MOTOR NUCLEI IN PHYLOGENY a2% 
question of the course of the motor glossopharyngeus and its 
relation to the motor VII nucleus in these forms (72). 
Motor facialis nucleus and root (Nu. et rad. mot. N. VII). In 
Solea, the rostral motor VII nucleus is placed for the most part in 
the ventricular gray, Jateral to the most dorsal fibers of the 
NuVil.m.(1) 
¢ 
Nr ee 
. ae. ¢ R.VIlm.asc 
re AAS m. <5 
Sa a, ‘ 
SS 
, R.desc. 
AT r.tc.b.cruc. 
\Tr.tc.b.rec. 
30 
Fig. 30 Solea vulgaris. Transverse section of brain stem to illustrate the 
relations of the ascending motor glossopharyngeal root. 
Fig. 31 Solea vulgaris. Transverse section of brain stem at the exit level 
of the motor facial root. Abbreviations: Cb., cerebellum; Com.ac., decussating | 
fibers of acusticum; Nuw.ret., nucleus reticularis; Nu.VII.m.(1)., rostral moiety 
of motor facial nucleus; Nu.VJ., abducens nucleus; R.V/J., abducens rootlet; 
R.VII.m., emergent motor facial root; R.VII.m.asc., ascending motor facial 
root; R.VII.s., descending sensory facial root; R.IX.m., emergent fibers of motor 
glossopharyngeus passing laterad through motor facial’ nucleus; R.JX.m.asc., 
ascending motor glossopharyngeus root; VJJIJ., lateralis nerve below which the 
sensory facial root is seen. Other abbreviations as before. 
fasciculus Jongitudinalis medialis, and resting upon the bundles 
of the fasciculus longitudinalis lateralis (figs. 30 and 40 A). The 
size of the nucleus increases somewhat towards its caudal end, 
where many of the motor cells together with their larger den- 
drites lie in between the bundles of the fasciculus longitudinalis 
lateralis, and thus occupy a more ventral position than those 
