550 



THE CEREBRUM. 



particles, aggregated into small compound masses, which are again 

 collected into larger groups. It is composed of the so-called aniyla- 

 ceous or amyloid bodies, and of earthy salts combined with animal 



Fig. 385. 



Fig. 385. — View op the Medulla Oblongata, Tons Takolii, Cr'jra Cerebri, and 

 Central Parts of the Encephalow froji the Right Side. (Allen Thomson.) 



Tlie corpus striatum and thalamus opticus have been preserved in connection with the 

 central lolje and crura cerebri, while the remainder of the cerebrum has been removed. 



St, upper surface of the coi-pus striatum ; Th, back part of the thalamus opticus ; C, 

 placed on the middle of the five or six convolutions constituting the central lobe or island 

 of Reil, the cerebral substance being removed from its circumference ; Si/, fissure of 

 Sylvius, from wliich these convolutions radiate, and in which are seen the white strice of 

 the olfactory tract ; I, tlie olfactory tract divided and hanging down from the groove in 

 the convolution which lodges it ; II, optic nerves a little way in front of the commissure ; 

 a, right coi-pus albicans with the tuber cinereum and iuf undibulum in front of it ; h, 

 hypophysis or pituitary body ; e, external, and i, internal corpus geniculatum at the back 

 part of the optic tract ; P, peduncle or crus of the cerebrum ; /, fillet ; III, right oculo- 

 motor nerve ; ^, pineal gland ; q, corpora quadrigemina ; IV, trochlear nerve rising from 

 v, the valve of Vieussens ; V, placed on the pons Varolii above the right nervals trige- 

 minus ; s, the superior, m, the middle, and in, the inferior peduncles of the eras cerebelli 

 cut short ; VI, the sixth nerve ; VII a, facial nerve ; VII I, auditory nerve ; on the 

 medulla oblongata the parts are indicated as follows : VIII, placed opposite to the cut end 

 of the pneumo-gastric nerve ; a, the glosso-pharyngeal ; and b, the uppermost fibres of 

 the spinal accessory nerve ; IX, the hyj^oglossal nerve ; p a, anterior pyramid ; o, olivary 

 body ; a r, arciform fibres ; p p, posterior pyramid ; r, restiform body ; t7; eminence 

 correspondiuL; to the tubercle of Rolando ; at tlie commencement of the spinal cord, c a, 

 indicates the anterior, c p, the posterior, and c I, the lateral columns ; C I, anterior and 

 posterior roots of the suboccipital or first cervical nerve. 



