THE POISONOUS SNAKES OF INDIA. 75 



(2) That in the case of so fatal a snahe as the cobra, it is quite 



possible to be poisoned, hut to receive a sublethal dose. 

 (Lamb says that 30 per cent, of cobra poisoned subjects 

 would not die for this reason.) 



(3) It is possible for a person to die from the bite of a harmless 



snale, death being brought about hj the depressing 

 influence of fear or anxiety on the heart. Such cases 

 have been already cited. 



Snake Poisons. 



I propose first to state briefly the main effects of snake poisoning, 

 explain the mode of action, and where possible illustrate my remarks 

 by quoting well reported cases in medical literature. 



Before doing so perhaps I should say that in the present re- 

 cognised system of classification, the snakes of the world are divided 

 into 9 families. All the known poisonous species belong to one or 

 other oftwo of these families, riz., the Golubridce, and the Viperidce. 

 Many Colubrines are harmless, but all Vipers are poisonous, and 

 among our Indian poisonous snakes we have several representatives 

 of both families. 



Now snake venoms of the Colubrine class difier but slightly 

 among themselves in their composition, and main effects upon 

 animals, and the same remark applies to the Viperine class. The 

 symptoms evoked by the Colubrine class taken collectively differ 

 considerably from those produced by the Viperine. 



Colubrine poisons act chiefly on the central nervous system (cord 

 and brain) and cause death by paralysing the respiratory centre in 

 the brain. Their effects upon the blood are slight compared with 

 the Viperine class, so that haemorrhages are not usual, and when 

 present are not severe. 



Viperine poisons have no paralysing effect upon the nervous 

 system, except on the vaso motor centre, but a very marked effect 

 on the heart and blood, death being usually brought about by 

 paralysis of the vaso motor centre, exhaustion from profuse and 

 persistent bleeding, or from septicaemia (a blood poisoning due to 

 germs). 



