xm 



PHYLUM CHORDATA 



355 



of their toes to run readily over vertical or overhanging smooth 

 surfaces. A few, on the other hand (Water-Lizards), live habitually 

 in fresh water. The Flying Lizards (Draco, Fig. 1019) are arboreal, 

 and make use of their wings or, to speak more accurately, 

 aeroplane or parachute to enable them to take short flights from 

 branch to branch. Chlamydosaurus and Amphibolurus are excep- 

 tional in frequently running on the hind-feet, with the fore-feet 

 entirely elevated from the ground. A tolerably high temperature 

 is essential for the maintenance of the vital activities of Lizards, 

 low temperatures bringing on an inert condition, which usually 

 passes during the coldest part of the year into a state of suspended 



FIG. 1019. Draco volans, x f . (From the Cambridge Natural History.) 



animation or hibernation. The food of Lizards is entirely of an 

 animal nature. The smaller kinds prey on Insects of all kinds, 

 and on Worms. Chamaeleons, also, feed on Insects, which they 

 capture by darting out the extensile tongue covered with a viscid 

 secretion. Other Lizards supplement their insect diet, when 

 opportunity offers, with small Reptiles of various kinds, Frogs and 

 Newts, small Birds and their eggs, and small Mammals, such as 

 Mice and the like. The larger kinds, such as the Monitors and 

 Iguanas, prey exclusively on other Vertebrates ; some, on occasion, 

 are carrion-feeders. Most Lizards lay eggs enclosed in a tough 

 calcified shell. These they simply bury in the earth, leaving them 



