!;o 



THE CRAXIAL NERVES. 



descends in close contact with it, and is partly distributed to the submaxillary 

 ganglion and partly blended with the lingual nerve in its distribution to the 

 tongue. As this nerve crosses the tympanum, it is said to supply a twig to the 

 laxator tympani muscle. 



The ni'rri' to ihe f<fainHl\vs mvxdc arises from the trunk of the facial opposite 

 the pyramid, and passes obliquely inwards to the fleshy belly of the muscle. 



Fi?. 343. 



Fig. 343. — Geniculate Ganglion of 

 TiiK Facial Nerve and its Connec- 

 tions FKOM ABOVE (fiom Bidder). 



The dissection is made in the middle 

 fossa of the skull on the riglit side ; the 

 temporal bone being removed so as to 

 open the meatus internus, hiatus Fal- 

 lopii, and a part of the canal of the facial 

 nerve, together with the cavity of the 

 tympanum, a, the external ear ; h, 

 middle fossa of the skull with the 

 meningeal arteiy ramifying in it ; 1, 

 facial and auditory nerves in the meatus 

 auditorius internus ; 2, large super- 

 ficial petrosal nerve ; 3, small super- 

 ficial petrosal nerve lying over the ten- 

 sor tympani muscle ; 4, the external 

 superficial petrosal joining sympathetic 

 twigs on the meningeal artery ; 5, facial 

 and chorda tympani ; 6, nerves of the 

 eighth pair. 



The chorda t;y-mpani is regarded 

 by some anatomists as a continua- 

 tion of the great superficial petrosal 

 nerve. According to Owen, in the 

 horse and calf, the portio dura being less dense in structure, the Vidian branch 

 of the fifth may be distinctly seen crossing the nerve after penetrating its 

 sheath, and separating into many filaments, with which filaments of the seventh 

 nerve are blended, while a ganglion is formed by the superaddition of gi-ey 

 matter ; and the chorda tympani is continued partly from this ganglion, partly 

 from the portio dura. (Hunter's Collected Works, vol. iv., p. 194, note.) 



Posterior auricular branch. — This branch arises close to the 

 stylo-mastoid foramen. In front of the mastoid process, it divides into 

 an auricuhir and an occipital portion, and is connected with the great 

 auricular nerve of the cervical plexus. It is said to be joined by the 

 auricular branch of the pneumo-gastric nerve. 



a. The anricular division supplies filaments to the retrahent muscle 

 of the ear, and ends in the integument on the posterior aspect of the 

 auricle. 



h. The occipital Iranch is directed backwards beneath the small 

 occipital nerve (from the cervical plexus) to the posterior part of the 

 occipito-frontalis muscle ; it lies close to the bone, and besides sitppljing 

 the muscle, gives upwards filaments to the integument. 



Digastric and stylo-hyoid branches. — The digastric branch arises 

 in connnon with that for the stylo-hyoid muscle, and is divided into 

 numerous filaments, which enter the digastric muscle : one of these 

 sometimes perforates the digastric, and joins the glosso-pharyngeal 

 nerve near the base of the skull. 



The stylo-hyoid branch, long and slender, is directed inwards from 



