56 COMPARATIVE ANATOMY OP 



island or rock, the facility with which they ac- 

 complish their object is altogether astonishing. 

 They then make especial use of their fore-paws ; 

 and those which have claws implant them like 

 so many grappling-irons, and having thus secured 

 a fixed point, by means of the admirable struc- 

 ture we have been considering, they uplift their 

 monstrous carcases with the greatest rapidity and 

 ease. 



Having thus noticed that the external struc- 

 ture of these Amphibia is admirably adapted for 

 their watery element, and yet made wonderfully 

 conformable to their requirements on land, we pro- 

 ceed to remark, that their vital functions also are 

 strikingly fitted for their peculiar exigencies. Their 

 respiration, as might readily be inferred, differ? 

 considerably from what is observed in most other 

 animals. Even the air passages undergo a change, 

 which ought not to be overlooked. We refer par- 

 ticularly to the nostrils, whose state, unlike that of 

 other quadrupeds, is that of being habitually closed, 

 instead of being uniformly open. This was first 

 noticed, we believe, in a Walrus domesticated in 

 England, of which, as will appear in our account of 

 that animal, it was said, " It can open and shut its 

 nostrils at pleasure." The Count Buffon, again, 

 pointed out the peculiarity in a tame Seal which he 

 examined " In the intervals of breathing, the nos- 

 trils were accurately closed, and, on the act of in- 

 spiration being completed, they were shut as be- 



