138 



The Journal of Heredity 



ing to my theory, have a tendency to form 

 the special growth of tissue of which the 

 incipient antler consists, but ipart of the 

 stimulus is wanting, and is not completed 

 until the testicular hormone is produced and 

 diffused into the circulation — that is to say, 

 when the testes are becoming mature and 

 functional. 



I do not claim that this theory is com- 

 plete — it is impossible to understand the 

 process completely in the present state of 

 knowledge — but I maintain that it is the 

 only theory which affords any explanation 

 of the remarkable facts concerning the in- 

 fluence of the hormones from the reproduc- 

 tive organs on the development of secondary 

 sexual characters, while at the same time 

 explaining the adaptive relation of these 

 characters or organs to the sexual habits of 

 the various species. 



The author makes various digres- 

 sions from time to time to show how. 

 in his opinion, various adaptive fea- 

 tures can have arisen as a result of 

 Lamarckian factors. The explanations 

 suggested are invariably ingenous and 

 interesting, if not always convincing. 

 He uses the term hormone, it should 

 be pointed out, in a much broader 

 sense than is warranted by our actual 

 knowledge, inasmuch as indisputable 

 evidence of the existence of such in- 

 ternal secretions is as yet confined to 

 the products of relatively few organs. 



The book is too diverse in its scope 

 to permit of concise summarization. 

 As a whole, it is an interesting dis- 

 cussion, interspersed with bits of in- 

 formation which are of value to 

 biologists, particularly those interested 

 in the problems of evolution, individual 

 development, and secondary sexual 

 characters. 



It will be difficult, indeed, for the 

 author to persuade the majority of 

 geneticists today that (p. 55), "The 

 Mendelian theory is merely a theory 

 in words, which have an apparent re- 

 lation to the facts, but which when 

 examined, do not correspond to any 

 real conceptions," or to lead them to 

 believe (p. 139) that, "There is a 

 tendency among Mendelians and mu- 

 tationists to overestimate the import- 

 ance of experiments in comparison with 

 reasoning, either inductive or deduc- 

 tive." 



To the reviewer, the grounds ad- 

 vanced for the author's theory are sug- 

 gestive rather than conclusive, and 

 they will doubtless remain so for many 

 biologists until more definite experi- 

 mental evidence is forthcoming. 



M. F. GUYER, 



University of Wisconsin. 



For Those About to Marry 



Die Gattenwahl, ein artzliches Rat- 

 geber bei der Eheschliessung, by Dr. 

 Max Hirsch. Pp. 43. Price, 30c. 

 Leipzig, Curt Kabitsch Verlagsbuch- 

 handlung, 1933. 



Dr. Hirsch, editor of the Archiv 

 fur Frauenkunde und Eugenetik, has 

 attempted the useful task of furnish- 

 ing in a brief and simple form such 

 information regarding hereditary de- 

 fects and infectious diseases as might 



be useful to one about to marry. Be- 

 sides describing the bearings on mar- 

 riage of the principal physical and 

 mental maladies, he considers such re- 

 lated subjects as alcoholism. A con- 

 cluding section urges on all candidates 

 for marriage the desirability of a 

 thorough medical examination. A 

 similarly practical and inexpensive 

 booklet in the English language ought 

 to be available. — P. P. 



