SNAKES OF CEYLON. 515 



(3) " Hsemorihagin " destructive to the lining membrane 



of blood vessels (Ounningham). 



(4) A depressor to cardiac muscle (Lamb). 



(5) A vaso -constrictor (Rogers). 



(6) " Cytolysins " destructive to (as) liver, kidney, and 



testis cells (Flexner and Noguchi), and (b) to tissue 

 cells at the site of the wounds. 



{j) Analysis of toxic action — • 



(1) (ft) The depression of the vasomotor centre is seen 



in the reduction of blood pressure, and cardiac 

 weakness culminating in early death. 



(6) The depression to nerve cells generally explains the 

 great depression of spirits and reduced vitality 

 in daboia poisoning. It is not sufficient to 

 produce paralysis. 



(2) (a) In large doses blood clots firmly within the vessels, 



and convulsions, ending in death, occur almost 

 immediately. The daboia cannot inject sufficient 

 venom into the human subject to bring about this 

 eifect, which is only seen in relatively small animals 

 injected with very large doses. 



(6) In moderate doses a contrary effect is produced in 

 the blood, and this, in conjunction with (3), 

 accounts for the hsemorrhages which so frequently 

 occur. 



(c) "Hsemolysin " is potent in this venom and still 



further lowers the general vitality induced by ( 1 ) ( 6) . 

 It also has some effect in embarassing the res- 

 piration. 



(d) Reduces the normal resistance to microbic invasion. 



(3) "Haemorrhagin,"by damaging the lining membrane 



of the arterioles, favours leakage of the vessel 

 contents. In conjunction with (2) (6) haemorrhages 

 are frequently the result. 



6(6)20 



