ZOOLOGY. — MYSTICETUS. 469 



many hours at a time. Whales are seldom found 

 sleeping ; yet, in calm weather, among ice, instances 

 occasionally occur. 



The food of the whale consists of various species of 

 actiniae, cliones, sepise, medusae, cancri, and helices; 

 or, at least, some of these genera are always to be 

 seen wherever any tribe of whales is found stationary 

 and feeding. In the dead animals, however, in the 

 very few instances in which I liave been enabled to 

 open their stomachs, squillae or shrimps were the 

 only substances discovered. In the mouth of a whale 

 just killed, I once found a quantity of the same kind 

 of insect. 



When the whale feeds, it swims with consider- 

 able velocity below the surface of the sea, with its 

 Jaws widely extended. A stream of water conse- 

 quently enters its capacious mouth, and along with 

 it, large quantities of water insects ; the water 

 escapes again at the sides ; but the food is entangled 

 and sifted, as it were, by the whalebone, which, from 

 its compact arrangement, and the thick internal co- 

 vering of hair, does not allow a particle the size of 

 the smallest grain to escape. 



There does not seem to be a sufficient dissimi- 

 larity in the form and appearance of the mysticete 

 found in the polar seas, to entitle them to a division 

 into other species ; yet such is the difference observ- 

 ed in the proportions of these animals, that they 

 may be well considered as sub-species or varietieSc 



