412 HEREDITY AND ENVIRONMENT 



progressive and there is no reason to sup- 

 pose that the elimination of the unfit and the 

 preservation of the fit will cease to be the 

 law of future evolution, as it has been of the 

 past. 



There are four principal types of the hu- 

 man species — white, yellow, brown, and 

 black — and many subtypes and races. These 

 types and races differ in many regards in physi- 

 cal, mental and social characteristics, and their 

 comparative value has frequently been dis- 

 cussed. It is difficult to take an impartial 

 view of such a matter, though I suppose there 

 would be little question on the part of any 

 well informed person that the white and yel- 

 low types have contributed most to what we 

 call civilization. Nevertheless every race 

 probably has good qualities which could be 

 made of service to society. The various races 

 of cattle, horses, sheep, etc., are all useful to 

 man, but in different ways and degrees, and the 

 same is true of various races of men with re- 

 spect to civilization. In general the dominant 

 races are the most capable intellectually and 

 socially, while those which have been left be- 



