Page:Natural History, Reptiles.djvu/95

Rh which these reptiles have been called in different localities, are derived from the sounds emitted by them, which are supposed to resemble these words. M. Duméril is unable to account for the production of this voice, the more especially as they are destitute of the dewlap, or goître, which we find in the Iguanadæ. He suggests, however, that the movement of the tongue may bear a part in its emission, and the reception of that organ in the concavity of the palate; perhaps in a similar way to that in which the cracking sound is produced by a rider, when he stimulates his horse,—the tongue being applied to the palate, and quickly withdrawn. The goître of the Anoles does not appear to us to be in any way connected with the emission of sounds.

The motions of the Geckos are slow and stealthy: they creep along with an almost imperceptible step, with the chin and belly resting on the surface on which they move; yet on alarm they display surprising agility. They watch, the whole day long, at the mouth of some hole or crevice, the head peeping out; and if they do venture to travel, rarely wander far from their retreat, into which they vanish in an instant, if disturbed. Their senses seem acute, and to be exercised by day, though night is the season of their activity.

The following summary of the habits of these animals we extract from the elaborate article on this Family in the Penny Cyclopædia, though a few of the remarks we have already anticipated, and though we cannot fully agree with some of the conclusions:—

"The Geckotidæ are none of them large in