THE BRAIN OF MODERN MAN 



829 



Tlu' ci'iitral ^n'ay niattcr (Cen) sunouiuls the Hour and lateral walls 

 of the SvKian ac]uc'clucl, and upon its \rntral maru'in arc- the extensive 

 bundles constituting the posterior longitudinal laseieulus ( PL 1, the predorsal 



FIG. ^j^. MAX. LEVEL OF THE LNFERIOR COLLICLLUS. 

 AQ, Aqueduct of Sylvius; CEN, Central Gray Matter; err, Central Tegmental Tract; cp. Cerebral Peduncle; 

 ic, Inferior (^olliculus; lf, Lateral Fillet; mf. Mesial Fillet; ntr, Trochlear Nucleus; PL, Posterior Longitudi- 

 nal Fasciculus; ref. Reticular Formation; Ksr, Rubrospinal Tract; sen. Substantia Nigra; spt. Spinothala- 

 mic Tract; spx. Crossing of the Superior Cerebellar Peduncle; tmt, Tractus Mesencephalici Trigemini. 

 [Accession Man. Section Nqi8. Actual Size 34 X i<) mm.) 



hundle (PD) and some scattered hundli'S of ni\elinlzed libers lorming 

 the mesencephalic root ol the lilth ner\e (Tmt). The te<imentum itsell 

 at this level is further conlused b\ the coinergent libers oi the superior 



