by the tracts connecting it with the nuclei of the V nerve in the oblongata. The occipital cortex is important for sight. The median portion of the dorsal cortex seems to be especially concerned in the innervation of the limbs. The text of 84 quarto pages is accompanied by eleven text-figures and seven plates, five occupied by elegant colored figures representing WEIGERT sections and two presenting the results of degeneration experiments. The paper is one of the most important recent contributions to the morphology of the vertebrate brain. J. B. JOHNSTON. The Optic Chiasma and the Post-optic Commissure. This subject has been treated in two papers by Dr. Burton D. MYERS. In the first' the chiasma alone was studied by the degeneration method in the toad, cat, dog, rabbit, monkey, owl and snake, the toad receiving the most thorough treatment. In the toad certainly and probably in the owl and snake the decussation in the chiasma is total. In the dog, cat and monkey the decussation is unquestionably partial. In the second paper' the same author makes a more thorough study of the relations in the rabbit, using the method of v. GUDDEN. The optic nerves and tracts do not begin to become medullated until twelve hours after birth; accordingly enucleations of the eye made during the first day will result in total failure of medullation of the corresponding optic nerve fibers and very clear pictures can be secured by the WEIGERT method, the animals having been killed at various intervals after the operation. The experiments show conclusively that the chiasma of the rabbit is partial, though the uncrossed fibers are few in numher. The relation of the optic fibers to the post-optic or inferior commissure can be determined by reason of the fact that the optic nerves become medullated earlier than the commissure. Comparisons of series of different ages made after enucleation of both eyes with similar series made after the enucleation of one eye permits an accurate study of the relations of the optic tracts to the commissure. In brief, three such commissures are recognized: 1 The Chiasma of the Toad (Bufo lentiginosus) and Some Other Vertebrates. Zeits. f. Morph. u. Anthropologie, III, 2, 1901. 2 Beitrag zur Kenntniss des Chiasmas und der Commissuren am Boden des dritten Ventrikels. Archiv f. Anat. u. Physiol. Anat. Abt., 1902. I. The commissura inferior of GUDDEN, or Commissura arcuata posterior of HANNOVER. GUDDEN termed this the com. inferior in transverse sections, but the com. superior MEYNERTI in horizontal sections. Its fibers are closest to the chiasma at their crossing and go out laterally closely associated with the optic tracts. 2. The rostral part of the decussatio subthalamica anterior of GANSER. This is GUDDEN'S commissure of MEYNERT, and it may properly retain the name, MEYNERT'S commissure. Its crossing lies dorsally of the com. inferior, and its fibers also go out with the optic tracts laterally. 3. The caudal part of the decussatio subthalamica of GANSER. This may retain the name GANSER'S commissure. Its fibers after the crossing run back on each side of the body nearer the median line than either of the others and they envelop the fornix tracts laterally of the third ventricle. The contradictory accounts of earlier authors are carefully reviewed in the light of the author's experimental results and it is to be hoped that the conclusions reached may set at rest the synonomy of this confusing region. It is needless to add that a real understanding of these commissures (or decussations, as they probably are) cannot be hoped for until we know the exact terminal relations of all the types of neurones involved. There is described a curious mesial slip of the optic tract which runs up along the inner side of the inferior commissural tract. There is, the reviewer may add, an exactly similar detached portion of the optic tract in the bony fishes, which terminates in the nucleus geniculatus externus. Peripheral Nerve Endings in Amphioxus.' C. J. H. The description of the course and distribution of the sensory and motor nerves confirms in general the results of HEYMANS and van der STRICHT. The most important part of the paper deals with the peripheral endings of the sensory nerves. Two sets of fibers are distinguished. The first pass through the homogeneous Hautschicht by means of special canals and reach a position immediately beneath the epithelial cells. Here they branch and form a subepithelial plexus from which "eine Menge feinster varicöser Fädchen" pass up and end between the epithelial cells, The second set of fibers have their cells 1 Das periphere Nervensystem des Amphioxus (Branchiostoma lanceolatum). Von A. S. DOGIEL, St. Petersburg. Anat. Heften, Heft LXVI. 147-213, P. XII-XXIX. 1902. p. of origin in the epithelium. These resemble the sense cells of invertebrates. Their outer ends reach to the surface but are not provided with sense hairs. Their inner ends are continued centrally as fibers which enter the sensory nerves. These sense cells are found generally in the epithelium and especially in the oral tentacles where they are grouped to form the special sense organs which have heretofore been compared with the taste buds and end buds of typical vertebrates. Nothing is stated with regard to the central relations of these two sets of fibers. The author describes certain structures which he regards as spinal ganglia but their finer structure is not sufficiently well made out to warrant any conclusion as to their character. On the Lobus Impar of the Brain of Cyprinoid Fishes.' J. B. J. In his work entitled, "Vom Bau des Wirbeltiergehirns," B. HALLER describes extensive anastomoses between nerve cells in the lobus impar of the medulla oblongata of the cyprinoid fishes and states that this structure is an especially favorable object for the demonstration of such anastomoses. GROTH examined haemalum, carmine and GOLGI preparations of several carp-like fishes in order to check up the observations of HALLER, but without finding any evidence of such anastomoses. There is an extensive but uncritical review of the literature of these brains and some description from his own preparations of the anatomical structure of this part of the brain, in the course of which, however, nothing of morphological importance is brought out. C. J. H. 1 GROTH, A. Ueber den Lobus impar der Medulla oblongata bei Cypri. noiden. Dissertation. München, 1900. A Monthly Journal Devoted to the Natural Sciences The journal aims to present to its readers the leading facts CONTENTS OF THE LAST NUMBER. I. Adaptations to Aquatic. Arboreal, Fossorial and Cursorial Habits II. Mutation in Plants Louis I. Dublin Distribution of the Fresh-Water Fishes of Mexico. Dr. S. E. Meek IV. Examination of Organic Remains in Postglacial Deposits Dr. P. Olsson-Seffer V. Notes and Literature: Exploration, Hatcher's Narrative of the All who are interested in the Scientific questions of the GINN & COMPANY, Publishers, SURGICAL SHOCK is reduced to a minimum by high rectal injections of BOVININE combined with an equal quantity of salt solution, heated to 70°F, and administered prior to, during, and subsequent to operation. BOVININE improves the heart action and circulation at once. The blood which has become non-ærated through ether administration is oxygenated by the introduction of a fresh supply, and is rapidly restored to normal condition. To this fact is due the power of BOVININE to prevent the thirst, nausea, and emesis, which usually follow anesthesia. Reports of numerous cases are cited in our scientific treatise on Hæmatherapy. It is yours for the asking. The Bovinine Company 75 West Houston Street, NEW YORK CONTENTS. CONTRIBUTED ARTICLES. The Rate of the Nervous Impulse in the Ventral Nerve-Cord of Certain Worms. By O. P. JENKINS and A. J. CARLSON. (From the Hopkins' Seaside Laboratory and the Physiological Notes on the Technique of Weigert's Method for Staining PAGE LITERARY NOTICES. |