8 



STORY OP THE AMPHIBIANS 



limbs are small and useless. The creature moves by 

 wriggling. (See Fig. 4.) 



"Mm 





M24!iSjdj±_ 



_i!i_ 



Fig. 4. — Congo snake iMuruenopsis tridactyla). 



The Csecilians have bands around the body, by 

 which they pull themselves through the ground. 



In the legged forms the number of the toes varies. 



In the grasping hand of the frogs and tree-toads, 

 there is found the first thumb in nature. So perfect 

 is this that many tree-toads can suspend themselves 

 for some time by a single hand. These have soft 

 round pads on the ends of the digits, which enable 

 them to stick to smooth surfaces — the slipping being 

 prevented by moisture. The cricket-frog can, by the 

 mere adhesion of its moist underparts, climb np ver- 

 tical glass and remain there even when so turned that 

 its back is downward ; and one little salamander, hav- 

 ing neither pads nor claws, can so run on ceilings. 



ClawB are very poorly developed in the amphibi- 



