PAET III. 

 THE ABNORMAL MAN. 



CHAPTER XVIII. 



HEREDITY,, INSANITY AND IMBECILITY. 



In Parts I and II we have studied the science 

 of heredity and the operation of its laws in the 

 production of the normal man. In this and suc- 

 ceeding chapters we shall consider heredity in its 

 relation to the abnormal man. We shall notice 

 especially the prenatal influences of the several 

 great social evils, such as intemperance, commer- 

 cialism, etc., and the part they play in heredity. 



The rapid increase in the dependent and delin- 

 quent classes in both Europe and America pre- 

 sents one of the most formidable problems of 

 the twentieth century. Despite the combined in- Increase of 

 fluences of law, education and religion, the feeble- egcn 

 minded, the insane and the criminal classes are 

 gaining in civilized countries at an almost in- 

 credible rate. 



In France crime nas more than trebled in the 

 last quarter of a century; the same may be said 

 of Italy, while Russia is not far behind. The 

 increase in crime in Germany is a little less than 



