8o THE HAUNTS OF LIFE 



there is a thick layer of fat or blubber, which 

 serves the double purpose of keeping the body 

 warm and lightening its weight in proportion 

 to its size. 



The whale catches the minute animals on 

 which it feeds by swimming with its mouth 

 open. But it must be able to breathe atmo- 

 spheric air, not air dissolved in water as a fish 

 does, and the nostrils, instead of being on the 

 snout as in other mammals, are far back on the 

 forehead, so that breathing can go on at 

 the same time as swallowing. In short, as 

 someone has said, if you took away from the 

 whale all that is adaptation to its mode of life 

 there would be very little of it left. 



The teeth, when there are any, have changed 

 in character, but in the "right" whale they 

 disappear before birth, and have been replaced 

 by long horny plates frayed at the ends, which 

 hang down into the mouth. There are from 

 three to four hundred of these plates, which 

 form the valuable "whalebone" of com- 

 merce. The whale swims with open mouth 

 through shoals of small animals like the sea- 

 butterflies and water-fleas we have spoken of, 

 and when it has secured a good mouthful it 

 shuts its jaws and lets the water trickle out at 



