174 



THE LOWER PRIMATES 



for the sense of hearing. This structure in the marmoset shows a high 

 degree of development which may be taken to indicate an auditory sense 

 still having a large representation at this lower level in the brain. Here, as in 



FIG. 



MARMOSET. LEVEL OF THE INFERIOR COLLICULUS. 



CEN, Central Gray Matter; ic, Inferior Colliculus, lf, Lateral Fillet; mcp. Middle Cerebellar Peduncle; 

 MF, Mesial Fillet; N4, Trochlear Nerve; pl, Posterior Longitudinal Fasciculus; pns, Pons, pv. Pyramid; ref. 

 Reticular Formation; scp, Superior Cerebellar Peduncle. (Accession No. 146. Section 139. Actual Size 

 9X7 rnm.) 



