318 



STRUCTURE OF THE BEAIN. 



Fig. 158. 



Diagram of the structure of the brain. 



tion ; r, restiform bodies passing to <?, the cerebellum ; d, corpus denta- 

 tum of the cerebellum ; 0, intercalation of the olivary body ; f, columns 

 continuous with the olivary bodies and central part of the medulla ob- 

 longata, and ascending to the tubercula quadrigemina and optic thalami ; 

 JP, anterior pyramids : v, pons varolii ; n, b, tubercula quadrigemina ; 

 <7, geniculate body of the optic thalamus ; , processus cerebelli ad testes; 

 #, anterior lobe of the brain ; q, posterior lobe of the brain. 



Fig. 159, the motor tract (from Sir C. Bell). A, A, fibres of the hem- 

 ispheres converging to form the anterior portion of the crus cerebri ; B, 

 the same tract when 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 portion having been dissected off to expose B. 1, 

 olfactory nerve in outline ; 2, union of optic nerves ; 3, 3, motor oculi ; 

 4, 4, patheticus ; 5, 5, trigeminus ; 6, 6, its muscular division ; 7, 7, its 

 sensory root ; 8, origin of sensory root from the posterior part of the me- 

 dulla oblongata ; 9, abducens oculi ; 10, auditory nerve; 11, facial nerve; 



