STUDIES ON ttEMOLYSIS. 35 



of buck A to isolysin B is a secondary one, due to the treatment; 

 for thus far, among the many normal goats examined, we have failed 

 to find a single one whose blood-cells are completely insensitive to 

 isolysins A or B. 



These phenomena require further and more extended investi- 

 gation, and in this we are at present engaged. 



In closing we should like to point out that the difference between 

 isolysins and autolysins emphasized by us makes several recent 

 attempts directed to the solution of certain pathological processes, 

 particularly those of autointoxication in man, appear questionable. 

 It has frequently been ascertained that serum secretions and excre- 

 tions of the diseased body are poisonous in animal experiments, 

 and the conclusion has been drawn that the substances to which 

 this poisonous action is due must exert an injurious effect on the 

 organism of the patient. From the above analysis we see that this 

 conclusion is not at all imperative. If, for example, the serum of 

 a scarlet fever patient is especially toxic to guinea-pigs, it is possible 

 that the same may be absolutely harmless to the patient himself. 

 Even if one demonstrates that the serum of anaemic individuals dis- 

 solves the blood-cells of other individuals, it does not prove that 

 this property is of any significance for the origin of the anaemia. 

 On the contrary it is highly probable that this hamolysin is only 

 an isolysin and not an autolysin. 



The above experiments may suffice to show how very complicated 

 the conditions are when the material of its own body is absorbed 

 by an organism. Drawing a general conclusion, however, we may 

 say that such an absorption, which as already stated extends to 

 the greatest variety of cells and occurs in numerous instances, will 

 not as a rule lead to permanent injury of the organism, owing to 

 the formation of reaction products. Only when the internal regu- 

 lating contrivances are no longer intact can great dangers arise. 

 In the explanation of many disease phenomena it will in the future 

 be necessary to consider the possible failure of the internal regu- 

 lations as well as the action of directly injurious exogenous or endog- 

 enous substances. 



