104 THE STORY OF REPTILE LIFE. 



opposed to the outer, just as the thumb is opposed 

 to the finger in the human hand, so that the 

 Chamseleons grasp a bough much as we grasp a 

 stick ; the difference being that the thumb and 

 first finger on the hand, and the great and second 

 and third toes on the foot are bound up together. 

 This makes a most perfect grasping, but a most 

 indifferent walking organ. In other words, it has 

 become highly specialised to perform a special 

 function. The tail is also peculiar, and like that 

 of many other arboreal creatures, is prehensile, and 

 used as a fifth limb. It differs, furthermore, from 

 that of most other lizards, in that it is not capable 

 of being renewed should it become accidentally 

 broken off. 



The eyes are no less remarkable than the feet. 

 Unusually prominent, they are closely encased 

 by the eyelids, the apertures of which are reduced 

 to a mere pinhole and have a very limited power 

 of movement. Thus the eyeball, closely invested 

 by the lids, moves loosely in the socket, that of 

 the right side being moved quite independently 

 of its fellow of the opposite side. Up and down, 

 forward and backward, in the most grotesque 

 manner, after the fashion of a search-light, they 

 are kept constantly at work. 



The skin is also peculiar, inasmuch as it is 

 scaleless and covered instead, with warty granules. 



Concerning the ancestors of this group, and 

 the steps by which it has reached its present 

 extraordinary form, we know nothing. As we 

 have already hinted, the Chamseleons, like the 

 Geckos, are regarded by zoologists as forming a 

 group by themselves quite distinct from the true 



