204 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



Flexner and Noguchi found that the cytolytic principles of snake venom 

 are still active after moist heating to 85° C. for 30 minutes and are not de- 

 stroyed by moist heat at a temperature of ioo° C. maintained for 15 minutes. 

 Dry heating for 2 hours at 140 C. suffices to diminish, but not to abolish, the 

 activity of daboia venom. 



The mechanism of venom cytolysis was also studied. They found that 

 previous heating of susceptible somatic cells and nerve cells to 55° C. for 

 30 minutes renders the cells almost insusceptible to the solvent action of 

 venom, although agglutination and some granulation of the cells may occur. 

 Addition of fresh serum or fresh body fluid to the mixture of the heated cells 

 and venom causes a certain amount of dissolution and disintegration, which 

 are never so strong as in the case of unheated cells. Repeated washings of 

 the fresh cells in sea-water or saline solution do not suffice to prevent or even 

 delay considerable solution of the cells by venom. They also pointed out 

 that the cytolysis can not be due to the action of proteolytic ferment of venom, 

 for the latter directly attacks the gelatin and is completely destroyed by 8o° C. 



In an extensive series of experiments these investigators were able to show 

 that venom contains a number of cytolysins, each having a special preference 

 for one given group of cells. They also consider that cytolysins of one group 

 attack their corresponding cells with varying severity according to the source 

 of the cells, which fact they regard as due to the differences in the receptor 

 apparatus of similar cells in different species of animals. 



Since the appearance of the above work of Flexner and Noguchi, the 

 important discovery by Kyes of the interaction between venom and lecithin 

 has appeared and makes it probable that the mechanism of venom cytolysis, 

 especially the dissolution of egg cells, may have some resemblance to the 

 venom-lecithin haemolysis. As is shown by Jacques Loeb and others, the 

 membrane of ova seems to be of a lipoidal nature and the deutoplasma 

 contains a considerable amount of lecithin. There may be, at least in part, 

 certain relation between the lecithinophilic property and the ovolytic processes 

 in this case. Loeb and others have shown that artificial parthenogenesis can 

 be accomplished by the combined effects of fat-solvent or fatty acids and 

 changes in the toxicity of the medium in which the ova are placed — in the 

 presence of oxygen. I have made an attempt to produce a similar phenome- 

 non by substituting fat-solvents with weak venom solutions, but so far with- 

 out definite result. It is significant that Flexner and Noguchi observed the 

 accelerating influence of weak venom solution upon blastula formation. 



In this connection the interesting observations of Fere" * on the influence 

 of venom upon the evolution of chicken embryos must not be overlooked. 

 This biologist introduced the venom of viper (in dose of 0.00005 g m - P er e SS) 

 into the egg-white and found that 83 out of 100 toxicated eggs presented vari- 

 ous anomalies of development when opened and examined 72 hours after the 

 inoculation. 



1 Fer6 Evolution de l'embryon de poule. Influence de l'introduction du venin dans l'albumen de 

 ' l'oeuf de poule. C. R. de la Soc. Biol., 1896. lime Serie, 8. 



