HEMOLYTIC PROPERTIES OF HELODERiLA. VENOM. 



169 



not sufficientlj' numerous to establish the latter point, and we can at present 

 only state that alkalis do not activate heloderma venom. 



CONCLUSIONS. 



I. Neither the venom of Heloderma susj)edum nor that of Heloderma hor- 

 ridum possesses hemolytic power when added to erythrocytes. 



II. When lecithin is added to the venom of either H. suspedum or H. 

 horridum, erythrocytes are hemolyzed. Horse, ox, sheep, dog, rabbit, guinea- 

 pig, turtle, frog, and heloderma corpuscles may thus be hemolyzed. The 

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

 the corpuscles varies between one-half and one-tenth of the quantity of lecithin 

 which by itself is able to produce hemolysis. In the experiments with turtle 

 and heloderma corpuscles, a quantity of lecithin equal to 15 and 405 respectively 

 of the hemolytic dose of lecithin is able to activate the venom. 



III. Sodium oleate also activates the heloderma venom, but its activating 

 power is less than the power of lecithin. 



IV. Alkalis (sodium hydroxide and sodium bicarbonate) do not activate 

 heloderma venom. 



V. The blood sera of the horse, dog, and turtle, either unheated or heated 

 to 56° C. or even 70° C, activate the venom of Heloderma. On the other hand, 

 ox, sheep, rabbit, guinea-pig, frog, and heloderma serum, either heated or 

 unheated, do not activate the venom. 



VI. The blood-corpuscles of Heloderma, although not immune against the 

 hemolytic properties of heloderma venom in combination with activators, were 

 occasionally found to be more resistant than other corpuscles tested. 



VII. Certain sera, which do not activate the heloderma venom, inhibit the 

 venom-lecithin as well as the venom-serum hemolysis. Heating does not de- 

 stroy this propertJ^ Heloderma serum shows this property more strongly than 

 guinea-pig serum. Rabbit serum varies in its inhibitory power; the serum 

 from one rabbit may inhibit hemolysis, while that of another may not. We 

 found that on the second day after the rabbit serum was separated from the 

 clot its inhibitory power was increased, but on the third day there was again a 

 slight decrease of the inhibitory power. Guinea-pig serum also inhibits venom- 

 sodium-oleate hemolysis, while the rabbit serum tested did not have this inhib- 

 iting power. The inhibiting power of the sera varies with the various corpus- 

 cles. In the case of the heloderma and rabbit serum, the protective power was 

 greatest in combination with their respective corpuscles. 



