150 



THE VENOM OF HELODERMA. 



the lecithin hemolysis and in such cases we were also unable to produce hemoly- 

 sis with the venom-lecithin mixture. However, in one case in which the cor- 

 puscles were less resistant than usual, we found that the combination of venom 

 and lecithin caused hemolysis of the corpuscles even if a quantity of lecithin 

 equal to only one-tenth the dose hemolytic for rabbit corpuscles was added. 

 The lecithin activates the venom for rabbit corpuscles as it does for ox, sheep, 

 and dog corpuscles. 



In testing the hemolytic action of a constant quantity of lecithin and a 

 diminishing quantity of venom we were unable to overcome the great resist- 

 ance of the rabbit corpuscles, and were thus unable to carry out satisfactory 

 experiments. 



Gtjinea-Pig Corpuscles. 



In our experiments, the guinea-pig corpuscles were fairly resistant to 

 hemolysis by lecithin alone, 0.1 mg. of lecithin being required for partial hem- 

 olj'sis. If, however, lecithin was added to 0.1 mg. of heloderma venom the 

 corpuscles were hemolyzed after addition of only 0.02 mg. of lecithin, only one- 

 fifth of the usual hemolytic dose. 



2 c.c. of 5 per cent suspension of guinea-pig corpuscles. 



With a constant quantity of lecithin and diminishing quantities of venom, 

 very small quantities of venom were able to cause hemolysis; even a.? little as 

 0.01 mg. of venom, added to the same quantity of lecithin, was sufficient to 

 cause hemolysis. It will be seen that in these experiments the degree of hemo- 

 lysis depended largely upon the amount of lecithin, while, for instance, 0.4 mg. 

 of venom plus 0.01 mg. of lecithin caused only moderate hemolysis, a similar 

 quantity of venom added to 0.1 mg. of lecithin (which of itself causes a trace 

 of hemolysis) caused complete hemolysis of the corpuscles. 



2 c.c. of 5 per cent suspension of guinea-pig corpuscles. 



