MAMMALIA 297 



in a Gasserian ganglion connected with the brain on the one 

 hand and the periphery on the other, divides into the sensory 

 ophthalmic which leaves the skull by the foramen laceruna 

 anterius, supplies the skin of the nose and upper parts of the 

 orbit and the muzzle. The sensory maxillary also leaves by 

 the foramen lacerum anterius, and is directed in palatine 

 branches to the palate and in a dental nerve to the teeth of the 

 upper jaw and to the skin of the face. The mixed mandibular 

 leaves by the foramen lacerum medium, and supplies the muscles 

 of the lower jaw, the tongue, and the teeth of the lower jaw. 



VI. abducent ; motor, floor of medulla, leaves the skull by 

 the foramen lacerum anterius, and supplies the external rectus 

 muscle of the eye. 



VII. facial ; mixed, forms the geniculate or facialis ganglion, 

 leaves the cranial cavity by the internal auditory foramen, 

 and, gaining the middle ear, passes out by the stylo-mastoid 

 foramen. It is originally the nerve of the hyoid cleft. It 

 gives off in succession the chorda tympani which unites with 

 the lingual branch of V, the palatine to the palate and the 

 floor of the nose, uniting with the maxillary branch of V, and 

 a hyomandibular distributer to the muscles of the face and 

 the external region of the mandible and to the hyoid. 



VIII. auditory ; sensory, with auditory ganglion leaves by 

 the internal auditory foramen and divides into cochlear and 

 vestibular branches in the internal ear. 



IX. glossopharyngeal ; mixed, forms a ganglion, leaves the 

 skull by the foramen lacerum posterius. It is originally the 

 nerve of the first branchial cleft, and supplies the tongue and 

 pharynx. 



X. vagus or pneumogastric ; mixed, forms a ganglion, 

 leaves the skull with IX. It is the nerve of the remaining 

 branchial clefts in the embryo. In the adult, it is distributed 

 in succession by branches: (1) the superior laryngeal to the 

 muscles of the larynx, (2) a nerve which descends the neck to 

 supply the heart, lungs, and stomach. It is accompanied by 

 (3) the depressor nerve of the heart, and at the level of the 

 heart (4) the recurrent laryngeal leaves the main nerve, that 

 of the right passing under the innominate artery, that of the 

 left under the aortic arch. It ascends along the trachea to 



