LEMUR MONGOZ 



49 



area. The tuberculum acusticum receives the fibers which arise in the 

 cochlear portion of the internal ear. In lemur it is particularly h\rge, thus 

 indicating a highly developed auditory sense. 



FIG. 25. LEMUR MONGOZ. LEVEL THROUGH MIDDLE OF INFERIOR OLI\E. 



CB, Column of Burdach; do. Dorsal Accessory Olive; fle, Dorsal Spinocerebellar Tract; Gow, Ventral 

 Spinocerebellar Tract; lo. Inferior Olive; mf. Mesial Fillet; nb, Nucleus of Burdach; NFS, Nucleus Fasciculus 

 Solitarius; ng, Nucleus of Goll; nhv. Hypoglossal Nucleus; nr, Nucleus of Rolando; nvd. Dorsal Vagal 

 Nucleus; N12 Hypoglossal Nerve; pd, Predorsal Bundle, pl. Posterior Longitudinal Fasciculus; pv, Pyramid; 

 REF, Reticular Formation; rst, Rubrospinal Tract; spt, Spinothalamic Tract; trd. Descending Trigeminal 

 Tract; vo, Ventromesial Accessory Olive. (Accession No. 147. Section 1 17. Actual Size 1 1 X 4 mm.] 



In the region formerly occupied by the tracts and the nuclei for the 

 conduction of impulses coming from the skin, the joints, the muscles and the 

 bones of the extremities, there now appear two groups of cells and fibers for 

 the reception of impulses arising in the proprioceptive organs of the vesti- 

 bule; i.e., the semicircular canals, utricle and saccule. These highly specialized 

 parts of the internal ear play a fundamental role in equilibrium. Near the 

 midline, in the dorsal field, immediately beneath the lloor of the fourth 



