NERVUS TRIGEMINUS. 461 



backwards on the superior face of the petrous bone, in a gutter 

 marked on the bone, and disappears through the Vidian fora- 

 men. It, in a short space, reaches the aqueduct of Fallopius, 

 and then continues to adhere to the facial nerve till the latter 

 almost reaches the stylo-mastoid foramen: it then abandons 

 the facial nerve, and, as mentioned in the account of the ear, 

 traverses the tympanum under the name of chorda tympani; 

 and, finally, emerging at the glenoid foramen, it runs to asso- 

 ciate itself with the lingual branch of the trigeminus. The su- 

 perficial petrous, in the early part of its course, at the point of 

 the petrous bone, detaches one or more filaments to the sym- 

 pathetic in the carotid canaL 



The Deep Petrous (Nervits Petrosus Profundus) is larger 

 than the other. It also penetrates through the cartilaginous 

 matter at the point of the petrous bone, and enters the cavity 

 of the cranium under the dura mater. It then advances to the 

 internal carotid artery, and anastomoses there with a filament 

 from the motor externus or sixth nerve. This anastomosis is 

 commonly called the beginning of the sympathetic nerve. 



The Palatine Nerve (Nervus Palallnus) proceeds from the 

 inferior part of the ganglion of Meckel, and gets to the soft 

 palate of the mouth through the posterior palatine foramen. In 

 this course, it detaches several filaments to the Schneiderian 

 membrane, which reach it either through the spheno-palatine 

 foramen, or by perforating the nasal lamella of the palate bone. 

 These are described in the account of the nose. 



The trunk of the palatine nerve, having reached the roof of 

 the mouth, bends forwards, and is divided into many filaments, 

 some of which are distributed along the gums of the upper jaw, 

 others are distributed on the lining membrane of the hard pa- 

 late and upon its mucous glands. 



There are two other nerves, which arise either immediately 

 from the palatine, or from the ganglion of Meckel, and go to 

 supply the soft palate. They are called the smaller palatine. 

 One of them, having proceeded for a short distance in the pos- 

 terior palatine canal, departs from it in a little canal of its own, 

 which opens behind the hook of the internal pterygoid process. 



40* 



