326 SMAKES, 



example, almost allying it to some of the fishes with long 

 tentacular appendages. Herpeton tentaailum is its name, 

 its pair of tentacles being scaly and flexible, and in appear- 

 ance somewhat like the African viper's horns, sticking out 

 horizontally from its snout. They are employed under 

 water as organs of touch, and probably to discern food. 



These are some of the most striking head-appendages ; 

 though in the way of pug-nosed ophidians and curious profiles 

 we might give a whole page of illustrations. 



In the acrobatic chapter, mention was made of a pair of 

 rudimentary hind limbs in some of the boas. Externally 

 the derm is condensed into 'claws' or * hooks.' In form 

 they are merely long, simple appendages, which in the 

 largest boas are about as big as a finger. Claws and hooks 

 they are in the matter of use, being a pair, and they no 

 doubt assist the climbing snakes in grasping. 



As a condensed form of the tegument, they are included 

 in this chapter ; but as they are truly vestiges of limbs, 

 I will digress a moment to add a word. 



Says Darwin on rudimentary and atrophied limbs : * The 

 disuse of parts leads to their reduced size : and the result is 

 inherited.' Some tame little lizards in my possession — our 

 native species — when crawling about their cages scratching 

 the sand or pushing their way among the moss and rubbish, 

 frequently made use of their fore legs only, allowing the 

 hind legs to drag after them, not because the latter were in 

 any way injured, but simply because the lizards could do well 

 enough without them. They were folded back or permitted 

 to lie passively prone against the tail, while the arms and 

 exquisite little hands were sufficient for the work required. 



