Page:Natural History, Reptiles.djvu/94

86 the tail. During the process, which lasts for a day or two, the half-detached skin hangs about the animal in loose folds, resembling the finest muslin, apparently to its great annoyance. The colours of the body after this shedding of the cuticle are much brighter and more definite.

By means of the singular lamellated structure on the under surface of the toes, the Geckos, or at least many of them, are enabled to cling to vertical or even inverted surfaces, as house-flies do. The mode in which this is effected, we do not thoroughly understand; but we may conjecture that it is by the raising of these imbricated plates by muscular action, so as to form a vacuum beneath the sole, when the pressure of the external air causes the toe to adhere firmly to the surface. The similarity of the structure to that of the coronal sucker in the Remora, suggests this explanation. A familiar illustration of the principle is seen in the leathern suckers which children make, which adhere so firmly that large stones are lifted by them.

M. Duméril has noticed a peculiarity in the œsophagus or gullet of this Family, which is the more extraordinary, since the part is not exposed to the light. In many species, both living and dead, which he examined, he found the interior of this tube, which is very wide, strongly coloured with different shades, uniform in the same individual, sometimes orange-yellow, but more generally deep black. We have observed something analogous to this in the rich Vermillion hue of the whole interior of the mouth and vomer of some West Indian fishes.

The names Gecko, Geitje, Tockaie, &c., by