242 SOCIAL HEREDITY AND SOCIAL EVOLUTION 



success SO far as Ms own struggle for life is con- 

 cerned, nevertheless the constant menace of insuffi- 

 cient nourishment is shown in a condition of things 

 which we call want. This is found most emphati- 

 cally in the tenement districts of our cities. The 

 greatest struggle for existence among men occurs 

 here. But the struggle is not one for personal exist- 

 ence, nor for producing children merely, but for the 

 opportunity of rearing them. In one single tene- 

 ment house, inside of three years, were born one 

 hundred and thirty-eight children. The reproduc- 

 tive power was great enough, but of these one hun- 

 dred and thirty-eight, inside of the same three years, 

 sixty-one — nearly fifty per cent — died. In these 

 tenement districts epidemics rage with greater vio- 

 lence than in the better parts of the community. 

 Even the mild epidemics, which in the better com- 

 munities are hardly regarded as serious, take the 

 lives of thousands of the children in these poorer 

 quarters of the city. Improper nourishment of the 

 children, improper care, improper air, and improper 

 treatment explain it all. Natural selection among 

 the lower classes thus affects the individual to a cer- 

 tain extent by reducing his power of bringing off- 

 spring into existence, but still more by diminishing 

 his ability to rear them up to maturity. Eearing 

 children after they are produced is the factor upon 

 which the life of the race is dependent. No race can 

 hold its own that has a large and growing class of 

 ''les miserahles." 



Among the lower classes of society mankind has 

 two great enemies to contend with, which determine 

 his struggle for existence. These two enemies are: 

 1. The microorganisms, which produce the epidem- 



