ME. J. L. CLAEKE ON THE INTIMATE STEUCTUEE OF THE BEAIN. 
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of the brain. On this and on other occasions I have pointed out the way in which the 
different parts of the grey and white substances of the spinal cord are disposed or modi- 
fied in the medulla oblongata. I have shown (1°) that from the outer (posterior) part 
of the cervix or neck of the posterior horn are developed the post-pyramidal and resti- 
form nuclei which, higher up, form the nuclei of the auditory nerve, while the caput 
cornu, or dilated extremity of the posterior horn, is thrown aside to be traversed by the 
vagus and glossopharyngeal nerves, and ultimately to become the principal nucleus of 
the large root of the trigeminus ; (2°) that from the base of the cervix cornu, behind the 
central canal, is developed the special nucleus for the spinal-accessory, vagus and glosso- 
pharyngeal nerves; (3°) that the base of the anterior grey substance in front and at the 
side of the central canal is developed into, or at least replaced by, the special nucleus 
giving origin to the upper roots of the hypoglossal nerve ; (4°) that the lateral parts of 
the grey substance between the extremitities of the anterior and posterior horns, in- 
cluding what I have named the tractus intermedio-lateralis , is especially connected with 
the lower roots of the spinal-accessory nerve ; and (5°) that, in ascending from the cord to 
the medulla, the remaining part of the anterior grey substance, which lies against the 
inner side of the anterior column, or the so-called non-decussating portion of the pyramid, 
and from which the lowest set of hypoglossal roots arise, — gives place to the groups 
of cells forming the lower end of the olivary body, which, as it swells out, becomes con- 
nected with the anterior part of the antero-lateral column (see figs. 6, 7 & 8, Plate VIII.). 
We have only to make a longitudinal section obliquely inward and backward through this 
column and the olivary body to see the connexion between them*. We must therefore 
regard the olivary body as a large motor nucleus, which is directly continuous by its 
white and grey substances, with the anterior white and grey substance of the spinal 
cord. The only other purely motor centre of the medulla oblongata, is the hypoglossal 
nucleus, which is developed from the base of the anterior grey substance. It is located 
apart from the olivary body, and is in the closest connexion with the vagus, spinal-acces- 
sory and glassopharyngeal nuclei with which it is destined to cooperate in reflex actions. 
Although distant from the olivary body it is, however, connected with it by a remarkable 
band of fibres. 
(86) It it probable that the olivary bodies are not only the centres through which 
different movements are coordinated for expressing the passions and emotions, but that 
they are the motor centres through which different movements are effected by sudden, 
violent, or peculiar impressions on the special senses ; for they are intimately connected 
with all the sensory ganglia of the medulla, — with the grey tubercle (trigeminus), the 
vagus nucleus, the post-pyramidal and restiform nuclei (auditory ganglia), the corpora 
quadrigemina (optic ganglia) through the fillet, and not improbably with the parts about 
the root of the olfactory bulbs, since I have traced the olivary columns nearly to the 
anterior perforated space. 
(87) I have a few remarks to make on paralysis of the facial and abducens nerves. 
* See my “Medulla Oblongata,” Plate XY. fig. 24, Philosophical Transactions, 1858* 
MDCCCLXVIII. 2 Y 
