MOUTH OF THE WHALE. 



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which they appear to grow : at their inner mar- 

 gins, the fibres, of which their 

 texture is throughout composed, 

 cease to adhere together ; but, 

 being loose and detached, form 

 a kind of fringe, calculated to 

 intercept, as in a sieve, all solid 

 or even gelatinous substances 

 that may have been admitted 

 into the cavity of the mouth, 

 which is exceedingly capacious ; 

 for, as the plates of whalebone 

 grow only from the margins of 

 the upper jaw, they leave a large 

 space within, which, though nar- 

 row anteriorly, is wider as it 

 extends backwards, and is ca- 

 pable of holding a large quan- 

 tity of water. Thus the whale is 

 enabled to collect a whole shoal 

 of mollusca, and other small prey, by taking into 

 its mouth the sea water which contains these ani- 

 mals, and allowing it to drain off through the sides, 

 after passing through the interstices of the net- 

 work formed by the filaments of the whalebone. 

 Some contrivance of this kind was necessary to this 

 animal, because the entrance into its oesophagus is 

 too narrow to admit of the passage of any prey of 

 considerable size ; and it is not furnished with teeth 

 to reduce the food into smaller parts. The principal 

 food of the Balcena Mysticetus, or great whalebone 

 whale of the Arctic Seas, is the small Clio Borealis, 

 which swarms in immense numbers in those regions 



si. Mi^-' " 



