FACIAL NERVE. 149 



root and the intermediary nerve then unite and form the 

 common trunk of the facial, which emerges from the cranial 

 cavity by the stylo-mastoid foramen. 



In the aquseductus Fallopii, the facial gives off numerous 

 branches, as follows : 



1. The large petrosal branch is given off from the gan- 

 glioform enlargement, and goes to MeckePs ganglion. 



2. The small petrosal branch is given off at the ganglio- 

 form enlargement, or a very short distance beyond it, and 

 passes to the otic ganglion. 



3. A small branch, the tympanic, is distributed to the 

 stapedius muscle. 



4. The chorda tympani, a branch of great physiological 

 interest, passes through the cavity of the tympanum, and 

 joins the lingual branch of the inferior maxillary division 

 of the fifth as it passes between the two pterygoid muscles, 

 with which nerve it becomes closely united. 



5. Opposite to the point of origin of the chorda tym- 

 pani, a communicating branch passes between the facial and 

 the pneumogastric, connecting these nerves by a double in- 

 osculation. 



The five branches above described are given off in the 

 aquseductus Fallopii. 1 The following branches are given off 

 after the nerve has emerged from the cranial cavity : 



1. Just after the facial has passed out at the stylo-mastoid 

 foramen, it sends a small communicating branch to the 

 glosso-pharyngeal nerve. According to Sappey, this branch 

 is sometimes wanting. 3 



2. The posterior auricular nerve is given off by the facial 

 a little below the stylo-mastoid foramen. Its superior branch 

 is distributed to the retrahens aurem and the attollens aurem. 



1 In the course of the facial in the aqueduct, two branches are sometimes 

 described, one going to the auditory, and another to the sympathetic filaments 

 accompanying the middle meningeal artery ; but their existence is denied by 

 many anatomists. 



2 SAPPEY, Traite d'anatomie descriptive, Paris, 1852, tome ii., p. 259. 



