5 6 IMMUNE SERA. 



a toxophore group. And just as those toxins which 

 had lost their toxophore group were called toxoids, 

 so Ehrlich and Morgenroth purpose to call comple- 

 ments which have lost their zymotoxic group com- 

 plementoids. 



Isolysins Autolysins Anti-isolysins. All of the 

 preceding studies in haemolysis have concerned 

 themselves with the results obtained by injecting 

 animals of one species with blood-cells of another. 

 Ehrlich and Morgenroth now sought to discover 

 what the result would be if they injected an animal 

 with blood-cells of its own species. They injected 

 goats with goat blood, and found that when the 

 amount injected at one time was large the serum 

 of the goat injected acquired haemolytic properties 

 for the blood of many other goats but not for all. 

 The substances thus formed the authors called 

 isolysins. These, then, are substances which will 

 dissolve the blood of other individuals of the same 

 species. Substances which dissolve the blood-cells 

 of the same individual are called autolysins. But 

 autolysins have so far been demonstrated experi- 

 mentally only once (by Ehrlich and Morgenroth). 

 If one tests the properties of an isolysin of a goat on 

 the blood of a great many other goats, it will be 

 found that this will be strongly solvent for the 

 blood of some, slightly for the blood of others, and 

 not at all for still others. 



By using a blood that was readily dissolved by 

 the isolysin, and proceeding in the same series of 



