NEUROLOGY. 119 



1 



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 bj 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 pyrainids 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. 137, ßg. 1, view of the brain from above. Fig. 2, base of the brain : 

 ', continuation of the great median fissure along the inferior surface of the 

 brain ; ', anterior cerebral lobes ; ', fissura Sylvii ; \ middle cerebral lobe ; 

 *, commissure of the optic nerves ; ", tuber cinereum, with the process pro- 

 ceeding from the pineal gland ; ', corpora mam miliaria ; *, 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; ^"j trochleator ; ", trigemini or fifth pair; ", abducens nerve; 

 ", facial and auditory nerves ; "', glosso-pharyngeal and jDueumogastric 

 nerve ; ", accessory nerve ; ", lingual nerve. Fig. 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 ; "", crura cerebri. Fig. ß, medulla oblongata ; ', fibres 

 separating to inclose the corpora olivaria ; ^, lateral fibres ; ', point where 

 these decussate ; *, posterior fibres of the olivary column ; "' ^', pyramids : 

 *'*', their continuations into' ; and ', the crura cerebri. Fig. 7, cross section 

 of the corpora olivaria : \ their cortical substance ; ^, corpus dentatum ; 

 % medullary substance. Fig. 8, vertical section of the pons Varolii, and of 

 the medulla oblongata. Fig. 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. 



3. Psychological Relations of the Brain. 



Numerous experiments have been made by accomplished physiolo- 

 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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