HABITS. 
109 
Tropical India as regards its Amphibians, while Australia and Africa are near 
akin to South America in regard to their tortoises, in respect of lizards there is no 
close connection between India and Africa, but an intimate relationship exists 
between India and Australia, where members of the same genera occur; while the 
Australian lizards are totally unlike their South American cousins. As might have 
been expected from their great numerical preponderance at the present day, lizards 
appear to be a comparatively modern group, their remains being rare in the lower 
Tertiary deposits, while in the Secondary period they are only known by a few 
species from the rocks of the Cretaceous epoch. That the group has originated 
from the tuateras, which were so abundant in the earlier strata of the Secondary 
period, may be regarded as most probable. 
Turning to their mode of life, we find that while a few members 
of the order resemble crocodiles, in spending the greater portion of 
their time in water, visiting the land only for the purposes of feeding, sleeping, 
or basking in the sun, by far the great majority of lizards are essentially land- 
animals, avoiding even damp situations. Although some inhabit trees, the greater 
number dwell either on the ground or among the clefts of rocks; the conformation 
of the body generally giving some indication of this diversity of habitat. Among 
the land forms, for instance, those with depressed bodies are generally to be found 
in open sandy deserts, where they seek shelter either beneath stones or in holes; 
whereas such as have the body compressed are more usually dwellers among 
bushes or in trees. Those, again, in which the body is more or less cylindrical, are 
in the habit of secreting themselves in the clefts of rocks or the chinks of tree- 
stems ; while the snake-like kinds live 011 the ground, and those with a more 
worm-like form beneath its surface. The movements of the greater number of 
species—whether they live on the ground, among rocks, on trees, or on cliffs or 
walls—are agile in the extreme; and while the majority run with their bodies 
close to the ground, many habitually raise themselves up at times by resting on 
their hind-legs and tails, and are able to spring, either on the ground or from 
branch to branch, to a considerable distance after their prey. Of the arboreal 
species, some make use of their tails to aid in maintaining their hold, while others, 
together with cliff- and wall-hunting species, like the geckos, are enabled to run 
along the under sides of boughs, or to ascend vertical surfaces by the aid of their 
expanded and disc-like feet. The peculiar flying lizard is enabled to take long, 
flying leaps, supported by a parachute-like membrane borne by the expanded ribs; 
while all the limbless species move somewhat after the manner of snakes, although 
making less use of the extremities of the ribs. The few aquatic forms swim and 
dive without the aid of webbed feet; but many other kinds swim well if 
thrown into water. 
In many cases elegant and graceful in form, although at others rendered more 
curious than beautiful by the presence of spines or warts, lizards are pleasing 
rather than repulsive animals; and, with the exception of the American heloderms, 
none are poisonous, although some will bite sharply. Few lizards possess a distinct 
voice, the majority merely uttering a low hiss; some, however, especially among 
those whose habits are nocturnal—emit a clear, sharp cry, which has been likened 
both to the scream of a frog, and to the chirp of a cricket. Of their senses, the 
