32 THE ANIMAL KINGDOM. 



even fruits, and one family of them feeds on crabs, which 

 it catches in the marshy places in which it likes to live. 



CETACEA. 



THE Cetacea may next claim our attention, for we can 

 separate them from all the rest of the Mammalia by their 

 fish-like form, and by their possessing only one pair of 

 limbs, which arc converted into swimming paddles. The 

 tail, instead of being parallel to the sides of the body as 

 in fishes, is placed at right angles to it that is, parallel 

 to the surface of the water. This arrangement is of great 

 service to the animals, for they not only use this tail fin for 

 ordinary progression (in which case they move it slantingly 

 downwards and sideways as we work our paddle in scul- 

 ling a boat), but it assists them materially in rising to the 

 surface of the water, which they arc compelled to do in 

 order to breathe. When you are told that the breadth of 

 the tail fin in some of the larger species is 20 feet, and its 

 surface not less than 100 square feet, you will not be sur- 

 prised to hear that by one blow of it, whaling-boats have 

 been thrown into the air and the bottoms of ships injured ; 

 in fact, such is its power, that by striking it against the 

 water, whales 80 feet long have been seen to leap clear 

 above the surface, as dace and other little fish do when 

 rising after flies. 



The manner in which the oily matter called blubber is 

 placed in whales requires some explanation. In other 

 animals, fat is placed as a layer beneath the skin and in 

 various depressions on the surface of the flesh, so that 

 when the skin is drawn off, the fat still remains. You will 

 have noticed this in the sheep, c., which arc hung up in 

 our markets ; but in whales the blubber is in the substance 

 of the skin itself. This arrangement is of great service to 

 the animals, firstly, because it keeps them warm byprevent- 



