7 66 



A MANUAL OF PPIYSIOLOGY 



are ascending, others descending. Some endogenous fibres may 

 also be intermingled with the fibres of certain of the long tracts, 



FIG. 316. MEDULLA OBLONGATA, PONS 

 AND CORPORA QUADRIGEMINA (DORSAL 

 OR POSTERIOR VIEW) (SAPPEY). 



i, corpora quadrigemina ; 2, nates ; 

 3, testes ; 4, anterior brachium uniting 

 the nates to the lateral geniculate body ; 

 5, posterior brachium uniting the testes 

 to the internal geniculate body 6 ; 

 7, posterior commissure ; 8, pineal gland 

 pulled forward to show nates ; 9, superior 

 peduncle of the cerebellum ; 10, n, 12, 

 valve of Vieussens ; 13, trochlear nerve ; 

 14, lateral sulcus ; 15, fillet ; 16, superior, 

 17, middle, and 18, inferior peduncle of 

 the cerebellum ; 19, floor of fourth ven- 

 tricle ; 20, auditory nerve ; 21, spinal 

 cord ; 22, postero-median column, con- 

 tinued in the medulla as the funiculus 

 gracilis ; 23, the clava, the continuation 

 of the funiculus gracilis. 



FIG. 317. MEDULLA OBLONGATA, 

 PONS AND CRTJRA CEREBRI (VEN- 

 TRAL OR ANTERIOR VIEW). 



i, infundibulum ; 2, tuber ciue- 

 reum ; 3, corpus mammillare ; 4, 

 cerebral peduncle or crus cerebri ; 

 5, pons ; 6, middle peduncle of 

 cerebellum ; 7, pyramid ; 8, decus- 

 sation of the pyramids ; 9, olive ; 

 10, tubercle of Rolando ; n, ex- 

 ternal arcuate fibres ; 12, upper end 

 of spinal cord ; 13, ligamentum den- 

 ticulatum ; 14, dura mater of spinal 

 cord ; 15, optic tract ; 16, chiasma ; 

 17, third or oculo-motor nerve ; 18, 

 fourth or trochlear nerve ; 19, fifth 

 or trigeminal nerve ; 20, sixth nerve 

 or abducens ; 21, seventh or facial 

 nerve ; 22, eighth or auditory nerve ; 

 23, nerve of Wrisberg (portio inter- 

 media), which unites with the 

 facial ; 24, glosso-pharyngeal nerve ; 

 25, vagus nerve ; 26, spinal acces- 

 sory nerve ; 27, hypoglossal nerve ; 

 28, 29, 30, first, second, and third 

 pairs of cervical spinal nerves. 



