THE ROOTS AND GANGLIA OF THE FACIALIS. 131 



as described above, and soon fuses with it. Like the lat- 

 ter, these fibres are of finer calibre than those of the fascic- 

 ulus, which are very large. The fibres of the VII nerve 

 soon withdraw from the fasciculus, but pass forward par- 

 allel with it for some distance. Whether the facial root 

 receives additions from the fasciculus or contributes to it 

 could not be determined. Presumably there is some re- 

 lation by collaterals or otherwise, as the union of the fibres 

 of the root and the fasciculus is here very intimate. 



This arrangement of the motor VII root is substantially 

 identical with that described by Goronowitsch in Acipenser 

 ('88, p. 498). Johnston ('98) finds by the Golgi method in 

 Acipenser that part of the motor VII root arises directly 

 from its nucleus and a larger part from the fasciculus 

 longitudinalis dorsalis. The entire course of these latter 

 fibres apparently, was not impregnated, so that it remains 

 uncertain whether they arise from cells of the VII nucleus 

 farther back or whether they belong to the fasciculus 

 proper. 



At 577 (Fig, 19) the facialis fibres turn abruptly toward 

 their exit. This motor root immediately after its exit 

 from the oblongata joins the ventral lateralis root proxi- 

 mally of its ganglion and follows the ventral surface of 

 that root, as shown on the plots. 



2. — The Communis Root. 



The communis root of the facialis passes into the fas- 

 ciculus communis and constitutes the whole of the pre- 

 auditory portion of that tract (Fig. 4, /. c). It emerges 

 from the oblongata closely wedged in between the dorsal 

 and ventral lateralis roots (Figs. 19, 20, com. VII., Fig. 11) 

 and passes, still between those roots, ventrally into the 

 geniculate ganglion. This ganglion is of an elongated 



