130 SOCIAL EVOLUTION 



so far as roundness of head is concerned. If American 

 environment can bring about a modification of head form 

 in the first generation, the question presents itself, may 

 it not be that other characteristics may be as easily 

 modified? A comparison of the width of face of Bohem- 

 ians with facial width of American-born individuals was 

 made. When the Bohemians were arranged according 

 to their ages at the time of immigration, the results 

 showed that there was a loss among those who had come 

 here as young children. When this comparison was 

 continued with the Americans, born one, two, and more 

 years after the arrival of their mothers, the width of 

 face was seen to decrease still further. It appears that 

 American environment caused a retardation of the 

 growth of the width of face. Professor Boas concludes, 

 "I think, therefore, that we are justified in the conclusion 

 that the removal of the east European Hebrew to America 

 is accompanied by a marked change in type, which does 

 not affect the young child born abroad and growing up 

 in American environment, but which makes itself felt 

 among the children born in America, even a short time 

 after the arrival of the parents in this country. The 

 change of type seems to be very rapid, but the changes 

 continue to increase so that the descendants of immi- 

 grants born a long time after the arrival of the parents 

 in this country differ more from their parents than do 

 those born a short time after the arrival of the parents 

 in the United States." 13 If this process of change ex- 

 plains the difference between racial types in America 

 it is possible that the same environmental influence has 

 operated in the past to produce many of the racial types 

 which appear stable to-day. In considering these conclu- 



i 3 Changes in the Bodily Form of Descendants of Immigrants, p. 52. 



