OPHIDIA. 167 



5. Sea Snakes, distinguished by a strongly compressed tail, and by the position of the 

 nostrils, which are placed as in the last group. They live in the sea only, occasionally 

 approaching the land, feed on marine fish, are viviparous, and venomous. One genus only 

 (Platurus) has the ventral shields so much developed as to be able to move on land. 



Although these five groups are not separated from each other by defined lines of demar- 

 cation, and frequently pass into one another by intermediate forms, yet a family and genus 

 which should be composed of species of several of these groups would be a very unnatural 

 assemblage of heterogeneous forms. 



Tropical India surpasses every other part of the globe in the number of Ophidian forms, 

 and almost every investigation of a limited but previously unexplored district is sure to add 

 largely to our knowledge of them. Unfortunately the proportion of venomous snakes is 

 somewhat large, and as we hope that this treatise will not be confined to the use of the 

 professed naturalist, we think it useful to add a few words on these dangerous animals in 

 general, and on the means to counteract the effects of their bite. 



The degree of danger depends but little on the species which has inflicted the wound, 

 but rather on the bulk of the individual, on the quantity of its poison, on the temperature, 

 and on the place of the wound. Large snakes have generally larger fangs, penetrating more 

 deeply into the flesh, and produce and inject a greater quantity of poison: the bite of a 

 snake not exceeding 18 to 20 inches in length will rarely be followed by a fatal result when 

 the wounded person is an adult. Further, it has been experimentally proved that a snake 

 which has bitten several times within a short time exhausts its stock of poison, and the 

 eff'ects of the fourth or flfth bite are much less dangerous than of those preceding, and it 

 may indeed be entirely harmless. Therefore the danger from a snake which has bitten a 

 person shortly after it has fed is considerably reduced. The temper of snakes generally 

 depends much on the temperature, so that the same individual snake which shows itself 

 extremely fierce during the hottest part of the day becomes sluggish when the temperature 

 sinks, biting only when provoked, and with but little energy. The parts of the human body 

 in which a wound inflicted by a snake is most dangerous are those which are distinguished by 

 the abundance of blood-vessels, or those which can be caught by the snake between both its 

 jaws, so that the animal is enabled to fix its fangs deeply. If unfortunately a larger blood- 

 vessel is pierced by the fang, the poison is carried instantaneously into the mass of the blood, 

 and sudden death is almost always the result. 



Although it is always possible to recognize the venomous nature of a snake from external 

 characters only, yet this requii-es such a knowledge of snakes as can be attamed only by a 

 special study of them ; it would, therefore, be a useless attempt to enumerate here the different 

 characters by which a dangerous species may be distinguished externally from a harmless 

 one. The wound itself speaks for or against the venomous nature of a snake which • . 

 has bitten. When there are numerous punctured wounds disposed in two lines, thus, : 

 the snake is not poisonous ; but when there are only two ( . . ) they are most '■ 

 probably inflicted by a venomous snake, although there is still some hope that it may have 

 been one of those innocuous snakes which have long, non-perforated fangs in front (Lyco- 

 donts, Dipsades, &c.) ; in such a case much anxiety may be spared if the snake is killed at 

 once and properly inspected. 



The treatment to be followed in all cases of poisoned wounds caused by snakes must be 



