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Throughout the organic realm a correlation of structure and function is demanded. It is our aim, in The Journal of Comparative Neurology and Psychology, to bring together anatomical, physiological and psychological facts in such a manner that their relations may appear. Thus, it is hoped, the specialists in structural work will be impressed by the importance of the functions of the organs which they study, while at the same time those whose chief concern is animal behavior will see more clearly that they cannot work to advantage unless they know what is functioning. If we are to understand life we must consider the organism not as a structural unit, nor yet as a sum of activities, but as a functioning structure.
R. M. YERKES.
THE MID-WINTER MEETINGS.
Though abstracts of the proceedings of most of the societies which met during convocation week have already been published, it may be of interest to enumerate in a single list the more important papers read which bear upon our problems, as an aid to the annual invoice of scientific achievement which one naturally makes at this time of year.
At St. Louis the zoological section of the American Association and the Central Branch of the American Society of Zoologists held joint sessions at which the following papers of neurological interest were read:
Further Observations on the Breeding Habits and on the Functions of the Pearl Organs in Several Species of Eventognathi, by JACOB REICHARD. The breeding habits of certain shiners and suckers were described and illustrated by instantaneous photographs. Phototaxis in Ranatra, by S. J. HOLMES. Ranatra is positively
, phototactic and a great variety of reactions can be produced at will with mechanical precision.
The Correlation of Brain IVeight with Other Characters, by RAYMOND PEARL. A statistical review of the data for the human brain.
The Morphology of the Vertebrate Head from the Vien-point of the Functional Divisions of the Nervous System, by J. B. JOHNSTON. This paper
appear in full in this Journal in the course of the current year.
The Brain and Nerve Cord of Placobdella pediculata, by E. E. HEMINGWAY. Wax models of the nervous system of this new leech were presented. The results in general confirm those of WHITMAN for Clepsine.
The Mechanism of Feeding and Breathing in the Lamprey, by JEAN DAWSON. The anatomical work was controlled by observations on the living animals which add to our knowledge of the habits of the species, notably the fact that the lamprey feeds on the soft tissues as well as the blood of its host.
Some Reactions of Mnemiopsis leidyi, by G. W. HUNTER. This paper will be published in this Journal.
A Theory of the Histogenesis, Constitution and Physiological State of Peripheral Nerve, by PORTER E. SARGENT. To be printed shortly in full in this Journal.
The Association of American Anatomists met in Philadelphia. There were five neurological papers, aside from the memoir by Dr. Wilson which appears in our present issue.
On the Origin and Destination of Fibers of the Occipito-temporopontine Bundle (Türck's Bundle, Meynert), by E. Lindon MELLUS. In a circumscribed experimental lesion of the cortex of the temporal lobe in the monkey, involving the first and second temporal convolutions projection fibers degenerated, passing by way of the sublenticular segment of the internal capsule to the pes pedunculi, where they occupy the external fifth (occipito-temporo-Brückenbahn, FLECHSIG ; sensory tract, CHARCOT and others). To reach the pes these fibers break through the inferior portion of the lenticular nucleus in small bundles, pass around the external geniculate body just above the point of exit of the optic tract and enter the pes external to those fibers which form the posterior extremity of the internal capsule as it passes between the thalamus and the lenticular nucleus. Instead of turning downward toward the pons, like the capsular fibers, they pursue a course obliquely backward and slightly downward and, after a very short course in the pes, disappear, apparently passing to the anterior quadrigeminal body.
The Brains of Three Brothers, by Edw. ANTHONY SPITZKA. Opportunities for demonstrating the influence of heredity in the configuration of the human brain are exceedingly rare; adult material of this kind has only once before been described and by the same writer before this Association three years ago in the case of the brains of the two distinguished physicians SEGUIN, father and son. be remembered that in the SEGUIN brains there were found some notable resemblances which could be attributed to hereditary transmission. The writer again had the good fortune to test the question of encephalic morphological transmission in the brains of three brothers recently executed together in New York State. In the search for positive evidences of hereditary resemblance, only such parts of the cerebrum as are subject to great range of variation in different brains could be depended upon to support the proposition; it was found, in fact, that peculiarities of anatomical configuration of this class, uncommon enough in the general run of brains as they come to the
It may hands of anátomists, were similarly reproduced in the three brains. Illustrations were given.
The Bimeric Distribution of the Spinal Nerves in Elasmobranchii and Urodela, by CHARLES R. BARDEEN. In those vertebrates in which a definite metameric segmentation is maintained in the body wall, both the cutaneous and the motor nerves of each segment reach their distribution through the myoseptum and supply structures both cephalad and caudad to their septum. Occasionally a single motor nerve fiber may be seen dividing and sending one branch to the myotom anterior to the septum and the other to the myotom posterior. Attention is called to the difficulty of reconciling these facts with a strict adherence to an extreme form of the neuro-muscular theory such as is maintained by some morphologists.
A Description of the Gross Anatomy of the Adult Human Brain, by BERN BUDD GALLAUDET. The description was confined to the thalmus and was based on forty adult brains.
On the program of the Eastern Branch of the American Society of Zoologists, meeting at Philadelphia, the following titles, among others, were announced :
The Physiology of the Lateral Line Organs in Fishes, by G. H. PARKER. To appear in abstract in this Journal and in full in the Bulletin of the U. S. Fish Commission.
A Pair of Giant Nerze Cells of the Squid, by LEONARD W. Wil
The Nervous System of Lamellibranchs, by GILMAN A. DREW.
The Origin and Function of the Medullary Sheaths of Nerve Fibers, by PORTER E. SARGENT. To appear in full in this Journal.
The Relation of the Size of Nerve Elements and Their Constituent Parts to Structural and Functional Conditions, by PORTER E. SARGENT.
At the Philadelphia meeting of the American Physiological Society the following papers, of special interest to neurologists, were read:
The Survival of Irritability in Mammalian Nerves after Removal from the Body, by W. D. CUTTER and P. K. GILMAN. Making use of the fact noted by other observers that the mammalian nerve retains its irritability for some time after removal from the body, the authors attempted to determine the duration of this survival, the variations in irritability during the period of survival, and, lastly, the effect of prolonged anæsthesia upon the phenomenon. Irritability was determined by measuring the action current of the nerve when
stimulated by a series of induction shocks. The experiments were made upon dogs, and the sciatics of both legs were taken for observation. One sciatic was removed as soon as the animal was anæsthetized sufficiently for the operation. The nerve was placed at once in the moist chamber, and its action current was determined at intervals of half an hour, as long as a response could be obtained to stimulation. With the values of these action currents as ordinates, a curve was constructed, showing the duration and variations of irritability in the "unanästhetized nerve” during the period of observation. The other sciatic was left in the animal for a period of four to six hours, and during this time the animal was kept completely anæsthetized by morphia and ether. At the end of this period, there was a considerable fall in rectal temperature (300-31° C.). The anæsthetized nerve was then removed, and galvanometric observations were made similar to those just described. The results obtained show that the nerve removed from the anæsthetized and cooled) animal survives for a longer period than that taken from the animal at the beginning of the period of anæsthesia, the difference in time of survival being as much as four or five hours. A more marked difference, however, is that the “anästhetized" nerve exhibits throughout a much greater irritability. The curves obtained were irregular; but that for the “unanästhetized” nerve shows a small increase in irritability occuring shortly after the excision, and soon followed by a steady decline to zero; while that for the “anæsthetized ” nerve exhibits, as its most marked feature, a large and sudden increase in irritability coming on some hours after the excision, and followed by a more rapid fall to zero.
The Condition of the Vasoconstrictor Neurones in “Shock,” by W. T. PORTER and W. C. QUINBY. The normal fall of blood-pressure produced by stimuli of uniform intensity applied to the central end of the depressor nerve was measured in the rabbit and the cat. In the same animals the shock was then brought on, and the measurements repeated. The experiments make clear (1) that the normal percentage fall in blood-pressure may be obtained by stimulating the depressor nerve during shock; (2) if during shock the blood-pressure be raised to normal values by the injection of suprarenal extract or normal saline solution, and the depressor nerve be stimulated while the pressure is still high, the absolute fall in blood-pressure may be as great as it was in the same animal before shock began. Exhaustion of the vaso-constrictor neurones cannot therefore be the essential cause of the symptoms termed shock.
Demonstration of Rabbit's Nerres, Showing the Effect of Ligation