CHAPTER XII. 



THE SAURIANS. 



Class, Reptilia. Order, Lacertilia. 



Belonging to the same class as the snakes, the lizards might 

 properly have followed them in order ; but there is so much in 

 frog development to throw light on that of other forms, that I 

 ventured to deviate from the usual routine by introducing the 

 Batrachians between the two groups of reptiles. In point of size, 

 too, the snakes exceed the frogs ; and our little zootica, being 

 almost the least of reptiles, will complete the list of our thirteen 

 British species. 



Lizards are allied to snakes by many close gradations. The 

 slow- worm, in form a snake, but a limbless lizard, is one example 

 of this. The integument of lizards is much more varied than in 

 snakes. In some it is composed of strong hard shields, in others 

 it is spiny, warty, or like a polished cuirass ; but in our three 

 native lizards it is of fine scales, more approaching the ophidian 

 cuticle than in many of the larger saurians. The anatomy, too, 

 and movements of many are snake-like, even where there are 

 four limbs ; but which scarcely raise the body from the ground, 

 and are of little use in locomotion, or are rather assisted by the 

 undulations of the body. Others have well-developed feet or 

 claws, furnished with five toes each, and often strong hard nails, 

 with which they scratch and dig into the earth, either in search 

 of food or to hide themselves. You may see lizards in captivity 

 constantly scratching the earth or sand, or any dry surface ; or 

 persevering, hour after hour, at the glass sides of their cages ; 

 which does not say much for their intelligence in not learning by 

 experience that many weeks of such labour produces no effect 

 upon the glass. Most lizards are good climbers, especially the 

 small and agile species which inhabit rocks, walls, and trees. Other 

 saurian characteristics are that they have movable eyelids, non- 

 extensible jaws and mouth — which compels them to limit the 

 size of their prey — and movable ribs. A sternum is always 



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