NOV., '07] ENTOMOLOGICAL NEWS. 403 



Selection ; VII. Various Theories of Species-Forming and Descent Con- 

 trol ; VIII. Geographic Isolation and Species- Forming ; IX. Variation 

 and Mutation; X. Heredity; XI. Inheritance of Acquired Characters; 

 XII. Generation, Sex and Ontogeny; XIII. Factors in Ontogeny and 

 Experimental Development; XIV. Paleontology; XV. Geographical 

 Distribution; XVI. Adaptations; XVII. Parasitism and Degeneration; 

 XVIII, Mutual Aid and Communal Life among Animals; XIX. Color 

 and Pattern in Animals ; XX. Reflexes, Instinct and Reason ; XXI. 

 Man's Place in Nature. 



It is all clearly and interestingly told, with every here and there a happy 

 phrase, such as "Natural selection does not create species, it enforces 

 adaptation " (p. 63). or " It may be said that the inside of an animal tells 

 what it is. the outside where it has been" (p. 174). The arguments for 

 and against each theory of species-forming are briefly and impartially 

 stated. The most valuable feature is the explanation of the fundamental 

 characteristics of recent biological advances and their relations to evolu- 

 tionary problems frequently referred to in the literature of today, such 

 as fluctuating variations and Quetelet's law (p. 140), the theory of the 

 purity of the germ cells as an explanation of Mendelian inheritance (p. 

 191). the significance of the chromosomes in inheritance (pp. 252-275) 

 (but nothing of chromosomes as possible sex-determinants). It is not 

 always easy to lay one's hand on simple explanations of such subjects. 



The examples cited in the book are both old and new. If our old 

 friend, Darwin's elephant, "the slowest breeder of all animals," again 

 greets us (p. 60), we are refreshed with the symbiosis of the Aztec ants 

 and the imbauba tree (p. 378). The egg-laying of the quinnat, or king 

 salmon, is a favorite with the authors, as it is described three times (pp. 

 59, 342, 439), and twice (pp. 39, 343) do frozen Alaskan fish, fed to Esqui- 

 maux dogs, thawing, make their escape from the stomach alive, although 

 one does not learn all this from the index. 



It is of special interest in this place to mention that insects and ento- 

 mological works are largely drawn on for illustration. We naturally 

 expect this, since the junior author is a distinguished entomologist. 

 Thus, the one definition of species quoted (pp. 12, 13) is that of Rambur ; 

 much of chapter IX is drawn from the studies of Kellogg and Bell on 

 Coleoptera and Hymenoptera, while XVIII and XIX are largely entomo- 

 logical. Many interesting insects are figured throughout the book. 



Pages 471-475 comprise an Appendix consisting of " references to gen- 

 eral and special treatments of the subjects included in this book, arranged 

 according to chapters. These references are confined to books and 

 papers published in English .... [and] .... are mostly not to origi- 

 nal papers, but to manuals, summaries and digests of evolution subjects." 

 Many of the chapters contain quotations from authors other than those 

 listed in this Appendix and we think that even "general readers and 

 elementary students" would often like to know where to find the context 

 of the citations. — p. p. c. 



