2io THE POPULAR SCIENCE MONTHLY 



by fifty million, and Professor A. B. Hart does not hesitate to go up to 

 three hundred and fifty million. We are by no means disposed to dis- 

 pute all of these figures, but there are considerations which point in the 

 other direction, as for example that the percentage of increase went 

 down in the decades between 1860 and 1900. 



"We have also the check of advancing civilization. That voluntary 

 restriction follows a higher scale of needs is shown in France, in lesser 

 degree in Great Britain and probably in all lands of advancing culture. 

 Thus there is color for the view that France with her disturbing birth 

 rate has only arrived first at the condition to which all cultivated peoples 

 are moving. Motives of economy and of opportunity for self and chil- 

 dren press more strongly as standards rise, and it has recently been 

 urged, that even Ireland, with new land laws and with peasant pro- 

 prietorship, will become more restrictive of population. It seems to be 

 as true with man as in the general field of natural history, that the 

 higher the type the fewer the progeny. 



Perhaps also this tendency will fall in with the natural limit of 

 food production. Indeed, the latter will have a controlling causal effect 

 on the former, following the ever-operative law that higher prices or 

 approaching scarcity is accompanied by restriction of population. That 

 which is temporary in the latter case may well be found permanent in 

 the other. 



To the present time immigration has been one of the chief sources 

 of our growth. We are already seeing a check of the inflowing current, 

 and this may well become permanent in future years. The restrictive 

 measures of the government count for something. The narrowing of 

 opportunities, as for free land, is another and more powerful factor, and 

 a further consideration of unknown significance is rising in our view, 

 namely, the improvement of conditions and the triumphs of democratic 

 aspiration in the lands from which the foreigner comes. In proportion 

 as life in the old countries becomes endurable, not to say attractive, the 

 fountains of immigration will begin to go dry. 



On the other hand, there is a source of increase upon which we 

 may look with full content, reasons, applicable alike to us, which a 

 European authority has assigned, for the increase of European popula- 

 tion during the last half century. These reasons are in relation to the 

 lowering of the death rate by diminution of war, by the elimination of 

 epidemics and by better hygiene. These advances would seem to mean 

 more than a lower death rate. Not only are people kept alive, but 

 they are made more productive workers and reasonably, it would seem, 

 may become more prolific as well as better conditioned. Whatever our 

 views of population or progress, it would hardly be prudent to disagree 

 with Mr. Mackaye's proposition that it is not so important to get nitro- 

 gen into the soil and raise more food as to make right use of the food 

 we have. We should, he thinks, avoid undue increase of our population, 



