562 COLLECTED STUDIES IN IMMUNITY. 



complementophile group of the complement. Each of these two 

 haptophore groups will therefore be able to excite the production 

 of corresponding antibodies, a fact to which attention was called 

 in the Croonian lecture, 1900. 1 



"The lysin, be it bacteriolysin or hsemolysin, possesses altogether 

 three haptophore groups, of which two belong to the immune body 

 and one to the complement. Each of these haptophore groups can 

 be bound by an appropriate antigroup." Three ' antigroups ' are thus 

 conceivable, any one of which, by uniting with one of the haptophore 

 groups of the lysin, can frustrate the action of the lysin." 



In other words, according to the amboceptor theory two different 

 antiamboceptors are at once conceivable, either of which would 

 inhibit the action of the amboceptor. One would act by preventing 

 the union of amboceptor and cell, the other by preventing the comple- 

 ment from uniting with the amboceptor. Originally the antiambo- 

 ceptors produced by immunization were regarded as being directed 

 against the cytophile group. 2 In view of this it was extremely de- 

 sirable for the support of the amboceptor theory that the existence 

 of antibodies for the complementophile group should be demon- 

 strated. This has recently been done by Bordet, 3 and it is strange 

 to see that he employs his discovery in combating the receptor theory 

 when it really is a very neat confirmation of this. 



Bordet finds that antiamboceptors can be produced not only by 

 immunization with hsemolytic immune serum, but also with normal 

 serum of the same species, even though this normal serum contains 

 no corresponding amboceptors. He treated guinea-pigs with normal 

 rabbit serum which contains no hsemolytic amboceptors for ox 

 blood, and obtained an immune serum, which yet was able to in- 

 hibit the action of the amboceptors derived by immunizing with 

 ox blood. That, certainly, is a discovery which cannot readily be ex- 

 plained in harmony with Bordet's sensitization theory. According 

 to Bordet, as we know, these immune bodies (his "sensitizers") 

 possess the one property of combining with the susceptible cell 

 and thus rendering this vulnerable to the action of the complement. 

 This being the case it is incomprehensible how a serum which.possesses 



1 P. Ehrlich, On Immunity, Proceedings Royal Society, 1900. 



2 Ehrlich and Morgenroth, VI. Communication, page 88. 



3 J. Bordet, Les propriete's des antisensibilatrices et les theories chimiques 

 de l'immunite\ Annal. de 1'Instit. Pasteur, 1904, No. 10. 



