444 SNAKES OF CEYLON. 



the yield from one specimen measuring 4 feet 5 inches was 

 only 0*2 mgms. of dried poison. Another specimen only 



2 feet 8 inches long yielded 4"0 mgms., and a third specimen 



3 feet 6 inches long yielded 51 '4 mgms. ! It will be seen 

 from this that paradoxical as it may appear, a large krait 

 does not necessarily inject a larger dose than a small one. 



(c) Physical Properties : When freshly secreted the poison 

 is a clear amber coloured fluid, resembling olive oil. 



(d) Toxicity : Lamb, by experiments on rabbits, estimated 

 the virulence of the poison at four to five times that of cobra 

 venom. Rogers, operating on pigeons, estimated it at twice 

 that of cobra venom. Acton and Knowles, by experiment 

 on monkeys, estimate that it is sixteen times more potent 

 than cobra venom ! 



(e) Lethal Dose for Man : Acton and Knowles, assuming 

 that man is as susceptible as monkeys, fix the approximate 

 lethal dose for man at 1 mgm. of dried poison, 



(/) Toxins — 



(1) Toxins operating on nerve cells : 



(a) A depressor that paralyses the respiratory centre 



(Lamb, Rogers). 



(b) A depressor that paralyses centres in the bulb. 



(Inferred from Lamb and Rogers and by clinical 

 manifestations.) 



(c) A depressor paralysing the ends of the phrenic 



nerves (Rogers). 



(2) Toxins affecting the constitution of the blood : 



(«) "Hsemolysin" destructive to erythrocytes (Rogers). 



(3) Toxins destructive to other cells : 



{a) " Hsemorrhagin " destructive to the intima of arte- 

 rioles. (Inferred from post mortem changes, Elliot.) 



