284 Heredity and Environment 



Racial Amalgamations. In the human species the only absolute 

 barrier to the intermingling of races is geographical isolation. 

 Every human race is fertile with every other one, and though 

 races and nations and social groups may raise artificial barriers 

 against interbreeding we know that these artificial restraints are 

 frequently disregarded and that in the long run amalgamation does 

 take place; and in general the further amalgamation progresses 

 the faster it goes. In Australia 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 eight million full 

 blooded negroes and two million 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 prevails wherever 

 different races occupy the same country. Even the Jews, who 

 were long supposed to be a peculiarly separate and distinct peo- 

 ple, have received large admixtures of Gentile blood in every 

 country in which they have lived. 



Whether we want it or not hybridization of human races is 

 going on and will increase. Partition walls between classes and 

 races are 'being broken down; complete isolation is no longer pos- 

 sible, and a gradual intermixture of human races is inevitable. 

 We are in the grip of a great world movement and we cannot 

 reverse the current, but we may to a certain extent direct the 

 current into the more desirable channels. 



There is a popular belief that hybrid races are always inferior 

 to pure bred ones, but this is by no means the case. Some hy- 

 brids are undoubtedly inferior to either of the parents but on the 

 other hand some are vastly superior; only experience can deter- 

 mine whether a certain cross will yield inferior or superior types. 

 Society may well attempt to prevent those crosses which produce 

 inferior stock while encouraging those which produce superior 

 types. 



