10 AUSTRALIAN SNAKES. 



Snakes have one lung developed, largely at tlie 

 expense of the other. While in the great majority 

 of lizards they are of equal size ; rarely one of 

 the lungs is aborted. Most snakes swallow their 

 prey whole, and the jaws are specially distensible 

 to permit of this ; some, which consume only 

 small fry, have this peculiarity in slight degree, and 

 in such respect resemble lizards. It has been mentioned 

 that certain snakes possess rudiments of limbs ; they 

 ^re visible outside the body in the form of small spurs, 

 and internally there may be not only a leg bone but 

 traces of the pelvis also. Such snakes, therefore, have 

 something in common with those lizards wlierein the 

 limbs are reduced to a single pair, and tliose very 

 rudimentary. Lizards, however, approach much more 

 nearly the typical legless snakes, for some are without 

 the slightest external trace of limbs, and are thus very 

 snake-like indeed. In such, the head and neck are 

 indistinguishable, and from above, no indication of the 

 •division into body and tail exists. Taking all these 

 factors into consideration, it would appear to be difficult 

 to give absolute distinguishing characters. 



Snakes cannot wink ; they have no eyelids, 

 members with which (and again we must qualify 

 the sentence) the great majority of lizards are amply 

 provided, nor can they cast off their tails like geckos 

 and some other lizards. One cannot find the ear- 

 opening of a snake ; it is concealed beneath a scale, 



