176 WORLD-POWER AND EVOLUTION 



before us. In the first place, Boas found no evidence of any dis- 

 tinct physical change in adult immigrants. In the second place, 

 he found that when very young children come to this country 

 they suffer slight changes of the same kind as those occurring in 

 children born here, but not of great significance. Thirdly, chil- 

 dren born in this country show distinct and systematic differ- 

 ences from their brothers and sisters born abroad. These differ- 

 ences increase in proportion to the length of time since the mother 

 came to the United States, or at least they are greater in the 

 children born after the mothers have been here ten years than 

 when the mothers have been here a shorter time. Finally, the 

 break between the foreign-born and the American-born is sharp, 

 and is far more pronounced than the difference between the chil- 

 dren born earlier and later in this country. 



Now as to the nature of the changes. One of the first subjects 

 of inquiry is complexion. This was examined with care, but no 

 consistent changes were observed. Apparently the complexions 

 of children born of foreign parents in this country are identical 

 with what they would be if the children were born ajbroad. This 

 agrees with what we have seen as to the Jews in Europe. It is 

 quite possible that life for generation after generation in some 

 parts of America might weed out the blond children, while life in 

 other parts might weed out the darkest type. Thus there might 

 arise a change such as that which seems to have differentiated the 

 Mediterranean Jews of the Shephardim type from the Central 

 European Jews of the Ashkenazim type. Such a change, how- 

 ever, is quite different from the sudden changes with which we 

 are now dealing. 



The next point to claim attention is stature. From the age 

 of five years at which the measurements begin, the stature among 

 the American-born children of East European Jews and of the 

 non-Jewish group from the same region is greater than the stature 

 of similar children bom in the old country. Among the Italians, 

 on the contrary, the reverse is the case. The Sicilian children 



