46 NERVE COMPONENTS OF BONY FISHES. 



the spinal V tract laterally and dorsally until, at the level of 

 the caudal vagus roots, it occupies the extreme dorso-lateral 

 angle of the oblongata, where it forms a projecting cord 

 or band. This relation is maintained back to the level of 

 the exit of the first spinal nerve, where the spinal V tract 

 merges into the nucleus funiculi and the dorsal comu. 



Between the cephalic and caudal vagus roots the spinal 

 V tracts receives a small bundle of fibres from the jugu- 

 lar ganglion of the vagus. 



Haller ('96, p. 64), describes for Salmo, Perca and 

 Anguilla, and figures in the latter case a large tract run- 

 ning from the lobus vagi adjacent to the ventricle to 

 emerge with the trigeminus root. He also figures a 

 smaller root running from the lobus vagi into the VII 

 nerve and says that the chief trigeminus nucleus is 

 directly continuous and serially homologous with the lobus 

 vagi. 



Haller's account of the V and VII roots in the eel 

 appeared to me so remarkable that I have myself exam- 

 ined the matter. From a study of both transverse and 

 longitudinal sections of the brain of Anguilla chiysypa 

 Raf. it appears that the V and VII roots of the eel are 

 typical, as compared with Menidia, and that the differences 

 between Haller's account and mine arise from the fact 

 that he has wrongly identified several of the roots. 



In Anguilla, the lateralis system is developed about as 

 in Menidia; the general cutaneous system is the same in 

 plan, but enormously developed, the spinal V tract being 

 especially enlarged; the communis system is much 

 reduced. The lobus vagi and its roots are small, doubt- 

 less correlated with the reduction of the gills. The com- 

 munis root of the facial is, however, very large. It runs, 

 as in Menidia, directly to the ventricular wall and turns 



