LIZARDS. 15 



such a degree of specialization as the Chatnas'eon. The tongue, 

 eyes, limbs, tail, skin, lungs are modified in a most extraordinary 

 manner to serve special functions in the peculiar economy of 

 these animals. They lead an exclusively arboreal life : each of 

 their feet is converted into a grasping hand, by means of which, 



Ficr. 11. 



Common Chamseleon. 



assisted by a long prehensile tail, they hold to a branch on which 

 they are sitting, so fast that they can be dislodged only with 

 difficulty. Their Tnovements are slow and awkward on the 



Fis. 12. 



Hand of OhamBeleon. 



ground, and still more so in the water, where they are nearly 

 helpless. The tongue (fig. 11) is exceedingly long, worm-like, 

 with a club-shaped viscous end ; they shoot it out with incredible 

 rapidity towards insects, which remain attached to it, and are thus 

 caught. The eyes are almost entirely covered by a thick lid, pierced 

 with a small central hole, and not only can be moved in any direc- 



