94 REPTILES 



are really very different. The chamaeleon, for instance, has a 

 granulated skin, while that of the chamaeleon-lizard is scaly. 

 The latter species also lacks the telescopic eye of the chamaeleon, 

 and the toes of each foot are not divided into opposing groups 

 for grasping, nor is the tail prehensile. The chameleon's pro- 

 trusile tongue has, moreover, no parallel in the lizard. 



The resemblance between the two reptiles is, in fact, super- 

 ficial, and doubtless correlated with their mode of life, both 

 being purely arboreal creatures, of slow and sluggish habits, 

 and feeding upon insects. The strange thing about the matter 

 is that the resemblance should be as close as it is, seeing that 

 chameleons are unknown in the countries east of the Bay of 

 Bengal, and therefore that it cannot be due to mimicry of the 

 one species by the other. The suggestion might arise that 

 chameleons once inhabited the Malay countries, but there is no 

 evidence of this. Moreover, the chameleon-lizard belongs to a 

 rather large genus, some of the members of which inhabit 

 India and Ceylon, where chameleons are found ; but these 

 species do not present anything like the same resemblance to 

 chameleons as is shown by the chameleon-lizard and a few 

 allied Malay species. 



In connection with chameleons, it may be mentioned that 

 these reptiles exhibit a modification in the structure of the feet 

 unique in the class, although paralleled among birds by cuckoos 

 and certain allied groups. Not only are the limbs of chame- 

 leons relatively long and slender, but two of the toes of each foot 

 are permanently opposed to the other three ; the first three 

 toes in the fore-foot being opposed to the other two, while in 

 the hind limb the inner division includes only the first and 

 second toes, to which the other three are opposed. Additional 

 aid in climbing is afforded by the prehensile tail, the tip of 

 which can be curled downwards round a branch. Here, 

 then, we have a function parallel to what exists among 

 arboreal mammals, such as spider-monkeys, tree-porcupines, 

 and opossums. The tail of the pythons and certain other 

 snakes is also endowed with the power of prehension. 



Geckos display a different modification of the toes for the 

 purpose of enabling them to cling to walls, cliffs, and even 

 ceilings, upon the latter of which they run back-downwards, like 

 flies. This clinging function is effected by means of a number 



