igo THE TREND OF THE RACE 



has been going on for a long time it is supposed that the greater 

 preponderance of the dolichocephalic race in the city population, 

 and especially in the higher levels of wealth and culture is the 

 result of the action of natural selection in favor of the superior 

 type. The city draws the best of the country stock, and of the 

 inhabitants that have migrated to the country the more dolicho- 

 cephalic succeed best in the struggle for wealth and power. 



We may admit that Ammon has shown that in Baden changes 

 have been taking place in the characteristics of the inhabitants. 

 It is not so clear, however, that these changes have been chiefly 

 the result of natural selection. The racial composition of com- 

 munities is very apt to change as the result of migration and the 

 operation of differential fecundity. Many of us have witnessed in 

 this country a marked change in the character of the population 

 of restricted localities within a period of a few decades. And it 

 is quite evident that such changes are not due to natural selection. 

 Observation of a change in the inhabitants occurring in a small 

 area and in a comparatively short interval of time will not offer 

 conclusive evidence regarding the factors producing the change. 

 Most of the anthropometric data assembled to prove the opera- 

 tion of natural selection is not convincing in that it does not 

 exclude the operation of other possible causes. 



Any consideration of the role of natural selection in man must 

 take account of the much discussed question of the selective 

 nature of the infant death rate. The first year is by far the most 

 precarious period of life. The infant mortaUty rate varies enor- 

 mously in different countries, according to social and economic 

 conditions and the general enlightenment of the inhabitants. 

 In Chile in 1903 it was over 352 per thousand births. For several 

 decades in most countries of Europe the infant mortality rate has 

 been somewhere between 100 and 200 per thousand. It is high in 

 Prussia, Austria, Hungary and Russia, but exceptionally low in 

 Norway and Sweden. It is low in Australia and lowest of all in 

 New Zealand where it reached the remarkable figure of5iini9i2. 

 The infant mortality of the United States has been estim.ated at 

 124 for 1910, although in the absence of data on the birth rate 



