58 IMMUNE SERA. 



large bloody effusions and haemorrhages might lead 

 to the formation by the organism of autolysins 

 against its own blood-cells. Gengou, a pupil of 

 Metchnikoff, in a very recent work, believes to have 

 shown experimentally that the destructive action 

 of these autolysins is hindered by the simultaneous 

 production of an auto-anti-immune body which 

 immediately inhibits their action. 



In order that isolysins may be formed, it seems 

 necessary to overwhelm the organism once or sev- 

 eral times with large amounts of cells or cell prod- 

 ucts of the same species; to produce, as Ehrlich 

 says, an ictus imniunisatorius . I tried, by using 

 various blood poisons, such as haemolytic sera, 

 toluylenediamine, etc., for a continued length of 

 time, to cause the formation of these isolysins, but 

 without success, although in these experiments 

 each injection was followed by an appreciable de- 

 struction of red cells and absorption of their decom- 

 position products. The gradual and even repeated 

 absorption of not too large quantities of decom- 

 posed red cells does not therefore lead to the forma- 

 tion of isolysins; but, as already said, a sudden 

 overwhelming of the organism by large amounts 

 of the cells or their products is necessary. 



