THE VIPER, OR ADDER. 71 



These fangs fall backwards,, and lie concealed in 

 a groove of the gum when not in use. 



The following elaborate description of the 

 mode by which the Viper wounds and envenoms 

 its prey scarcely leaves anything to be desired : 

 "When a viper is struck, it first coils itself 

 up, leaving its head in the centre or at the sum- 

 mit of the coil, and drawn a little back, as if for 

 the purpose of reconnoitering. Speedily the 

 animal uncoils itself like a spring. Its body is 

 then launched out with such rapidity, that, for a 

 moment, the eye cannot follow it. In this move- 

 ment the viper clears a space nearly equal to its 

 own length; but it never leaves the ground, 

 where it remains supported on its tail or pos- 

 terior portion of the body, ready to coil itself 

 up again and aim afresh a second blow, if the 

 first should fail. To do this the Viper distends 

 its mouth, draws back its fangs, arranges them 

 in the right direction, and then plunges them 

 into its enemy by a blow of the head or upper 

 jaw : this done the fangs are withdrawn. The 

 lower jaw, which is closed at the same moment, 

 serves as a point of resistance and favours the 

 entrance of the poison-fangs ; but this assistance 

 is very slight, and the reptile acts by striking 

 rather than biting. There are times, however, 

 when the Viper bites without coiling itself up 

 and then darting forth. This occurs, for instance, 



