CYTOLYSINS IN SNAKE VENOM 205 



CYTOLYTIC ACTION OF SNAKE VENOM ON MICRO-ORGANISMS. 



Flexner and Noguchi * first stated that snake venom produces on B. anthra- 

 cis, B. colt, and B. typhi rapid involutions, degeneration, and plasmolysis 

 when it is mixed with nutrient media. Cobra venom was the strongest and 

 crotalus venom the feeblest, while ancistrodon and daboia venoms were 

 intermediate. (Plate 32.) 



Somewhat later Calmette and Noc ^ found that i per cent cobra venom 

 quickly dissolves Vibrio cholera and asporogenous strain or young culture of 

 B. anthracis. Staphylococcus aureus, B. diphtherice, and young B. subtilis 

 were equally affected, while B. pestis, B. coli, and B. typhi were more 

 resistant; and B. pyocyaneus, and B. prodigiosus were almost unaffected. 

 B. tuberculosus proved totally insusceptible. The removal of the bacteriolytic 

 substance for one kind means the same for the rest, showing the non-specific 

 nature of this particular principle of venom. 



Calmette's antivenin effectively stops the bacteriolytic action of cobra 

 venom. The reappearance of this property out of the neutral mixture of 

 venom and antivenin does not occur when heated to 80° C. The bacterio- 

 lytic property disappears when heated to above 85° C. for 30 minutes; hence it 

 is not due to the proteolytic property of venom, which disappears at 80° C. 



Trypanosomes are also dissolved by i per cent cobra venom in 30 minutes.^ 



1 Flexner and Noguchi. Snake venom in relation to haemolysis, bacteriolysis, and toxicity. Jour. 



Exp. Med., 1902, VI, 294. Foot-note. 



2 Noc. Ann. Inst. Pasteur, 1905, XIX, 209. 



3 Calmette. Les venins. 1907, Paris. Goebel. Ann. Soc. Med. de Gand, 1905. 



