89 



NOTICES OF BOOKS. 



Feesh-water Biology. By Prof. H. B. Ward and Prof, 0. C^ 

 Whipple, with the collaboration of a stafi of specialists.. 

 5| in. X 9 in., ix + 1,111 pages, with 1,547 text figures, 

 (New York : John Wiley & Sons, Inc. [London : 

 Chapman & Hall, Ltd.], 1918. Price $6, or 285. net.) 



Elaborate monographs on fresh -water organisms as a whole^ 

 and on single groups, have appeared in various European coun- 

 tries, but until the appearance of this important work no such, 

 attempt h.ad been made to deal with North American fresh-water 

 life in its entirety. We may say at the outset that this volume 

 will prove to be quite indispensable in the biological laboratory,. 

 and wherever biological problems are studied in other than a 

 superficial manner. 



The first few chapters are devoted to a discussion of general 

 biological factors, and the mass of material relating to the 

 problems and methods of hydrobiology condensed into the 

 chapter on " Conditions of Existence " renders it particularly 

 valuable to the general student of whatever country he may be. 

 Each of the special chapters is devoted to a single group of 

 organisms, animals or plants, and conforms to the same general 

 plan throughout the book, with the exception of the chapter 

 dealing with Aquatic Vertebrata. A general account of the 

 occurrence and history of the group is followed by a description 

 of the anatomy of the forms treated, dealing chiefly with such 

 features as are of special value in the synoptic key. Similarly 

 the life-history is given in condensed form. Attention is devoted 

 to the general biological relations of the group, special features 

 being left for later treatment under the individual species, except 

 where they illustrate general questions. Care has been exercised 

 to include descriptions of special methods for collecting, pre- 

 serving, and studying the organisms of each particular group. 



Fresh -water biology is comparatively a new field of study, and 



