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. Phisalix 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 Phisalix 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 (Pityophis catenifers) is less so. Taking up the 
hemolysis 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 
Cobra, Ancistrodon, and Crotalus. They have, however, noticed that the 
antihemolytic 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 
1 Phisalix and Bertrand. Sur les effets de ablation des glandes & venin chez la vipére. C.R. Soc. 
Biol., 1894, ro ser., I, 747. C.R. Acad. Sci., 1894, CXIX, g19. 
2 Phisalix and Bertrand. Sur l’emploi du sang de vipére et de couleuvre comme substances antiveni- 
meuses. C. R. Soc. Biol., 1895, ro ser., II, 751. C. R. Acad. Sci., 1895, CXXI, 754. 
3 Calmette. Le venin des serpents. 1896, Paris. 
4 Flexner and Noguchi. Constitution of snake venom and snake sera. Jour. of Path. and Bacteriol. 
1903, VIII, 379. 
