ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 423 



to the spermatic ampullae. It does not seem to have any haematopoietic 

 significance. 



Interstitial Cells of the Testis.* — P. Stephan agrees with Loisel 

 that these elements are sister-cells of the germinative elements, but he 

 differs from Loisel in regarding their secretory or nutritive role as 

 entirely secondary, — a falling away from the primary germinative path. 



Nerves of Lorenzini's Ampullae.!, — A. Coggi has studied the de- 

 velopment of these ampullae in Torpedo, Pristiurus, Mustelus, and Raja, 

 and comes to the conclusion that the mode of development and the 

 details of structure show that the ampullary nerves are in their nature 

 somewhat different from those of the lateral organs. They seem to be 

 sensory nerves of a more general character. 



In another paper \ Coggi discusses the number and arrangement of 

 the ampullae, the time and place of their formation, and the various 

 stages in their development. 



Spines of Spinax. § — H. Koppen has made a study of the minute 

 structure and the development of the fin-spines in Spinax niger, with 

 especial reference to the epithelial cells in the protective cap of the 

 spine, which are arranged in a network. This is compared to the cells 

 in the enamel-pulp in mammalian teeth, and to similar tissue beneath 

 the horny teeth of Myxine, and elsewhere. 



c. General. 



Chemical Organisation of the Cell.|| — F. Hofmeister seeks to ex- 

 plain what must be the organisation of the living cell in order that 

 protoplasm — the functions of which are chemical — may do its work. 

 The manifold activities of liver-cells are discussed in illustration. 

 Hydrations, oxidations, reductions, condensations, — all are accomplished 

 through the activity of catalytic agents, colloidal in nature, which are 

 the important agents in the chemical transformations of the cell. There 

 is no necessity for calling upon other than well-known forces for an 

 explanation of the work done. 



Practical Course of Zoology.^ — W. Kiikenthal has published a 

 second edition of his useful outlines of a practical course in Zoology. 

 Some additions, e.g. as to parasites, have been made, and new illustra- 

 trations have been added or substituted. 



Story of Animal Life.** — B. Lindsay has written a terse and yet 

 interesting introduction to the study of animals. It might be described 

 as a bird's-eye view of the animal kingdom, supplemented by more 

 detailed pictures of particular corners, e.g. of sea-shore life. Most of 

 the booklet is devoted to an illustrated survey and classification of 



* Comptes Rendus, cxxxiv. (1902) pp. 299-302. 



t Atti (Rend.) R. Accad. Lincei, xi. (1902) pp. 33S-40. 



J Tom. cit., pp. 289-97. 



§ Zool. Jahrb., xiv. (1901) pp. 477-522 (3 pis. and 1 fig.). 



|| Die Chemische Organisation der Zelle, Braunschweig, 1901, 8vo, 29 pp. See 

 Review Amer. Journ. Sci., xiii. (1902) pp. 241-2. 



% Jena, 1902, 8vo, 304 pp. and 169 figs. 



** The Story of Animal Life (Newnes' Library of Useful Stories), London, 1902, 

 viii. and 208 pp. and 47 figs. 



