THEORIES OF IMMUNITY. 



The two H groups are bound together, thus: 



/II+T+X 



\h+x 



therefore the T group in the toxine cannot be 

 bound to anything else, and the substance exists 

 as a harmless material in the blood stream. 



The production of the antitoxine by the injec- 

 tion of the toxine maybe represented as follows: 

 Tissue cell molecule contains . . H+X+X 

 Toxine cell molecule contains . . H+T+X 

 The H groups bind the two together; but 

 the H group of the tissue cell molecule is nec- 

 essary for the metabolism of the cell ; it must be 

 reproduced if the cell is to live; being so repro- 

 duced the reproduction occurs in excess, and 

 then the H groups are thrown off and exist free 

 in the blood stream as 



H+X, which is the antitoxine. 



Bordet's work on Hemolysis, and Ehrlich's 

 later work, showed that two substances were 

 necessary for other reactions, and necessitated 

 the supposition of the existence of two hapto- 

 phorous atom-groups. In accordance with this 



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