BACTERIOLYSINS AND H.EMOLYSINS 93 



source of an alexin, but claim that this is different 

 from that found in serum. Wassermann believes 

 that the leucocytes are a source of complements 

 (alexins), for he succeeded in producing anticom- 

 plement by means of injections of pure leucocytes 

 which had been washed free from all traces of serum, 

 and which had been obtained by injections of aleu- 

 ronat. In view of the plurality of the comple- 

 ments, Wassermann expressed the view that the 

 leucocytes are probably one source, but not the 

 only one, for the complements of the serum. Land- 

 steiner and Donath have confirmed this experi- 

 mentally. They succeeded in producing anticom- 

 plement by the injection, not only of leucocytes, 

 but of other animal cells. Furthermore, the experi- 

 ments of Ehrlich and Morgenroth already mentioned, 

 in which the complements disappeared after the 

 destruction of the liver function, show that the liver 

 cells are concerned in the formation of complements. 

 Structure of Complements Haptophore and Zy- 

 motoxic Groups Complementoids. - - The structure 

 of the complement has been studied particularly by 

 Ehrlich and Morgenroth, and by P. Miiller. We 

 have seen that the complements lose their power 

 when heated to 55C. If, however, we inject ani- 

 mals with a normal serum that has previously been 

 heated to 55C., we shall still excite in these ani- 

 mals the production of anticomplements. This 

 shows that the heating has not destroyed the entire 



