Control of Heredity: Eugenics 293 



all parts of the world and lead to a checking of the great increase 

 in population which has characterized the last two hundred years. 

 This approach to a stationary population is both a normal and a 

 desirable thing, for no one could wish to see the population in- 

 crease more rapidly than the supply of food or other necessaries 

 of life; and of the two possible methods of checking population 

 few would hesitate to choose a decreasing birth rate as preferable 

 to an increasing death rate. 



It is not therefore the declining birth rate in the general popu- 

 lation that should cause alarm but rather the declining birth rate 

 in the best elements of a population, while it continues to increase 

 or at the least remains stationary among the poorer elements, and 

 there is abundant evidence that this is just what is taking place. 

 The descendants of the Puritans and the Cavaliers who have raised 

 the cry for "fewer and better children" are already disappearing 

 and in a few centuries at most will have given place to more fer- 

 tile races of mankind. Many of the old New England families are 

 dying out and their places are being taken by recent immigrants. 

 The few exceptions are merely eddies in the current that is 

 bearing them to doom. In Massachusetts the birth rate of the for- 

 eign born is twice* that of the native population while the death 

 rate is about the same for both. The same is true of the older 

 families in many parts of the world. 



Cattell has made a statistical study of the families of 917 

 American men of science and he finds that the average size of 

 family of the parents of these men was 466 children, whereas 

 the average size of family of these men is 2.22 children. In one 

 generation the fertility of these lines has been reduced by more 

 than half. The causes of this decline are chiefly voluntary being 

 assigned to health, expense and other causes. 



Death of Families. — But the causes of sterility are not only 

 social and voluntary ones, which could be changed by custom and 

 public opinion ; there are also involuntary and biological causes 

 of a deep-seated nature. Fahlenbeck has made a study of 433 

 noble families of Sweden which have become extinct in the male 



