62 THE LOWER PRIMATES 



LEVEL OF THE INFERIOR COLLICULUS (fIG. 32) 



At the level of the inferior collicuius, the appearance of certain 

 strikino; features alters the external conlicruration of the stem. Among these 



FIG. 32. LEMUR MONGOZ. LEVEL OF THE INFERIOR COLLICULUS. 



CEN, Central Gray Matter; ctt. Central Tegmental Tract; cp. Cerebral Peduncle; ic, Inferior Collicuius; 

 IT, Aqueduct of Sylvius; lf. Lateral Fillet; mf. Mesial Fillet; N4, Trochlear Nerve; pl, Posterior Longitudinal 

 Fasciculus; ref. Reticular Formation; rst, Rubrospinal Tract; sbn, Substantia Nigra; spt, Spinothalamic 

 Tract; tmt, Tractus Mesencephalici Trigemini; xscp, Crossing of Superior Cerebellar Peduncle. [Accession 

 No. 147. Section 255. Actual Size, 11 X 7 mm.] 



