reflex theory of phototaxis. This is a feature of the creature's behavior which, I am inclined to believe, we shall not be able to understand until we can explain the physiology of the process whereby certain stimuli when they have been received one or more times are sought either directly, or indirectly, by a more or less round-about method, while other stimuli when they are experienced one or more times come to be avoided. Did light afford a stimulus of an unpleasant nature, it is probable that the positive phototaxis of Ranatra would soon be inhibited. If the phototaxis of Rantra falls to a certain extent under the category of reflex action, as much in its behavior indicates, the reflexes concerned are in line with a strong instinctive interest of the animal in seeking the light. This interest may lead to successful attempts to get to the light in situations in which purely reflex responses alone would fail. It acts as a sort of regulatory agent in the conduct of the insect, bringing its actions to a successful issue, which could not be attained by a purely machine-like mode of response.

It is through instinctive interests in certain things rather than by simple or even complex reflex acts that the conduct of higher animals is mainly guided. The play activities of higher animals, for instance, are performed, not because they are reflex responses to particular things in the environment, but because the animal is so constituted that it derives satisfaction from their performance. An animal interest may be chained, by virtue of its organization, to certain ends, such as the capture of a certain kind of prey, or the construction of a particular kind of habitation; but at the same time its conduct may show considerable plasticity as regards the methods by which these ends are attained. In instinctive behavior, as in the morphogenic processes which lead to the establishment and maintenance of the normal form of the body there is an apparent effort to reach a certain end result, despite obstacles and unusual conditions. The explanation of this peculiarity of animal behavior is a problem of fundamental interest. If we attempt to resolve highly complex modes of behavior into simple direct reflexes, we soon find ourselves at the end of our tether. Even in so apparently

mechanical procedure as the phototaxis of Ranatra we encounter peculiarities which indicate that we have not struck bottom in our analysis of the phenomenon.

In many ways the phototaxis of the Ranatra seems to be intermediate between purely reflex conduct on the one hand and conduct of the pleasure-pain type on the other. These two kinds of behavior seem to be harmoniously combined in many instincts, if not in most of the more highly involved modes of instinctive action. Just what the steps are which lead from the one to the other we do not know. We are still in want of a satisfactory explanation of the pleasure-pain type of response. When we are able to supply one we shall be in a position to give a more adequate interpretation of the phototaxis of higher forms than can be supplied at the present time.

LITERARY NOTICES.

Verhandlungen der Anatomischen Gesellschaft auf der Achtzehnten Versammlung in Jena. Anat. Anz. Erganzungsheft zum

1904.

25 B.

Schultze, O. Ueber die Entwickelung des peripheren Nervensysteme. 2-7. The growing nerves in the embryo are syncytial in structure. The sheath nuclei are derived from the nuclei of this nervous syncytium. The plexus nervosus profundus of amphibian larvae (CZERMAK) is a sensory syncytium which is, and has arisen, in continuo with the developing nerve, and is not derived by a fusion of independent units. SCHULTZE'S interpretation is in opposition to the neurone theory. Koelliker, A. Ueber die Entwickelung der Nervenfasern. 7-12.

This paper is directly opposed to SCHULTZE's and in favor of the neurone theory. Each axone grows out as a process of a single nerve cell and the sheath nuclei are mesodermal in origin. This mode of development, the author asserts, is followed in Vertebrata, Arthropoda and Mollusca. The process may be simpler in lower forms.

In the discussion which follows these two papers, FRORIEP argues for the ectodermal origin of the sheath nuclei by a migration from the central system along the nerve roots. RETZIUS, BENDA, BALLOWITZ, HARRISON and DISSE cite various instances and observations in favor of the neurone theory. The necessity of experimental work upon the regeneration of the peripheral end of the severed nerve fiber is emphasized by Roux and BARFURTH.

Joseph, H. Ueber eigentümliche Zellstrukturen im Zentralnervensystem von Amphioxus. 16-26.

The cells in question are the large cells in the anterior region of the nerve cord which v. KUPFFER called "dorsale Ganglienplatte." The author finds similar cells in the corresponding position in the caudal region of the cord. All of these dorsal cells, contrary to other authors who differ among themselves, are unipolar, and, in structure, correspond exactly with the "Sehzelle" of HESSE. They are not, however, capped with the pigment cell which is characteristic of the typical "Sehzelle." Their axones pass towards the periphery of the cord and probably enter the posterior roots. In the caudal region of the cord "Sehzelle" occur without the pigment cap, in which case they are identical in structure with the dorsal plate cells of the same region.

Hochstetter. Ueber die Nichtexistenz der sogenannten Bogenfurchen an den Gehirnen lebensfrisch konservierter menschlicher Embryonen. 27-34. Schaper, A. Zur Frage der Existenzberechtigung der Bogenfurchen am Gehirne menschlicher Embryonen. 35-37.

Both of these papers on the embryonic fissures agree with the recent work of RETZIUS, MALL and GOLDSTEIN, who find no true fissures in the well preserved human brain during the period to which His assigned his "Bogenfurche."

Ramström. Ueber die Innervation des Peritonaeums der vorderen Bauchwand.

This study was made upon intra vitam methylene blue impregnations of the peritoneum and associated tissues. In the mouse, the peritoneum on one side the median line was mounted entire. No fibers from the phrenic were found entering this region. The innervation is wholly from the intercostal nerves, through a complicated system of plexuses. Lubosch, W. Uber den Bau und die Entwickelung des Geruchsorganes von Petromyzon. 67-75.

This paper bears upon BLAUE's theory of the origin of the olfactory epithelium by a process of fusion of primitive cutaneous sense organs. The author conceives the olfactory buds of Petromyzon as representing a protracted ontogenetic process. The fundament of the olfactory organ is in the form of a bud-like differentiation of the integument. The organ develops by a repetition of this process. LUBOSCH Considers that BLAUE'S theory may be tenable upon the hypothesis that in the olfactory organ the nerve cell has maintained the primitive position, which it originally held in both olfactory and taste organs. Perfectly closed follicles are found in the nasal cavity of ten-centimeter larvae.

G. E. C.

Rutter, Cloudsley. Natural History of the Quinnat Salmon. Bull. U. S. Fish Commission for 1902, 65-142. 9 Pls., 13 Figs. 1904.

The objects of this investigation were to determine when young salmon should be liberated from the hatcheries, to discover a method for removing and fertilizing the eggs left in the fish after artificial. spawning, and to fix the site for a new hatchery. Other matters of interest discussed are the activity of spermatozoa after the milt is mixed with water, the fertilization of the ova, care in handling embryos, alevins and their enemies, the fry and their food, parasites, and migrations, the food of young salmon and their period of growth. The adult salmon are treated in relation to migrations, changes after entering fresh water, sexual differentation, natural propogation, injuries and diseases, and death which ensues after once spawning. This contribution is of considerable scientific importance as well as being of practical value.

I. A. FIELD.

Kerr, J. Graham. On Some Points in the Early Development of Motor Trunks and Myotomes in Lepidosiren paradoxa (FITZ.). Trans. Roy Soc. Edinburgh, 41, Part 1 (No. 7), pp. 119–128, 6 plates, 1904.

The author's observations support the conclusion that the motor spinal nerves of Lepidosiren first appear as strands of soft granular protoplasm, extending between the spinal cord and the myotome. These strands are not cellular. They later become fibrillated and invested by mesenchymatous sheaths.

C. J. H.

Coggi, Alessandro. Le ampolle di Lorenzini nei Gymnofioni. Monitore Zoologico Italiano, 15, No. 249-56.

On the basis of the figures and descriptions of the SARASINS, the author compares the "Nebenohren," or accessory lateral line organs on the head of Ichthyophis with the ampullae of LORENZINI of elasmobranchs, concluding that the organs are strictly homologous, thus strengthening the current belief in the archaic character of the Gymnophiona.

It will be recalled that the reviewer has suggested (this Journal, vol. 13, p. 135) a similar homology between the ampullae of LORENZINI and a type of "small pit organs" found in the skin of the North American siluroid fishes, though the evidence for this relationship is not regarded as conclusive C. J. H. Freidenfelt. T. Ueber den feineren Bau des Visceralganglions von Anodonta. Lunds Universitets Arsskrift, Bd, 40, Afd. 2. Nr. 5. Lund, 1905. A detailed description of the neurones of the visceral ganglion and their connections, after methylene blue preparations, illustrated by four good plates. The author finds no true net-work (protoplasmic continuity of the older authors) in the neuropil, but refrains from expressing an opinion on the question of continuity of the neuro-fibrils of APÁTHY and BETHE.

Tumors of the Cerebellum.

C J. H.

Under the above title, the A. R. Elliott publishing Co., of New York, has re-printed six papers by Drs. MILLS, Frazier, de SchwEINitz, Weisenburg and LODHOLZ. While the clinical and surgical details do not fall within our limits, we call attention to the cases reported and to the summaries of literature as important contributions to the theory of cerebellar functions. C. J. H. Banchi, Arturo. Di un cervello senze commessure e con funzioni apparentemente normali. Archivio di Fisiologia. Vol. 1, pp. 614-618, 1904.

A brief statement of a remarkable case of cerebral malformation where the mental life seemed perfectly normal. An extended account of the case will shortly appear in the Archivio Italiano di Anatomia e di Embriologia J. C. B