346 COLLECTED STUDIES IN IMMUNITY. 



In studying the sediments the question is always whether these 

 have taken up amboceptor or not. This is most easily determined 

 by the addition of complement. This procedure, however, should 

 be supplemented by the more difficult and troublesome investigation 

 of the binding power of the blood-cells for newly added amboceptor. 

 In this case, of course, a parallel test with untreated blood-cells fur- 

 nishes the basis for comparison. As a rule experiments at moderate 

 temperatures suffice; only hi case II is a variation of temperature 

 required. 



In case I the complement is deflected by means of an anticomple- 

 ment. One must take into consideration both natural anticom- 

 plements and those artificially produced by immunization; further- 

 more, attention must be paid to similarly acting derivatives of the 

 amboceptors, the amboceptors, whose complementophile group has 

 been preserved. 1 The behavior of the amboceptoids, especially in 

 those cases in which the affinity of the complementophile group of 

 these amboceptoids has become increased, will in no way differ from 

 that of the anticomplements. Finally we must remember that the 

 .amboceptors can act in a way like anticomplements as a result of 

 the deflection of complements by excess of amboceptor, a phenomenon 

 first described by Neisser and Wechsberg (see page 120). In that 

 case, of course, the decanted fluid contains the excess of amboceptors 

 .and the complement bound to the same. 



II. In case II the complementophile group of the amboceptor is 

 blocked. Here we must first consider the action of complementoids 

 (see Ehrlich and Sachs, page 209) , although, according to our present 

 experiences, these only seldom come into play because, in the forma- 

 tion of complementoid, there is usually a decrease of affinity. 



III. The third possibility is the action of antiamboceptors which 

 fit into the cytophile group of the amboceptors. They may be 

 present normally or produced artificially by immunization. From 

 a theoretical standpoint these antiamboceptors are to be identified 

 with the receptors of the cells into which the amboceptors fit. Hence 

 thrust-off receptors present in solution will act as antiamboceptors. 2 

 According to recent investigations the serum against snake venom 



1 Wechsberg, Wiener klin. Wochensch. 1902, No. 28; E. Neisser and Friede- 

 mann, Berl. klin. Wochenschr. 1902, No. 29. 



'Morgenroth, page 241; also P. Miiller, Munch, med. Wochenschr. 1902, 

 No. 32. 



