148 



THE VENOM OF HELODERMA. 



more, in the experiments with the fresh venom the addition of a quantity equal 

 to only one-quarter the hemolytic dose of lecithin was needed in order to cause 

 hemolysis, while with the dissolved dry venom a quantity equal to two-fifths of 

 the hemolytic dose of lecithin was added. 



We also tested the hemolytic doses of venom and lecithin with a constant 

 quantity of lecithin and variable doses of venom, and found that when minute 

 quantities of venom were added to a quantity of lecithin equal to two-fifths of 

 the hemolytic dose, the ox corpuscles were hemolyzed. 



2 ex. of 5 per cent suspension of ox corpuscles. 

 [Lecithin, 0.02 rag. added to each tube.] 



SHEEP CORPUSCLES. 



A similar series of experiments was carried out with sheep corpuscles. 

 2 c.c. of 5 per cent suspension of sheep corpuscles. 



From these experiments we may conclude that, to lecithin alone, the sheep 

 corpuscles are more resistant than the ox corpuscles, and that the latter are 

 more resistant than the guinea-pig corpuscles. 



When venom and lecithin are mixed the sheep corpuscles are hemolyzed 

 by quantities of lecithin smaller than the hemolytic dose of unmixed lecithin. 

 Thus with fresh venom we obtained hemolysis of the corpuscles with a quantity 

 of lecithin equal to one-quarter the usual hemolytic dose; with the dissolved 

 dry venom (0.2 mg.) about one-tenth the usual hemolytic dose of lecithin 

 was required. 



2 c.c. of 5 per cent suspension of sheep corpuscles, lecithin 0.02 mg. added to each tube. 



