72 OUR REPTILES. 



noitering. 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 movement 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 posterior 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 fangs are withdrawn.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, when it meets with some small animal, 

 which it destroys at leisure and without anger, or 

 when it is seized by the tail or middle of the body, 

 in which case it turns round and plunges in its fangs. 

 As the teeth are buried in the tissues of the body 

 struck, the poison is driven down the canals which 

 pass through them by the action of the muscles 

 which close the mouth, and the injection takes place 

 with a force proportionate to the vigour and rage of 



