THE PINE LIZARD AND ITS ALLIES 



359 



There are more than twenty-three hundred species of 

 snakes in the world. Of these, less than 1\ per cent are 

 poisonous. In North America a still smaller percentage 

 are poisonous. Several species of rattlesnakes (Fig. 185), 

 copperheads, water moccasins, and coral snakes are poison- 

 ous, but together they cause only a few deaths a year. This 

 is in sharp contrast to conditions in India and some regions 

 of South America. It is 

 estimated that in Brazil 

 alone about nineteen thou- 

 sand persons are bitten 

 annually by snakes, and 

 of these close to forty- 

 eight hundred die. 



The poisons produced by 

 different kinds of snakes 

 act in entirely different 

 manners on the human 

 body. Some destroy the 

 blood corpuscles. Others 

 produce paralysis. The 

 old idea that whisky is an 



antidote for any kind of snake bite is absolutely false. The 

 most successful treatment is by use of a serum called anti- 

 venin. By injecting small doses of the poison of a given 

 kind of snake into horses, their blood produces a serum 

 which counteracts the effects of the poison when injected 

 into a person bitten by the same species of snake. 



The poisonous snakes of the United States are the pret- 

 tily colored coral snake {Micru'rus ful'vius, Fig. 186) and 

 the water moccasin (Agkis'trodon pisciv'orus) of the South- 

 ern states ; the copperhead (Agkistrodon mok'aseri), found 

 from New England to Wisconsin and southward; and 

 more than a dozen species of rattlesnakes (Fig. 185), found 



Fig. 185. Photograph of a rattlesnake 



