200 REPTILES OF THE WORLD 



needle. The viperine snakes possess these instruments 

 in the greatest degree of perfection; their "fangs" are 

 caniculated teeth, in the forward part of the upper jaw, 

 rigidly attached to a movable hone. On the front face, 

 at the tip of the fang, is an elongated orifice for the 

 ejection of venom. When the mouth is closed, the fangs 

 of the viperine snakes fold back against the roof; as 

 the jaws are opened they spring forward, ready for 

 action. Each fang connects, at its base, with a canal, 

 which extends back of the eye, thence fuses into an 

 almond-shaped gland secreting a poison designed by 

 Nature to be used in purposes of killing the creature's 

 prey and which is thoroughly successful in its applica- 

 tion. Secondarily, the venom apparatus is used for pur- 

 poses of defense. From the situation of the fangs it 

 can be immediately understood that the forked tongue 

 is not a "sting" nor in any way related to the source of 

 danger from the most deadly of snakes. Differing 

 from the Viperine — the thick-bodied poisonous snakes — 

 the Cobras and their allies, really comprising a distinct 

 group in the family containing the harmless snakes, dif- 

 fer in having short, rigidly-set fangs that are not per- 

 fectly caniculated, as they show strong traces of an 

 external groove. A third group of snakes, the Opis- 

 thoglypha, have rigidly-set, grooved fangs in the rear 

 of the upper jaw; a small proportion among their spe- 

 cies may be rated as dangerous to man. We may take 

 the members of the Opisthoglypha as tj^pes of poisonous 

 serpents having the crudest venom apparatus — the fangs 

 merely grooved ; the Cobras and their allies, and the Sea 

 Snakes, are the next highest types, the fangs having 

 closed about the groove so as to form a canal within 

 them, yet leaving a strong external trace of the groove. 

 In the development of the viperine snakes' fangs, the 



