The Evolution of Man and his Mind.1 This bulky volume, which contains much that is admirable, is designed to be a popular exposition of the course of human evolution, particularly from the point of view of certain sociological defects of our present status. This makes a striking background for an exposé and arraignment of certain corrupt tendencies in our political and social organization. The literary style is colloquial and catchy and the book should do good in directing popular attention toward these abuses. As a whole, however, it is so ill-balanced and full of inaccuracies that it can hardly be commended as a helpful scientific contribution. C. J. H. The Brain and Nerves of the Anamnia.' Professor JOHNSTON'S summary of recent progress in our knowledge of the central and peripheral nervous system of the Ichthyopsida is one of the notable papers of the year. The point of view from which he writes is so distinctively his own that his article is more than a mere abstract or critical review; it is a positive contribution toward the solution of some of the major problems of comparative morphology. This point of view he has already presented in this Journal (March, 1902), under the title, "An Attempt to Define the Primitive Functional Divisions of the Central Nervous System," being essentially the correlation of central with peripheral differentiation of the nervous system. We venture the prediction that the next decade will see this principle worked out successfully in several fields at present open merely to the methods of descriptive anatomy. The conclusions of students of nerve components as formulated at the present moment may or may not stand the test of time, but the essential aims and methods of work which they have introduced into comparative neurology will surely in the end yield results of permanent value. Professor JOHNSTON'S Referat is therefore very timely. C. J. H. 1 CLEVENGER, S. V. The Evolution of Man and his Mind. A History and Discussion of the Evolution and Relation of the Mind and Body of Man and Animals. Chicago, 1903. 2 JOHNSTON, J. B. Das Gehirn und die Cranialnerven der Anamnia. Merkel und Bonnet's Ergebnisse, Bd. XI, for 1901. Wiesbaden, 1902, pp. 973 II12. The Dorsal Spino-cerebellar Tract.' Sections of the spinal cords of dogs at different thoracic and cervical levels show that the longest fibers of the direct dorso-lateral cerebellar tract, i. e., those arising in the lowest levels of the spinal cord, are most superficial in position and that the shorter fibers are added successively along the inner side of this zone. Το The authors verify previous findings of degeneration in the cells. of CLARKE'S column below the lesion after section of the dorso-lateral cerebellar tract. In these cases the fibers of the tract between the degenerated cells and the lesion show no degeneration under the MARCHI procedure, WEIGERT stain, anilin blue-black, picrocarmine, etc. test the condition of these fibers further the authors made a right lateral transection of the Xth thoracic segment 260 days subsequent to a total transection at the IId thoracic level. The animal (dog) was sacrificed 20 days after the establishment of the second lesion. The right cerebellar tract above the second lesion was found fully presenting all the signs of WALLERIAN degeneration under the MARCHI reaction. The left cerebellar tract appeared normal and without any degeneration. "It would seem therefore that atrophy, severe and long-lasting, probably permanent, of CLARKE'S cell-column induced by spinal transection in the the lower cervical or upper thoracic region, far from destroying the dorsal cerebellar tract, leads to no obvious or easily demonstrable degeneration of at least the main body of the fibers of the tract. Further, after the severe atrophy of CLARKE'S column has set in and become established, transection of the tract in the very region of atrophy of the cell-column still causes full WALLERIAN degeneration of the fibers head-ward of the transection." These results obviously have an important bearing on the theory of the physiology of the neurone and its biological interpretation. C. J. H. The Optic Chiasma in Symmetrical and Asymmetrical Teleosts.' The author in continuing his observations on the optic chiasma of fishes develops several results which bear directly on the morphology and phylogeny of the flat fishes. He has previously shown that in 1 SHERRINGTON, C. S. and LASLETT. E. E. Remarks on the Dorsal Spinocerebellar Tract. Journ. of Physiol., XXIX, 2, March, 1903. 2 PARKER, G. H. The Optic Chiasma in Teleosts and its Bearing on the Asymmetry of the Heterosomata. Bull. Mus. Comp. Zool., XL, 5, 1903. 3 The Crossing of the Optic Nerve in Teleosts. Biol. Bull., II, 1901, pp. 335-336. the symmetrical teleosts the right and left optic nerves are dorsal in an approximately equal number of cases. He now extends the observations to the flat-fishes and finds that the two families into which the sub-order Heterosomata is divided by recent systematists differ conspicuously in this character. In the Soleidae the chiasmata are dimorphic, as in symmetrical teleosts; i. e., the right optic nerve is dorsal in about half of the observed cases and ventral in about half. In the Pleuronectidae, on the other hand, the chiasmata are monomorphic for each species; in dextral species the left nerve is dorsal, in sinistral species the right nerve is dorsal. All species of this family that turn in only one direction have their dorsal nerves connected with their migrating eyes. In all species that have both dextral and sinistral individuals, the dorsal nerve is connected with that eye which in the greatest number or in the nearest of kin migrates. The unmetamorphosed young of the Pleuronectidae are not symmetrical in the same sense that symmetrical teleosts are, for they have monomorphic chiasmata. The Soleidae are not degraded Pleuronectidae, but degenerate descendants of primitive flat-flshes, from which the Pleuronectidae have probably been derived. The monomorphic condition of the optic chiasma of the Pleuronectidae can be explained only on the assumption of natural selection. The flat-fishes afford striking examples of discontinuous variation. C. J. H. Brain Weights of Eminent Men.1 Dr. SPITZKA has tabulated 96 cases and made comparisons with the statistics of 800 brains of ordinary persons as given by BISCHOFF and MARCHAND. "The average (arithmetical) brain weight of the 96 individuals is 1473 grams, exceeding the various averages given for the European brain by 75 to 125 grams, and this without allowing for the advanced age of this series; the average of 92 being 63 years." "It is further shown that the period of decrease [in brain weight] with age is deferred for fully a decade among the more intellectual persons, a point already alluded to by DONALDSON, and significant in connection with the longevity of healthy persons endowed with high intelligence." The paper is accompanied by several instructive curves and tables. C. J. H. 1 SPITZKA, EDWARD ANTHONY. A Study of the Brain Weights of Men Notable in the Professions, Arts and Sciences. Philadelphia Medical Journal, May 2, 1903. The Lateral Sensory System of the Eels.' In this paper of 48 pages and three good plates we have a detailed description of the lateral line canals and associated sense organs in the conger eel and a more brief account of three related species of Muraenidae, viz., Ophicthys serpens, Myrus vulgaris and Muraena helena. The nerves supplying these sense organs have been traced only in their peripheral portions and we are promised a later research upon the innervation of these structures in the conger. In connection with the innervation of the pit organs there is one correction of minor importance on page 42 of the reprint, to which attention might be drawn. Mr. ALLIS describes a pit line running parallel with the squamosal lateral canal which is innervated by a nerve formed from an anastomosis between a branch of the facial, which is regarded as a portion of the ramus opercularis facialis, and a branch of the glossopharyngeus or vagus. In discussing the morphology of these pit organs the author says, "If they be pit organs, it is practically certain that they cannot be innervated by the facialis, for there is no single instance that I know of, of lateral sensory fibers accompanying the ramus opercularis of that nerve." As a matter of fact I have described just such a condition in Menidia (this Journal, vol. IX, p. 294, seqq.), BAUDELOT's descriptions strongly suggest the same thing, and I have no doubt that a careful search of the literature would reveal other such cases. Confusion arises in this connection (and this is the occasion of this note) from the fact that there are two opercular rami in teleosts which are not always distinguished. The ramus opercularis profundus VII is a purely motor nerve, and this is the only one of these branches which is mentioned by STANNIUS. On the other hand, the ramus opercularis superficialis VII is a mixed nerve, containing in Meridia both general cutaneous and lateralis fibers and in other cases apparently it may contain communis fibers also or be fused with the motor fibers belonging to the ramus hyoideus VII. This superficial nerve frequently anasomoses with the vagus or glossopharyngeus and in Menidia at any rate it is clear that the vagal fibers are all of general C. J. H. cutaneous nature. 1ALLIS, E. P. The Lateral Sensory System in the Muraenidae. Monatsschrift f. Anat. u. Phystol., XX, 4-6, 1903. Intern. |