POISON APPARATUS OF VENOKOUS SIIAKSS 



The fluid, or venom, is injected into the snake's victim by means of 

 specialized teeth on the maxillary "bone of the upper jaw, wiiich differ from 

 normal reptilian teeth in having a groove, or canal, from "base to apex. 

 These venom ftngs in the dangerous species are large and readily observed. 

 The canals of the fangs are fed with fluid through ducts from the poison 

 glands. Venom does not flox freely except when txie snake is actually striking, 

 for the end of the duct, which is not in contact with the "base of the fang, 

 is normally compressed "by a sheath, or fold of mucous m.em"br;ine. A rattlesnake 

 may open its mouth to the fullest extent yet m.ay or may not erect the fangs. 

 The snake apparently has perfect control over its fangs, raising or depressing 

 them at will. The venom is injected by the combined action of several muscles, 

 which open the m.outh, erect the fangs, compress the poison glands, and thus 

 force the venomous fluid through the connecting duct into and through the 

 fangs in the brief space of time in vchich the snake strikes its victim;. 



At the end of a stroke the fangs of a poisonous snake are quickly 

 withdrawn from the flesh; the whole action is the work of an instant. Unless 

 the snake strikes again, the mouth closes as the fangs fold back, mechanical 

 compression constricts the excretory duct, and pressure is relieved from 

 the poison glands by relaxation of the enveloping muscles. A ooisonous sna.ke 

 often miscalculates the distance of the object at which it is striking. In 

 case the object is too close, the fangs are not fully erect when the snake 

 strikes and hence do not penetrate. Conversely, if the thing strack at is 

 beyond reach, the whole stroke may be completed without touching the object 

 of attack. In this case it may happen that the venom is projected several 

 feet, an action that has given rise to repeated acco-onts of our poisonous 

 snakes spitting venomi. 



In human beings the bite of a venomous snake is usually followed by 

 painful sym.ptom.s and occasionally by death. Other animals are affected in 

 various ways. The hog, for example, has a degree of immunity from the bite 

 of venomous snakes, because of its thick skin and protecting layer of fat. 



poison Fangs 



Though the fangs of our crotaline venom.ous snakes are shed frequently, 

 it cannot be said that they are shed periodically. On each side of the 

 upper jaw there is a hollov^ or grooved poison fang firnily ankj^'losed to the 

 maxillary bone. This pair of functional fangs is supplejiiented by several 

 pairs of smaller teeth growing loosely in the flesh and buried in the soft 

 sheath of the gurn. When from any cause one of the large fangs is broken off, 

 the reserve fjing nearest to it soon mioves over in its place, grows fast to 

 the maxillary bone, and becomes the functional poison fang. In case of 

 accident to either of the fangs in use there is always a reserve fang ready 

 to replace it. 



Length of Stroke 



The idea that a venomous snake can strike its full lengfn or even a 

 greater distance is another loopular but erroneous belief. When a snake 



