464- FUNCTIONS OF 



of the face concerned with respiration and expression, when 

 the mere descent of the lower jaw which accompanies surprise 

 proves the aganglionic portion of the trigeminus nerve to be, 

 as almost any nerve of voluntary motion may be, a nerve of 

 expression." 



the motiferous and respiratory. As the motiferous convey a stimulus, so there- 

 fore probably do the respiratory. Unquestionably those which are voluntary 

 nerves are like all other voluntary nerves. Such are the facial, phrenic, and 

 partly the pneumono-gastric, which are similar to the common motor of the eye, 

 the abductor, and the hypo-glossal. This really tends nothing to the argument. 

 Indeed the analogy does not hold with respect to all, for the glosso-pharyngeal, 

 however similar in structure to nerves of motion, is a nerve of sense. 



6. The sensiferous and ganglionic nerves do not transmit the galvanic in- 

 fluence; while the motiferous and respiratory transmit it with facility. But this 

 proves no more than the fifth argument ; and I know not that all the latter do. 



7. A stimulus applied to the trunks of these nerves occasions in general a 

 display of irritation in parts sympathetically connected with them. I believe 

 this is the case with all nerves of motion, as well as those concerned in the 

 motions of respiration. Stimulation of even nerves of sense will often excite 

 those of motion which are sympathetically connected with them. Indeed, the 

 acceleration of respiration after a time is said to follow the irritation of the 

 glosso-pharyngeal a nerve of only specific sense, as much as of the accessory 

 and pneumono-gastric. 



8. When the respiratory nerves are divided, the effects of passion and 

 sympathy upon the parts which they supply are lost. This is true of those 

 which convey the effects of volition, for this they can do no longer, nor, of 

 course, can they convey involuntary any more than voluntary excitement to the 

 muscles to which they run. But the fact amounts to no more than would be true 

 of the division of any nerve of voluntary motion. The division of the glosso- 

 pharyngeal can have no such effect, for, being a nerve of sense, its sense 

 (taste) only is lost in the part which it supplies. Various disturbances follow 

 the division of the pneumono-gastric, but various ill effects also ensue upon 

 the divisions of the sensiferous fifth. 



Although I consider Dr. Fletcher's views equally unfounded with those of 

 Sir C. Bell, I must not omit to mention that he puts them forth most candidly 

 and rationally as purely hypothetical, and intended to give way to whatever 

 shall be proposed of a more satisfactory nature. 



It may be well to mention here that Sir Astley Cooper has lately published 

 an account of the ligature of the two great sympathetic nerves in rabbits, and 

 found no evident effect. One rabbit was killed at the end of seven days, when one 

 nerve was found ulcerated through and the other nearly so ; another rabbit was 

 alive, at the end of a month, when the account went to press. (Guy's Hospital 

 Reports, No. in.) 



u For his three discoveries Sir C. Bell deserves great praise, and his name 

 will endure as long as the physiology of these respective nerves. But, when 



