2G THE WANDERINGS OF ANIMALS [OH. 



corresponding race or species lias no spots, but longi- 

 tudinal stripes ; and the species of the same genus 

 which live in the desert have a pale ground-colour 

 with dark spots. 



Most of the inhabitants of tropical forests lead an 

 arboreal life. There is no need for hurry, but they 

 must be able to climb well. 



The majority of the Aiiura have acquired arboreal 

 characters. The hind limbs are long and slender, to 

 jump distances, and for catching hold of a leaf or twig 

 the fingers and toes are provided with adhesive disks. 

 Such arboreal Anura are found in all suitable forests, 

 and the significant fact is that these climbers by 

 no means all belong to the family of Hylidae, but 

 nearly every one of the various families of the Anura 

 has produced at least some typically arboreal genera 

 in spite of the considerable internal, structural differ- 

 ences which distinguish, for instance, toads from frogs. 

 The majority belong to the family Hylidae, but where, 

 as in Africa and Madagascar, there are no Hylas, 

 the 'tree-frogs' are modified Ranidae, since these 

 happen to be the material available for counterfeit- 

 ing them. In this respect the forests have succeeded 

 so well that it is for instance impossible to dis- 

 tinguish certain green tree-frogs of the African genus 

 Rappia from a Hyla, unless we cut them open. 

 If they lived side by side, which they do not, this 

 close resemblance would be extolled as an example 



