H&MOLYSINS. 47 



Anti-complement. Since the complements are 

 constituents of normal serum, it should be possible 

 to produce anti-complements by injecting animals 

 merely with normal serum ; and they can, in fact, 

 be so produced. If rabbits are treated by inject- 

 ing them several times with normal guinea-pig 

 serum, a serum may be obtained from these rabbits 

 which contains anti-complements against the com- 

 plements of normal guinea-pig serum. A serum 



n. 

 [ 



COMPLEMENT 



COMPLEMENT 



ANTICOMPLEMENT 

 IMMUNE BODY 



CELL m m {: U CELL 



FlG. 3. (After Levaditi.) 



obtained in this way of course contains only one of 

 the anti-haemolytic bodies, the anti-complement, 

 and not the anti-immune body. This is because 

 normal serum is too poor in immune body (inter- 

 body) to excite the production of any anti-immune 

 body. 



If to a haemolytic serum derived from guinea-pigs 

 we add an anti-complement serum derived, as just 

 stated, from rabbits and containing an anti-com- 

 plement specific for guinea-pig complement, the 



