324 THE INTERMEDIATE PRIMATES 



At the level of the middle of the pons VaroHi ( Pns ) thisstrueture attains 

 its full dimensions and shows its three major layers, the stratum superficiale, 

 the stratum profundum and the stratum complexum. Scattered among these 



FIG. 151. BABOON. LEVEL .\T THE MIDDLE OF THE PONS \AROLII, SHOWING 

 THE ENTERING FIBERS OF THE TRIGEMINAL NERVE. 



CEN, Central Gray Matter; GOW, Ventral Spinocerebellar Tract; mcp, Middle Cerebellar Peduncle; mf, 

 Mesial Fillet; nj, Trigeminal Nerve; nm. Nucleus Masticatorius Trigemini; nr. Nucleus of Rolando; I'N, 

 Pontile Nuclei; pns, Pons Varolii; Pyramid; pv, ref, Reticular Formation; rst, Rubrospinal Tract; scp, 

 Superior Cerebellar Peduncle; so, Superior Olive; spt. Spinothalamic Tract; trp. Trapezoid Body; tur, 

 Tractus Uncinatus of Russel (Hook Bundle"); ver. Vermis. [Accession No. 150. Section 282. Actual Size 

 22 X 16 mm.] 



transverse fibers of the stratum eompleximi are groups of separated bundles 

 of the pyramidal system ( Py ) and the large nuclear aggregations of the pontile 

 nuclei ( PN ). All of the libers emerging from the pons proceed laterally and, 

 after relay m the pontile nucleus, assemble to form the middle cerebellar 



