H6 



THE INHABITANTS OF THE SEA. 



thick layer of fat, and by their simple or double blow-hole, which 

 is situated at the top of the head, and corresponds to the nostrils 



of the quadrupeds, though not for 

 the purpose of smelling, but 

 merely as an organ of respiration. 

 Our knowledge of the ceta- 

 ceans is still very incomplete ; and 

 this is not to be wondered at, when 

 we consider that they chiefly dwell 

 in the most inaccessible parts of 

 the ocean, and that when met with, 

 the swiftness of their movements 

 rarely allows more than a flighty 

 view of their external form. Thus 

 their habits and mode of living 

 are mostly enveloped in obscurity ; 

 and while doubtless many ceta- 

 ceans are to the present day un- 

 known, one and the same species 

 has not seldom been described 

 under different names, to the no 

 small confusion of the naturalist. 

 The cetaceans are either with- 

 out a dental apparatus, or pro- 

 vided with teeth. The former, or 

 the whalebone whales, have two 

 blow-holes on the top of the head % 

 in the form of two longitudinal 

 fissures ; while in the latter, 

 (sperm-whales, unicorn-fish, dol- 

 phins,) which comprise by far the 

 greater number of species, there 

 is but one transversal spout-hole. 

 In all whales the larynx is con- 

 tinued to the spouting canal, and deeply inserted or closely 

 imbricated within its tube. Thus no tones approaching to a 

 voice can be emitted except through the spiracles, which are 

 encumbered with valves, and evidently badly adapted for the 

 transmission of sound. Scoresby assures us that the Green- 

 land whale has no voice, and Bennett frequently noticed sperm 



Bones of the Anterior Fin of a Whale. 



