Chameleon (chameleo, Brongn.), a genus of saurian reptiles, inhabiting the warmest parts of Africa and India. The genus is characterized by teeth on the upper edge of the jaws, toes united into two groups, prehensile tail, and body compressed and covered with squarish scales, with or without a series of spiny processes along the back, belly, chest, and tail. The skin is chagreened with small scaly grains, the back is sharp, the tail round and slender. There are five toes on each foot, divided into two parcels, one of two and the other of three, each united by the skin as far as the claws. The tongue is fleshy, cylindrical, and capable of an elongation of six or seven inches; the teeth are trilobed; the eyes are large, almost covered by the skin, except a small hole opposite the pupil, and are capable of movements independent of each other. The back of the head is raised in a pyramidal form; there is no visible external ear; the first rib is united to the breast bone, the rest being continued to their fellows of the opposite side, enclosing the abdomen in an entire circle. The lungs are large, and admit of great inflation.

The most common species is the chameleo vulgaris (Lacep.), so well known to travellers in Egypt and northern Africa. Many other species are described from the Seychelles islands, Isle of Reunion, Mauritius, and the Cape of Good Hope. The chameleon is well described by Aristotle in his "History of Animals." The name is derived from the Greek, and signifies little lion, or, as some maintain, camel lion. There is probably no animal about which more prejudices and errors have existed from the remotest antiquity than the chameleon. The two most remarkable faculties attributed to it are those of being able to live on air, and of changing color according to the objects to which it comes near; the first it certainly does not possess, and the latter but partially. Like all other reptiles, it can remain for months without eating, which, with its sudden changes of bulk, gave rise to the opinion that it lived on air. Chameleons eat flies and other insects, which they seize by means of their long sticky tongues, the only part of their bodies which they move with any vivacity. It is true that the chameleon changes its colors with great rapidity, but the changes are not determined by the colors of surrounding objects, nor by the greater or less amount of blood sent to the skin.

Other reptiles possess this power of changing color, as also do many fishes, as the coryphcena (vulgarly called dolphin), and many of the mollusks, as the argonaut and the squid. It has been ascertained by experiments that the varieties of color in the squid are due especially to changes in the surface of the skin from the voluntary contractions of the muscular fibres in the dermis, modifying the reflections from the pigment spots as well as from the colorless portions of the skin. It is probable, considering the scaly character of its skin, that similar surface reflections, from contraction of the muscular fibres of the dermis, are the causes of the changes of color in the chameleon; and that the inflation of the lungs and body, and the changes in the cutaneous circulation, are merely secondary agents. The natural color of the animal is a fine green, tinged in some parts with reddish brown and grayish white; from this the hues vary to deep bluish green, yellow, blackish, and various shades of gray; the colors are the brightest in the warmest and sunniest weather. They are often seen of the same colors as surrounding objects, which they doubtless assume instinctively as a means of protection against their numerous enemies.

The chameleon can also inflate its body even to its feet and tail, by slow and irregular motions; this in a moderate degree may aid the muscular contractions of the skin in the production of its brilliant surface changes. The chameleon moves very slowly; it will remain for days on the branch of a tree, to which it fixes itself very firmly by means of its peculiarly divided feet and prehensile tail. This slowness of motion, and the absence of all defensive and offensive weapons, render it an easy prey to its enemies. Whether upon a tree or on the ground, it is an awkward animal. The native Africans and Asiatics consider chameleons harmless creatures, and even pet them in their dwellings on account of their destruction of insect pests. "When kindly treated they are very gentle, but they readily fight with each other, slowly opening and shutting their jaws, like the blades of scissors. The female lays about a dozen eggs, which she deposits in the sand, leaving them to be hatched by the heat of the sun.

Were it not for their great fecundity the species would soon be destroyed.