682 
yet to be discovered. The anatomical con- 
nection of each anterior prams with the 
= ey cord, however, affords some clue to it. 
is takes place, it will be remembered, not 
by the decussating fibres only, but by straight 
and perpendicular ones also; so that each py- 
ritpia, is connected with both halves of the 
spinal cord, first and principally with the op- 
Sot half; and, secondly, and by much fewer 
bres, with that of the same side. When those 
ba of the brain are affected, with which the 
ecussating fibres are connected, the paralysis 
will be crossed ; when, on the other hand, the 
direct fibres are engaged, the pelyve affection 
will occur on the same side of the body as that 
on which the lesion has occurred. But even 
on this explanation it is difficult to understand 
how these latter cases should be of such rare 
occurrence, and still more, how hemiplegia is 
so frequently accompanied with a perfect. state 
of sensation and motion on the other side. In 
the present state of our knowledge, however, 
this is the only contribution which anatomy 
can Offer towards the determination of this 
difficult question. 
Of the restiform bodies.—The lateral, and, in 
gteat part, the posterior portion of the medulla 
Fig. 386. 
Posterior view of the medulla oblongata, with mesocephale 
and part of cerebellum of an infant. ( After Foviile, ) 
S, pineal gland. 
D, nates. 
D’, testes. 
+ +, point of emergence of fourth pair of nerves. 
Y, posterior pyramids. 
X, restiform columns. 
A, F, floor of the fourth ventricle, formed by the olivary The fibres which form the lateral and 
columns, the fissure between which is the calamus scrip- sora ing of the restiform bodies pa 
torius. 
Y’, posterior surface of mesocephale. 
B, valve of Vieussens. 
N, anterior surface of crus cerebri. 
R, corpus dentatum or rhomboideum. 
NERVOUS SYSTEM. (Nervous Centres. Tut Encepnaton.) 
oblongata is formed on each side by a thick — 
and rounded rope-like column, called the corpus — 
restiforme. It is composed chiefly of fibr 
matter, and its constituent fibres take a 
gitudinal direction. There is no line of demar- 
cation between them and the fibres of the sp 
cord, with the antero-lateral and posterior 
lumns of which they seem to be continu 
Traced upwards, the restiform bodies p 
little outwards, and by their divergence e 
tribute to the increased size of the med 
oblongata at its base. 
To see the connexions of these bodies ¢ 
pletely, the posterior surface of the medu 
oblongata should be examined, The resti 
bodies form the greater part of this 
They increase in thickness as they n¢ 
Their outer margin forms a gentle curve, whi 
is concave. Their inner border is connected it 
its lower portion to two small bands of fibrot 
matter, between which the posterior media 
fissure is situate ; these are the posterior p 
ramids (Y, fig. 386). In its apes portion, 
inner border of each restiform body is free, a 
forms the outer boundary of a lozenge-s! 
depression, the fourth ventricle, hilst t 
connection of the cerebellum with the po 
terior surface of the medulla oblongata is u 
disturbed, the exact relation of these bodies 
the ventricle cannot be seen. It is necess: 
to raise up the inferior portion of the 
lobe of the cerebellum, to expose the cay 
of the ventricle; or this may be effectec 
writing the median lobe along the midi 
ine, a 
Each restiform body ascends to the her 
sphere of the cerebellum of the cc ( 
ing side. The whole of its fibres 
to penetrate that organ, and contribut 
the formation of its crus, the middle la 
or peduncle of which it forms. This i 
well shown in the analytical figur 
667, (fig. 380,) where r is the restifi 
body passing upwards and out in 
the hemisphere of the cerebellum. __ 
The distinction between the a 
olivary bodies on the surface is indic 
by the line of origin of the eighth 
nerves, which may be said to emerge ; 
the anterior margin of the former. A 
row band of fibres, very distinct in § 
brains, occupies the depression betweet 
posterior edge of the prominent oli 
and the line of emergence of thes 
This band has been well delineat 
Rolando, Reid, and others; it pr 
forms a part of the cerebral fibres | 
medulla oblongata, and ascends # 
the ns. , ie vi 
The direction of the fibres of the res 
bodies is longitudinal. Those wh 
situate most posteriorly pass directly « 
wards, and are dstoaig cai uous 
the posterior columns of the spinal 
™ 
. 
estifo 
2 and Seemeeiesoee antero-latera 
lumns. A superficial groove, varying 
much in pcre in different 
which passes upwards from the 
P Bint 
