MOTOR NUCLEI IN PHYLOGENY 531 
The nucleus intrudes its cells and their large dendrites between 
the bundles of the fasciculus longitudinalis lateralis for some 
distance into the tegmentum. ‘They pass in the direction of the 
substantia reticularis grisea which lies below and medial to the 
descending trigeminus root, and in the neighborhood of the 
. 
Grx22, ool rtc.b.cnie. 
Fig. 34 Solea vulgaris. Transverse section of brain stem on the level of 
the caudo-ventral moiety of the motor trigeminus nucleus. 
Fig. 35 Solea vulgaris. Transverse section of brain stem on the level of 
the rostro-dorsal moiety of the motor trigeminus nucleus. Abbreviations: 
Nu.V.m.(1)., rostro-dorsal moiety of motor trigeminus nucleus; Nwu.V.m.(2)., 
caudo-ventral moiety of motor trigeminus nucleus; R.V.m., emergent fibers of 
motor trigeminus root; R.V.s., entering fibers of sensory trigeminus root. Other 
abbreviations as before. 
small secondary ascending gustatory tract (fig. 34). Like the 
rostral motor VII nucleus, the most caudal cells of the ventral 
motor V nucleus lie deepest in the tegmentum. The motor V 
root passes laterad in a curved course and emerges from the 
medulla dorsal to the sensory root as in Lophius (64). 
In Ameiurus, the motor V root emerges in two bundles, as in 
Silurus, though in the latter form the bundles are not so definitely 
THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 27, NO. 4 
