514 SNAKES OF CEYLON. 



(h) Uncertainty of Effects : As in the case of other poi- 

 sonous snakes, it does not, in the least, follow that a serious 

 bite will cause death if left untreated. There is abundant 

 evidence to show that a percentage of cases, hard to determine, 

 do not die even though the local injuries are such as to warrant 

 the gravest apprehension. No more instructive record on 

 this score is to be found in snake literature than that quoted 

 by Elliot. He says : "I myself saw a large powerful daboia 

 (3 feet 8 inches long) strike fairly at a dog, hold it, shake it, and 

 only let go when the dog had fled yelping several yards, 

 dragging the snake along the ground. The part bitten was 

 soft and fleshy, the bite was apparently a fair one, the glands 

 of the snake, when dissected, though emptier than usual, both 

 proved to contain poison. From one gland alone I obtained 

 more poison than another daboia emitted through a leaf in a 

 vigorous bite. Add to all this that there was a well-marked 

 subcutaneous extravasation round the bite, and the case 

 seems perfect .... though it became rather ill, did 

 not die. Eight days later the same animal was fairly 

 struck by a vicious daboia (3 feet 4 inches long), the bite being 

 almost instantaneous in its shortness, and this time the 

 victim died in less than three hours." 



Haly mentions a bite from this snake, from which the man 

 suffered no ill-effects. 



(i) Toxins: — 



(1) Toxins operating on nerve cells — 



(a) A depressor paralysing the vasomotor centre 



(Rogers). 



(b) A depressor to nerve cells generally. 



(2) Agents affecting the constitution of the blood — 



(a) A fibrin ferment clotting the blood (Lamb). 



(b) An antifibrin ferment reducing the clotting power 



of blood (Cunningham, Lamb). 



(c) "Hemolysin" destructive to red blood cells 



(Cunningham, Lamb). 



(d) " Leucolysin " destructive to white blood cells 



(Cunningham). 



