SINGLE NATURE OF HEMOLYTIC IMMUNE BODIES. 337 



still the ability to absorb additional portions of alexin. I have 

 found also that stromata produced by heating corpuscles to 55 

 degrees for half an hour retain unimpaired their power of absorbing 

 immune body, or, if previously sensitized, of absorbing alexin. 

 Rabbit corpuscles are completely hemolyzed by this temperature, 

 but ox corpuscles, although showing a reduction of hemoglobin, 

 remain, for the most part, microscopically intact. The affinities 

 of ox corpuscles after heating to 55 degrees are shown by the follow- 

 ing experiment: 



THREE TUBES ARE PREPARED AS FOLLOWS: 



Tube A. Ox corpuscles previously heated to 55 degrees (not hemo- 

 lyzed) 0.2 c.c. 

 Serum rabbit > ox, 55 degrees 0.8 c.c. 

 S. guinea-pig (alexin) 0.5 c.c. 

 Tube B. Ox corpuscles, 55 degrees 0.2 c.c. 

 S. normal rabbit, 55 degrees 0.8 c.c. 

 S. guinea-pig 0.5 c.c. 

 Tube C. Ox corpuscles, 0.2 + Serum rabbit > ox, 0.8, heated 

 to 55 degrees 

 S. guinea-pig 0.5 c.c. 



In tubes A and C hemolysis is complete; in B nul. 

 To the centrifugalized supernatant fluids of A, B and C is added 

 subsequently 



Ox corpuscles 0.1 c.c. 



S. rabbit > ox, 55 degrees 0.4 c.c. 



Tube D (control). Ox corpuscles 0.1 c.c. 



S. rabbit > ox, 55 degrees 0.4 c.c. 



S. guinea-pig 0.2 c.c. 



In tubes B and D hemolysis is complete. 



In tubes A and C hemolysis nul. 



Similar results may be obtained with rabbit corpuscles with the 

 exception that they are hemolyzed by heating to 55 degrees. 



In considering the nature of the guinea-pig > rabbit immune body 

 I shall give an example in which the relative doses of the immune 

 body and the alexin of rabbit or of guinea-pig chanced to be the 

 same as in the classical example of Ehrlich. Of course it is under- 

 stood that this relation is not a fixed one, as Ehrlich has shown. In 

 this case, in order to produce hemolysis of rabbit corpuscles in the 

 presence of sufficient rabbit alexin, it took ten times the amount of 

 heated immune serum as when using guinea-pig alexin. In the 

 language of the Ehrlich hypothesis, the necessary dose of immune 

 serum with rabbit alexin may be represented by 10 "A" + 1 "B," 

 "A" being the partial immune body suitable for guinea-pig alexin 



