88 REPTILES AND BIRDS. 
and partly hides them, like a sheath, when they are at rest. 
They are attached to the upper maxillary bones, which are small 
and very mobile, and are put in motion by two muscles. Behind 
them are dental germs, intended to replace them when they fall out. 
The other teeth in the roof of the mouth belong to the palate, where 
they form two rows. 
Such are the terrible weapons of the Viper group. It is not, 
therefore, as many persons still believe, with the tongue that the 
Adder inflicts its wound ; the forked, projecting tongue serves them 
as a feeler, and to drink with, but cannot inflict a wound. We 
have said that when in a state of repose the hooked teeth are 
hidden; when the animal wishes to use them, they issue from 
Fig. 23.—Fangs.and tongue of an Adder. 
their fleshy sheath, somewhat in the same manner as the claws of 
a cat when about to be used as weapons of offence. 
Adders use their fangs to seize the small animals which serve 
as their prey. They do not voluntarily attack a man. But if he 
imprudently places his foot on or attempts to seize them, they will 
defend themselves vigorously. Let us note how this reptile takes its 
prey. In this case it may be supposed to act without passion, merely 
obtaining food, when it simply seizes, sinking its fangs into the body 
of its victim. In proportion as these penetrate the body of the 
animal the poison flows into the canal, which again conducts it to 
the fangs under the influence of the contracting muscles, by which 
they are raised and made to press upon the gland; causing the 
venom to be injected into the wound. 
Adders bite in this manner when seized by the tail or middle of 
the body; but when they are at liberty, and become irritated, they 
strike rather than bite. At first they coil themselves up into several 
