Though ordinarily concealed, it is capable of protrusion till it exceeds in length the whole body of the creature. No sooner does an incautious fly venture within reach than the extremity of this treacherous weapon is disclosed, broad and cuneiform, and covered with a viscid fluid; and this, extended to its full length, is darted at its prey with an unerring aim, and redrawn within the jaws with a rapidity that renders the act almost invisible.[2791]
Whilst the faculty of this creature to assume 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 its brain, and the two sets of nerves that permeate the opposite sides of its frame. Hence, not only has each of the eyes an action quite independent of the other, but one side of its body appears 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.
Ceratophora.—This which till lately was an unique lizard, known by only two specimens, one in the British Museum, and another in that of Leyden, was ascertained by Dr. Kelaart, about five years ago, to be a native of the higher Kandyan hills, where it is sometimes seen in the older trees in pursuit of insect larvæ. The first specimen brought to Europe was called Ceratophora Stoddartii, after the name of its finder; and the recent discovery of several others in the National Collection has enabled me, by the aid of Dr. A. Günther, to add some important facts to their history.
This lizard is remarkable for having no external ear; and it has acquired its generic name from the curious horn-like process on the extremity of the nose. This horn, as it is found in mature males of ten inches in length, is five lines long, conical, pointed, and slightly curved; a miniature form of the formidable weapon, from which the Rhinoceros takes its name. But the comparison does not hold good either from an anatomical or a physiological point of view. For, whilst the horn of the rhinoceros is merely a dermal production, a conglomeration of hairs cemented into one dense mass as hard as bone, and answering the purpose of a defensive weapon, besides being used for digging up the roots on which the animal lives; the horn of the ceratophora is formed of a soft, spongy substance, coated by the rostral shield, which is produced into a kind of sheath. Although flexible, it always remains erect, owing to the elasticity of its substance. Not having access to a living specimen, which would afford the opportunity of testing conjecture, we are left to infer from the internal structure of this horn, that it is an erectile organ which, in moments of irritation, will swell like the comb of a cock. This opinion as to its physiological nature is confirmed by the remarkable circumstance that, like the rudimentary comb of the hen and young cocks, the female and the immature males of the ceratophora have the horn exceedingly small. In mature females of eight inches in length (and the females appear always to be smaller than the males), the horn is only one half or one line long; while in immature males five inches in length, it is one line and a half.
Among the specimens sent from Ceylon by Dr. Kelaart, and now in the British Museum, there is one which so remarkably differs from C. Stoddartii, that it attracted my attention, by the peculiar form of this rostral appendage. Dr. Günther pronounced it to be a new species; and Dr. Gray concurring in this opinion, they have done me the honour to call it Ceratophora Tennentii. Its "horn" somewhat resembles the comb of a cock not only in its internal structure, but also in its external appearance; it is nearly six lines long by two broad, slightly compressed, soft, flexile, and extensible, and covered with a corrugated, granular skin. It bears no resemblance to the depressed rostral hump of Lyriocephalus, and the differences of the new species from the latter lizard may be easily seen from the annexed drawing and the notes given below.[2811]
Geckoes.—The most familiar and attractive of the lizard class are the Geckoes[2812], that frequent the sitting-rooms, and being furnished with pads to each toe, they are enabled to ascend perpendicular walls and adhere to glass and ceilings. Being nocturnal in their habits, the pupil of the eye, instead of being circular as in the diurnal species, is linear and vertical like that of the cat. As soon as evening arrives, the geckoes are to be seen in every house in keen and crafty pursuit of their prey; emerging from the chinks and recesses where they conceal themselves during the day, to search for insects that then retire to settle for the night. In a boudoir where the ladies of my family spent their evenings, one of these familiar and amusing little creatures had its hiding-place behind a gilt picture frame. Punctually as the candles were lighted, it made its appearance on the wall to be fed with its accustomed crumbs; and if neglected, it reiterated it sharp, quick call of chic, chic, chit, till attended to. It was of a delicate gray colour, tinged with pink; and having by accident fallen on a work-table, it fled, leaving part of its tail behind it, which, however, it reproduced within less than a month. This faculty of reproduction is doubtless designed to enable the creature to escape from its assailants: the detaching of the limb is evidently its own act; and it is observable, that when reproduced, the tail generally exhibits some variation from the previous form, the diverging spines being absent, the new portion covered with small square uniform scales placed in a cross series, and the scuta below being seldom so distinct as in the original member.[2821] In an officer's quarters in the fort of Colombo, a geckoe had been taught to come daily to the dinner-table, and always made its appearance along with the dessert. The family were absent for some months, during which the house underwent extensive repairs, the roof having been raised, the walls stuccoed, and the ceilings whitened. It was naturally surmised that so long a suspension of its accustomed habits would have led to the disappearance of the little lizard; but on the return of its old friends, it made its entrance as usual at their first dinner the instant the cloth was removed.
Crocodile.—The Portuguese in India, like the Spaniards in South America, affixed the name of lagarto to the huge reptiles that infested the rivers and estuaries of both continents; and to the present day the Europeans in Ceylon apply the term alligator to what are in reality crocodiles, which literally swarm in the still waters and tanks in the low country, but rarely frequent rapid streams, and have never been found in the marshes among the hills. The differences, however, between the two, when once ascertained, are sufficiently marked, to prevent their being afterwards confounded. The head of the alligator is broader and the snout less prolonged, and the canine teeth of the under jaw, instead of being received into foramina in the upper, as in the crocodile, fit into furrows on each side of it. The legs of the alligator, too, are not denticulated, and the feet are only semi-palmate.