SOCIAL AND WORLD ASPECTS 245 



advantageous. The decline is believed to have taken 

 place first in the higher classes, because they respond 

 more quickly to a change in economic conditions. 

 It is viewed with considerable equanimity, even as 

 regards its differential character, confined as it is 

 chiefly to the upper and middle classes, the latter, 

 through selection, including the great majority of 

 the best elements in the community. Other wTiters 

 take a much more serious view of this matter, and 

 apparently wdth good reason. It seems clear, for 

 instance, that in the United States the Anglo-Saxon 

 stock is failing to hold its own (see, for instance, 

 Holmes, 1921), and this is particularl}- true of the 

 more highl}^ trained graduates of the Universities. 

 Similarly in England the decline in the birth-rate 

 since the 'eighties has occurred chiefly in the elements 

 of the population whose inheritance is most valu- 

 able to the nation. Once a particular stock having 

 exceptional qualities is lost it is ver}- questionable 

 whether it can ever be replaced . The history of Greece 

 and Rome and other decayed nations shows that once 

 a human stock has disappeared, for whatever reason, 

 it is gone for ever. An obvious duty rests upon the 

 most highly endowed members in all ranks of society 

 to perpetuate their kind. 



Before leaving the subject of quantity in popula- 

 tion, we ma}^ refer to some recent results on the 

 question of population growth. Pearl and Reed 

 (1920) have applied a logarithmic formula to the 

 growth of population in the United States since 1790, 

 and they conclude that the ultimate population of 

 that country will not exceed 197 millions — i.e., less 

 than double the present population. East (1920, 

 1 921), from a consideration of the agricultural 

 possibilities of the country, concludes that there are 

 about 800 million acres of arable land. If the popula- 

 tion limit were placed at 2-5 acres per man, which is 



