INFECTION AND IMMUNITY. 593 



a product that is detrimental to the pathogenic activity 

 of the anthrax bacilli. In a later paper 1 Emmerich, in 

 association with Low, offers still another explanation for 

 the phenomenon. They believe that the protection 

 afforded an animal from a specific infective organism 

 by the injection into it of another organism or the 

 products of its growth is due to the direct bacteriolytic 

 action of the enzymes peculiar to the latter upon the 

 former species. In their opinion, the enzymes of the 

 latter organism enter into a more or less stable combina- 

 tion with the living protoplasm, and in this state are 

 actively destructive (digestive) for the invading patho- 

 genic species. 



Pawlowsky, 2 who obtained similar results from the 

 introduction into animals of cultures of bacillus pro- 

 digiosuSj of micrococcus aureus, and of micrococcus lan- 

 ceolatus, believes them to be due to the induction of 

 increased energy on the part of the wandering cells, 

 preparing them thus for the difficult task of destroying 

 the more virulent organisms with which the animal is 

 subsequently to be inoculated. 



Protection afforded in this way apparently contra- 

 indicates a specific relation between the morbific ele- 

 ments of particular infections and the protective sub- 

 stances that are present in the body of the animal that 

 has been rendered insusceptible to them. It is proba- 

 ble, however, that this is only apparent, and that the 

 observations of Emmerich and Mattei and of Paw- 

 lowsky can be interpreted in another way: in the blood 

 of animals there is present what may be termed a nor- 



1 Emmerich und Low : Zeitschrift fur Hygiene und Infektionskrank- 

 heiten, 1899, Bd. xxxi. S. 1-5. 



2 Pawlowsky: Virchow's Archiv, vol, cviii. p. 494, 



38 



