THEORIES OF IMMUNITY. 



The cell (of the body in which the 

 injection is made) the molecule 

 contains . . . . . H+^T+K"-|-X 



The complement (molecule con- 

 tains) ..... iZH-P+X 



The H groups are reproduced in excess as 

 before, and exist free as 



H+.//+X, the immune body necessary for this 

 reaction. 



Anti-complement reaction is shown : 

 The complement molecule contains . H+L+X 

 The anti-complement molecule con- 

 tains ...... H+L 



The two H groups combine, and the comple- 

 ment is rendered harmless by this combination. 



The production of the anti-complement is 

 shown thus: 

 The injected serum (containing complement) 



molecule contains H+N+X 

 The receiving blood molecule contains H+(II 



-hH+H+H+etc.)+X+X. 



The two H atom-groups combine, the one in 



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