176 NATURE-STUDY REVIEW [14:4— April, 1918 



man a creator; the visible basis of heredity; some apparent exceptions; are 

 acquired modifications heritable? the inheritance of human characters, 

 physical and mental ; the practical problem of human heredity. At the end of 

 each chapter are questions which will lead the pupil to make his own deduc- 

 tions from the facts given. 



We confess that we have lingered the longest over a chart on which is 

 tabulated the pedigree of Alix, a famous race horse. This is a most graphic 

 representation of the fact that "Blood will tell." A very valuable list of 

 references for further reading is given at the end of the book. We predict 

 a useful and successful future for this important little volume. 



Fresh-water Biology, by Henry B. Ward and George C. Whipple, with the 

 collaboration of a staff of specialists. J. Wiley & Sons, New York City. 

 $6.oo. 



Among the recent books dealing with the plant and animal life there is none 

 more welcome to the student of nature than this uoo paged, richly illustrated 

 volume upon the life of pond, lake and stream. By its means most of the 

 smaller freshwater plants and animals of this country may readily be deter- 

 mined. The first few chapters deal with general biological factors. Following 

 these are twenty-seven chapters upon bacteria, algae, larger aquatic plants, 

 protozoans, sponges, hydrozoans, free living and parasitic worms, rotifers, 

 crustaceans, mites, insects, bryozoans, mollusks, and fish. A sixteen page 

 chapter on "Technical and Sanitary Problems," the junior editor's contribu- 

 tion, completes the volume. In each chapter, descriptions of special methods 

 of collecting, preserving, and studying the organisms of the group considered, 

 are given, followed by a key for the determination of the genera and in many 

 cases, species. The descriptions are concise and the illustrations, though 

 simple, are adequate. Each chapter has been written by a well-known special- 

 ist, twenty-five collaborators having assisted the editors in their work, thus 

 rendering the production far more authoritative than if written by one individ- 

 ual. The treatment is conservative in the matter of scientific names: in a 

 number of instances we note that an old and well established term is used in 

 preference to one which is in strict conformity with the usages of the inter- 

 national code of nomenclature. This, however, in the opinion of the reviewer, 

 is commendable, in a general work of this kind. The bibliographies following 

 the chapters, though confessedly brief and incomplete, are for the most part 

 well selected. Considering the vast field that is covered and the number of 

 collaborators, the work is quite uniform in its manner of presentation. 



Judged by its title alone it would appear that this book duplicates in sub- 

 stance, that of Needham & Lloyd "The Life of Inland Waters" reviewed in 

 these pages in 191 6. A comparison, however, shows that this is not the case, 

 the earlier work is upon the natural history of the life in fresh water, while the 

 present volume is primarily designed for the identification of the various 

 organisms found there. The former emphasizes the ecologic, the latter the 

 systematic side. Both should find a place on the reference shelves of the 

 nature-study teacher. To the student of aquatic life they are quite indis- 

 pensable. O. A. J. 



