248 INFECTION AND IMMUNITY 



The Specificity of Hemolysins. In the sections preceding we have 

 seen that the blood cells of one animal, injected into an animal of an- 

 other species, give rise to a hemolytic substance in the blood serum of 

 the second animal, which is strictly specific for the variety of cells in- 

 jected. Such hemolysins, when produced in one animal against blood 

 cells of another species, are spoken of as heterolysins. In studying the 

 nature of hemolysis,* Ehrlich and Morgenroth 1 now discovered that 

 hemolysins could also be produced if an animal were injected with red 

 blood cells of a member of its own species. Such hemolytic substances 



lenient 



I (S.fp-- -Red bipod cell 



3. /p^- 



If (2) present, no haemolysis. 

 If (2) not present, haemolysis. 



FIG. 64. SCHEMATIC REPRESENTATION OF COMPLEMENT FIXATION IN THE 

 BORDET-GENGOU REACTION. 



they called isolysins. In their experiments they injected goats with 

 the washed red blood corpuscles of other goats and found that the 

 serum of the recipient developed the power of causing hemolysis of 

 the red blood 'cells of the particular goat whose blood had been used 

 for injection. It did not, however, possess the power of producing 

 hemolysis in the blood of all goats, nor did it produce hemolysis with the 

 red corpuscles of its own blood. It is thus shown that the specificity 

 of the hemolysins extends even within the limits of species, and is, to 

 a certain extent, an individual property. 



The production of autolysins, that is, of substances in the blood 

 serum which will produce hemolysis of the individual's own corpuscles, 

 has, so far, been unsuccessful. 



1 EhrUch und Morgenroth, Berliner klin. Woch., xxi, 1900. 



