PAR VAGUM. 



883 



lower and external part of this ganglion a 

 small nerve arises, (ramus auricularis nervi 

 vagi,) which is seen joined by another small 

 branch from the lower part of the ganglion 

 petrosum of the glosso-pharyngeal.* The ramus 

 auricularis proceeds outwards and a little back- 

 wards anterior to the jugular vein, and lies in a 

 groove in that portion of the petrous portion of 

 the temporal bone which assists in forming the 

 fossa jugularis, perforates the osseous partition 

 between the fossa jugularis and the aqueduct 

 of Fallopius, and enters the internal side of the 

 latter about one or two lines above its lower 

 termination in the stylo-mastoid foramen. It 

 now divides itself into two branches, a small 

 ascending twig which joins the portio dura 

 nerve, and a larger portion which enters a canal 

 on the external side of the aqueduct of Fallo- 

 pius, proceeding outwards and a little back- 

 wards through that portion of the spongy por- 

 tion of the temporal bone which forms the lower 

 wall of the external meatus. The larger branch 

 subdivides into two other branches as it lies in 

 this canal. One of these emerges upon the 

 external surface of the cranium through a small 

 opening between the mastoid process and the 

 posterior margin of the meatus auditorius, and 

 divides into two or three twigs, which pass 

 through openings in the cartilage of the pavilion 

 of the external ear, and are ultimately distri- 

 buted upon the tegumentary covering of the 

 internal surface of the concha and meatus audi- 

 torius externus. The other branch of the nerve 

 passes through the mastoid process and joins 

 itself to the auricular branch of the portio dura, 

 and along with it is distributed upon the pos- 

 terior surface of the pavilion of the external 

 ear.f The trunk of the spinal accessory is 

 closely connected to the posterior surface of the 

 superior ganglion of the vagus by cellular tissue, 

 and immediately below the lower end of the 

 ganglion it throws a considerable branch into 

 the vagus. The exact place and manner in 

 which these auxiliary fibres from the accessory 

 join the vagus differ in different individuals, 

 and sometimes in the two sides of the same 

 individual, but most genera'ly the spinal acces- 

 sory divides itself at the lower part of the fora- 

 men lacerum into two branches, the internal 

 and external branches of the spinal accessory. 

 The internal branch runs immediately into the 



Capitis, plate iv.) represents an anastomosis be- 

 tween the accessory and ganglion jugulare. Krause 

 (Hanbuch der Menschlichen Anatomie. S. 1066, 

 1843, and Hein (Muller's Archives for 1844. Heft 

 iv. p. 337) describe the superior filaments of the 

 root of the accessory as connecting themselves to 

 the lower filaments of the vagus, and that a few of 

 the filaments of the accessory may enter the ganglion 

 jugulare of the vagus. Bischoff (Nervi ;\ccessorii 

 Willisii Auatomia et Physiologia, 1832) neither 

 delineates nor describes any communicating fila- 

 ments pnssing between the spinal accessoiy and 

 the ganglion jugulare of the vagus. 



* In Valentin's description (opus cit. p. 483) of 

 this auriculai" branch, the strengthening twig is said 

 to come from the hypoglossal nerve, (aus dem 

 zungenfleisclinerven,) but this must either be some 

 error of the press or some lapsus scribendi. 



t Vide Arnold's Icones Nervorum Capitis, tabul. 

 iii. et v. 



anterior and outer part of the vagus, and while 

 one portion of its fibres goes to form a part of 

 the superior pharyngeal branch of the vagus, 

 the other portion joins itself to the trunk of the 

 vagus, and accompanies it down the neck. 

 Sometimes the fibres of the internal branch of 

 the accessory are arranged in two bundles, and 

 in such cases the one generally joins itself to 

 the vagus a little below the other. The exter- 

 nal branch of the accessory proceeds downwards 

 and outwards, perforates the upper part of the 

 sterno-cleido-mastoid muscle, and ultimately 

 terminates in the trapezius muscle. 



The superior ganglion of the vagus was known 

 to Ehrenritter.* It appears also to have been 

 well known to Wutzer, for it is both mentioned 

 and figured by him in his monograph De Cor- 

 poris Humani Gangliorum Fab. et Usu, 1818. 

 Wutzer has in fig. vii. certainly represented it 

 as being placed somewhat inferior to the gan- 

 glion petrosum of the glosso-pharyngeal, instead 

 of being rather above it : yet as he terms it 

 ganglion primum n. v. and figures the ganglion 

 secundum in its proper position, there can be 

 no doubt that he was well aware of its exist- 

 ence. It has been supposed by some that 

 Lobsteinf had also pointed out the existence of 

 this ganglion, while others maintain that his 

 description is not sufficiently explicit to enable 

 us to decide whether it refers to the upper or 

 lower ganglion of the vagus. It appears, how- 

 ever, much more probable that it is the superior 

 ganglion, for after mentioning that the vagus 

 presents a reddish appearance, similar to a 

 ganglion, (rubella parum quasi ganglion men- 

 tiretur,) he describes the superior pharyngeal 

 branch of this nerve as arising below it. MiillerJ 

 has attempted to shew that Comparetti was the 

 first anatomist who described this ganglion, 

 and that he was even acquainted with the ramus 

 auricularis of the vagus; but Arnold, on the 

 other hand, maintains, and we think justly, that 

 the description of Comparetti applies equally 

 well, if not better, to the ganglion petrosum of 

 the glosso-pharyngeal. Desmoulins and Ma- 

 gendie|| observed the superior ganglion of the 

 vagus in the carnivorous Mammalia and in the 

 Kuminantia, and also a branch passing from it 

 to join the portio dura, but denied that this 

 ramus auricularis exists in man. Cuvierlf had 

 also previous to this pointed out the ramus 

 auricularis in the calf. It was not, however, 

 until Arnold's description of this ganglion had 

 been made public, that it became generally 

 known to anatomists, and its true nature and its 

 anatomical relations exactly ascertained.** Ar- 



* Salzburg, Med. Chir. Zeitung, 1790. B. 4. S. 

 319, as quoted by Bendz. 



t Dissertatio de Nervo Spinali ad Par Vagum Ac- 

 cessario. Ludwig Scrip. Nerv. Min. Select, torn, 

 ii. p. 235. 



t Archiv. fur Anat. Phys, &c. Heft ii. s. 275, 

 1837. 



Bemerkungpn iiber den Pan des Hirns und 

 Riickenmarks, &c. S. 178. Zurich, 1838. 



|| Anatomie des Systemes NerveuK des Animaux 

 a Vertelires. Deuxierne partie, p. 435 & 463, 1825. 



Tl Idem opus, p. 435. 



** Der Kopttheil der yegetativen Nerven Sys- 

 temes. Heidelberg und Leipsic, 1831. 



3 L 2 



