112 MAMMALIA. 



The odorous substance, named ambergris, appears to be a concretion formed 

 in the intestines of the Cachalot, particularly during certain states of disease. 

 The species of the Cachalots are far from being well ascertained. 



BAI..I:N.\, Linnceus. 



THE Whales are equal in size to the cachalots, and in the proportional magni- 

 tude of the head, although the latter is not so much 

 enlarged in front; but they have no teeth. The two 

 sides of their upper jaw, which is keel-shaped, or fur- 

 nished with thin, compact, transverse laminae, called 

 whalebone, formed of a kind of fibrous horn, fringed at the edges, which serve 

 to retain the little animals on which these enormous cetacea feed. Their lower 

 jaw, supported by two osseous branches arched externally and towards the 

 summit, and completely unarmed, lodges a very thick and fleshy tongue; and 

 when the mouth is closed, envelopes the internal part of the upper jaw, and the 

 whalebone with which it is invested. These organs do not allow whales to 

 feed on such large animals as their size might induce us to imagine. They 

 live on fish, but principally on worms, mollusca, and zoophytes, selecting, it is 

 said, the very smallest, which become entangled in the filaments of the 

 whalebone. 



Bal. mysticetus, Lin. (The Common Whale). Has long been considered 

 the largest of all animals ; but from the late observations of Captain Scoresby, 

 it appears that it scarcely ever exceeds seventy feet, a length frequently sur- 

 passed by the wrinkle-bellied whales. It has no dorsal fin. To procure its 

 fat or blubber, which is sometimes several feet in thickness, and contains 

 immense quantities of oil, whole fleets are annually equipped. Formerly 

 sufficiently bold to venture into our seas, it has gradually retired to the 

 extreme north, where the number is daily diminishing. Besides oil, it 

 produces black and flexible whalebone, eight or ten feet in length, each 

 individual having from eight to nine hundred strips on each side of the palate. 

 One hundred and twenty tuns of oil are obtained from a single whale. Shell- 

 fish attach themselves to its skin, and multiply there as on a rock, and some 

 of the Balanus family even penetrate into it 



r OF THE OVIPAROUS VERTEBRATA. 



ALTHOUGH the three classes of the Oviparous Vertebrata differ greatly from 

 each other in their quantum of respiration, and in all that relates to it, viz. the 

 power of motion and the energy of the senses, they present several common 

 characters when opposed to the Mammalia, or Viviparous Vertebrata. 



Oviparous production consists, essentially, in this the young animal is not 

 attached to the parietes of the oviduct, but remains separated from it by its 

 most external envelope. Its aliment is prepared beforehand, and enclosed in 



