306 
ME. J. L. CLAEKE ON THE INTIMATE STEUCTUEE OE THE BEAIN. 
corresponds to the upper line of the transverse section, fig. 60, in which J is the anterior 
portion of the hypoglossal nucleus. V is the white column between it and the raphe. 
O" is the white olivary column lying between it and the vagal nucleus (H). The slender 
longitudinal column of the vagus is seen at n ; and c' o' is the lower end of the outer 
auditory nucleus, formed by the grey substance of the restiform body and posterior pyra- 
mid. It will be seen, then, that in fig. 59, the white column (V) between the raphe (F) 
and the entrance of the abducens nerve into the nucleus (Q") is continuous, in fig. 60, 
with the white column (V) between the hypoglossal nucleus (J) and the raphe. This 
column (V) is seen longitudinally in fig. 58, and is only a deeper longitudinal section of 
the lateral band which descends in fig. 57, from the longitudinal portion of the loop (T") 
of the facial nerve. At the lower end of fig. 58, this white column is seen on the inner 
side of the remains of the hypoglossal nucleus (J), instead of immediately beneath it. 
The olivary bundles (o", fig. 58) run up in a plexiform manner, partly from the remains 
of the hypoglossal nucleus (J), through the facial nucleus (Q"). 
(65) From the longitudinal portion of the loop of the facial nerve, some fibres ascend 
along the side of the median furrow, in company with those which ascend from its 
under surface. They all curve upward and forward beneath the inner portion of the 
superficial grey layer of the ventricle to form part of the longitudinal column imme- 
diately beneath the nucleus of the third nerve on the same side. Adjoining them on 
the outer side, the longitudinal bundles which passed through and beneath the common 
nucleus (Q") of the facial and abducens nerves, now ascend beneath the outer portion of 
the superficial grey layer, and contribute to form part of the crescentic column imme- 
diately beneath the same side of the third nerve. A longitudinal but horizontal section, 
from below upward, along the floor of the fourth ventricle, on the left side, and at the 
inner surface of the superficial grey layer, is represented in fig. B. a is the grey 
tubercle of Bolando, seen in the transversely-cut end of the 
pons Varolii, just above the level of the facial nerve. From 
its base at a! the longitudinal section is carried upward along 
the fourth ventricle, b is the cut surface of the superior pe- 
duncle of the cerebellum passing beneath the fillet c. The 
outer border of the grey tubercle running upward and inward, 
from its base, along the inner side of the superior peduncle 
is seen at d. Along the inner side of this is a layer of black 
matter or pigmentary cells (e), from which a number of fibres 
ascend and curve inward to the side of the nucleus (/') of the 
third nerve. From the inner side of the grey tubercle (a !) — 
at its junction with the upward continuation of the inner auditory nucleus — and from 
the pigmentary matter, transverse fibres ascend obliquely to the superficial grey layer 
{h) at the side of the median furrow of the ventricle. On the outer side of this furrow, 
the band of white fibres (V) ascends from the loop of the facial nerve, and from beneath 
it, to the side of the nucleus (f) of the third nerve. 
Eig. B. 
