SEALS. 69 



that if they are benighted at a distance from shelter, 

 they can make themselves tolerably comfortable, pro- 

 vided that there be only a reasonable depth of snow 

 into which they can burrow. And this very property 

 is utilized by the Seal, which, like the human inhabi- 

 tants of the same land, finds a shelter and a home 

 beneath the ice-cold snow. 



Having thus seen how the structure of the Seals is 

 modified according to the surrounding conditions, 

 and enables them to divide their lives between the land 

 and water, we will briefly notice one or two of the 

 most conspicuous species, and see how their habits 

 agree with their structure. 



The Common Seal (Phoca vitulind) is too familiar 

 to need description, and we will therefore proceed at 

 once to the two species which are represented on 

 Plate I. 



The figures in the foreground represent the 

 Walrus, an enormous species of Seal, measuring, when 

 adult, no less than fifteen feet in length ; and being, 

 as may be seen by reference to the illustration, very 

 stout in the body. 



On looking at the Walrus, the first point that 

 strikes the observer is the enormous development of 

 the canine teeth of the upper jaw, which form two 

 long and powerful tusks, slightly curved, and gradually 

 tapering to a point at the tip. 



The reader may remember that in the description 

 of the narwhal, a doubt was expressed as to the purpose 

 served by the one enormous tooth that projects from 

 the jaw of the male. The chief difficulty lies in the 



