472 BACTEBIOLOaY. 



animals be subjected to injections of the poisonous pro- 

 ducts of growth of certain virulent bacteria, they re- 

 spond to this treatment by more or less pronounced 

 constitutional reactions, and that during this period, 

 and for a short time following, they are protected from 

 the invasion of the virulent bacteria themselves. This 

 observation has, moreover, not been confined to those 

 cases in which injections of the products of growth have 

 been followed by inoculations with the bacteria by 

 which they were produced, but, what is still more in- 

 teresting and confirmatory of Buchner's view, it is 

 claimed that a sort of protection from certain specific 

 infections can also be afforded to animals by the injec- 

 tion into them of cultures of entirely different species of 

 bacteria, or their products, and that in some cases these 

 are not of necessity of the disease -producing variety. 

 For instance, Emmerich and Mattel^ claim to have 

 rendered rabbits insusceptible to anthrax through injec- 

 tions into them of cultures of the streptococcus of ery- 

 sipelas. 



This, they claim, is not due to any antagonism be- 

 tween the organisms themselves, for in culture experi- 

 ments the two organisms grew well together, without 

 any alteration in their pathogenic properties, but rather 

 to the induction of a tissue-activity by which resistance 

 to the inroads of the virulent bacilli was established. 

 Emmerich and Mattel interpret this " reactive tissue- 

 change" as a power acquired by the integral cells of the 

 body, through the influence of a stimulus, of generating 

 a product that is detrimental to the pathogenic activity 

 of the anthrax bacilli. 



1 Einmericli und Matti : Portschritte derMedizin, 1887, p. 653. 



