840 



THE CENTRAL NERVOUS SYSTEM 



descending. The septo-marginal bundle consists also largely of fibres 

 which begin and end in the cord (proprio-spinal fibres). Some endog- 



Fig. 335. Medulla Oblongata, Pons and 

 Corpora Quadrigemina (Dorsal or Pos- 

 terior View) (Sappey). i, 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, pos- 

 terior commissure; 8, pineal gland 

 pulled forward to show nates; 9, su- 

 perior peduncle of the cerebellum; 10, 

 n, 12, valve of Vieussens; 13, troch- 

 lear nerve; 14, lateral sulcus; 15, fillet; 

 16, superior, 17, middle, and 18, in- 

 ferior, peduncle of the cerebellum; 

 19, floor of fourth ventricle; 20, audi- 

 tory nerve; 21, spinal cord; 22,postero- 

 median column, continued in the me- 

 dulla as the funiculus gracilis; 23, the 

 clava, the continuation of the funiculus 

 gracilis. 



Fig. 336. Medulla Oblongata, Pons 

 and Crura Cerebri (Ventral or An- 

 terior View). i, inf undibulum ; 

 2, tuber cinereum; 3, corpus mam- 

 millare; 4, cerebral peduncle or crus 

 cerebri; 5, pons; 6, middle peduncle 

 of cerebellum; 7, pyramid; 8, decus- 

 sation of pyramids; 9, olive; 10, tu- 

 bercle of Rolando ; n, external 

 arcuate fibres ; 12, upper end of cord ; 

 13, ligamentum denticulatum ; 14, 

 dura mater of cord; 15, optic tract; 

 1 6, chiasma; 17, third nerve; 18, 

 fourth nerve; 19, fifth nerve; 20, 

 sixth nerve; 21, seventh nerve; 22. 

 eighth nerve; 23, nerve of Wrisberg 

 (portio intermedia), which unites 

 with the facial; 24, glosso-pharyn- 

 geal nerve; 25, vagus; 26, spinal 

 accessory; 27, hypoglossal; 28, 29, 

 30, first, second, and third pairs of 

 cervical spinal nerves. 



enous fibres may also be intermingled with the fibres of certain of 

 the long tracts, both in the antero-lateral and posterior columns, and 



