174 



THE NERVOUS SYSTEM. 



[Gaskell has proved that this nerve contains both sympathetic and 

 vag-al elements, and that it is therefore really a vago-sympathetic] 



The branches 

 Fig. 1 1 6. and commvuiica- 



tions of the pneu- 

 mogastric nerve 

 are : — 



a. Communica- 

 tions between the 

 ganglion of the 

 pneumogastric and 

 sympathetic 



the 



Right half of skull of l{aita esculeiita, seen from with 



system (Fig. 1 1 1 

 /S)j), which again 

 connect it with 

 the Gasserian gan- 

 glion of the tri- 

 geminal nerve 



(see sympathetic 

 system). 



b. [The Ramus cnianeus dorsalis (Fischer) is considered by Stan- 

 nius and Fiirbringer to be the homologue of the liaiiiiis anricnlaris ; 

 it passes outwards between the digastricm and tenqwralis to be 

 distributed in the skin of the suprascapular region. This nerve 

 is the persistent portion of the N. lateralis nervi vagi of the 

 tadpole.] 



c. During its course over the petroliijoidei the vagus gives off a 

 few twigs (Fig. 114 pp)^ which form a fine plexus to supply these 

 muscles and the pharynx [also a twig to the trachea, according to 

 Hoffmann]. 



d. The Bawns accessories (Fiirbringer, Hoffmann, Ecker), (Fig. 

 114 AT) is usually a single small nerve which runs between the 

 intertransversarii muscles and the trajoezitis : it supplies the mider 

 surface of the latter mviscle. 



e. The Banins scapularis (Hoffmann) is a very slender nerve arising 

 near the liamns accessoritis ; it passes along the under surface of 

 the trapezius to the inner s\u-face of the in/erscapHlar is,' which it 

 supplies. 



