564 COLLECTED STUDIES IN IMMUNITY. 



of complements. Naturally the different complements must have 

 different complementophile groups corresponding to them. Eut, as 

 was stated in the Sixth Communication on Hsemolysins, 1 an immune 

 body, in addition to a particular cytophile group, contains two, three, 

 or more complementophile groups. In a later paper Ehrlich and 

 Marshall offered experimental evidence for just this point; besides 

 this, Bordet's experiments, according to which an amboceptor after 

 having combined with cellular elements is able almost completely 

 to rob a serum of its complement, also support this view. 2 



We must therefore conceive the amboceptor to be structurally 

 a polyceptor, and assume further that the amboceptors of a distinct 

 species are all supplied with a large number of complementophile 

 groups which vary considerably in detail but in their entirety repre- 

 sent a uniform complex. This complex is reproduced in all the 

 amboceptors of the same serum. In general the amboceptors are 

 different and specific only so far as the cytophile group is concerned. 



This being so it will at once be clear that antiamboceptors directed 

 against the complementophile groups, and obtained through immuni- 

 zation with any particular amboceptor, will act against all ambocep- 

 tors of the same animal species no matter whether these ambo- 

 ceptors are normally present in the serum or have been produced 

 by immunization. For the complementophile amboceptor apparatus 

 is the same for all types of amboceptors of the same species. As a 

 result of this, an immune serum obtained through immunization 

 with normal serum contains, thanks to the normal amboceptors in 

 the serum, antiamboceptors directed against the artificially produced 

 amboceptors of the same species. This explains also the earlier 

 observations made by Pfeiffer and Friedberger 3 that antiamboceptors 

 obtained by immunizing with cholera serum act also against typhoid 

 serum; 4 it also explains the recent experiments made by Pordet. We 



1 Ehrlich and Morgenroth. See page 88. 



2 P. Ehrlich and H. T. Marshall, Uber die complementophilen Gruppen 

 der Amboceptoren. Berl. klin. Wochenschr. 1902, No. 25. 



3 R. Pfeiffer and E. Friedberger, Weitere Beitrage zur Frage der Antisera 

 mid deren Beziehungen zu den bacteriolytischen Amboceptoren. Centralblatt 

 f. Bacteriol. 1904, Vol. 37; also 1903, Vol. 34. 



4 Naturally the statement made by Ehrlich and Morgenroth (Berl. klin. 

 Wochenschr. 1901, No. 21) that "it seems improbable, unless in a given case 

 a fortunate coincidence intervenes, that anti-immune bodies will be obtained 

 directed against the bactericidal immune bodies" cannot apply to the antiambo- 

 ceptors directed against the complementophile groups. That statement applies 



