Physiological Evidence of the Fluidity of the Conducting Substance in the Pedal Nerves of the Slug-Ariolimax columbianus. By O. P. JENKINS and A. J. CARLSON. From the Physiological Laboratory of Leland Stanford, Jr., University. With one figure. The Nervous Structures in the Palate of the Frog: the Peripheral Networks and the Nature of their Cells and Fibers. By C. W. PRENTISS, Instructor of Biology, Western Reserve University. With 12 figures. The Beginnings of Social Reaction in Man and Lower Animals. On the Behavior and Reactions of Limulus in Early Stages of its Editorial. 85 93 118 124 138 165 Recent Studies on the Finer Structure of the Nerve Cell. By 203 THE JOURNAL OF COMPARATIVE NEUROLOGY AND PSYCHOLOGY is published bi-monthly. The annual volume of numbers comprises about 500 pages, with plates and text-figures. The subscription price is $4.00 a year, strictly net (foreign subscription, $4.30, 18 s., M. 18, 22 fr., L. 22), postage prepaid. 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LLOYD MORGAN, University College, Bristol Published bi-monthly DENISON UNIVERSITY, GRANVILLE, OHIO A Monthly Journal Devoted to the Natural Sciences Since its foundation in 1867 by four of the pupils of Louis Agassiz, THE AMERICAN NATURALIST has been a representative American magazine of Natural History and has played an important part in the advancement of science in this country. The journal aims to present to its readers the leading facts and discoveries in the fields of Anthropology, General Biology, Zoology, Botany, Paleontology, Geology, and Mineralogy, and the various subdivisions of those subjects. Annual Subscription, $4.00 net, in advance. Single Copies, H. KÜNDIG, Editeur, 11, Corraterie, GENÈVE. Archives de Psychologie PUBLIÉES PAR Th. Flournoy Ed. Claparède Dr en médecine. Prof. de Psychologie expérim. Dr en médecine. à la Faculté des Sciences de l'Université de Genève. Les Archives de Psychologie paraissent à époque indéterminée. Chaque fascicule se vend séparément et le prix en est fixé suivant sa grosseur et le nombre des figures. On peut toutefois souscrire d'avance au prix de 15 francs pour un volume (d'au moins 400 pages); avec le dernier fascicule du volume, les souscripteurs reçoivent le titre et les tables des matières.-Les fascicules sont envoyés franco de port aux souscripteurs. Tome ler, vol. broché de 424 pages et 57 figures . 15 fr. 15 15" Aux nouveaux souscripteurs du tome III, les tomes Ier et II sont laissés à leur ancien prix, soit 12 fr. chaque (frais de port compris). Comparative Neurology and Psychology Volume XIV 1904 Number 3 AN ENUMERATION OF THE MEDULLATED NERVE FIBERS IN THE VENTRAL ROOTS OF THE SPINAL NERVES OF MAN. By CHARLES E. INGBERT. (From the Neurological Laboratory of the University of Chicago). With 38 Figures in the Text. 1. II. III. Introduction. Historical Statement. Determination of the areas of the cross-sections of the ventral roots of the spinal nerves of man. IV. Determination of the number of nerve fibers in the ventral roots of the 3. Comparison of STILLING'S estimate with the author's enumeration. V. The number of nerve fibers per square millimeter of the cross-section of the ventral roots of the spinal nerves of man. I. Determinations and comparisons. 2. Discussion of Figure 3. VI. Relation between the ventral and dorsal roots. VII. I. Relation of areas of cross-sections. 2. Relation of the sizes of the nerve-fibers. 3. Relation of numbers of nerve fibers. 4. Comparison of the ratio of the number of nerve fibers in the ventral and the dorsal roots of the frog, of the rat, and of man. On the relative area of the cross-section of the roots forming the brachial and lumbo-sacral plexuses in the male and the female. VIII. Summary. Having completed "The Enumeration of the Medullated Nerve Fibers in Dorsal Roots of the Spinal Nerves of Man" (June, 1903), the author attempted to determine how many these dorsal root fibers innervated the muscles and other deep tissues, and how many, the skin. For this purpose it was necessary first to determine the number of nerve fibers in the ventral roots. This was done. Using the number obtained in this enumeration, an estimate was made "On the Density of the Cutaneous Innervation in Man" (October, 1903). The purpose of this present paper is to give in detail the results obtained from the study of the number of fibers in the ventral roots. II. Historical Statement, Although estimations of the number of medullated nerve fibers in different spinal and cerebral nerves of man and determinations of the areas of their cross-sections have been made by D. ROSENTHAL (1845), STILLING (1859), TERGAST (1872), KUHNT (1879), W. KRAUSE (1876 and 1880), SALZER (1880), and VOISCHVILLO (1883), no complete count of the spinal nerves had been made prior to the author's observations cited above (June, 1903). We are now able to add a similar enumeration of the medullated nerve fibers in the ventral roots of the spinal nerves of the same man. For a description of the material, the reader is referred to the paper first mentioned above. III. I. Determination of the Areas of the Cross-Sections of the Kölliker's Determination.-Under conditions which have been described elsewhere in detail (INGBERT, June, 1903, p. 55), KÖLLIKER (1850, p. 434) determined the area of all the cross-sections of all the ventral roots of the left spinal nerves 1 KÖLLIKER does not give the areas of the ventral roots of the sacral nerve IV and V. We estimate their combined area as about 0.2 mm2 and have corrected his results by adding this amount. |