3i6 



THE INTERMEDIATE PRIMATES 



the internal ear, but in this case, from the cochlear portion of it. It is inti- 

 mately associated with the function of hearmg. These collections of ceils 

 in the ol^longata form the cochlear nuclei, one of which appears as the 



FIG. 148. BABOON. LEVEL OF THE NESFIBULAK NUCLEL 



DT, Deiterso-spinal Tract; Gow, Ventral Spinocerebellar Tract; hel, Spino-olivary Tract of Hclweg; ICP, 

 Inferior Cerebellar Peduncle; 10, Inferior Olive; mf. Mesial Fillet; nd, Deiters' Nucleus; nr. Nucleus of 

 Rolando; nsc. Nucleus of Scliwalbe; n8, Auditory Nerve; pd, Predorsal Bundle; PL, Posterior Longitudinal 

 Fasciculus; pv, Pyramid; ref. Reticular Formation; rst. Rubrospinal Tract; spt, Spinothalamic Tract; trd. 

 Descending Trigeminal Tract; tub, Tuberculum Acusticum. [Accession No. 150. Section 175. Actual Size 

 16 X 7 mm.] 



large protuberance on the dorsolateral aspect ot the axis forming the tuber- 

 culum acusticum (Tub). The vestibuh^r nuclei comprise the triangular 

 nucleus of Schwalbe (NSc) which occupies a position in the central gray 

 matter in the dorsal held immediately below the floor of the fourth ventricle; 

 and a nucleus consisting of large cells dispersed among which are many 

 bundles of axons, Deiters' nucleus (ND). Both of these vestibular nuclei 

 receive fibers from the vestibular portion of the ear, and although the 

 exact function of each nucleus is not adequately understood, pathological 



