86 A NATURALIST IN BORNEO 



bitten by one which darted at his eye ; * two punc- 

 tures were made by the snake on his eyelids, and a 

 tooth of the snake was found in one of the wounds. 

 Capt. F. Wall, 2 a leading authority on the snakes of 

 India, relates that an Indian native bitten by a Dry- 

 ophis mycterizans had his hand and forearm greatly 

 swollen, and though there was no pain they felt 

 numb, and the swelling did not subside for about two 

 days ; so there can be no doubt that the secretion of 

 the salivary glands of this species possesses toxic pro- 

 perties. I have never known D. prasinus to bite, so 

 cannot say if it resembles its congener in the degree 

 of potency of its salivary secretion, but it is probable 

 that all the Opisthoglypha secrete poison which is 

 sufficient to paralyse their prey. 



The third arboreal green species is the Tree-Viper, 

 Lachesis wagleri, a snake with a head like the ace of 

 spades in shape, a short tail, and a covering of small 

 scales. All the Viperidce are venomous, but L. wagleri 

 is not dangerous to man, and though the fangs are 

 rather formidable-looking the poison-gland is small. 

 Whilst in Sarawak I heard of one or two cases of 

 Viper-bite, but in no case was the bite followed by 

 death, or even by much pain and inconvenience. 

 Some varieties of the green Tree-Viper are ornamented 

 with narrow red bands, and the young (which are 

 brought forth alive) are always red-banded, yet these 

 red bands do not in the lights and shades of the forest 

 render the snakes conspicuous, but serve rather to 

 break up its outlines, cause the animal to merge into 

 its background. 



1 Journ. As. Soc. Bengal, LXVII., Pt. II. (1898), pp. 66-7. 



2 Journ. Bombay N.H. Soc., XVI. (1904 -5), p. 549. 



