88 PRODUCTION OF NATIONALITY 



more than a neutral feeder of her embryo. There 

 are even selective factors at work. Statistics col- 

 lected in one country showed that the average size 

 of the head was greater in still-born chlidren than 

 in children born alive. No doubt the relative size 

 of the brain, especially at the time of birth, is an 

 indication of the possible degree of intelligence that 

 would require much correction from other factors, 

 but it is not without significance. It is clear that 

 the conditions of the environment, such as climate, 

 food and air, the requisites sought for in wives, and 

 the treatment accorded to pregnant women all differ 

 from country to country, and probably have some 

 direct action in determining the average brain-size 

 of a nation. Equally important, and varying with 

 the social environment from country to country, is 

 the relative fertility of different classes of the com- 

 munity. Populations in which large families are 

 encouraged, or the reverse, respectively in the upper 

 and lower classes, or in the agricultural or urban 

 sections, will soon come to show marked differences, 

 not so much because the material differs, but because 

 it will be reared under different conditions. 



The direct effect of the circumambient media on 

 the youth and on the adult is better known. When 

 a special environment acts even for a limited time on 

 a young man, we notice the results as producing an 

 unfamiliar and foreign air. Who has not marked 

 such effects on an American who has spent some 

 years in Paris, a Scot who has been in a New York 

 counting-house, or the member of an English em- 

 bassy home on leave from any foreign country ? We 

 set down the changes to imitation, conscious or 



