THE NERVES OF THE TEETH. 265 



The posterior branch, called the pterygoid or vidian* 

 passes from the ganglion of Meckel in the backward direc- 

 tion, through the vidian canal at the root of the pterygoid 

 process, then enters the cranium through the foramen 

 lacerum medius, and divides into an inferior and superior 

 branch. The former, called the carotid branch, enters the 

 cavernous sinus and unites with the plexus surrounding 

 the carotid artery, formed by the ascending branches of 

 the superior cervical ganglion. The superior branch rep- 

 resents rather the continued trunk of the vidian, and 



* Very great confusion of description and wide diversity of opinion prevail 

 among anatomists in regard to this nerve and its connections. By some it is 

 regarded as a sensory nerve, coming off from the fifth pair. By others it is con- 

 sidered as a sympathetic nerve originating from Meckel's ganglion, and binding 

 together the various superficial and deep nerves of this region. 



Before its entrance into the hiatus fallopii, it is found to connect itself by 

 filaments with many nerves at the base of the skull, entering the hiatus. It is 

 ordinarily described as uniting with the facial at its angle, where the intu- 

 mescentia genuformis (or gangliformis) is found. The researches of Morganto, 

 Brinton, and Malagati, show that this intumescence does not belong to the 

 facial, but to a third division of the old seventh nerve, first described by Mis- 

 berg, and called by him porlio intermedia, because it lies between the facial 

 and auditory nerves. It is clearly traced into the medulla oblongata in one 

 direction, and into this geniculate ganglion in the other. Malagati infers from 

 his recent investigations that this portio intermedia is really a nerve of organic 

 life, entering the brain, and associating the ear with that viscus as well as with 

 the viscera of the thorax and abdomen a theory which accounts for the re- 

 markable sympathies known to exist between the ear and these various organs, 

 how it is with this geniculate ganglion, that the superior branch of the vidian 

 (nervus petrosus superficialis major of Arold) is connected. With it also is joined 

 the nervous petrosus superficialis minor, which may be regarded either as a branch 

 of the optic ganglion, or of the tympanic plexus. In any case, however, it con- 

 nects the glosso-pharyngeal with this petrosal branch of the vidian, through the 

 medium of Jacobson's nerve. 



From this same geniculate ganglion, which thus appears to be a highly im- 

 portant sympathetic centre, the chorda tympani comes off', and, as described in 

 the text, passes through the Glasserian fissures and unite itself with the gusta- 

 tory branch of the fifth pair. It seems to exercise an influence upon the sense 

 of taste ; for impairment of this function always occurs when the facial js in- 

 jured, when its injury can involve those of the chorda tympani. 



The termination of the chorda tympani has been stated according to the 

 views of the English anatomists. It cannot, however, be wholly traced into 

 the submaxillary ganglion. Some anatomists have failed entirely to establish 

 the connection. Guarini traces it into the lingualis muscle. At most, only a 

 portion of the nerve can be connected with this ganglion. 



