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IX. The Geography of Man in Relation to Eugenics. Charles 

 Benedict Davenport, Station for Experimental Evolution, 

 Carnegie Institution of Washington, 



While not pretending to be exhaustive in scope, these combined 

 lectures treat of the most important problems of heredity and 

 eugenics. It is doubtful if a clearer and a more authoritative 

 presentation of these topics, as they are understood to-day, could 

 be made. The authors are leading investigators in their respec- 

 tive fields and they discuss the problems in the concrete, drawing 

 freely upon experimental data and presenting conclusions with 

 the use of few technical terms. There are ninety-eight illustra- 

 tions and diagrams which are of considerable value to the reader. 

 The book is planned to meet the demands of the general reader. 

 It seems to have done this with unusual success. In the last 

 two chapters there is a discussion of various phases of heredity 

 in man and a resume of the eugenics movement. 



While there is a general acceptance by the various authors of 

 the application of Mendelian inheritance, there is not the extreme 

 application which has been somewhat general of late. Each 

 of the joint authors expresses considerable caution, which is to be 

 commended, in discussing the "unit character," which it is to 

 be noted is the fundamental conception of Mendelian inheritance. 



For example we find such statements as the following: "There 

 are strong reasons for believing that mendelizing characters 

 can be modified by selection, though this idea is vigorously 

 denied by many Mendelians. I prefer to think with Darwin 

 that selection can do more than this, that it can heap up quanti- 

 tative variations until they reach a sum total otherwise un- 

 attainable and that it thus becomes creative" (Castle, p. 56). 

 On this question East (p. 112) states that "stabihtyis a relative 

 thing. Many unit-characters are high in the scale of stability, 

 others may be low," and Davenport (p. 269) says: "We find 

 useful the principle of the unit character. Whether it be ulti- 

 mately accepted or discarded, it is useful today, and so we accept 

 it as a guiding hypothesis." These points of view are of special 

 value as they come from investigators whose particular experi- 

 mental work has required a careful analysis of characters. 



