—273. 12) — — The Sensory Canal System of Fishes. Part 1: Ganoidei.

Quart. Journ. Micr. Sc., N. S. No. 144 (Vol. 36, Part 4), August 1894, p. 499—537.

13) — — On the Sensory Canal System of Fishes. Teleostei. Proc. Zool, Soc., London, 2 April 1895, p. 274—299.

14) Erpı, M. P., Beschreibung des Skeletes des Gymnarchus niloticus nebst Vergleichung mit Skeleten formverwandter Fische. Abhandl. d. math.-physik. Classe, Bd. 5, 1847, Abth. 1.

15) Fritsch, Ant., Fauna der Gaskohle u. d. Kalksteine der Permfor- mation Béhmens. Prag.

16) Gaupr, E., Beiträge zur Morphologie des Schädels. III. Zur ver- gleichenden Anatomie der Schläfengegend am knöchernen Wirbel- thierschädel. Morphol. Arb., Bd. 4, 1894, Heft 1, S. 77—128.

17) GEGENBAUR, Cart, Ueber das Kopfskelet von Alepocephalus rostratus Risso. Morphol. Jahrb., Bd. 4, Suppl. 1878, p. 1—42.

18) Huxrey, T. H., Preliminary Essay upon the Systematic Arrange- ment of the Fishes of the Devonian Epoch. Mem. Geol. Sur., Decade 10, London 1861.

19) — — A Manual of the Anatomy of Vertebrated Animals. New York, D. Appleton & Co., 1872.

20) Maceı, L., Résultats de recherches morphologiques sur des os et des fontanelles du crane humain. Arch. Ital. de Biol., T. 27, Fase. 2, 26 June 1897, p. 230—238.

21) — — Autres résultats de recherches morphologiques sur des os

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cräniens et cränio-faciaux et sur des fontanelles de homme et d’autres mammiferes. Ibid., T. 30, Fasc. 2, Dec. 1898, p. 161—171.

22) Macc, L., Placche osteodermiche interparietali degli Stegocephali e rispondenti centri di ossificazione interparietali dell’uomo. Rendic. R. Ist. Lomb. di Sc. e Lett., Ser. 2, Vol. 30, 1898, p. 1—38.

23) Mc Movrricu, J. PLayraır, The Osteology of Amiurus catus (L.) gill. Proc. Can. Inst., Vol. 2, No. 3, October 1884, p. 270—310.

24) Parker, Wm. K., On the Structure and Development of the Skull in the Salmon (Salmon salar L.). Phil. Trans., 1873, p. 95—145.

25) — — On the Development of the Skull in Lepidosteus osseus. Ibid., 1882.

26) Pottarp, H. B, On the Anatomy and Phylogenetic Position of Polypterus. Zool. Jahrb., Bd. 5, Heft 3/4, October 20, 1892, p. 525 —550.

27) SAGEMEHL, Max, Beiträge zur vergleichenden Anatomie der Fische. I. Das Cranium von Amia calva L. Morph. Jahrb., Bd. 9, 1883, Heft 2, p. 177—228.

28) — — Beiträge zur vergleichenden Anatomie der Fische. III. Das Cranium der Characiniden nebst allgemeinen Bemerkungen über die mit einem Weser’schen Apparat versehenen Physostomenfamilien. Ibid., Bd. 10, 1884, Heft 1, p. 1—119.

29) — — Beiträge zur vergleichenden Anatomie der Fische. IV. Das Cranium der Cyprinoiden. Ibid., Bd. 17, 1891, Heft 4, p. 489—595.

30) SCHMID-MoNNARD, CARL, Die Histogenese des Knochens der Teleostier. Zeitschr. f. wiss. Zool., Bd. 39, 1883.

31) Traquair, R. H, On the Asymmetry of the Pleuronectidae as elucidated by an Examination of the Skeleton in the Turbot, Halibut and Plaice. Trans. Linn. Soc, Vol. 21, 1865, p. 263 —296.

32) — — On the Cranial Osteology of Polypterus. Journ. Anat. and Phys., Ser. 2, No. 7, Nov. 1870, p. 166—182.

33) VROLIK, A. J., Studien über die Verknöcherung und die Knochen des Schädels der Teleostei. Niederl. Archiv f. Zool., Bd. 1, Heft 3, Juni 1873.

34) WIEDERSHEIM, R., Morphologische Studien. III. Das Skelet und Nervensystem von Lepidosiren annectens (Protopterus ang.). Jena 1880.

35) — -— Grundriss d. vergl. Anatomie d. Wirbeltiere. Jena 1893.

36) van Wine, J. W., Ueber das Visceralskelet und die Nerven des Kopfes der Ganoiden und von Ceratodus. Niederl. Archiv f. Zool., Bd. 5, Heft 3, Juli 1882, p. 207—320.

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Nachdruck verboten.

Die Entstehung der Luftsäcke bei den Kugelfischen. Von Dr. med. Orro Tuto in Riga. Mit 2 Tafeln.

Es bereitet uns keine erheblichen Schwierigkeiten, zu verstehen, wie an Tieren, welche durch Lungen atmen, Luftsicke in der Um- gebung der Lungen entstehen können.

Dieses Verständnis wird in hohem Grade erleichtert, durch jene „Luftgeschwülste‘“ (Emphyseme), welche als krankhafte Veränderungen an den Lungen der Menschen nur zu häufig vorkommen. Jeder Arzt hat es gesehen, wie nach Stichverletzungen der Lungen große An- sammlungen von Luft unter der Haut eintreten können, jeder Arzt weiß es, daß bei Verletzungen der Nasenhöhle sogar an den Augen- lidern bisweilen Luftgeschwülste sich bilden. Noch allgemeiner be- kannt sind jene „Lungenerweiterungen“, welche nach Asthma und auch als eine Alterserscheinung beim Menschen vorkommen. Sie weisen sehr nachdrücklich darauf hin, wie die Luftsäcke der Vögel, Reptilien und anderer Tiere entstanden sind.

Viel größere Schwierigkeiten bereitet es, zu verstehen, wie an Fischen Luftsäcke entstehen können, die nicht durch Lungen atmen. Diese scheinen uns doch nicht die Fähigkeit zu besitzen, größere Mengen von Luft in ihre Körperhöhlen aufzunehmen und zu verdichten. Bei ihnen können doch wohl nur ganz besonders zusammengesetzte Vorgänge zur Entwickelung jener ungeheuren Luftsäcke führen, die an den Kugelfischen sehr auffallen.

Diese Vorgänge wurden mir erst verständlich, als ich genauer den Körperbau und die Lebensverhältnisse der Kugelfische und ihrer nahen Verwandten untersuchte. Erst hierdurch entdeckte ich jene Ueber- gangsformen, welche die Entstehung der Luftsäcke an Fischen erklären. Ein Blick auf die beigefügten Abbildungen zeigt uns, daß ein Bauchsack an Triacanthus und Monacanthus granulosus (Fig. 1 u. 2) noch nicht vorkommt, daß jedoch an Monacanthus setifer und Monacanthus tros- sulus (Fig. 4 u. 5) schon die Anfänge jenes Bauchsackes bestehen, der bei Tetrodon (Fig. 6) so hochgradig entwickelt ist.

Als ich die Bauchhöhle von Triacanthus (Fig. 7) eröffnete, so be-

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merkte ich, daß der Träger der Bauchstacheln!) mit einem breiten Knochenfortsatz sich gegen den Schultergürtel stützt. Die Stützungs- verhältnisse der Träger von Stacheln habe ich eingehend in meiner Abhandlung „Die Umbildungen an den Gliedmaßen der Fische“ be- sprochen ?). Ich habe dort nachgewiesen, daß die Träger von Flossen mit weichen Strahlen bewegliche, knorpelhafte Gräten sind, welche zwischen Muskeln und Haut liegen. Werden jedoch die weichen Flossen- strahlen zu harten, knöchernen Stacheln umgebildet, so nehmen auch die Flossenträger an Härte und Umfang zu. Aus den schlanken, knorpelhaften Gräten werden breite, knöcherne Pfeiler, auf denen die Stacheln ruhen und sich gegen die Wirbelsäule oder andere feste Unterlagen stützen.

Beim Karpfen z. B. ist der Träger einer Bauchflosse nichts anderes als ein flacher, beweglicher Knochenstab, welcher zwischen Haut und Muskeln, parallel zur Wirbelsäule liegt.

Bei Triacanthus hingegen bemerkt man am Stachelträger einen breiten Knochenfortsatz, mit dem er sich gegen den Schultergürtel stützt. Aber auch diese Stützung ist offenbar nicht ausreichend und daher wird sie vervollständigt durch einen paarigen Hautknochen, welcher Stachelträger und Schultergürtel zu einem dreiteiligen Gerüste abschließt. (Fig. 7 Bauchknochen). Solche dreiteilige Gerüste gelten in der Baukunst als ganz besonders fest. Man kann es z. B. an Holzbauten bemerken, daß man bemüht ist, zwei unter einem Winkel an einander gefügte Balken durch einen dritten Balken (Strebe) zu einem Dreiecke abzuschließen. An den Knochengerüsten kann man solche „Verstrebungen“ vielfach bemerken und durch sie den Zweck vieler Knochen erklären, die bisher ganz unverständlich waren.

Bei Triacanthus also (Fig. 7) hat der Bauchknochen die Bedeutung einer Strebe.

Die Rückbildung derartiger Stützungsverhältnisse tritt ein, wenn ein Stachel zuriickgebildet wird, wie z. B. bei Monacanthus setifer (Fig. 8). Wir finden hier das dreiteilige Gerüst gelöst. Der Stachel- träger stützt sich nicht mehr gegen die Mitte des Schultergürtels, sondern gegen das untere Ende des Schultergiirtels. Er ist aus dem Innern des Fisches nach außen verschoben und so zu einem Haut- knochen geworden. Wir sehen also, die Rückbildung des Stachels hat eine Lösung der Stützungsverhältnisse bewirkt. Nur eins fällt auf.

1) Dieser Knochen wird in vielen anatomischen Werken als „Becken“ bezeichnet. Ich vermeide den Ausdruck, da, es mir nicht festzustehen scheint, daß er dem Becken anderer Wirbeltiere entspricht.

2) Morpholog. Jahrb., 1896, p. 330 u. 345.

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Obgleich der Stachel fast vollständig zurückgebildet ist, so hat doch sein Trager keine dem entsprechende Riickbildung erfahren. Der wagrechte Teil (S Fig. 7 u. 8) erscheint allerdings hochgradig ver- kleinert, aber der obere Teil des Trägers hat sogar eine Vergrößerung erfahren.

Diese Vergrößerung widerspricht unseren Beobachtungen bei Rück- bildungen von Gliedmaßen ; denn beim Schwund einer Gliedmaße pflegt auch der Träger derselben zu schwinden, jedenfalls sich nicht zu ver- größern.

Für diese auffallende Vergrößerung findet man eine Erklärung, wenn man eine größere Anzahl von Monacanthusarten untersucht. Man bemerkt dann, daß der Stachelträger eine bedeutende Beweglich- keit besitzt und daß auch Muskeln an ihm vorhanden sind, welche den Fisch befähigen, willkürlich den Stachelträger so zu drehen, daß der Teil S (Fig. 8) einen Kreisbogen beschreibt.

In Fig. 16 bemerkt man bei Monacanthus setifer nicht unbe- deutende Muskeln am Stachelträger (m u. m!.) Diese Muskeln sind paarig.

Die Beweglichkeit des Stachelträgers wurde von mir an mehreren Arten gemessen, die ich der großen Güte der Professoren KLUNZINGER und LÜTTKEN verdanke.

Am größten ist die Beweglichkeit bei dem zottigen Monacanthus penniciligerus (Fig. 3). Sie beträgt 45°. Der Fisch kann den Stachel so weit nach vorn drehen, daß er mit dem aufgerichteten Rückenstachel in eine gerade Linie zu liegen kommt (Fig. 3). Bei Monacanthus granu- losus (Fig. 2) beträgt die Beweglichkeit 30°, Monacanthus pardalis 20°, Balistes assasi 30°, Balistes ringens 15°. Sehr bedeutend muß sie bei Triodon sein, nach den Angaben GÜnTHEr’s!) zu urteilen. Leider habe ich von diesem seltenen Fische nur trockene Präparate gesehen.

Ebensowenig ist es mir gelungen, jene höchst interessanten Misch- formen von Triacanthus und Balistes zu untersuchen, welche in der Kreide vom Monte Bolca und Glaris vorkommen (Protobalistum, Acanthoderma, Acanthopleurus). Einige dieser Fische sollen zugleich an Triacanthus und an Balistes erinnern. Sie wären also gleichsam Sammelformen beider. Vergl. mein Litteraturverzeichnis 7, 8, 9.

Die Beweglichkeit des Stachelträgers und die ihn bewegenden Muskeln verhinderten offenbar seine Rückbildung, ja sie bewirkten sogar die Vergrößerung eines Teiles des Stachelträgers.

Der wagrechte Teil S hat seine Stützung verloren und ist deshalb

1) Günruer, Handbuch der Ichthyologie, p. 496.

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zurückgebildet. Der Teil S hatte außerdem noch einen anderen Zweck. An ihn legte sich der niedergelegte Stachel und wurde hierdurch ver- hindert, mit seiner Spitze den Fisch zu verletzen. Mit der Riick- bildung des Stachels wurde dieser Schutz unnötig. Die Längsfurche am Stachelträger von Monacanthus (Fig. 8) entspricht einer tiefen Rinne bei Triacanthus (Fig. 7). In dieser Furche, die paarig ist, ver- läuft der paarige Muskel, welcher den Stachel aufrichtet.

Wir sehen also, die Muskeln oder die Bewegungen haben sozusagen diesen Teil des Stachels erhalten.

Wozu dienen nun diese Bewegungen? Hierauf antwortet die Lebensweise des Monacanthus und seiner Verwandten.

KLUNZINGER !) berichtet uns, daß die Balistiden, zu denen ja auch der Monacanthus gehört, Klippfische sind. Wenn sie verfolgt werden, ziehen sie sich in ihre Schlupfwinkel, enge Felsspalten, zurück, aus denen sie schwer hervorzuziehen sind, da sie sich mit ihrem Rücken- stachel gegen die Decke der Spalten stützen. Für den Aufenthalt in engen Felsspalten ist der flache Körper des Monacanthus ganz besonders geeignet. Das Schwimmen in sehr engen Spalten ist kaum möglich. Der Fisch kann sich nur mit Hilfe seines stacheligen Schwanzes, mit dem Rückenstachel und Bauchstachel vorwärts und rückwärts schieben. Beide Stachel müssen jedoch kurz sein wie die Beine eines Dachses. Besonders günstig für das Vorwärtsschieben in engen Gängen ist der bewegliche Stachelträger mit dem kurzen rauhen Stachel. Er bietet auch die Möglichkeit, den Umfang des Körpers beim Durchschlüpfen zu verringern. Bei den hierzu erforderlichen Bewegungen wird die Bauchhöhle bald erweitert, bald verengert und so ein Hohlraum ge- schaffen, in dem Luft ein- und austreten kann. Die Aufnahme von Luft ist für den Monacanthus besonders wichtig, da in den engen Spalten oft nur wenig Wasser vorhanden sein kann und der Sauerstoff in demselben bald verbraucht wird. Hat sich der Fisch mit Luft ge- füllt, so braucht er nur immer ganz kleine Mengen von Luft in die wassergefüllte Kiemenhöhle streichen zu lassen. Er kann dann leben wie in lufthaltigem Wasser. Diese Art der Atmung wird dem Mon- acanthus ganz besonders durch seine engen Kiemenspalten erleichtert. Ja man kann sogar sagen, ein Monacanthus ist nicht im Stande, so zu atmen wie z. B. ein Hecht, welcher seine weiten Kiemenspalten öffnet und lufthaltiges Wasser durchstreichen läßt.

Die Füllung des Magens mit Luft geht bei Monacanthus um so besser von Statten, als seine Bauchhöhle nicht so beengt wird durch

1) Kıunzınger, Synopsis der Fische des Roten Meeres, p. 629.

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Teile des Knochengerüstes, wie z. B. bei Triacanthus. Wir haben gesehen, daß bei dieser Fischart der Träger des Bauchstachels weit in die Bauchhöhle hineinragt und unbeweglich fest am Schultergürtel haftet (Fig. 7). Der Schultergürtel ist wiederum mit dem Schädel verwachsen. Bei Monacanthus hingegen liegt der Stachelträger — wie erwähnt — außerhalb der Bauchhöhle unter der Haut und ist sehr beweglich. Außerdem wird seine Bauchhöhle von Rippen fast gar nicht umschlossen. Seine Rippen sind geradezu verkümmert. Ich fand an einem Monacanthus von 25 cm Länge 7 Rippen, von denen die längste 1,5 cm lang war, an einem Balistes vetula von 31 cm Länge 6 Rippen, die längste 2,5 cm lang. Auch an Triacanthus sind die Rippen ebenso verkümmert. Ich finde an ihm nur 6 Rippen, welche dieselben Längen- verhältnisse zeigen wie bei Monacanthns und Balistes.

Da bei Monacanthus der Stachelträger aus der Bauchhöhle ver- schoben ist und schon bei Triacanthus die Rippen verkümmert sind, so besitzt die ganze Bauchhöhle eine bedeutende Dehnbarkeit, und man bemerkt in Fig. 11, 12 und 13, daß der Magen von Monacanthus im Vergleich zu Triacanthus sehr bedeutend erweitert ist. Triacanthus hat einen kurzen, nur wenig gewundenen Darm, welcher vom Schlund bis After überall fast ganz gleich breit ist. Er erinnert an den Darm eines Schlammpeitzgers (Cobitis fossilis). Nur ist bei Cobitis der Darm viel dickwandiger. Cobitis ist als ein Fisch bekannt, der größere Mengen von Luft in den Darm aufnehmen und durch den After mit sroßem Geräusche entweichen lassen kann!). Bei ihm können sich trotzdem keine luftsackartigen Erweiterungen des Darmes bilden, weil die Bauchhöhle vollständig von Rippen umschlossen ist. Ich zähle an einem Cobitis fossilis gegen 30 Rippen, welche einander in der Mittellinie des Bauches berühren.

Bei Triacanthus wären stark entwickelte Rippen ganz zwecklos. Nach unten schließt der Bauchstachelträger die Bauchhöhle ab, seitlich jederseits ein starker, breiter Hautknochen, welcher das obere Ende des Schultergürtels mit dem Bauchstachelträger vereinigt (Fig. 7 Bauch- knochen) ?). Diese Bauchknochen ersetzen dem Triacanthus sozusagen seine Rippen und bilden einen starrwandigen Hohlraum, welcher hoch- gradige Erweiterungen durch Luft ausschließt. Bei Monacanthus setifer sind die starren Wände gelöst, und wir finden einen bedeutend ver-

1) Breum’s Tierleben, Bd. Fische, p. 300.

2) Dieser Knochen führt in der Litteratur viele Namen, z. B. Post- clavicula, Epicoracoideum u. dergl. Vielleicht wird der neutrale Namen „Bauchmuskelknochen“ dauerhafter seien als die bisherigen. Für die Abbildungen wählte ich die kurze Bezeichnung „Bauchknochen“.

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größerten Magen (Fig. 12). An Monacanthus trossulus ist der Magen noch mehr vergrößert (Fig. 13).

Wir bemerken aber auch, daß an dieser Fischart der Träger des Bauchstachels zu einem dünnen Knochenstabe rückgebildet ist (Fig. 9). Der Teil S (Fig. 7 u. 8) fehlt an ihm vollständig. Gänzlich ge- schwunden ist der ganze Bauchstachelträger bei Tetrodon, und an dieser Fischart hat der ganze Bauchsack eine so große Ausdehnung erlangt, daß der Name Kugelfisch für Tetrodon wohl höchst passend ist.

Wir sehen also, der Bauchstachelträger ist geschwunden, nachdem er so wesentlich zur Erweiterung der Bauchhöhle beigetragen hat. Die Bauchhöhle kann ohne ihn aufgeblasen werden wie ein Handschuh, den man aufblasen kann, weil er mit dem Handschuhausweiter ge- dehnt wurde.

Ganz besonders auffallend ist bei Monac. tross. (Fig. 13) die Lage des Pförtners. Er liegt an der vorderen Wand des Magens und erscheint somit nicht als sehr geeignet für Entleerungen des Magens in den Darm hinein. Aber gerade diese Lage deutet auf die Ent- stehung der Magenerweiterung hin. Bläst man den Magen von Monac. setifer auf (Fig. 12), so bemerkt man, daß hauptsächlich die hintere Wand sich aussackt, jedenfalls wohl, weil die Kopfknochen eine Aus- sackung nach vorn verhindern. Eine Vergrößerung dieser hinteren Aussackung führt zur Magenform von Monac. tross. (Fig. 13). Be- günstigt wird die hintere Aussackung durch die Lage des Pförtners an der vorderen Magenwand; denn infolge dieser Lage wird der Darm abgeknickt und so der Austritt von Luft erschwert. Aber auch die hintere Aussackung stößt schließlich auf Hindernisse.

Es ist wohl hauptsächlich die stark entwickelte Schwimmblase aller Haftkiefer, welche hier Erweiterungen unmöglich macht. In- folgedessen erfolgt dann die Aussackung nach unten oder vorn. Hier stößt sie auf einen geringen Widerstand, da der Bauchstachelträger schon bei Monacanthus trossulus (Fig. 9) zu einem schmächtigen Knochenstäbchen zurückgebildet ist.

Bei Tetrodon fehlt er gänzlich, und somit ist hier jede Schranke fortgeräumt. Durch die Aussackung der vorderen Magenwand bei Tetrodon wird der Pförtner nach hinten gedrängt (Fig. 14). Der Austritt von Luft in den Darm wird verhindert durch eine ringförmige Klappe am Pförtner.

Wir haben gesehen, daß an den Haftkiefern bei fortschreitender Erweiterung des Luftsackes ein allmählicher Schwund des Bauch- stachelträgers eintritt (Fig. 8 u. 9). Gleichzeitig mit dem Schwunde dieses Knochens bemerken wir die Vergrößerung eines anderen Knochens.

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Wir finden schon an Triacanthus den mittleren Kiemenhautstrahl breiter und länger als die übrigen (Fig. 7 X). Noch größer ist er bei Mon- acanthus setifer und trossulus (Fig. 8 u. 9 K). Bei Tetrodon jedoch bildet er eine breite, dreieckige Platte. Sie wird vom Fische dazu benutzt, die Kiemenhöhle zu erweitern und zu verengern, und so Luft in den Magen zu pumpen. Zu diesem Zwecke ist sie mit besonders kraftigen Muskeln versorgt. Ein Muskel entspringt von der Außenseite der Platte X und setzt sich an den vorderen Teil des Zungenbeines. Er dient zum Erweitern der Kiemenhöhle. Ihm entgegengesetzt wirkt ein Muskel, der von der Innenfläche der Platte X entspringt und gleichfalls zum Zungenbein hinzieht. Er drückt die Platte K gegen die Kiemenhöhle. Vervollständigt wird dieser Druck durch einen Muskel, der quer über beide dreieckige Platten X verläuft. Er verbindet den unteren Rand des rechten Kiemendeckels mit dem linken. Zur Verengerung der Kiemenhöhle tragen auch Muskeln bei, welche von der Innenseite die Kiemendeckel zu der Platte K nach unten ziehen. An den Kiemenbögen selbst findet man nur Muskeln, welche von der unteren äußeren Fläche des Kiemenkorbes entspringen und an die Innenfläche der Kiemendeckel sich setzen. Sie erweitern die Kiemen- höhle.

Der Rücktritt der Luft aus dem Magen in die Kiemenhöhle wird verhindert durch ringförmige Muskeln, welche den Schlund um- schließen, gleich unterhalb des letzten Kiemenbogens. Man sieht also, daß dieser Verschluß durch Muskeln bewirkt wird, während der Ver- schluß am Pförtner, wie erwähnt, selbstthätig durch eine Klappe er- folgt. Genau entsprechend diesen anatomischen Verhältnissen schreibt KLUNZINGER, daß er trotz seines vieljährigen Aufenthaltes am Roten Meere nie einen toten Tetrodon im aufgeblasenen Zustande fand. Ganz selbstverständlich kommen hier nicht jene Tetrodon in Betracht, welche ich selbst so häufig am Nil im aufgeblasenen und getrockneten Zustande zum Verkauf ausbieten sah. Diese werden nach dem Tode von den Fischern aufgeblasen und so dadurch erhalten, daß man ihnen den Rachen zustopft.

Die kräftig entwickelten Muskeln des Kiefergerüstes deuten darauf hin, daß viel Kraft zur Füllung des Bauchsackes erforderlich ist. Hierauf weisen auch die Angaben zuverlässiger Beobachter hin. Unter anderen teilte mir KLUNZINGER mit, daß er es oft gesehen habe, wie der Tetrodon seinen großen Luftsack in etwa einer Minute füllt. Wenn man die Größe des Bauchsackes mit der Kleinheit der Kieferhöhle ver- gleicht, so erscheint mir eine Minute als eine sehr kurze Zeitdauer.

Die Größe des Bauchsackes bestimmte ich an einem 8 cm langen

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Tetrodon hispidus. Ich führte ein dünnes Rohr, welches an einem Gummischlauche befestigt war, in den Rachen und füllte den Bauch- sack mit Wasser. Das eingeströmte Wasser entleerte ich aus dem Bauchsacke in ein Maßglas. Ich fand 100 ccm.

Die Größe der Kiemenhöhle konnte ich durch Einführen meines fünften Fingers bestimmen. Das erste Glied des fünften Fingers konnte ich von der Bauchhöhle aus knapp in die Kiemenhöhle schieben. Die Größe dieses ersten Gliedes berechnete ich auf 3 ccm. Also

Inhalt des Bauchsackes = 100 ccm

Inhalt der Kiemenhöhle = 3 ccm 100 237 —= 33.

Demnach ist die Kiemenhöhle 33 mal in der Bauchhöhle enthalten, und es sind mindestens 33 Druckbewegungen der Kiemenhöhle erforder- lich, um den Bauchsack in einer Minute mit Luft zu füllen.

Erwägt man, daß die Größe des Rumpfes bei einem 8 cm langen Tetrodon etwa 30 ccm beträgt, so erkennt man, daß durch die Auf- nahme von 100 ccm Luft der Fisch sich in einer Minute um das Dreifache seines Umfanges vergrößern kann. Ich hielt diese Leistung nur dann für möglich, wenn der Tetrodon beim Einpumpen der Luft keine großen Widerstände beim Ausdehnen des Bauchsackes zu über- winden hat, ja ich überlegte sogar, ob er nicht im Stande ist, einen luftleeren Raum zu erzeugen, welcher die Luft in ähnlicher Weise aufsaugt wie der erweiterte Brustkorb des Menschen beim Einatmen.

Bei genauerer Untersuchung der Bauchmuskeln des Kugelfisches fand ich denn auch eine Vorrichtung, welche ihn befähigt, wenigstens einen Teil der 100 ccm aufzusaugen.

Die Bauchmuskeln eines Kugelfisches sind sehr hochgradig ent- wickelt. Das fällt besonders auf, wenn man einen Kugelfisch mit Triacanthus vergleicht (Fig. 17 u. 15). Schon oben wurde darauf hingewiesen, daß bei Triacanthus die Rippen durch einen langen, breiten Hautknochen ersetzt werden. Dieser Knochen liegt unmittelbar auf einer Sehnenhaut (Fasc. transversa), und nur sehr spärliche Muskeln entspringen von ihm, da er ja als Stützknochen nicht bewegt wird (Fig. 15).

Bei Monacanth. setif. (Fig. 16) ist der Bauchknochen vollständig von Muskeln umschlossen. In noch höherem Grade geschieht dieses beim Kugelfisch. Zwei breite, dicke Muskeln entspringen von ihm (Fig. 17 M,, M;). Der vordere (M,) setzt sich an das untere Ende des Schultergürtels, der hintere (M,) an den Träger der Afterflosse. Diese beiden kräftigen Muskeln deuten auf eine große Beweglichkeit des

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Bauchknochens hin, und allerdings kann der Kugelfisch mit der unteren Spitze des Bauchknochens einen Bogen von nahezu 90° beschreiben. Er kann also seine beiden Bauchknochen sozusagen wie einen Regen- schirm aufklappen und so einen großen Hohlraum erzeugen. Die Größe des Hohlraumes ermißt man leicht, wenn man erwägt, daß jeder Bauchknochen !/, der gesamten Körperlänge des Fisches hat. Der obenerwähnte Tetrodon hispidus wird wohl seine 100 ccm Luft nicht ausschließlich mit diesem Hohlraum aufsaugen, wohl aber einen großen Teil derselben. Den Rest wird er wohl durch seine Druckpumpe — die Kiemenhöhle ergänzen. Beim Füllen des Luftsackes wird wohl haupt- sächlich der vordere Muskel (M,) thätig sein, beim Entleeren der hintere (M,). Doch reicht wohl M, zur vollständigen Entleerung nicht aus.

Mögıus !) beobachtete auf der Insel Mauritius, „daß ein aufge- blähter Tetrod. nigropunctatus plötzlich Luft aus dem Munde treten ließ. Der Bauch sank ein, aber die Seiten des Kopfes blieben noch aufgebläht ; die Spitze des Mundes ragte aus dem Wasser hervor, und der Fisch sah aus, als hätte er angefüllte Backentaschen“. |

Diese Erscheinung erkläre ich folgendermaßen. Die hinteren Bauchmuskeln (M?) klappen die beiden Bauchstacheln herunter. Hier- durch wird der hintere Teil des Bauchsackes entleert. Der vordere Teil erhält sich als „Backentaschen“. Zum Entleeren des vorderen Teiles dient ein großer Hautmuskel, welcher den ganzen Fisch um- schließt. Fig. 17 zeigt den Hautmuskel durchschnitten und auseinander- geschlagen. Besonders auffallend ist ein langer, paariger Muskel (Fig. 17 m), welcher vom untersten Teile des Schultergürtels entspringt und in den großen Hautmuskel übergeht. Die Wirkung dieses Muskels trägt wohl sehr wesentlich zur Entleerung des Luftsackes bei. Zieht man an diesem Muskel, so wird das untere Ende des Schultergürtels nach hinten und unten gezogen. Der Schultergürtel ist aber durch Muskeln mit dem Zungenbeine verbunden (s. Fig. 16 M,). Es wird also auch das Zungenbein nach unten und hinten gezogen, wenn man den Schultergürtel nach unten und hinten zieht. Hierdurch wird die