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nervous structures of in frog, 93. * Paramecium, behavior of, 441. Paraphysis, development of in fowl, 369. PARKER, G. H. The phototropism of the mourning cloak butterfly, 291. *PEARL, R. On the behavior and reactions of Limulus, 138. Pecten, eye of, 292. *Perception, of space in tortoises, 17. Periplaneta, nervous cytology of, 287. Phototropism, of butterfly, 291.
of Daphnia pulex, 289.
in man, 376. Physiology, of the nervous system, 364.
comparative method in, 271.
and psychology, 511. PIPER, H. Electro-motor changes in the retina of Eledone, 434. POLICE, G. Nervous system of scorpion, 37'. PORTER, J. P. Preliminary study of psychology of the English sparrow, 439. * PRENTISS, C. W. The nervous structures in the palate of the frog, 93. * Psychology, comparative, 360.
and physiology, 511. Ra
aces, encephalic anatomy of, 369.
*RANSON, S. W. Degeneration in corpus callosum of white rat, 381. *Rat, degeneration in the corpus callosum of, 381.
form and contents of nucleus in the spinal cord of, 27.
psychology and growth of nervous system of, 70. Rate of impulse, in sensory nerves, 206.
in hagfish, 204.
of Limulus, 138.
social, in animals, 118.
alamander, habits of, 380.
SARGENT, P. E. The torus longitudinalis of the teleost brain, 289.
a new cranial nerve in, 281. *Senses, of guinea pig, 293.
lateral line in Torpedo, 368.
W. M. Natural history of some nudibranchs, 440.
Sound, subjective sensations of, 207.
nerves, medullated fibers, 209.
nerves in selachians, 285. SPITZKA, E. A. The encephalic anatomy of the races, 369. Staining, vital, in Corethra, 368. Statistical methods, in psychology, 76. STREETER, G. L, Anatomy of the floor of the fourth ventricle, 369. *Structure and function as correlative concepts, 63. STUART, T. P. A. Mechanism of accommodation of the eye for distance, 378. *Swine, olfactory nerve in, 390. THORNDIKE, E... Educational psychology, 76, Tortoises, degeneration of fibers in brain of, 203.
--, space perception of, 17.
V anessa antiopa, phototropism of, 291.
Ventricle, fourth, 369.
Some unemphasized aspects of comparative psychology, 360.
Structure and function as correlative concepts, 63.
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and Quix, F. H. Sensitiveness of the human ear to tones, 378.
Comparative Neurology and Psychology
THE RELATION OFMAHEA. MOFOK
THE MUSCLE OF THE FROG, TO NEIGH
GORDON (From the Hull Anatomical Laboratory of the University of Chicago.)
With Plates I and II.
It is obviously a matter of some importance in the study of the relation of nerve excitability to muscle contraction, to determine the manner in which the peripheral part of the neurone is related to the muscle fiber.
Nor has it been neglected; it has long been a favorite subject for investigation and a prolific field for speculation and debate. At the present time renewed attention is being called to it by the recent works of of Apáthy, RUFFINI, GRABOWER and others. In these writings special emphasis is being laid on the presence of fine fibrillae, called by RUFFINI ultra-terminal fibrillae, which are projected from nerve endings to various neighboring parts.
From an historical standpoint it is extremely interesting to compare the results of KÜHNE with those of RUFFINI, DOGIEL, HUBER, SIHLER and others, and to observe that as methods and technique improve, a corresponding complexity can be shown in the relation of nerve to muscle. This is well exemplified in the ending of the motor neurone on the frog's muscle. As regards this animal one must acknowledge that the remarks of Apáthy on nerve endings in invertebrate muscles are not inappropriate :
“Wenn ich auch hier und da schlechthin von Nervenendigungen spreche, •so will ich doch gleich hier von vorn herein betonon, dass ich eine Endigung der leitenden Primitivfibrillen nirgends mit Sicherheit constatiren konnte; ich kann nur sagen, bis wie weit ich eine leitende
Primitiv fibrille, oft wohl bereits Elementarfibrille, an einer bestimmten Stelle meiner Präparate zu verfolgen im Stande bin.” 1
In 1877 GERLACH described the nerve endings of the frog as branching dichotomously to form an intravaginal network which runs through the contractile substance of the muscle fiber in close relation to, if not in actual continuity with, the contractile fibrillae. He appears to have been influenced in his deductions by the fact that in staining with gold chloride, he obtained reactions from certain elements of the sarcous substance which were similar to those obtained in nerve endings. In 1889 he repeated these investigations with methylene blue, and claimed that this method substantiated his previous views. Subsequent research by others has not confirmed his results nor upheld his deductions; nor can his own drawings be said to support the claims he attempted to establish. To one conversant with intra-vitam staining with methylene blue, it will appear a very doubtful procedure to base results on the similarity of staining reactions. By this intra-vitam method one constantly sees fine blue-stained fibers in the intermuscular connective tissue which, taken alone, might simulate nerve fibrillae. At times one observes beautifully stained examples of myofibrillae either as very fine closely-arranged points or as continuous structures. On this ground alone, therefore, it is obvious that it would not be possible to deduce a nervous plexus either within or without the muscle-cell. In addition, there must be present an undoubted continuity of structure with an unmistakable nerve fiber, together with any characteristic appearance which one is accustomed to find in corresponding terminals.
In 1896 APÁTHY drew attention to the manner in which the axis cylinder divides in invertebrate muscle fibers. He describes the primitive fiber as entering the muscle cell and there dividing into fine fibrillae (primary fibrils). These, however, do not form a plexus but either send comparatively thick branches (secondary fibrils) to adjacent muscle-cells there to form terminations from which it may be that further branches
1 Mitheil. a. d. Zoolog. Station zu Neapel., Bd. XII, 1896, p. 505.
(tertiary fibrils) may proceed to other muscle cells; or they divide repeatedly into ever finer fibrils till ultimately perhaps, elementary fibrillae result.
He often saw very
fine nerve fibrillae pass out of a muscle cell into the neighboring connective tissue and it might be, branch there. As to the ultimate fate of the finest fibrillae he is uncertain, but he declares: "Es kommt mir an wahrscheinlichsten vor, das sie mit anderen ähnlichen ein intermuskulares Elementargitter bilden.” 1
The results of Apáthy led RUFFINI in 1900 to re-examine nerve endings in the human muscle which he had stained by his chloride of gold method. Here he found in some of his specimens fine fibers which he had not previously noted and which he now described under the name of ultra-terminal fibrillae. These are very fine, non-medullated fibrillae which pass out from the motor end-plate. This fibrilla" (ultraterminal), he says, “after an unbranched course, more or less long, may terminate in the same muscular fiber on which rests the plate from which it is derived, or, as is often the case, put itself into relation with one of the neighboring striated fibers. From it collaterals may at times come off.” It may end in a swelling or in a second small plate (plaquette); in one case from a plaquette another fibre was seen to pass out, but its course could not be followed. Summing up the results of his examination, he says: “The motor plates in man do not represent the true and real terminations of motor nerves, because beyond the plate there exists a well demonstrable anatomical continuity shown by non-myelinated nerve fibrillae of which we do not know the last relations. This is obviously a statement very closely akin to that given by Apáthy in the summing up of his results.
Later PERONCITO, working with Ruffini and using his gold chloride method, describes in Lacerta muralis and Lacerta viridis the ultraterminal fibrilla as separating itself from the
1 Ibid., p. 695. ? RUFFINI: Sulle fibrille nervose ultraterminale nelle piastre motrici dell'
Rivista di pat. nerv. e ment., 1900, V. 5.