52 



THE AMERICAN NATURALIST [Vol. XLI 



("Ueber die Kolbenzellen in der Epidermis der Fische." Jen. 

 Zeitschr. /. Naturwiss., vol. 40, pp. 589-646, pis. 22-26) goblet cells 

 occur in the epidermis of cyclostomes and most physostomous teleosts. 

 All goblet cells are modified epithelial cells from the deepest or germinal 

 layer of the epidermis. They are undoubtedly specialized unicellular 

 glands which may have in addition some supporting function. 



The Selachian Eye. From a study of the eyes of some eighteen 

 species of sharks and rays Franz ("Zur Anatomic, Histologic, und 

 functionellen Gestaltung des Selachierauges.' Jen. Zeitschr. f. Natur- 

 wiss., vol. 40, pp. 697-840, pi. 29), has shown that while there are 

 many specific differences, the eyes of this group as a whole are clearly 

 distinguishable from those of other vertebrates. What is especially 

 peculiar in them is the tapetum lucidum, an epithelial musculature in 

 the iris instead of the usual mesodermal one, a specialized zonula 

 zinnii, and the absence of a falciform process characteristic of other 

 fishes. The adaptations shown by the eyes of different species are 

 discussed at some length. 



G. H. P. 



BOTANY 



Bergen and Davis's Principles of Botany.^ — One of the most 

 successful American elementary botanical text-books has been Bergen's 

 Foundations of Botany. With its author. Dr. Davis has been asso- 

 -ciated in the preparation of the present book, which is certain to find 

 favor with the users of its predecessor and to ^\'m many new friends 

 since in addition to what was best in the earlier text there is now 

 given a consecutive series of studies of representative spore plants 

 so treated as to outline the evolutionary history of the plant world. 

 Both authors are experienced teachers, and also familiar with research 

 problems at first hand, and they have brought to their task unusual 

 care in grouping and handling the subject matter an<l in well illus- 



The book is said to furnish material for a full velar's work. It 

 contains, indeed, enough to occupy considerably more than this time, 



1 Bergen, J. Y., and Davis, B. M. Principles of Botany. Boston. Ginn 

 & Co., 1906. 12mo, ix + 555 pp., 14 pL, 402 figs. 



