348 
COMPARATIVE ZOOLOGY. 
7. Cetacea , or Whales, have the form and life of Fishes, 
yet they possess a higher organization than the preceding 
orders. They have a broad brain, with many and deep 
foldings; the foramen magnum of the skull is entirely 
posterior; the whole head is disproportionately large, and 
the jaws greatly prolonged. The body is covered with a 
thick, smooth skin, with a layer of fat (“blubber”) under- 
Fio. B41.—Outline of the Sperm-whalfe ( Physeter ): a, blow-hole ; b, the case contain¬ 
ing spermaceti; c, junk ; d, bunch of the neck—between it and the corner of the 
mouth is the eye; k, hump; i, ridge ; k, the small; /, tail, or flukes. Between 
the dotted lines are the spiral strips of blubber. Maximum length, sixty feet. 
South Atlantic. 
neath; there are no clavicles; the hind-limbs are want¬ 
ing, and the front pair changed to paddles; the tail ex¬ 
pands into a powerful, horizontal fin; neck and external 
ears are wanting; the eyes small, with only two lids; the 
nostrils (“blow-holes”)—double in the Whale, single in 
the Porpoise—are on the top of the head. All are carniv¬ 
orous, and essentially marine, a few Dolphins only be¬ 
ing found in the great rivers. In the Whalebone Whales, 
the teeth are absorbed, and disappear before birth, and 
their place is supplied by horny “ baleen ” plates. “ The 
Whale feeds by putting this gigantic strainer into opera¬ 
tion, as it swims through the shoals of minute Mollusks, 
Crustaceans, and Fishes, which are constantly found at the 
surface of the sea. Opening its capacious mouth, and al¬ 
lowing the sea-water, with its multitudinous tenants, to fill 
the oral cavity, the Whale shuts the lower jaw upon the 
baleen plates, and, straining out the water through them, 
swallows the prey stranded upon its vast tongue.” In the 
