ANTIBACTERIAL SERUMS. 373 



because of its spontaneous degeneration. Theo- 

 retically, this difficulty may be obviated in three 

 ways: First, one may use serums which are fresh 

 from the immunized animal ; second, one may com- 

 plement the solution of amboceptors (old immune 

 serum) by the addition of fresh serum from a nor- 

 mal animal which is known to contain suitable 

 complement; or, third, one may inject the comple- 

 ment-free serum and place reliance on the comple- 

 ment which exists in the plasma and lymph of the 

 patient for activation of the amboceptors. It is 

 sufficiently established that none of these proce- 

 dures enhances the curative value of the serums to 

 a satisfactory extent. 



Eegardless of the amount of foreign comple- Absorptio 

 ment which is introduced, it appears to be di- 

 verted from its function. It has been shown ex- the 

 perimentally that the tissues may absorb a foreign 

 complement, and the mere fact that anticomple- 

 ments are formed so readily indicates that comple- 

 ment may be bound by the tissues. In accordance 

 with a rather general principle, if the animal 

 which furnishes the serum is remote from man 

 zoologically there is all the more likelihood of the 

 complement being fixed by human tissues. 



It has been suggested that if one should choose choice of 



. ... i T i Animals 



for immunization animals which are closely re- for immn 

 lated to man, as chimpanzees and monkeys, a 

 double advantage would be gained : First, the for- 

 eign complement may be identical or similar to 

 that in man and consequently would be less likely 

 to be absorbed by the tissues; and, second, the 

 complementophilous haptophores of the ambocep- 

 tors may be so constructed that human comple- 

 ment would serve for activation. Theoretically, 



