A NOTE ON POISONOUS SNAKES 



By Mar 11 Cynthia Diclccrson 



A snake group recently put on view in the reptile exhibit of the secon:l floor i-epresents 

 a small part of a South Carolina swamp with its logs and stumps, vines and water hyacinths, 

 the last of interest because often an obstruction to navigation in southern rivers. The 

 group shows side by side poisonous snakes, the water moccasin (Ancittrodon piscivorus) and 

 non-poisonous, the brown water snake (Natrix taxispilotun). It also exemplifies the vivipa- 

 rous type of snake, the brood of sixty representing the offspring of one of the water snakes. 



IT would be fortunate if there were some certain rule for distinguishinfj 

 a poisonous from a non-poisonous snake. That the non-poisonous 

 has large scales on the head is not an infallible guide since the cobras 

 and their allies are quite as innocent looking; that the poisonous has usually 

 a triangular head distinct from the neck is again untrustworthy as many 

 harmless species, like the water snakes, when under tlK> influence of fear, 

 inflate the sides of the head to a seinl)lance of concealed poison glands. 

 Neither does an antagonistic manner tell much because certain harmless 

 forms, like the hog-nosed snakes, so-called "spreading adders", are aggres- 

 sive in a higher degree than many deadly si)(>cies. 



This lack of distinction is not, for Nortli iVmerica at least, tlie gra\e 

 misfortune it would seem however, for there has been exaggeration in the 

 popular iniiui as to the numl)er of poi.sonous species. In India to l)e sure, 



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