The Common Viper or Adder (Pelias berus), Fig. 58, belongs to the order Ophidia of the class Reptilia, and to the section Viperina, family Viperidae or Vipers. The upper maxillae bear two canali-culated fangs and are of small size. The palate bears two rows of teeth, and the lower jaw is provided with a row on each side. The head is of triangular shape, broadest behind, and the scales covering the head are small.

The Common Viper or Adder.

Fig. 58. - The Common Viper or Adder.

The Common Viper or Adder is the only venomous reptile inhabiting Britain, and, semi-gregarious or local in distribution, it is most prevalent in sandy heaths, and other relatively hot and dry places. It has retreats in the ground, and is torpid in winter. Unless "cornered" or trod upon it seldom attempts to "strike," but when opportunity offers speedily disappears from the presence of man. If "pinned" or trodden upon it strikes and bites fiercely, the bite being venomous, induces pain, sickness, even delirium, and sometimes proves fatal. The adder is seldom found in gardens or cultivated grounds, remaining hidden in the forest, heath, or hayfield, shunning, as a rule, the neighbourhood of man. Its food consists of grass-voles, frogs, unfledged small birds, hatching eggs, insects and their larvae. The adder is viviparous, and it is asserted that when danger threatens, the female viper opens her mouth and permits her brood to hide themselves, but this is by no means an ascertained fact.