78 



STORY OP THE REPTILES 



" shoulder girdle " even, is ever found in a serpent ; 

 and no lizard — though appearing legless in front 

 or everywhere — has ever been found without these 

 shoulder-bones. Hence, by dissection a limbless liz- 



FiG. 39.— Glass-snake {Opheosaurus ventraUs). The tail is twice the 

 length of the body, and breaks off at the slightest blow. When 

 broken off it grows again. 



ard may be known from a snake ; but we shall see 

 later that the tongue also will usually distinguish all 

 limbless forms. 



By the walking on the toes only, the reptiles 

 brought in the first outlook for speed afoot which 

 finds such high development in the running birds 

 and the strictly toe-walking mammals, such as the 

 horse, the antelope, the greyhound, etc. 



In keeping with this, one of the extinct reptiles 

 had its toes hoofed instead of clawed. 



