NEUROLOGY. | 119 
— Corpora restiformia, or the inferior peduncles of the cerebellum, are two 
thick longitudinal white cords on each lateral and posterior surface of the 
medulla, separated from the olivaria by a groove, in which the roots of the 
eighth pair of nerves are lodged. Each of these connects the spinal cord 
and the medulla oblongata with the cerebellum. 
Posterior pyramids are two long narrow columns which extend on each 
side of the posterior fissure of the cord to its lower extremity. They are 
seen on each side of the calamus scriptorius in the lower part of the 
ventricle, and terminate abruptly. By their deep surface they appear con- 
tinuous with the posterior part of the olivary tracts. 
Pi. 187, fig. 1, view of the brain from above. jg. 2, base of the brain: 
‘, continuation of the great median fissure along the inferior surface of the 
brain; *, anterior cerebral lobes; °*, fissura Sylvu; *, middle cerebral lobe ; 
* commissure of the optic nerves; °, tuber cinereum, with the process pro- 
ceeding from the pineal gland; ‘, corpora mammillaria; *, crura cerebri ; 
* pons Varolii; **, cerebellum ; ”, limit of the superior lobe of the cerebellum ; 
* the flocculus; *, inferior vermiform process; “, anterior pyramids; 
* olivaria; “*, restiformia; ”, olfactory nerve; “, optic nerve; ”, motor 
oculi; *, trochleator; *, trigemini or fifth pair; ”, abducens nerve; 
2 
** facial and auditory nerves; *, glosso-pharyngeal and pneumogastric 
nerve; ™, accessory nerve; *, lingual nerve. /%g. 3°, lingual nerve; 
*, glosso-pharyngeal, pneumogastric, and accessory nerves; ’, facial and 
auditory nerves; *, trigemini; *, abducens oculi; “, optic nerve; ", cauda 
equina; *, lumbar enlargement of the spinal cord; *, cervical do.; “, me- 
dulla oblongata; **, anterior spinal fissure; *, lateral do.; ”, olivaria; 
*, pyramids; “, pons; *, cruracerebri. /%. 6, medulla oblongata; *, fibres 
separating to inclose the corpora olivaria; *, lateral fibres; *, pomt where 
these decussate; *, posterior fibres of the olivary column; **, pyramids: 
** their continuations into’; and ’, the crura cerebri. ig. 7, cross section 
of the corpora olivaria: *, their cortical substance; *, corpus dentatum ; 
*, medullary substance. /g. 8, vertical section of the pons Varolii, and of 
the medulla oblongata. 7%. 12, cross section at the point of decussation of 
the pyramidal columns. Fig. 13, cross section of the central portion of the 
medulla oblongata. fig. 14, cross section at the point of union between 
the medulla oblongata and the pons. 
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2 
3. PSYCHOLOGICAL RELATIONS OF THE BRAIN. 
Numerous experiments have been made by accomplished pbhysiolo- 
gists to determine the modus operandi of the brain as the source of 
voluntary action and the recipient of sensitive impressions. We may 
point to a few general conclusions as tolerably well established by 
careful research, although still open to examination. They are as fol- 
lows: | 
1. The vesicular matter of the brain is the source of nervous power. In 
mental actions it is the part immediarely associated with changes of the 
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