Viper
a genus of venomous snakes, This family includes many important forms-e. g., the common adder (Vipera tending as far N. as Sweden; the Afritending as far N. as Sweden; the African horned viper (V. cerastes) and puff adder (Clotho or Echidna arietans); the Indian daboia or Russell's viper (Daboia russellii); and the Indian Echis carinata.
The head is relatively broad, somewhat triangular, and generally covered with scales; the eye has a vertical pupil, and there is no pit between it and the nostril; the maxilla bears on each side one functional fang, usually with several reserve fangs beside it; the poison is virulent.
The vipers are widely distributed through Europe and Australia; the majority are African. As far as is known they are viviparous.
The common viper or adder is the only poisonous snake indigenous to Great Britain. in. It lives especially on dry heaths and waste places, often among Britain. It lives especially on dry stones and brushwood; it is commoner in Scotland than in England, and does not occur in Ireland. It is widely distributed throughout Europe. Often confused with the innocent grass snake fused with the innocent grass snake guished by its markings. It has two diverging marks between and rather behind the eyes, a spot on each side of the hind the eyes, a spot on each side of the hinder part of the head, a row of conalong the upper surface of the whole along the upper surface of the whole of small irregular, almost black, triangular spots on each side. The under parts are of a lead color. The characteristic ground color varies considerably, from nearly olive, rich deep brown, or brownish-yellow, to almost black. some parts of England a black viper is Thus in occasionally met with; its ground color VIRCHOW intense black than the rest. There is a rich black, and the markings of a more an almost white viper, with black markan almost white viper, with black markings. The viper seldom exceeds two feet in length. It feeds on mice, frogs, small birds, and other small animals, which lowed entire. are killed by its poison fangs, and swalseveral months of the year, and several It hibernates during may then be found twined together in a torpid state. It is a good swimmer, and may occasionally be seen on lakes, such land to another. The young are proas Loch Lomond, crossing from one isduced in early summer, from 10 to 15 or more at a birth. The eggs have soft, thin envelopes, and are hatched within the oviduct. The young viper is coiled almost a solid mass, but the moment it is set free it is active, and ready to up so closely in the egg as to appear throw itself at once into an attitude of is set free it is active, and ready to defense. a