152 



THE VENOM OF HELODERMA. 



puscles. In testing the influence of venom plus lecithin on the heloderma 

 corpuscles we used corpuscles from normal animals as well as from those whose 

 venom glands had been removed some time previously. At the same time a 

 comparison was made with guinea-pig corpuscles. 



Venom, 0.1 mg. in each tube. 



From these experiments it may be seen that the heloderma corpuscles are 

 very much more resistant to hemolysis by venom and lecithin than are guinea- 

 pig corpuscles, and (in one experiment) that the corpuscles of the glandless 

 animal were somewhat more resistant than those of the normal heloderma. 



In another experiment we found the heloderma corpuscles much more sen- 

 sitive to the hemolytic action, by the addition of small quantities of lecithin, 

 to both fresh and dissolved dry venom. We found the addition of ^ of the 

 usual hemolytic dose of lecithin to a small quantity of venom (0.001 c.c. or 0.1 

 mg.) was sufficient to cause hemolysis of 1 c.c. suspension of the heloderma 

 corpuscles. The heloderma corpuscles are not resistant to heloderma venom- 

 lecithin hemolysis. 



/ c.c. of 5 per cent suspension of heloderma corpuscles {nornml). 



Summary. 



Lecithin activates venom in the case of all corpuscles used in these experi- 

 ments, namely, corpuscles of ox, sheep, dog, rabbit, guinea-pig, turtle, frog, and 

 Heloderma. The susceptibility of the various corpuscles toward the venom- 

 lecithin mixtures varies, but in general the corpuscles of the warm-blooded ani- 

 mals are hemolyzed if a quantity of lecithin equal to from one-half to one-tenth 

 of the hemolytic dose of lecithin is added to the venom, while the corpuscles 

 of the cold-blooded animals are hemolyzed by the addition to the venom of 

 a quantity of lecithin equal to ^ to j^ of the hemolytic dose of lecithin. 

 Since the quantity of lecithin which must be added to venom in order to cause 

 hemolysis varies only within a relatively small range in the case of various cor- 



