114 



COLLECTED STUDIES IN IMMUNITY. 



are concerned. In this connection it is particularly interesting 

 to note that by long-continued treatment of a goat with rabbit 

 serum we obtained an anticomplement serum which acted also 

 against guinea-pig serum. Table XI will make this clear. All of 

 the experiments are made with an immune body derived from a 

 rabbit by immunizing with ox blood. 



TABLE XL 



+ + + = strong protection; ++ = fairly strong protection; + = very slight 

 protection. 



With the assumption of a plurality of complements we are led to 

 the view that the various complementophile groups of the immune body 

 here concerned (contained in rabbit serum) are complemented by a 

 like number of partial complements. As a result of this fact the possi- 

 bility exists that certain of these complements are not constant, occurring 

 in the blood only from time to time. 



We may perhaps give another example of these partial com- 

 plements, which concerns one of a number of rabbits treated with 

 repeated injections of goat serum. As already described in a previous 

 communication, this results in the disappearance of certain com- 

 plements and their replacement by corresponding autoanticomple- 

 ments. In the example mentioned, this disappearance manifested 

 itself by the fact that large amounts of the rabbit serum were 

 unable to activate the single or the double fatal dose of the 

 immune body from a rabbit immunized with ox blood. How- 

 ever, when thirty times the amount of immune body was employed 

 complete solution ensued. Evidently the principal portion of the 

 complements usually present had disappeared from this serum, but a 

 partial complement had remained which acted on a partial-immune 

 body present in relatively small amounts. The circumstances in this 

 case therefore are entirely analogous to those above described in 



