ORDER OPHIDIA. 



265 



under the eye. It is this fluid, poured into the 

 wound by the tooth, which carries destruction into 

 the bodies of animals, and produces effects more 

 or less fatal, according to the species of the serpent 

 from which it comes. This tooth is concealed in a 

 fold of the gum, when the serpent does not choose 

 to make use of it, and there are behind it several 

 germs destined to replace it, if it should be broken 

 in a wound. Naturalists have named these venomous 

 teeth mobile fangs, but it is, properly speaking, the 

 maxillary bone which moves. It bears no other 

 teeth whatsoever, so that in this kind of maleficent 

 serpents only the two ranges of palatine teeth are 

 visible in the top of the mouth. 



All these venomous species, whose mode of re- 

 production is well known, bring forth their young 

 alive, because the eggs disclose before they have 

 been laid. This is what has caused them to receive 

 the general name of vipers j which is a contraction 

 of viviparous. 



The venomous serpents with isolated fangs, pre- 

 sent external characters pretty nearly of the same 

 nature as those of the preceding ; but the great ma- 

 jority have the jaws very dilatable, and the tongue 

 remarkably extensible. Their head, large behind, 

 has, in general, a ferocious aspect, answering in 

 some manner their natural character. There are 

 particularly two great genera of them, the crotaUy 

 and the vipers, the second of which lias suffered 

 various dismemberments. 



