160 



THE VENOM OF HELODERMA. 



corpuscles, but has no inhibitory influence on rabbit and dog corpuscles. In 

 the case of dog corpuscles, the lysis of the corpuscles appears more slowly in the 

 tubes to which heated guinea-pig serum is added than in those with fresh serurn. 

 When 0.1 mg. of venom mixed with 0.05 mg. of lecithin was added to 2 c.c. 

 of a 5 per cent suspension of guinea-pig, horse, or 1 c.c. of a 5 per cent suspen- 

 sion of turtle or heloderma corpuscles, hemolysis was complete or nearly com- 

 plete, but when sufficiently large quantities of guinea-pig serum were added to 

 these combinations hemolysis was prevented. When, for instance, 0.1 c.c. of 

 guinea-pig serum, either heated or unheated, was added to mixtures contain- 

 ing either horse or guinea-pig corpuscles, no hemolysis occurred. The addition 

 of 0.4 c.c. of serum was sufficient to completely prevent hemolysis with turtle 

 or heloderma corpuscles, while 0.1 c.c. had some inhibitory effect. 



Mixtures of 0.1 mg. of venom and 0.1 mg. of lecithin. 



With dog corpuscles no inhibitory action whatsoever could be observed 

 when either heated or unheated guinea-pig serum was added. The same was 

 true in the case of the rabbit corpuscles. 



No difference existed between the action of heated or unheated guinea- 

 pig serum in those cases in which an inhibitory action was demonstrated. 

 Qualitatively and quantitatively their action was the same. 



When heated horse serum was used as an activator instead of lecithin, 

 guinea-pig serum (both heated and unheated) inhibited hemolysis, very mark- 

 edly with horse corpuscles and slightly less markedly with guinea-pig corpuscles. 



Mixtures of 0.1 mg. of venom and 0.1 c.c. 

 of heated horse serum. 



Mixtures of 0.1 mg. of venom and 0.1 c.c. 

 heated dog serum and 2 c.c. of a 5 per cent 

 suspension of guinea-pig corpuscles. 



