A MANUAL OF PHYSIOLOGY 



of some of the tracts unexpectedly full and minute, though 

 meagre in regard to others. But to render it intelligible it 

 is necessary, first of all, to describe briefly 



FIG. 241. MEDULLA OBLONGATA, 

 PONS AND CORPORA QUADRIGEMINA 

 (DORSAL OR POSTERIOR VIEW) 



(SAPPEY). 



1 1 corpora quadrigemina ; 2, nates; 

 3, testes ; 4, anterior brachium uniting the 

 nates to the lateral geniculate body ; 5, pos- 

 terior 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 ventricle ; 20, auditory nerve ; 

 21, spinal cord ; 22, postero-median column, 

 continued in the medulla as the funiculus 

 gracilis ; 23, the clava, the continuation of 

 the funiculus gracilis. 



FIG. 242. MEDULLA OBLONGATA, 

 PONS AND CRURA CEREBRI 

 (VENTRAL OR ANTERIOR VIEW). 



i, infundibulum: 2, tuber cinereum ; 

 3, corpus mammillare ; 4, cerebral 

 peduncle or crus cerebri ; 5, pons ; 



6, middle peduncle of cerebellum ; 



7, pyramid ; 8, decussation of the 

 pyramids; 9, olive; 10, tubercle of 

 Rolando ; u, external arcuate fibres ; 

 12, upper end of spinal cord ; 13, liga- 

 mentum denticulatum ; 14, dura mater 

 of spinal cord ; 15, optic tract ; 16, chi- 

 asma ; 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 intermedia), which 

 unites with the facial ; 24, glosso- 

 pharyngeal nerve ; 25, vagus nerve ; 

 26, spinal accessory nerve ; 27, hypo- 

 glossal nerve ; 28, 29, 30, first, second, 

 and third pairs of cervical spinal 

 nerves. 



The Arrangement of the Grey and White Matter in the Upper 

 Portion of the Cerebro-spinal Axis. In the medulla oblongata the 



