Mr. Shaw on the Facial Nerves. 237 



that in natural laughter. But as this is done throu|;hthe Vth., 

 instead of the Vllth., it makes the expression on one side quite 

 different from that on the other, and consequently gives a pecu- 

 liarly ludicrous appearance to the whole countenance. 



The experiment of cutting the facial respiratory nerve was 

 performed on a dog. The following is the note made a few 

 days after the nerve was cut : The dog is now quite well, having 

 suffered very little from the operation ; when he fawns, the right 

 side of his face is completely motionless ; (the nerve of the right 

 side was cut.) When I threaten to strike him, although there is 

 a tremulous motion expressive of fear in all the muscles of the 

 left side of the face, the other is perfectly still ; he cannot even 

 close the eyelid, and instead of winking when he expects to be 

 struck, the eyeball itself is turned up. When he is excited, 

 there is an expression of alacrity in all the muscles of the left 

 side of the face, and a brilliancy in the left eye, while the right 

 is perfectly inanimate. This is shewn in an extraordinary de- 

 gree when he is fighting with another dog. 



The difference between the two ears is not so distinctly mark- 

 ed, for though the left ear be more elevated than the right, still 

 there is au expression of alacrity in the erection of both ears. 

 However, at this I was not surprised, as I had found, in a 

 dissection which I had made of a dog, previous to performing the 

 experiment, that the principal branches, which pass to the 

 muscles of the ear, were so deeply situated, that to have cut 

 them, would have probably endangered the animal's life. Tiie 

 effect upon the respiratory muscles of the right nostril, was 

 not so distinct as in the experiment upon the ass, (which will be 

 detailed presently,) but the power of giving that peculiar twist 

 to the nose, which is so distinctly seen in a pointer setting, was 

 destroyed. 



This dog, in the course of two months, perfectly recovered 

 the use of all the muscles which had been paralyzed; but this 

 circumstance involves the question of the rc-union of nerves, 

 iipoii wliich I shall not at present enter. 



1 ri|Kutcd the experiment on another dog in the month ol 

 May, and ul the same lime cut the infra orbital nerve of tin: 



