388 HEMOLYSINS 



suitable amboceptor. This is known as the main or dominant comple- 

 ment; other complements that may aid in the process are termed non- 

 dominant. In general, it is held that those complements that are 

 especially active in hemolysis are but slightly active in bacteriolysis, and 

 vice versa. Although the amboceptor is depicted as having but one 

 haptophore arm for the dominant complement, it is really a polyceptor, 

 and is so constituted that it combines with the cell to be dissolved, on the 

 one hand, and with a number of complements, on the other. 



Bordet has never accepted these views. He holds that the antibody 

 is not an amboceptor for uniting cell and complement, but that it sensi- 

 tizes the cell and renders it susceptible to the direct lytic action of the 

 alexin or complement. According to his views, both antibody and 

 complement may unite directly with the cell, and he has borne out this 

 belief by making experiments almost exactly similar to those made by 

 Ehrlich. 



In accepting Ehrlich's view, it is a question of considerable practical 

 importance whether the complement may unite directly with free am- 

 boceptor. Ehrlich maintains that the two may enter into a loose and 

 easily dissociated chemical combination, which is hastened by heat and 

 retarded by cold. The union of hemolytic amboceptor in cobra venom 

 with the lecithin of corpuscles (Kyes' cobra lecithid), which acts as com- 

 plement, while it tends to strengthen this view can hardly be accepted 

 as direct proof, as lecithin differs markedly from the ordinary comple- 

 ments found free in serum. Likewise the theory of Neisser and Wechs- 

 berg regarding complement deviation, whereby it appears that an excess 

 of amboceptor may combine directly with complement and in this 

 manner rob those amboceptors that are attached to cells of the comple- 

 ment necessary to produce lysis, is quite complicated, and is not uni- 

 versally accepted, the evidence of direct union of complement and am- 

 boceptor having not been proved beyond the peradventure of a doubt. 

 It follows, then, as Emery has stated, that we must either assume that 

 the complementophile haptophore of an amboceptor united with its 

 antigen has an increased affinity for complement over and above that of 

 free amboceptors, or we must agree with Bordet that cell and comple- 

 ment unite directly after the former has been sensitized by the action of 

 the antibody. This latter view of the separate union of cell with anti- 

 body and complement is supported by the observations of Muir, who 

 found, upon saturating red blood-corpuscles with antibody and then with 

 complement, that some of the former but none of the latter may be dis- 

 sociated from the combination and become free in the fluid. However, 



