STRUCTURE AND CONNECTIONS OF MEDULLA OBLONGATA. 



277 



Varolii. The Pons has been correctly designated as the great Commissure 

 of the Cerebellum, inclosing the Crura Cerebri; and its transverse fibres not 

 only surround the longitudinal bands which connect the Cerebrum with the 

 Spinal Cord, but pass through them ; so as in some degreee to isolate the 



Fis?. 140. 



Course of the Motor tract, according to Sir C. Bell. A, A, fibres of the hemispheres, converging to form 

 the anterior portion of the cms cerebri ; B, the same tract where passing the crus cerebri ; c, the right 

 pyramidal body, a little above the point of decussation ; D, the remaining part of the pons Varolii, a por- 

 tion having been dissected off to expose B. 1, olfactory nerve, in outline; 2, union of optic nerves; 

 3. motor oculi; 4, 4, patheticus ; 5, 5, trigeminus; 6, 6, its muscular division ; 7, 7, its sensory root ; 8, ori- 

 gin of sensory root from the posterior part of the medulla oblongata ; 9, abducens oculi ; 10, auditory 

 nerve ; 11, facial nerve ; 12, eighth pair ; 13, hypoglossal ; 14, spinal nerves ; 15, spinal accessory of right 

 side, separated from par vagum and glosso-pharyngeal. 



two lateral halves from one another, and to form a complete septum between 

 the anterior and posterior portions of each. The Motor tract is brought into 

 view, by simply raising the superficial layer of the Pons, and tracing upwards 

 and downwards the longitudinal fibres which then present themselves. It is 

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