510 SNAKES OF CEYLON. 



(4) In conjunction with 1 (a) this causes heart failure, 



(5) A vaso -constrictor has been demonstrated by Rogers. 



By reducing the calibre of the blood vessels, blood 

 pressure would be raised and the heart reinforced. 

 Any tendency towards such action appears to be 

 nullified by a more potent element operating on 

 the vasomotor centre, viz.. 1 (a). 



(6) Causes sloughing locally with the formation of an 



ulcer. 



The venom is three to five times less potent than cobra 

 venom according to Lamb. 



Its action upon the blood is as follows : A toxic body 

 (hemolysin) destroys the red blood cells, whose function it is 

 to carry oxygen to the various tissues. As a result all vital 

 processes are lowered. Another toxic principle (antifibrin 

 ferment) very profoundly alters the consistency of the blood, 

 and reduces its clotting powers. The action of this latter 

 principle is exactly that of citric, phosphoric, oxalic, and other 

 acids, and is, probably like them, due to a precipitation of the 

 calcium salts in the blood. This in itself does not account 

 for the transudation that occurs ; but the fact that the lining 

 membrane of the walls of the blood vessels themselves are 

 damaged by another toxic element (haemorrhagin) renders 

 them more permeable. The effect of these two toxins is 

 seen in the great tendency to haemorrhages which are 

 characteristic of the Viperine class of poisons. These 

 haemorrhages may be visible or invisible, and the w r hole case 

 may imitate scurvy or purpura, diseases mainly characterized 

 by similar blood changes. It frequently happens that the 

 fang punctures continue to bleed or discharge bloody serum, 

 or having stopped, bleeding recommences some hours or even 

 days later. There may be bloody discharges from any 

 mucous orifice. Invisible haemorrhages* in the' abdomen 

 may cause pain, tenderness, and vomiting, recalling to the 



* These are specially well exemplified in the cases of Echis poisoning 

 referred to later. 



