POPULATION PROBLEMS 209 



gathers at present from land and sea (there are scores 

 of devices waiting to be tried) ; and while it is impossible 

 to predict what biochemical advances await discovery, 

 it seems common sense to attend to Professor East's 

 warning. For it points towards a policy which is bound 

 to be progressive whatever the future has in store, — 

 the policy, namely, of trying to secure a more masterly 

 and therefore more economical exploitation of the 

 resources of Nature, and of trying to evade the cruder 

 forms of the struggle for existence by always preferring 

 quality to quantity. // faut cultiver son jardin — ^in 

 more senses than one. 



§ Q. Causes of the Falling Birth-rate 

 No complete answer can as yet be given to the 

 question : What are the causes of the falling birth- 

 rate ? The problem is in the hands of investigators. 

 The birth-rate depends on many factors, and these are 

 variable. It depends on the age-composition of the 

 community, on the number of wives under forty-five, 

 on the age at marriage, on the duration of marriage, 

 on the loyalty of husband and wife, on the amount of 

 illegitimacy, on the economic conditions which affect 

 control either through continence or through some 

 evasion of parentage, and on some other factors like 

 alcoholism and reproductive diseases. Nutritive factors 

 do not seem of direct importance ; mental development 

 does not seem to have much, if any, direct effect. 



Among men who have a high standard of taste and 

 restricted means of satisfying this, the marriage-rate 



o 



