162 



SCIENCE 



[N. S. Vol. XLII. No. 1074 



of scientists can properly receive, understand and 

 discuss such highly-specialized topics. 



I am perfectly convinced, Mr. Secretary, that 

 your complacent Pan-scientists vrould reject the 

 recommendation in parte et -in toto, but thinking 

 men outside will agree that they should accept it, 



and be thankful! 



Jos. W. ElCHARDS 



SCIENTIFIC BOOKS 

 Heredity and Environment in the Development 



of Men. By E. G. Conklin. Princeton 



University Press, 1915. Pp. xiv + 533, 



illustrated. 



This book is based on a course of public lec- 

 tures designed to present in non-teclinical 

 terms a judicial view of eugenics as seen by a 

 trained biologist. Tbe author is particularly 

 well qualified to undertake the task because of 

 the breadth and depth of his biological knowl- 

 edge, his own important contributions to sev- 

 eral of the fields surveyed, his sound and well- 

 balanced judgment, and his preeminent success 

 as a teacher. He has succeeded remarkably 

 well in a very difiicult undertaking. Por the 

 lay reader can not fail to be interested in the 

 wonderful array of post-Darwinian achieve- 

 ments in biology which are here marshalled in 

 such a clear way; and the biologist familiar 

 with the detailed discoveries to which mere 

 reference is made by way of evidence or illus- 

 tration, will profit much by the survey of a 

 whole field in well-balanced perspective. The 

 general reader, who gets from current litera- 

 ture quite contradictory and often distorted 

 views as to the undertakings and the possibil- 

 ities of the eugenics movement, will here find 

 a correct and sane inventory of both. 



The book is divided into six chapters, which 

 deal with the following subjects: 



I. Pacts and factors of development. II. 

 Cellular basis of heredity and development. 

 III. Phenomena of inheritance. IV. Influence 

 of environment. V. Control of heredity: Eu- 

 genics. VI. Genetics and ethics. 



The conclusions reached in Chapter I. are 

 concisely summed up thus: "... that every 

 living thing in the world has come into exist- 

 ence by a process of development ; that the en- 

 tire human personality, mind as well as body. 



has thus arisen; and that the factors of devel- 

 opment may be classified as intrinsic in the or- 

 ganization of the germ cells, and extrinsic as 

 represented in environmental forces and con- 

 ditions. The intrinsic factors are those which 

 are commonly called heredity, and they direct 

 and guide development in the main; the ex- 

 trinsic or environmental factors furnish the 

 conditions in which development takes place 

 and modify, more or less, its course." 



In dealing with the " cellular basis of hered- 

 ity and development" (Chap. II.) the author 

 is most at home, for this is the field of his own 

 special investigations. He emphasizes the con- 

 clusions that the germ-cells are the exclusive 

 basis of inheritance and probably of sex deter- 

 mination and that their structure is " almost 

 incredibly complex." 



In dealing with the " phenomena of inher- 

 itance " (Chap. III.) the author presents a 

 careful digest of present-day and orthodox 

 Mendelism, including the pure-line theory and 

 the consequent ineffectiveness of selection, the 

 theory that all inheritance is due to recom- 

 bination of Mendelian factors, even when 

 blending results are obtained, and that Mende- 

 lian factors are devoid of variability. The pres- 

 entation is a remarkably lucid one, but one 

 suspects that, had the author been as familiar 

 with the phenomena of inheritance as with 

 their cellular basis, he would not have been 

 content to explain the former as relatively 

 simple and clear-cut while declaring the latter 

 " almost inconceivably complex." There is no 

 ground for thinliing inheritance phenomena 

 less complex than their cellular basis, for which 

 reason theories which call for " pure gametes " 

 and " pure lines " are likely to be short lived. 



Chapter IV. presents some of the more strik- 

 ing results from the experimental study of 

 development. 



Chapter V. contains the familiar argument 

 for eugenics (human reproduction controlled 

 with a view to biological improvement of the 

 race), viz., the differentially declining birth- 

 rate, involving the more rapid increase of the 

 poorer strains of humanity, with the recom- 

 mendation that reproduction of the socially 

 unfit be limited and that of the socially supe- 



