Читать книгу Venoms: Venomous Animals and Antivenomous Serum-therapeutics - A. Calmette - Страница 26

We shall not recapitulate here the characters of the Genus Vipera, which we described in dealing with the vipers of Europe. The genus is represented by several species, the geographical range of which is chiefly confined to Eastern and Central Asia.

(1) Vipera renardi.—Resembles V. berus, but the snout is pointed and soft, with a turned-up tip; a single series of scales between the eyes and the lips; nostril pierced in the lower half of a single nasal shield; 8–9 supralabial shields; 4 infralabials. Body scales in 21 rows; 130–150 ventrals; 24–37 subcaudals.

Coloration the same as in the European V. ursinii, but the snout and lips are spotted with black or brown.

Total length, 395–620 millimetres; tail 40–75.

Habitat: Central Asia, Turkestan.

(2) V. raddii.—Snout rounded; supraocular shields erectile; eyes surrounded by a complete circle of 14–17 scales; 9–10 supralabials; body scales in 23 rows; 150–180 ventrals; 23–32 subcaudals.

Coloration pale brown or grey on the back, with a dorsal series of small reddish spots arranged in alternating pairs. A black mark like a circumflex accent on the occiput, and a black band behind the eyes. Belly yellow, speckled with black and white.

Total length, 740 millimetres; tail 50.

Habitat: Armenia.

(3) V. lebetina.—Snout rounded and obtuse, with a well-marked prominence; 7–12 longitudinal series of scales between the eyes; supraocular shields well developed or narrow, or broken up into several small portions; 12–18 scales round the eyes; 9–12 supralabials; 4–5 infralabials; body scales in 23–27 rows; 147–180 ventrals; 29–51 subcaudals.

Coloration variable, grey or pale brown on the back, with a series of large dark spots. Large brown mark like a circumflex accent on the crown of the head and another on the occiput. Belly whitish, speckled with grey-brown; end of tail yellow.

Total length, 960 millimetres; tail 120. The female may attain the length of 1,350 millimetres.

Habitat: Cyprus, Galilee, Syria, Asia Minor, Transcaspia, Persia, Mesopotamia, Afghanistan, Baluchistan, Cashmir.

(4) V. russellii (Daboia, or Russell’s Viper). (fig. 28.)—This viper, which may attain a length of as much as 2,000 millimetres, is magnificently coloured. Its dorsal surface is brownish-yellow, marked with large oval spots of blackish-brown, edged with yellow or white. The belly is covered with transverse bands, with beautiful triangular black spots, bordered with white. The head, which is long, ends in front in a thick, rounded snout; it is covered above with small keeled scales. The nostril, which is large and laterally placed, is surrounded by three shields and soft smooth skin.

Fig. 28.—Vipera russellii (Syn. Vipera elegans. Daboia, or Russell’s Viper). India. (After Sir Joseph Fayrer.)

The species is found throughout India, from Bombay to Bengal, in Ceylon, Burma, and Siam. It is particularly common in Burma, around Rangoon. For walking in the jungle and rice-fields, the natives of this region encase their feet and legs in a special kind of jack-boots made of coarse jute-cloth, in order to protect themselves from the bites of this snake, which cause a large number of fatal accidents.

The Daboia ascends the Himalayas to an altitude of 5,250 feet. It lives in thickets, under stones, and in the clefts of rocks. When disturbed it makes a terrible hissing, but bites only when attacked or irritated.

It feeds upon small vertebrates, such as mice, rats, birds, and frogs, and often enters houses in pursuit of rats.

“Schrott had the opportunity of observing a Daboia on the defensive. A lady carrying a child on her arm was returning home towards evening; she had almost reached her house when a bulldog accompanying her began to bark furiously. Although the lady saw nothing, she was, nevertheless, frightened and called for help. Schrott, who was not far away, ran to the spot, and saw a Daboia lying across the path by which the lady had to proceed. The reptile had its neck thrown back and its head in a horizontal position; its bright eyes followed all the movements of the dog, to whose barks it replied by shrill hisses. It was only waiting for an opportunity to strike. Schrott called off the dog, and the snake at once disappeared among the high grass close by. Next day it was killed at the same spot” (Brehm).

The venom of this viper is terribly potent. According to Russell, a large dog exhibited symptoms of poisoning five minutes after being bitten. At the end of a quarter of an hour it lay down, uttering heartrending cries, began to breathe with difficulty and noisily, was seized with spasms of the jaws and cramps, and died in frightful agony less than half an hour after the wound was inflicted. Fowls in most cases die in less than two minutes. A horse succumbed in half an hour, and another in eleven hours.

It appears that in India many cattle are killed by Daboias while grazing (Fayrer).