16 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XVII. 



cobra venom intoxication are observed. Still these symptoms differ so 

 much in relative degree as to render it doubtful if they can be spoken 

 of as identical. Further when we come to consider the question of 

 antivenomous serums, we shall see that cobra venom is quite different 

 from the poison of the Krait. 



Nevertheless, experiments show that death by krait poisoning is due 

 to failure of the respiratory mechanism, probably due to a direct action 

 of the venom on the respiratory centre in the medulla oblongata. 

 There is no doubt that this poison has also a direct action on the heart 

 and on the circulatory apparatus through the nervous system. There are, 

 however, many problems still to be solved. We have, nevertheless, been 

 able to demonstrate that Bungarus cceruleus poison also causes a break- 

 ing up, chromatolysis as it is technically called, of the nerve cells in 

 the spinal cord and brain. Further, this poison has no action on the 

 coagulability of the blood, but has a power to break up, under certain 

 circumstances, the red corpuscles of the blood. 



There is no doubt that bites from Bungarus cceruleus are extremely 

 dangerous and that a considerable percentage of the total deaths frcm 

 snake bite in India, especially in Northern India, is due to this snake. 

 Although the snake is small and injects only a comparatively small 

 quantum of poison, the venom is very deadly, being at least four times as 

 strong as that of the cobra. It is of interest here to put down in tabular 

 form the minimum lethal doses for rabbits, of the more important poisons 

 expressed in milligrammes per kilogramme of weight, when the injection 

 is made subcutaneouslv. 



Species of snake. 



Minimum lethal dose in mil 

 grammes per kilogramme. 



Naia tripudians (Cobra) 

 Naia bungarus • King Cobra) 

 Bungarus cceruleus (Common Krait) 

 Bungarus fasciaius (Banded Krait) 

 Enhydrina valakadien ^Sea Snake)... 

 Notech's scutatus (Australian Tiger Snake) 

 Vipera Russellii (Daboia or Russell's Viper) 

 Echis carinata (Phoorsa or Kupper) 



0-35 



0-35 



0-08 



2-5 — 3 



0-05 



0-05 



1—2 



1—2 



From this table it is seen that the most poisonous of all snakes are 

 the common Sea Snake and the Australian Tiger Snake : then comes the 

 Krait followed by the Cobra and the King Cobra. The Banded Krait 



