92 
ANATOMY AND PHYSIOLOGY 
deposited, denominated blubber, is the true skin of the 
animal, modified certainly for the purpose of holding 
this fluid oil, but still being the true skin. Upon close 
examination it is found to consist of an interlacement of 
fibres crossing each other in every direction, as in com- 
mon skin, but more open in texture, to make room for 
the oik Taking the hog as an example of an animal 
covered with an external layer of fat, we find that we 
can raise the true skin without any difficulty, leaving a 
thick layer of cellular membrane loaded with fat of the 
same nature as that in the other parts of the body; on 
the contrary, in the whale it is altogether impossible to 
raise any layer of skin distinct from the rest of the 
blubber, however thick it may be ; and in flensing a 
whale the operator removes this blubber, or skin, from 
the muscular parts beneath, merely dividing with his 
spade the connecting cellular membrane .” — Dublin Phil. 
Journal , voh i. p. 35 6 . 
This construction of the skin appears to be useful in 
obviating the effects of pressure when the animal is situ- 
ated in the depths of the ocean, and which ei operates,” 
says Sir William Jardine, “like so much caoutchouc, 
possessing a density and resistance which the more it is 
pressed it resists the more,” 
OF THE TEETH. 
“ There is a very great variety,” says Hunter, “ in the 
formation of the mouths of this tribe of animals. Some 
catch their food by means of teeth, which are in both 
