380 



THE AMERICAN NATURALIST [Vol. XL 



Hancock's well known paper "On the Anatomy and Physiology 

 of the Tunicata," originally published in the Journal of the Linnean 

 Society, 1867, is appropriately reprinted here. 



Naturally and very wisely, Mr. Hopkinson has refrained from any 

 revisions of the text beyond what was absolutely necessary to rectify 

 obvious typographic errors. It results from this that in several partic- 

 ulars both as to interpretation of structure, and classification, there is 

 Avant of conformity to views now held. The most striking thing in 

 this regard is the contention for the molluscan affinities of the tuni- 

 cates. (The only discussion, however, of this question is that con- 

 tained in Mr. Hancock's memoir above referred to.) The arguments 

 put forward in support of this view are decidedly interesting reading 

 from a historical point of view, and from the standpoint of now 

 approved criteria of homology. It is surprising that Hancock 

 should have failed even so much as to mention the theory of the 

 vertebrate relationships of the group. One must suppose thjIT at 

 the time of writing this memoir the author had not yet become 

 acquainted with Kowalevsky's important paper on embryology, 

 published the year before. The only clue given us as to what either 

 author's later views were on this fundamental matter, is found in the 

 reference to a paper by Hancock, published in 1870, "On the Larval 

 State of Molgula" etc. Here the author concluded that since there 

 are two distinct modes of development in closely allied genera of the 

 Tunicata, the tadpole condition is non-essential; and he expressed 

 the belief that this fact would influence the theory of the vertebrate 

 relationship of the group. 



This volume treats only of the genus Ascidia, in the systematic 

 part, as the genus was then understood. Thirty species are regarded 

 as "good," and five varieties are recognized. 



Although the volume is numbered one, I see no indication that 

 another is to follow. 



It is certainly well that this work is now published, but as certainly 

 it would have been much better could it have been done long vears ago, 

 W. E. R. 



Schillings's With Flash-Ught and Rifle — The rapidity with which 

 the larger mammals of Africa are becoming exterminated makes it 



1 Schillings, C. G. With Flash-lvjhl and Rifle. Photographing by Flash- 

 light at Xight the Wild Animal World of Equatorial Africa. Translated and 

 abridged by Henry Zick, Ph. D. New York, Harper Brothers, 1905. 8vo, 

 xiii + 421 pp., illus. 



