CONTROL OF HEREDITY: EUGENICS 449 



illation began. The population of Europe, 

 which was about 1 75 millions in 1800, increased 

 to 420 millions in 1900, and this in spite of the 

 fact that about '65 millions migrated from 

 Europe to new countries during this period. 

 This great increase in the population of Eu- 

 rope was due primarily to reduction of the 

 death rate since the birth rate also declined 

 slightly during this period, while in the newer 

 countries there was both an increase in the 

 birth rate and a decrease in the death rate. 



It is perhaps an open question how long the 

 advances of science in rendering available the 

 natural resources of the earth may be able to 

 keep pace with increasing population, but it is 

 evidently impossible for this great increase in 

 the population of the world to go on in- 

 definitely; sooner or later it must come to an 

 end and the population again become station- 

 ary. Already the birth rate is decreasing more 

 rapidly than the death rate in all the western 

 countries of Europe and this movement must 

 ultimately extend to all parts of the world and 

 lead to a checking of the great increase in 

 population which has characterized the last two 



