GECKOS, LIZARDS, AND CHAMELEONS. 105 



lizards. This distinction, in the case of the 

 Chamseleons, is made on account of the peculiar 

 structure of the tongue and certain skeletal 

 characters, of which the peculiar form of the feet 

 is not the least important. 



The home of the Chamaeleons is Africa and 

 Madagascar, and the neighbouring islands. One 

 species, however, occurs in Europe Andalucia. 

 Two are found in the island of Socotra, a third in 

 Southern Arabia, and one in India and Ceylon. 



In size they vary greatly, the smallest species, 

 which occur in Madagascar and tropical Africa, 

 not exceeding three inches in length, while the 

 largest, Chamceleon parsoni, of Madagascar, attains 

 a length of two feet ! 



Adaptation to environment, so strikingly illus- 

 trated by the Chamaeleons, not seldom causes 

 animals not in the least related to assume a 

 strong superficial resemblance. Sometimes this 

 resemblance affects the whole body, at others 

 only certain parts are affected ; but in nearly all 

 cases a close examination will bring out the real 

 affinities of animals which are suspected of having 

 fallen under the spell of " convergent evolution." 



The two following instances are excellent 

 examples of convergent evolution. 



The genus Anolis, which is represented by 

 more than one hundred species, is a near ally of 

 the Iguanas, being indeed a member of the same 

 family. But it has the curious adhesive pads 

 found elsewhere only on the toes of the Geckos, 

 which are a totally distinct group, belonging, as 

 has just been remarked, to a different sub-order. 

 The members of the genus in question, like the 



