CONTROL OF HEREDITY: EUGENICS 429 



modern times there has developed a greater 

 uniformity of ideal. In a complex society all 

 types of service are needed and many differ- 

 ent types of individuals are socially useful. If 

 the social good were the supreme end, as it is 

 in a colony of ants or bees, the greatest dif- 

 ferentiation of individuals for particular kinds 

 of service would be desirable. There should 

 be a hereditary class of laborers, of business 

 men, of scholars, of artists, etc., and for the im- 

 provement of each class there should be in- 

 breeding in that class. Such methods are now 

 used by breeders of various races of domestic 

 animals and cultivated plants with the best of 

 results. No breeder would think of trying to 

 improve draft horses by crossing with race 

 horses, nor of improving milk cows by crossing 

 with beef cattle. In other countries and ages 

 the development of hereditary classes and 

 castes in human society has been tried, and 

 survivals of it persist to this day, but they are 

 only vestigial remnants of an old order which 

 is everywhere being replaced by a new ideal in 

 which the good of the individual as well as that 

 of society is the end desired. 



