SOCIAL AND WORLD ASPECTS 239 



an unhapp}^ outlook for the results of the hetero- 

 geneous intermixture which is going on in America 

 on a scale never before equalled. Yet we can scarcely 

 believe this is the whole story. German and Gallic 

 tribes shifted and invaded their neighbours' territories 

 in great numbers even before the advent of Caesar. 

 The immediate cause of some at least of these move- 

 ments was a flood or unfavourable harvest season, 

 which destroyed their narrow margin of food reserves 

 and made it necessary for large numbers to seek their 

 subsistence in more hospitable conditions. This 

 appears to have been particularly true of some of the 

 early Scandinavian tribes. An increasing population 

 in relation to local climatic conditions and food- 

 supply must then often have been the impelhng 

 power. Nevertheless, relative stability of tribal 

 relations was maintained, and indiscriminate mingling 

 of unrelated races only began under Roman rule. 



It is also arguable that all the historic civilisations 

 have been correlated with the presence of a race of 

 superior courage and initiative dominating the 

 activities of an inferior race. Their civilisation died 

 out when the ruling race failed to maintain its numbers, 

 either through miscegenation or from a variety of 

 other causes. 



Since about 1876 the birth-rate in various 

 European countries has steadily declined, falling 

 from 36 per 1,000 in England and Wales to about 

 24 before the war. Similarly in Germany the rate 

 fell, with fluctuations, from nearly 41 in 1875 to 27-5 

 in 191 3. But the death-rate dropped concurrently 

 in England and Wales from 237 in 1 864 to the pre-war 

 figure of 14, and a similar decline occurred in Germany. 

 After many w^ars a rise in the birth-rate soon restores 

 the population. Statistics even show a rise in the 

 frequency of male births during and after a war. 

 Although it is difficult to understand how war con- 



