358 C. JtTDSON HERRICK 



and peripheral processes arising from opposite poles of the cell 

 body, and an occasional transitional form in which the two proc- 

 esses arise close together from the same side of the cell body. 

 The single process of the unipolar cell is always very slender, 

 but beyond the T-form division both central and peripheral 

 branches may increase in size very abruptly, the axones of some 

 of these lateralis fibers being very large. The fine fibers of the 

 dorsal lateralis VII root which enter this ganglion in general 

 connect with the smaller cell bodies. The bipolar cells may be 

 either large or small, the larger bipolar cells being related to some of 

 the coarsest axones, though in this case also the fibers are greatly 

 reduced in size before connecting with the cells. 



The posterior lateralis VII ganglion (of the ramus mentalis 

 VII) has the same internal structure as the anterior ganglion, save 

 that no bipolar neurones were observed, either among the large 

 cells related to the coarse fibers or among the much less numerous 

 cells of medium size related to the fine fibers. 



The lateral line roots of the vagus. There are two of these roots, 

 dorsal and ventral, which unite immediately external to the brain 

 to form the first vagal root in the enumeration on page 35 1 . These 

 roots by some neurologists have been associated with the IX 

 nerve (IX^ of Osborn, the first vago-glossopharnygeal root of 

 Strong, 1X^+2 of Kingsbury, X 1 of Coghill). The fibers of the 

 lateralis component of the vagus are for the most part very coarse, 

 with a few of fine calibre scattered among them. Their ganglion 

 is composed of very large and medium sized neurones, most of 

 which are unipolar, like those of the lateralis VII ganglia, only an 

 occasional bipolar neurone being observed. 



The lateralis X fibers separate, before entering the oblongata, 

 into dorsal and ventral roots which enter respectively dorsally 

 and ventrally of the ventral lateralis VII root. Each of these 

 root fibers divides into ascending and descending branches immedi- 

 ately upon entering the oblongata, the ascending and descending 

 dorsal and ventral fascicles maintaining very nearly the same 

 relations to the other tracts of the oblongata as at t^e superficial 

 origins of their roots. Some of the descending, f,! •' -"s of both 

 fascicles reach to the extreme caudal end of the acustico- 



