400 HEREDITY AND ENVIRONMENT 



the great ocean of life. What intellectual de- 

 velopment, what social institutions, what con- 

 trol of natural processes may come in the long 

 ages of futurity it has not entered into the 

 heart of man to conceive. And yet so far as 

 we may judge by the small portion of the 

 record of the past which we can read there 

 has been no necessary progress. There has 

 been "eternal process moving on," but not 

 eternal progress. Stagnation, degeneration, 

 elimination, as well as progression, have 

 occurred all along the path of evolution. 

 And yet on the whole evolution has been 

 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, broAvn, and 

 black — and many subtypes and races. These 

 races differ in many rega-rds in physical, men- 

 tal and social characteristics, and the compar- 

 ative value of these races has frequently been 

 discussed. It is difficult to take an impartial 



