566 



THE AMERICAN NATURALIST 



[Vol. LIII 



direct modifying effect of temperature and moisture actually 

 demonstrated only as regards the rate of ontogeny. 



With regard to the general philosophic speculations of the 

 author, which occupy a large portion of this volume, little need 

 be said, as this sort of thing is largely a matter of taste. The 

 author states very unmistakeably that his viewpoint is purely 

 mechanistic, but there is much that will scarcely be accepted as 

 such by most mechanists. For instance, his list (p. 6) of the 

 "Categories of Organic Characteristics" — (1) Specific Prop- 

 erties or Qualities," (2) "Attributes" and (3) "Conditions"— 

 will be regarded with suspicion by those to whom metaphysics is 

 the bete noir of biology. The same may be said of his aversion 

 to "particularistic" theories of heredity. His objections, like 

 most other recent ones, are based on a supposed identification of 

 the gene with a somatic "unit character." Yet he is himself 

 guilty, to an extraordinary degree, of such a confusion in his 

 "scheme of classification of the agents of the germ plasm" 

 (p. 86), where his hypothetical factors are classified entirely ac- 

 cording to their apparent somatic effects. This scheme is also 

 dominated by the "organism as a whole" dogma — tliat the 

 "basic" characteristics of th<^ race are transmitted tlirougli the 

 cytoplasm, only trivial characters through the chromosomes and 

 capable of dissociation from the "species complex." 



On the whole, it may be said that Profes.sor Tower has con- 

 vincingly demonstrated the truth of his fundamental premise, 

 that "the general philosophical coiicoptions from which we 

 interpret nature will largely (lett'i-mine the logical, philosophical, 

 and experimental methods used in invest i-;ition and the hypoth- 

 eses created." C. R. Plt^nkett 



LlTKRATrHK 



Tower, W. L. 



1906. An Investigation of Evolution in chrysoin.'lM B.'ptlos of the 



1910. The Determination of Dominance an.l the ^^o<lifi,•atio/ of Be- 

 havior in Alternative (Mendelian) Inheritance by Tonditions 

 Surrounding or Incident upon the Germ Cells at Fertilization. 

 Biol. Bull., 18. 



1918. The Mechanism of Evolution in Leptinotorm. Carne^rie In-titn- 



