THE FACIAL NERYE. 553 



exercises on the movements of the lingualis and the 

 adjacent muscular fibres of the tongue ; and, according to 

 some, or probably in some animals, on the movements of 

 the stylo-glossus. We may therefore suppose that the 

 accurate movement of these muscles in the tongue is in 

 some way connected with the proper exercise of taste. 



Together with these effects of paralysis of the facial 

 nerve, the muscles of the face being all powerless, the 

 countenance acquires on the paralyzed side a characteristic, 

 vacant look, from the absence of all expression : the angle 

 of the mouth is lower, and the paralyzed half of the mouth 

 looks longer than that on the other side ; the eye has an 

 unmeaning stare. All these peculiarities increase, the 

 longer the paralysis lasts ; and their appearance is exag- 

 gerated when at any time the muscles of the opposite side 

 of the face are made active in any expression, or in any of 

 their ordinary functions. In an attempt to blow or whistle, 

 one side of the mouth and cheek acts properly, but the 

 other side is motionless, or flaps loosely at the impulse of 

 the expired air ; so in trying to suck, one side only of the 

 mouth acts ; in feeding, the lips and cheek are powerless, 

 and food lodges between the cheek and gum. 



As a nerve of expression, the seventh nerve must not 

 be considered independent of the fifth nerve, with which it 

 forms so many communications ; for, although it is through 

 the facial nerve alone that all the muscles of the face are 

 put into their naturally expressive actions, yet the power 

 which the mind has of suppressing or controlling all these 

 expressions can only be exercised by voluntary and well- 

 educated actions directed through the facial nerve with the 

 guidance of the knowledge of the state and position of 

 every muscle, and this knowledge is acquired only through 

 the fifth nerve, which confers sensibility on the muscles, 

 and appears, for this purpose, to be more abundantly sup- 

 plied to the muscles of the face than any other sensitive 

 nerve is to those of other parts. 



