_Blood-suckers_.--These, however, are but the stranger's introduction to innumerable varieties of lizards, all most attractive in their sudden movements, and some unsurpassed in the brilliancy of their colouring, which bask on banks, dart over rocks, and peer curiously out of the decaying chinks of every ruined wall. In all their motion there is that vivid and brief energy, the rapid but restrained action which is associated with their limited power of respiration, and which justifies the accurate picture of--
"The green lizard, rustling thro' the grass, And up the fluted shaft, _with short, quick, spring_ To vanish in the chinks which time has made."[1]
One of the most beautiful of this race is the _green calotes_[1], in length about twelve inches, which, with the exception of a few dark streaks about the head, is as brilliant as the purest emerald or malachite. Unlike its congeners of the same family, it never alters this dazzling hue, whilst many of them possess the power, like the chameleon, but in a less degree, of exchanging their ordinary colours for others less conspicuous. The _C. ophiomachus_, and another, the _C. versicolor_, exhibit this faculty in a remarkable manner. The head and neck, when the animal is irritated or hastily swallowing its food, becomes of a brilliant red (whence the latter has acquired the name of the "blood-sucker"), whilst the usual tint of the rest of the body is converted into pale yellow. The _sitana_[2], and a number of others, exhibit similar phenomena.
[Footnote 2: Sitana Ponticereana, _Cuv_.]
_Chameleon_.--The true chameleon[1] is found, but not in great numbers, in the dry districts in the north of Ceylon, where it frequents the trees, in slow pursuit of its insect prey. Whilst the faculty of this creature to blush all the colours of the rainbow has attracted the wonder of all ages, sufficient attention has hardly been given to the imperfect sympathy which subsists between the two lobes of the brain, and the two sets of nerves which permeate the opposite sides of its frame. Hence, not only have each of the eyes an action quite independent of the other, but one side of its body would appear to be sometimes asleep whilst the other is vigilant and active: one will assume a green tinge whilst the opposite one is red; and it is said that the chameleon is utterly unable to swim, from the incapacity of the muscles of the two sides to act in concert.