CHAPTER IV.

_CHAMÆLEONS AND TUATERA._

CHAMÆLEONS.

The CHAMÆLEONS differ in so many important structural points from the ordinary lizards that they are usually regarded now by scientists as a distinct reptilian sub-order. The essential characters, externally recognisable, that serve to distinguish the chamæleons are:--Firstly, the extraordinary development of their worm-like extensile tongue, the tip of it club-shaped and highly viscous, and the shaft cylindrical and as elastic in texture as india-rubber. Adapted for the special object of catching flies, this organ can be projected from the mouth to a distance of 6 or 8 inches or more with lightning-like rapidity, and rarely misses its quarry. Comparing small things with great, the chamæleon's tongue and its action might be likened to a schoolboy's popgun, having its pellet secured to the barrel by a long elastic ligament. Presuming further that the pellet is covered with a viscid secretion such as bird-lime, and that the object shot at is hit and brought back to the shooter's pocket by virtue of the ligament's intrinsic elasticity, we have an almost veritable replica of the chamæleon's fly-catching apparatus. The second remarkable structural peculiarity of the chamæleon is the independent relationship of the two eyes. The eyes themselves are unlike those of any other lizards; they are large, prominent, skin-covered cones, perforated only at their extreme apex for the minute pupil-opening: while one eye may be fixed on an object in front of it, the other may be rolling around in search of a second quarry. This independent capacity of vision, while peculiar among reptiles to the chamæleon, is common to many fishes, such as blennies and flat-fishes. A third anomaly in the chamæleon's structure is the character of the feet; these resemble those of a parrot, the toes being bound together in two opposable bundles. In the fore foot the inner bundle contains three and the outer one two toes only, while in the hind foot the order of their amalgamation is precisely reversed. In either case these feet subserve, as in parrots and other perching-birds, as most effective organs for maintaining a close grip upon the tree-branches among which they habitually live. The tail of the chamæleon is, finally, highly prehensile, and, as with the New World monkeys, constitutes a veritable fifth hand, wherewith to ensure it against falling off its perch.

The colour-changing properties of the chamæleon have been the subject of enthusiastic but in many instances exaggerated descriptions from the earliest times. As a matter of fact there are other lizard species which share this kaleidoscopic property to an equal or even greater degree. The Indian tree-geckos, referred to on a previous page, as also the calotes from the same region, are cases in point. Chamæleons are undoubtedly possessed of marvellous colour-changing faculties, and it would appear to be scarcely in all instances, as is more usually represented, a case of adapting themselves to the tints of their environment. The assumption of leaf-green, grey, brown, reddish, or yellowish tints, in accordance with their surroundings, is the ordinary record. Some examples which formed the subjects of the writer's experiments exhibited, however, interesting deviations from the beaten track. Male individuals, in particular, were observed to assume tints and decorative patterns that rendered them remarkably conspicuous objects, in spite of their leafy environment. The normal ground-colour of these specimens in full daylight was so dark a green that it might be almost characterised as black. Upon this were superimposed lines and spottings of strongly contrasting tints. The more dominant of these was a brilliant orange, that was distributed in bold lines along the head and cheeks, and formed a radiating pattern on the skin-covered eye-cones: The same colour formed somewhat broken-up bars across all four limbs, and was dispersed in bold spots over the entire remaining body-surface: along the tail these spots were concentrated in threes, giving it a semi-barred appearance. All among these orange limb- and body-spottings were distributed a secondary series of somewhat smaller spots, the tint of which was a pale but very brilliant emerald-green. This chamæleon asleep at night was a very different animal. The ground-colour was transformed from almost black to a bright grass-green. The orange lines became lighter in colour and broken up into patches; many of the orange spots on the body disappeared, but those remaining were of larger size and concentrated in threes in two lines along each side, these triple spots enclosing centrally a larger elongated spot or patch of bright pink or puce. The bright emerald-green secondary spots, as seen in daylight, were almost white. If handled during the daytime, the chamæleon was wont to assume a colour nearly identical with his night garb; the two lines of pink patches, previously invisible, would appear, and, while the orange spotting remained constant, the emerald-green changed to lemon-yellow.

A chamæleon in a rage is a decidedly grotesque object. The back is arched, the body and more especially the throat-pouch are inflated to their fullest extent, the mouth is opened, the eyes roll, and the creature rocks itself to and fro and hisses in a most threatening manner. When, as often happens, it also simultaneously sits up on its haunches, the effect is doubtless as terrifying as it is intended to be to a rival chamæleon or any small animal which may venture to approach it. A number of other lizards, including tree-climbing varieties, were introduced to the company of the examples under observation, and until friendly acquaintanceship had been established their advances towards the chamæleons were always repelled.

The majority of the chamæleons lay eggs, but a small number produce living young, as with skinks and other lizards. Examples of the common European and North African species kept by the writer excavated holes in the earth, in which they laid their eggs, and then carefully covered them up again. Unfortunately these eggs were not fertilised. One South African species has been reported to the writer as being in the habit of placing and separately wrapping and fastening up each egg as deposited in the leaves of the tree in which it resided. While Africa and Madagascar represent the head centres of distribution of the fifty odd known species of chamæleons, they enter Europe through the Spanish Peninsula, and extend eastward to Arabia, India, and Ceylon. The largest known variety, which inhabits Madagascar, attains a length of 15 inches; the smallest pygmy chamæleon of the Cape scarcely measures 2½ inches.

THE TUATERA.

That singular reptile found on certain small islands lying to the north-east of New Zealand, and known as the TUATERA, differs in so many structural characters from all other lizards that it is assigned to a separate order. Externally the tuatera does not differ materially in form from an ordinary lizard. The skin, however, is peculiar for its leathery, granulated, and wrinkled texture; there is no trace of external ears; the eyes, adapted for nocturnal vision, have in daylight vertical pupils; and the bases of the toes are united by connecting webs. The deeper internal characteristics include the possession of supplementary so-called abdominal ribs, the presence of which are readily apprehended on handling the living animal. These structures, while absent in ordinary lizards, find their near equivalent in the breastplate of tortoises and turtles. The teeth are not implanted in distinct sockets, but attached to the summits of the jaws, which are developed in a beak-like manner, and in older individuals fulfil, after the manner of a beak, the functions of the worn-out incisor teeth.

Tuateras have been exceedingly scarce of recent years, and in view of their scientific interest, and the risk of their possible extinction, are now protected by the New Zealand Government. Among the multitudinous gifts of which their Royal Highnesses the Prince and Princess of Wales were recipients during their recently accomplished world-embracing tour, a pair of living tuatera lizards formed one of the most singular and highly prized contributions accepted from the loyal New Zealanders.

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