INHERITANCE OF ACQUIRED CHARACTERS 93 



integral part of the fertilized egg and thus cross the 

 "hereditary bridge" which joins two generations. 

 A general predisposition to bacterial disease, that is, a 

 lack of resistance to bacterial invasion due to de- 

 fectiveness in physical or physiological equipment, 

 may be present as a combination of characters in 

 the germplasm, or an individual, as the result of 

 disease, may "acquire" a generally weakened germ- 

 plasm and so produce a progeny exhibiting general 

 liability to disease ; but it is doubtful if such a con- 

 dition can properly be termed the inheritance of 

 an acquired character, since the particular definite 

 disease in question is not demonstrably heritable. 



When alcoholism "runs in a family," its reappear- 

 ance in the son is probably due to the fact that he 

 is derived from the same weak strain of germplasm 

 as his father. The fact that the father succumbed 

 to the alcohol habit is not the determining cause of 

 drunkenness in the son. The same thing that caused 

 the father to become an alcoholic, namely, weak 

 germplasm, and not the resulting drunkenness in the 

 parent, is the causal factor for alcoholism in the son. 



At the same time it is entirely probable that hered- 

 itary alcoholism may in some cases arise through 

 "parallel induction," that is to say, acquired alco- 

 holism may end in the simultaneous poisoning and 

 consequent modification of both the somatoplasm and 

 germplasm of the parent, with the result that the 

 germplasm has less resistance to alcoholism in a suc- 

 ceeding generation. The offspring are consequently 

 more likely to succumb to the disease. This, how- 



