146 THE OCEAN. 
exigency; the mouth has no teeth, but from each 
upper jaw proceed more than three hundred horny 
plates, set parallel to each other, and very close; 
they run perpendicularly downwards, are fringed on 
the inner edge with hair, and diminish in size from 
the central plate to the first and last, the central one 
being about twelve feet long. The plates are com- 
monly called whalebone, and their substance is well 
known to everybody; they form an important object 
of the fishery. ‘The lower jaw is very deep, like a 
vast spoon, and receives these depending plates, the 
use of which is this: when the Whale feeds, he swims 
rapidly just under or at the surface, with his mouth 
wide open; the water with all its contents rushes 
into the immense cavity, and filters out at the sides 
between the plates of the whalebone, which are so 
close, and so finely fringed, that every particle of 
solid matter is retained. : 
Though the Whale, like all other Mammaha, is 
formed for breathing air alone, and is therefore ne- 
cessitated to come to the surface of the sea at certain * 
intervals, yet those intervals are occasionally of great 
length. We well know that we could not intermit 
the process of breathing for a single minute without 
great inconvenience, and the lapse of only a few mi- 
nutes would be followed by insensibility and perhaps 
death. The Whale, however, can remain an hour 
under water, or, in an emergency, even nearly two 
hours, though it ordinarily comes up to breathe at 
intervals of eight or ten minutes, except when feeding, 
when it is sometimes a quarter of an hour, or twenty 
minutes submerged. Now the object of breathing 
