266 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



were used experimentally, but only those of the major maxillary glands were 

 found to possess the poisonous action described. The blood of these snakes 

 was also found to be poisonous, and from it a precipitate was secured which 

 behaves exactly like the active principle secured from the blood of vipers. 



As a logical consequence it should follow that the removal of the poison 

 gland must also remove the toxic properties of the blood of venomous snakes. 

 An experiment of this sort is by no means easy to perform. PhisaHx and 

 Bertrand ^ have, however, carried out this experiment on 46 vipers. The 

 poison glands were removed from one-half of them. After 168 days from 

 the ablation of the glands the blood was taken from the heart under the 

 influence of chloroform and tested for its toxicity. All guinea-pigs survived, 

 while the blood from the control vipers was highly poisonous and killed the 

 animals. 



The same authors^ went further in this inquiry and finally found that the 

 infection of the blood of viper or adder heated to 68° causes no symptoms 

 in guinea-pigs, but confers upon the latter an increase in resistance to the 

 toxic effect of viper's venom. This phenomenon was considered by them 

 to be analogous to the protection conferred by the injection of the attenuated 

 viper's venom. 



Calmette ^ found that the bloods of Cobra, Naja tripudians and Naja haje, 

 Crotalus, and Cerastes are highly toxic upon guinea-pigs, but instead of accept- 

 ing the hypothesis of Phisahx and Bertrand he considers the active principles 

 of the blood and venom of venomous snakes to be different. The toxicity 

 of the blood disappears on heating to 68° C, while the venom retains its 

 activity at this temperature. The repeated injection of the sublethal quanti- 

 ties of snake blood produces an immunity not only against the same blood 

 but also against the venom. From this Calmette infers that the toxicity of 

 the blood is due to the presence of a forerunner of venom from which the 

 latter is produced through the process of secretion of venomous glands. 



The later study of Flexner and Noguchi " shows that the blood serums 

 of Crotalus and Ancistrodon are highly toxic upon guinea-pigs, while that of 

 the innocuous pine snake (Fityophis catenifers) is less so. Taking up the 

 haemolysis as the test reaction these authors found that the antiserums of 

 Crotalus and Pityophis serums have neutralizing properties upon the hemo- 

 lysins contained in these serums as well as in the case of the venoms of 

 Cohra, Ancistrodon, and Crotalus. They have, however, noticed that the 

 antiha;molytic actions of these immune serums are quite specific and display 

 more protection against the serums with which they were produced. The 

 neutralization of toxicity of these two snake serums {Crotalus and Pityophis) 

 by their respective antiserums was also found to be highly specific. With- 

 out definite conclusion as to whether the venom is the cause of the toxicity 



» Phisalix and Bertrand. Sur les effets de I'ablation des glandes a venin chez la vipfere. C. R. Soc. 



Biol., 1894, 10 ser., I, 747. C. R. Acad. Sci., 1894, CXIX, 919. 

 2 Phisalix and Bertrand. Sur I'emploi du sang de vipfere et de couleuvre comme substances antiveni- 



meuses. C. R. Soc. Biol., 1895, 10 sen, II, 751. C. R. Acad. Sci., 1895, CXXI, 754. 

 * Calmette. Le venin des serpents. 1896, Paris. 

 " Flexner and Noguchi. Constitution of snake venom and snake sera. Jour, of Path, and Bactenol. 



1903, VIII, 379. 



