CHAPTER V. 



THE CRIMINALS, INCAPABLES, AND THOSE IN 

 DISTRESS. 



WE have seen in the last two chapters that there is 

 every reason to believe that, on account of improved 

 external conditions, and notably of the sanitary ad- 

 vances which result from the efforts of preventive 

 medicine, the race is deteriorating in general constitu- 

 tional robustness. Those selective agencies which in 

 more primitive times destroyed the sickly, especially 

 during their early years of life, have in part been re- 

 moved or modified, with the result that the sickly are 

 preserved and in larger numbers live through and into 

 the child-bearing period, raising the mean duration of 

 life, but notably increasing the rate of mortality after 

 middle age. These sickly ones leave children be- 

 hind, who, as a matter of course, transmit their con- 

 stitution to the race. In our study of disease we in- 

 cluded intemperance, for in cases where there is a 

 distinct liability to give way to drunken habits, and 

 apart from those cases where it is merely a habit 



acquired in bad company, we may look upon it as a 



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