THEORIES OF IMMUNITY. 



cess; then the H groups not needed are thrown 

 off into the blood stream and exist as 



H+iJ+X, or the immune body. 



The reactions in hemolysis having been made 

 more clear by the investigations of Ehrlich 

 spoken of above, it became evident that the 

 reaction in bacteriolysis (of which Pfeiffers 

 phenomenon was the first example) could be ex- 

 plained in the same way — and it can also be 

 shown by a formula similar to that used in the 

 demonstration of hemolysis, as follows: 



The bacteriolytic reaction requires for its 

 completion 



1. The bacterial cell, molecule=H+T+X 



2. The immune body, " =H.+H+X 



3. The complement, " =iJ+L+X 



Then, as before, the complement and the im- 

 mune body are bound together by one set of 

 haptophorous atom groups ; these two are bound 

 to the bacterial cell by another similar set of 

 atom groups, and when this has occurred, the 

 lysin atom group (L) can set up its action and 

 the bacterial cell may be destroyed. 



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