The eyes of a Snake are always wide open, for there are no movable eyelids to close them. The eyeball has slight power of movement under its transparent cover, which protects it much as the watch-glass protects the delicate hands of the watch. As in the Slow-worm, there is no external indication of ears, though these are present under the scales. The very long and slender tongue divides forwards into two branches, and when not in use is drawn into a sheath at its base. It is constantly used to ascertain the nature of things by contact, and for this purpose is protruded through a little gap in the front of the upper jaw. The gape of the mouth extends far beyond the eye. The forward extremity (glottis) of the wind-pipe can be thrust outside the mouth when, owing to the passage of a bulky victim, there is danger of obstruction by compression.

The British Snakes represent the two families Colubridæ and Viperidæ.

Every summer and autumn our daily newspapers afford evidence that on the subject of Snakes the average man has not advanced in knowledge beyond that of his prototype a thousand years or so back. With all that has been done in various ways during the last half-century to spread knowledge of natural things, it is astonishing that editors should admit scare reports about Snakes without a line to set the reader right. Internal evidence shows that nine-tenths of these alarming reports about poisonous and aggressive Snakes refer to the innocuous Grass Snake. This is the kind of thing that reflects the vaunted intelligence and calmness of the average Briton:—

"An enormous snake was killed yesterday at ——, only a few yards from where some children were playing. The Rev. Mr. Blank courageously seized the reptile behind the head, but when it hissed savagely at him he was forced to throw it down. Its head was then smashed with a pole, and finally it was despatched with the aid of a spade. The venomous monster was found to be over three feet in length. Its nest was found and a large number of eggs destroyed."

[Pl. 94.]][L 148.
Vipers.
The two sexes: the lower figure is the male.

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