Geckos, in common with many other lizards, are notable for the facility with which their tail becomes detached and left in the hands of their would-be captor. In course of time a new tail sprouts out from the truncated stump of the original member, and within a few more months equals it in dimensions. It not infrequently happens that two or even three new tail-sprouts take the place of the original appendage, imparting to the little creature a most bizarre appearance. The above photograph includes an example of the Madeiran species in which a new tail-bud of a normal character has just commenced to grow.
The nearest approach to the phenomenon of flight among lizards occurs in what are known as the Flying-dragons, belonging to the family of the Agamas, which next invites attention. These lizards are all of relatively small size, not exceeding a few inches in length, and inhabit the Indo-Malayan region. In these singularly specialised forms six or seven of the posterior ribs are abnormally produced on each side of the body, and so united together by thin, semi-transparent membrane as to form a pair of wing-like expansions. When not in use, these structures are folded, after the manner of a fan, closely against the animal's sides, while, when extended, they constitute a most effective parachute, wherewith the little creatures accomplish flying leaps from tree to tree, after the manner of the Flying-squirrels and Phalangers. The colour of these wing-like structures varies among the many different specific forms, being in some instances spotted or reticulated like those of a butterfly.
Photo by W. Saville-Kent, F.Z.S.] [Milford-on-Sea.
FLYING-DRAGON OF JAVA.
A lizard with wing-like membranes supported by the abnormally developed ribs. It takes long flights from tree to tree.
This same family of the Agamoid Lizards includes a number of species of very dissimilar aspect and habits, which are almost exclusively confined to the Old World or Oriental zoological region. Australia in particular is remarkably rich in representatives of this group, many of them of considerable size. Certain of these have within recent years been found to be endowed with the power of bipedal locomotion. The Frilled Lizard of Queensland and the northern territories of Western Australia was the first species in which this bipedal habit was authentically demonstrated in connection with examples observed in Australia and also brought to England by the writer, one of the last-named examples furnishing the photographs reproduced on page [567]. In other respects this lizard is one of the most remarkable of its tribe. The peculiar Elizabethan collar-like frill, capable of erection or depression at the creature's will, imparts to it a most singular appearance. When at rest or undisturbed, this membranous frill-like structure is folded down in neat, symmetrical pleats around the lizard's neck. Should the creature be approached by man or dog or other aggressive animal, the mouth springs open to its widest, and simultaneously with this action the frill is erected like the sudden opening of an umbrella, and stands out at right angles around the neck, imparting to it a most formidable and threatening aspect. Dogs, in fact, which will habitually chase and kill larger lizards, such as the Monitors, will frequently halt and retire discomfited when confronted with a frilled lizard at bay with its frill erected. The brilliant colour of this frill, more especially in the male, adds very considerably to the formidable appearance of this lizard. While the body of this lizard is usually of a light brown colour, with more or less distinct darker transverse bars and reticulations, the frill-like membrane has a ground-colour in which orange and chrome-yellow chiefly predominate, and upon which are superimposed splashings and speckles of brilliant scarlet. While the total length of this averages 2 feet, the expanded frill in adult males is not infrequently as much as 8 or 9 inches in diameter. The peculiar, grotesquely human aspect presented by the frilled lizard when running on its hind legs only will be appreciated on reference to the accompanying photographs. This erect attitude is only assumed when the frilled lizard is traversing more or less considerable distances and moving on level ground. Under other circumstances it progresses on all-fours, after the manner of the ordinary members of its class.
Photo by W. Saville-Kent, F.Z.S.] [Milford-on-Sea.
FRILLED LIZARD AT BAY WITH EXPANDED FRILL.