266 BACTERIOLOGY. 



especially light cases which, do not conform 

 to the schema. 



If we diminish the disposition of a man to- 

 ward a disease we influence his organization in 

 the sense of exalting its resistance to infection. 

 In this way the same effect is produced as when 

 we diminish the " contagious " or toxic quality 

 of the disease germ, the disposition of the man 

 to the disease remaining the same. The or- 

 dinary anthrax bacteria, for example, cause 

 in guinea-pigs a generalized blood-poisoning 

 which is speedily fatal, and in dogs, which are 

 naturally immune toward this disease they 

 cause at most an abscess, or a local suppuration. 

 But if we diminish to a certain extent the dis- 

 ease-producing power of the anthrax bacilli, 

 they provoke in the otherwise very susceptible 

 guinea-pig merely a local suppuration, which 

 readily heals. 



The disease germs remaining constant, it is 

 possible to heighten natural predisposition to 

 disease by starving animals, or chilling them, 

 or modifying their metabolism unfavorably, as 

 by inducing artificial diabetes. In such cases 

 animals succumb to the very disease germs 

 against which when in a normal healthy con- 

 dition they are immune. We know also that 

 through hunger, insufficient nutriment, and 

 disorders of metabolism such as diabetes, 



