94 



THE VENOM OF HELODERMA. 



We may conclude from these experiments that the addition of normal- 

 heloderma serum or of the serum of a Heloderma from which the venom gland 

 had been removed does not neutralize the venom. In a few cases the animals 

 which were injected with venom mixed with serum of a glandless heloderma 

 lived somewhat longer than controls injected with a similar quantity of venom; 

 and two animals recovered, while the controls died. In other cases, no effect 

 of the heloderma serum was noticeable. Inasmuch as guinea-pig serum and 

 ox serum had in a few cases a similar effect, wo can not attribute to the serum 

 of Heloderma, when mixed with heloderma venom, any specific antitoxic effect. 



We tested the serum of glandless helodermas, having in mind the possi- 

 bility that the venom gland might discharge some venom into the blood and 

 that the venom present in the blood might obscure a possible antitoxic propertj- 

 of the serum. 



We may, therefore, conclude that the resistance of the Heloderma to the 

 injection of large doses of venom is not due to an>' substance contained in the 

 circulating blood. 



DOES THE INJECTION OF VENOM PRODUCE A STATE OF ANAPHYLAXIS? 



We injected pigeons, mice, and rabbits with heloderma venom, and several 

 days or weeks later injected these animals a second time in order to determine 

 whether any phenomena of anaphylaxis could be found. 



Twelve pigeons were injected with doses of venom varying from 0.2 to 0.6 

 mg.; at various times from 4 to 33 days after the first, a second injection was 

 given. Three animals died after the second injection, but in all these cases 

 death was due to the administration of an overdose of venom. The nine 

 remaining animals showed no ill effects whatever from the second injection. 

 The results of these experiments are given in the following table : 



Experiments in anaphylaxis (pigeons). 



Eleven mice were injected with venom on two separate occasions. One 

 lot of six mice was given the second injection 14 days after the first; another lot 

 of five was injected a second time on the twentieth day after the first injection. 

 None of the mice showed any symptoms after the second injection. In the 

 table following the amount of venom injected and the time interval between 

 the two injections are given: 



