226 WHALES. 



largest ones are a little behind the middle of the mouth ; 

 and they become shorter, both toward the throat and 

 the snout. These plates are a little curved, and taper 

 toward their extremities. The front edges are nearly 

 smooth ; and the back ones, which are thinner, are 

 fringed with horny fibres, of the texture of coarse 

 hair, which increase towards the extremities. They 

 are sometimes black, and sometimes of a grayish 

 colour, though the latter often appears only in the 

 membrane with which they are covered. The sub- 

 stance of which these plates are composed, is nearly 

 the same as horn ; and so is the texture, though less 

 compact. Parallel to the flat surface, it can be divided 

 into smaller plates, of indefinite fineness ; but across 

 that direction the cleavage is rough and thready. It is 

 used for many purposes in the arts ; but though it has 

 considerable toughness, elasticity, and gloss, it is very 

 apt to split. It is sometimes substituted for bristles in 

 the manufacture of brushes ; but it is very inferior, 

 and lasts but a very short time. 



When the mouth of the whale is open, the fringes of 

 the whalebone are brought in contact with the surface 

 of the tongue ; and the mouth is thus filled with a kind 

 of net, in which the mollusca, which are the principal 

 food of the whale, are entangled, and by the joint 

 action of the tongue and the plates of whalebone, con- 

 veyed to the gullet. From the size and position of 

 the eyes, they can be of little use to the animal in 

 finding its food ; though they enable it to make its way 

 in the water, and to avoid those animals that are hostile 

 to it, and likewise submerged rocks, which, if it were 

 to strike when in full velocity, it would be severely 



