110 THE STORY OF REPTILE LIFE. 



organ of touch, and not as is so commonly sup- 

 posed, as stinging or poison-injecting organ. But 

 to this point we shall return. It is furthermore 

 peculiar in that, when at rest, it is withdrawn 

 into a sheath. 



The skeleton is remarkable for the enormous 

 number of the ribs, and of the bones which make 

 up the vertebral column, in some spines as many 

 as three hundred being present. Furthermore, 

 these vertebrae articulate with one another by 

 quite peculiar attachments, which, while adding 

 considerably to the strength of the backbone, 

 allow only of side to side movements between 

 individual vertebrae. The ribs commence with 

 the vertebra next behind that supporting the 

 head, that is to say, with the axis vertebra, and 

 extend backwards to within a short distance of 

 the end of the body. They are long, and readily 

 movable, and take the place of feet in loco- 

 motion. Limb girdles and breastbone are con- 

 spicuous by their absence. Only in a few cases 

 are vestiges of limbs to be found, and these 

 always represent the hinder pair. 



Teeth are borne not only by the jaws, but 

 by the palatine and pterygoid bones, which form 

 the roof of the palate as well. They are lodged 

 in shallow pits, and for greater security become 

 fused with their respective supporting bones. 

 Shaped like curved needles, with the points 

 directed towards the throat, these teeth are quite 

 useless for tearing purposes, and serve only as 

 obstacles to prevent the escape of food from the 

 mouth, inasmuch as this can pass in readily- 

 enough, but any backward movement thereof is 



