132 NATURAL SCIENCE. August. 



tion of each animal is introduced by a formidable-looking table show- 

 ing its systematic position. Now, were the book a guide complete in 

 itself, one would not hesitate to condemn the practice as a violation 

 of a most important educational principle. It is only after the 

 student has gained a fair knowledge of the anatomy of animals that 

 he should be shown what anatomical features may be selected for 

 systematic purposes, and how a classificatory table can be constructed 

 therefrom. To begin with, such a review is not only calculated to 

 discourage the beginner by overwhelming him. with a multitude of 

 strange names, but is likely to give him a false idea of the fixity of a 

 classificatory scheme. Since, however, it is quite conceivable, nay, 

 probable, judging from the reputation of the authors, that the mind of 

 the student has already been suitably prepared for these " Ueber- 

 sichten " in the lecture course, we say nothing. The book is illus- 

 trated by eighteen folding plates, carefully drawn and free from all 

 confusing detail. The figures, which with very few exceptions are 

 original, are printed in black, and the names of the parts written, with 

 but slight abbreviation, in brown ink. Both text and figures are 

 remarkably free from errors, although it might be pointed out that in 

 the Anodonta the lower of the two anterior retractor muscles is more 

 usually known as the "protractor pedis," that the duplicity of the 

 nerve cord of the crayfish in Taf. xii., fig. 2, might with advantage be 

 more clearly indicated, and that an unfortunate slip has occurred in 

 the numbering of the segments of the earthworm in Taf. xvii., fig. 7. 

 On the whole, the book should commend itself to teachers of 

 elementary practical zoology. W. G. R. 



A Zoology for Practical People. 



Text-book of Zoology. By J. E. V. Boas ; translated by J. W. Kirkaldy and 

 E. C. Pollard. Pp. xviii., 558, with 427 figures. London : Sampson, Low, 

 1896. Price 21S. 



This text-book has already appeared in two Danish and two German 

 editions. The second German edition was reviewed in Natural 

 Science, vol. v., no. 30, p. 142, August, 1894. The translators have 

 adhered faithfully to the plan of the original' work, though there are 

 certain differences between the English and German texts, as the 

 book before us has been thoroughly revised by the author. 



It is divided into two parts. The first or general part deals 

 briefly with histology, fundamental form, affinities of animals. Then, 

 in a series of short essays, such questions as "Parasitism," "Duration 

 of Life," "Protective Adaptation," and "Geographical and Geological 

 Distributions " are dealt with. The second or special part is 

 systematic. Here, as all through the work, it is evident that 

 Dr. Boas wishes his students to be naturalists, rather than mere 

 laboratory or lecture-room scholars. In the German edition the 

 description of the groups are followed by lists of familiar German 

 species. These have been admirably replaced in the translation by 

 similar lists of common British species. The illustrations are clear 

 and suggestive, and, on the whole, good, though somewhat unequal. 

 Certain desirable additions and improvements have been made on the 

 figures in the German edition. The form of the book, printing, and 

 indices leave nothing to be desired. 



The addition of references to special works or original papers 

 would, we think, greatly enhance the value of this book, as a guide in 

 the subject of zoology both for the student and the general reader. 



English students have to thank the translators for making 



