NERVES OF MAMMALIA. 



159 



in Birds (vol. ii. p. 124), is mainly distributed to the back part 

 of the tongue and to the pharynx in all Mammals ; passing thence 

 to the ' flocculus ' in its way to the jugular foramen, it retains its 

 proper fibrous sheath, and usually presents the two enlargements 

 called 'jugular' and c petrous ' ganglions, before emerging from 

 the skull. From the petrous ganglion a filament enters the 

 tympanum, where it joins a plexus from the sympathetic, and 

 supplies the membrane continued into the eustachian tube. The 

 pharyngeal branches are joined by filaments from the vagus and 

 sympathetic to form the pharyngeal plexus. Filaments are sent 

 to the tonsils and fore part of the epiglottis ; those to the tongue 

 supply the muscles at its base and the mucous membrane covering 

 the base and sides of the tongue, some filaments terminating in 

 the fossulate papilla). 



In the Porpoise the glosso-pharyngeal divides at its exit from 

 the skull into a smaller and larger branch. The former is dis- 

 tributed to the sphincter of the lower or palatal part of the nasal 

 canal, and unites there in a plexiform way with a branch of the 

 vagus. The larger division supplies the palate and base of the 

 tongue, and the muscles between the pyramidal larynx and the 

 hyoid. Some filaments pass 

 to the anterior ganglion of the 

 sympathetic. 



The glosso-pharyngeal is fi- 

 gured, in liv. pi. xxxi. fig. 2, 

 9, and pi. xxxii. fig. 3, 22 (Bos), 

 showing its communications 

 with the ( vagus ' and sympa- 

 thetic ; also ib. ib. fig. 3, 13 

 (Felis) showing connections 

 with the gustatory branch of 

 the trigeminal. In fig. 134, 

 from the human subject, the 

 emergence of the glosso-pha- 

 ryngeal, 4, from the post-pyra- 

 midal, c, and post-my clonal, cj, 

 tracts is shown at 2 : the petro- 

 sal ganglion and connecting 

 filaments with that of the upper 

 vagal ganglion at 8 and 10 : 

 7 is the auricular branch of the vagus, 9 the < ramus anastomo- 

 tic^ ' of Jacobson, 13 the trunk of the glosso-pharyngeal. 



The vagus, fig. 134, 3, or ( pneumogastric ' from the important 



Origins and connections of the constituents of the 

 1 eighth' or pneumogastric nerve, Man. lxvh". 



