CONTROL OF HEREDITY: EUGENICS 417 



and social groups may raise artificial barriers 

 against interbreeding we know that these arti- 

 ficial restraints are frequently disregarded and 

 that in the long run amalgamation does take 

 place; and in general the farther amalgama- 

 tion progresses the faster it goes. In Aus- 

 tralia and New Zealand, after little more than 

 a century's contact with white races, there are 

 about as many "half castes" as there are full 

 blooded aborigines. In the United States one- 

 quarter of all persons of African descent con- 

 tain more or less white blood; there are about 

 ieight million full blooded negroes and two mil- 

 lion mulattoes, and during the past twenty 

 years the latter have increased at twice the 

 rate of the former. In Jamaica, where there 

 are about seven hundred thousand blacks and 

 fifteen thousand whites, there are about fifty 

 thousand mulattoes. A similar condition pre- 

 vails wherever different races occupy the same 

 country. Even the Jews, who were long sup- 

 posed to be a peculiarly separate and distinct 

 people, have received large admixtures of 

 Gentile blood in every cotintry in which they 

 have lived. 



