70 PROPERTIES OF H^EMOLYTIC SERA 



combines with the same molecules as complement, viz. 

 with the complex receptors + immune-body. We claim, in 

 fact, that the existence of complementoids has been demon- 

 strated by test-tube experiments, and that Ehrlich's views 

 regarding these bodies have been completely confirmed. 

 It would, in fact, be impossible to explain the high dose 

 of complement necessary when the corpuscles are suspended 

 in guinea-pig's serum 55 on the theory that comple- 

 mentoids are merely attentuated complements, i.e. atten- 

 uated in combining affinity and toxic action in equal degree. 



Summary of results : 



1. The dosage of complement varies greatly according 

 to the medium in which the red corpuscles are suspended. 



2. The most striking variation observed was the very 

 high dose of guinea-pig's complement necessary to produce 

 lysis when ox's corpuscles are suspended in guinea-pig's 

 serum 55, a dose which is about six times the dose necessary 

 in salt solution and about three times the dose in ox's 

 serum 55. 



3. The high dose of complement necessary is chiefly 

 due to the complement being prevented from entering 

 into combination with the corpuscles treated with immune- 

 body. 



4. When the complement in guinea-pig's serum is 

 removed by combination instead of being converted into 

 complementoid by heating at 55 C., the dosage of com- 

 plement in such a treated serum is much diminished and 

 becomes approximately the same as in ox's serum 55. 



5. We conclude that the presence of a large amount 

 of guinea-pig's complementoid interferes with the com- 

 bination of complement, and the dose of the latter necessary 

 for lysis is thus increased. 



