When irritated, it puffs itself out to such an extent that its body becomes twice the ordinary size. It then doubles back its head and neck in the shape of an S, and emits a loud and prolonged hiss. Before biting, it first strikes a blow with its head as with a battering-ram, thus justifying its French name, vipère heurtante (Striking Viper).
Fig. 37.—Bitis arietans (the Puff Adder). (After Duméril and Bibron.)
The natives of South Africa assert that this Viper is able to spring high enough to strike a rider on horseback. It feeds upon rats and mice, in search of which it often approaches habitations.
The Hottentots hunt it in order to obtain its venom; they pound its head between stones, and mix the pulp with the juice of certain plants for the purpose of poisoning their arrows.
It lives for a fairly long time in captivity. At the Pasteur Institute at Lille I have succeeded in keeping one of these snakes for two years, feeding it by forcing milk and eggs down its throat.
(2) B. peringueyi.—Nostrils opening upwards and outwards. Head covered with small, strongly keeled scales, which are smallest on the vertex; 11 scales round the eye; 3 series of scales between the eye and the lip; 11-14 supralabials. Scales on the body in 25-27 rows, strongly keeled; 130-132 ventrals; 19-28 subcaudals.
Colour greyish-olive, with 3 longitudinal series of grey or blackish spots; head sometimes with a trident-shaped dark mark, followed by a cross; under surface whitish, with small dark spots.
Total length, 325 millimetres; tail 26.
Habitat: Angola and Damaraland.