NATURAL DEATH, PUBLIC HEALTH 257 



any very rapid rate after such a condition is reached. 

 East has shown that the United States has already entered 

 upon the era of diminishing returns in agriculture in this 

 country. Is it at all reasonable to suppose that by the time 

 this country has closely approached the asymptote here 

 indicated, with all the competition for means of sub- 

 sistence which the already densely populated countries of 

 Europe will then be putting up, there can be found any 

 portion of the globe producing food in excess of its own 

 needs to an extent to make it possible for us to find the 

 calories we shall need to import? 



Altogether we believe it will be the part of wisdom 

 for anyone disposed to criticize our asymptotic value of 

 a hundred and ninety-seven and a quarter millions because 

 it is thought too small, to look further into all the rele- 

 vant facts. This point of view is sustained in a recent 

 paper by East in which the future agricultural resources 

 of the country are particularly examined. 



The relation of this already pressing problem of popu- 

 lation to the problem of the duration of life is obvious 

 enough. For every point that the death rate is lowered 

 (or, what is the same thing, the average duration of life 

 increased) the problem of population is made more imme- 

 diate and more difficult unless there is a corresponding 

 decrease in the birth-rate. Is it to be wondered at that 

 most thoughtful students of the problem of population 

 are advocates of birth control? Or is it remarkable 

 that Major Leonard Darwin, president of the Eugenics 

 Education Society in England, should say in a carefully 

 considered memorandum to the new British Ministry of 

 Health: "In the interests of posterity it is most desirable 

 that parents should now limit the size of their families 

 by any means held by them to be right (provided such 



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