I40 THE TREND OF THE RACE 



cause they may produce great havoc before they are detected, or 

 at least before the extent of their damage is adequately realized. 



3. The elements of the population that are of subnormal 

 mentality exhibit at present the highest degree of fecundity. This 

 is the general verdict of most students of the birth rate of different 

 classes of the population. The higher death rate of the subnor- 

 mals probably does not offset completely their greater fecundity. 

 There are various factors, however, which tend to reduce the 

 fecundity of subnormal classes. Criminals have their families 

 reduced on account of penal servitude, and it is improbable that 

 tramps and hoboes, who as a class are of subnormal mentality, 

 leave sufficient offspring to replenish their stock. Prostitutes, 

 who constitute another subnormal class, are frequently sterile as a 

 result of venereal diseases, and they also purposely avoid having 

 offspring. We possess little data concerning the fecundity of 

 women of this calling. Many of them have had one or more 

 children before entering upon their professional career, and 

 they sometimes marry and bear children after the business of 

 prostitution has been abandoned. Although they come from 

 stocks that are more than usually proHfic, it is very doubtful if 

 they produce sufficient offspring to replace themselves. 



The subnormal elements of the population thus suffer in several 

 ways an extensive sterilization of their number. We have no 

 means of accurately measuring the extent of the losses to their 

 ranks. Notwithstanding crime, vagabondage, prostitution and 

 a high infant mortality, stocks like the Kallikaks, Jukes, Nams, 

 etc., somehow continue to increase in numbers. If their produc- 

 tiveness suffers from crime and vice, the celibate careers, late 

 marriages and restricted birth rate of the classes in the higher 

 social strata apparently reduce fecundity still more. At any rate, 

 the latter classes in general have a birth rate which cannot fail to 

 lead to extinction. This much is clearly indicated from a variety 

 of sources, while the springs of our defective inheritance have 

 shown no manifest signs of drying up. 



