48 COMPARATIVE ANATOMY 



muscular parts beneath, merely dividing with his 

 spade the connecting cellular membrane." (Dublin 

 Phil. Journ. vol. L 356.) Without prosecuting 

 this point farther, we can only in a word say, that 

 we doubt not that this is the more correct view, 

 which, by the by, had previously been maintained 

 both by Pallas and by Professor Giesecki ; and it is 

 interesting to see how, in the productions of nature, 

 often apparently the smallest possible alteration 

 effects the most wonderful change. This is very 

 conspicuous here. A soft wrapper of fat, though 

 double in thickness to that usually found in the 

 Cetacea, could not have resisted the superincumbent 

 pressure ; whereas, by its being a modification of 

 the skin, always firm and elastic, and, in this case, 

 being never less than several inches, and some- 

 times between one and two feet thick, it operates 

 like so much caoutchic, possessing a density and 

 resistance which the more it is pressed it resists the 

 more. 



Other uses of this peculiarity of the skin will 

 readily suggest themselves to the reader's mind. 

 The order is warm blooded, and yet is exposed to 

 the keenest cold in the deepest recesses of the 

 frozen seas. Hence this wrapper, or blanket, as 

 it has been appropriately called, being a bad con 

 ductor of caloric, will at once resist the surrounding 

 cold and retain the animal heat. On this account 

 alone, such an integument seems essential ; its 

 bulk and quantity is enormous, sometimes weighing 

 thirty tons, which might appear sufficient to over- 



