72 THE VENOM OF HELODERMA. 



when very small quantities (between 2 and 8 drops) of the fresh undiluted 

 venom were administered subdurally to rabbits we found that animals injected 

 subcutaneously with similar quantities of venom died as soon or sooner than 

 those which were injected subdurally. Whether these contradictory results 

 represent a difference between the reactions of guinea-pigs and rabbits to the 

 heloderma venom, we can not state, but it appears most probable that the 

 differences are to be explained by the injection of the large quantity of fluid in 

 the experiments wth the guinea-pigs. It therefore seems that when venom is 

 injected subdurally it is no more active than when injected subcutaneously. 

 Perhaps the dilution of the venom and the quantity of fluid injected determine 

 the rapidity with which the ganglia-cells are affected, and correspondingly the 

 time of death. 



When venom was injected directly into the stomach of a guinea-pig, by 

 opening the abdominal wall and passing the needle of the syringe through the 

 wall of the stomach, no effects due to the injection were observed. The same 

 negative result was noted when venom was injected into the small intestines. 

 Whether no venom is absorbed from the stomach and intestines, or whether 

 the venom is so changed by the gastric or intestinal secretions that it has lost 

 its toxic properties, we must leave undecided.* Similarly, venom of Colu- 

 bridae has very little or no effect when introduced into the intestinal tract, 

 while venom of Viperidse causes intense irritation of the intestinal mucosa. 



Yet another method of administrating the venom was tested by placing 

 collodion sacs containing venom in the peritoneal cavity of rabbits and guinea- 

 pigs. The results of these experiments will, however, be reported in another 

 place. 



We used 124 animals in testing the influence of the method of administer- 

 ing the venom, and the following examples have been selected as typical cases : 



Subcutaneous injection : Guinea-pig 58, 400 g. June 12, 3^ 55'° injected 0.1 c.c. of venom. 



June 13, died during night. 

 Intraperitoneal injection: Guinea-pig .57, 560 g. June 12, 3^56'" injected 0.1 c.c. of 



venom. Died during night. 

 Intravenous injection: Guinea-pig 64, 440 g. June 12, 5^ 05"' injected 0.1 c.c. of venom. 



5i> SO'" dead. 

 Subcutaneous injection: Guinea-pig 60, 420 g. June 12, 3^50"^ injected 0.05 c.c. of 



venom. No symptoms. 

 Intraperitoneal injection: Guinea-pig 59, 680 g. June 12, S'> 54™ injected 0.05 c.c. of 



venom. No symptoms. 

 Intravenous injection: Guinea-pig 65, 680 g. June 12, 4^ 55"' injected 0.05 c.c. of venom. 



5^ ^5" dead. 

 Subcutaneous injection: Guinea-pig 62, 640 g. June 12. 3^39" injected 0.02 c.c. of 



venom. No symptoms. 

 Intraperitoneal injection: Guinea-pig 61, 660 g. June 12, S'' 47'" injected 0.02 c.c. of 



venom. No symptoms. 

 Intravenous injection: Guinea-pig 66, 680 g. June 12, 4^ 40'° injected 0.02 c.c. of venom. 



5'' 20'" dead. 

 Subcutaneous injection: Guinea-pig 51, 740 g. June 12, 9^ 30"' injected 0.2 c.c. of venom. 



!>> 40'" (locid. 

 Intraperitoneal injection: Guinea-pig 52, 620 g. June 12, 9^33'" injected 0.2 c.c. of 



venom. 1'' 40'" only moderately affected. June 13, reco\-ered. 



*Compare the chapter on the biochemiatry of the venom, by Dr. Alsborg, It is not probable that the injurioua 

 influence of peptic and tryptic digestion upon the venom is sufficient to account for the lack of any symptoms after 

 this mode of application of venom. Other factors, as adsorption by the contents of stomach or intestines, imperfect 

 penetration through the wall of the alimentary tract, probably cooperate. 



