450 MANUAL OF ZOOLOGY SECT. 



many kinds are habitually arboreal ; but the Chameleons 

 are the only members of the group which have special modi- 

 fications of their structure in adaptation with an arboreal 

 mode of life. The Skinks and the Amphisbaenians are 

 swift and skilful burrowers. The Geckos are enabled by the 

 aid of the sucker-like discs on the ends of their toes to run 

 readily over vertical or overhanging smooth surfaces. A 

 few Lizards, on the other hand, live habitually in fresh 

 water. The Flying Lizards (Draco) are arboreal, and 

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

 aeroplane or parachute (thin folds of skin supported by 

 the greatly produced ribs) to enable them to take short 

 flights from branch to branch. Chalmydosaurus and 

 certain other genera are exceptional 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 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. Chamseleons, also, 

 feed on Insects, which they capture by darting out the ex- 

 tensile 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 y 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 to be hatched by 

 the heat of the sun. Some, however, are viviparous ; in 



