132 NERVE COMPONENTS OF BONY FISHES. 



pear shape with the larger end down. It is bounded 

 above by the dorsal lateralis root and ganglion, in front by 

 the Gasserian ganglion, below and behind by the ventral 

 lateralis root and ganglion. The cells of the geniculate 

 ganglion vary greatly in size. The largest ones are fully 

 50 micra in diameter, while the smaller ones are scarcely 

 more than 10. The large and small cells are irregularly 

 mingled with a tendency for the small cells, which are 

 less numerous than the large ones, to gather in the 

 interior of the ganglion (Fig. 21, gen. g. VII). 



J. — The Lateralis Roots. 



The two lateralis roots of the facial immediately upon 

 entering the oblongata fuse and enter the tuberculum 

 acusticum together, the fibres of the dorsal root farther 

 cephalad than those of the ventral one. These root fibres 

 throughout their internal course are so intimately mingled 

 with the most cephalic fibres of the VIII nerve that 

 analysis is impossible. 



After emergence from the oblongata the two lateralis 

 roots at once diverge and remain distinct throughout their 

 entire peripheral courses. The fibres from the dorsal 

 lateralis ganglion pass into the r. ophthalmicus superfi- 

 cialis facialis and the r. buccalis; those from the ventral 

 ganglion all pass into the truncus hyomandibularis. The 

 cells of these ganglia are very small, about 20 micra in 

 diameter, and as a rule only two or three times the 

 diameter of their fibres. They are usually not crowded, 

 but, like those of the lateral ganglion of the vagus, they 

 are scattered among the fibres (Figs. 4, 5, 11 and 19-22). 

 The dorsal root, before reaching its ganglion, receives 

 the small bundle of fibres from the VIII root, as described 

 in Section 6 and figured in Fig. 20. 



