1 1 8 INNERVATION. [CHAP. XX. 



movements of the pharynx, for when the trunk of the nerve was 

 cut on both sides, the movements of deglutition continued. 



Dr. Reid's experiments showed that section of the lingual branches 

 of this nerve did not destroy the power of taste, and therefore that 

 the glosso-pharyngeal cannot be regarded, according to the views of 

 Panizza, as the sole nerve of that sense. And this accords so com- 

 pletely with anatomy, which shows that a part of the tongue, en- 

 joying the gustatory power, is supplied by the fifth nerve and that 

 only, and that another part, also enjoying the same power, is sup- 

 plied only by the glosso-pharyngeal, that no doubt can be entertained 

 of the correctness of the view which assigns gustatory power to 

 this nerve as well as to certain filaments of the fifth pair. At a 

 former page we have referred to a case of paralysis of the fifth nerve 

 in which, while taste was altogether lost in the anterior part of the 

 tongue, it continued at its posterior part; the fifth nerve which sup- 

 plies the tongue in the former situation being paralysed, whilst the 

 glosso-pharyngeal, distributed in the latter region, was free from 

 disease. Two very interesting cases confirmatory of the same view 

 have since been published by Mr. Dixon, in the Med. Chir. Trans, 

 vol. xxviii. 



Disease, limited to this nerve, is of extremely rare occur- 

 rence. In one instance that we have met with, in which its neuri- 

 lemma was considerably thickened, there was not only total 

 inability to swallow, but likewise the mucous membrane of the 

 pharynx was quite insensible to stimuli, and that surface of the 

 fauces, which, in health, may be excited by the slightest touch of 

 a feather, admitted even of friction without any uneasiness to the 

 patient, or the least muscular contraction. 



The functions of the glosso-pharyngeal nerve are highly worthy of 

 an attentive study, in reference to the very important question dis- 

 cussed at a former page, as to the existence of distinct spinal and 

 cerebral fibres. We have in it an example of a nerve at once excitor 

 and sensitive; it is a most marked instance of a nerve, not motor 

 in itself, but capable of exciting motion by its influence on others. 

 Yet no part of the surface to which it is distributed can be touched 

 without sensation being excited, and with it motion. The stimula- 

 tion even of that portion of the tongue which receives filaments from 

 it is capable of exciting the pharyngeal muscles to contract, although 

 the action is not so energetic as when the stimulus is applied to the 

 isthmus faucium. In examining the fauces of patients, the practi- 

 tioner has frequent opportunity of observing the extraordinary sen- 

 sibility of the mucous membrane, where the glosso-pharyngeal never 



