io8 



THE LOWER PRIMATES 



LEVEL OF THE CAUDAL EXTREMITY OF THE INFERIOR OLIVE (fIG. 53) 



At this level the lower tip of the inferior olive makes its appearance 

 nO). An important fact concerning this structure in tarsius is its indecisive 



FIG. 



TARSIUS SPECTRUM. LEVEL OF CAUDAL TIP OF INFERIOR OLI\'E. 



CEN, Central Gray Matter; fle, Dorsal Spinocerebellar Tract; do, Dorsal Accessory Olive; dt, Deiterso- 

 spinal Tract; cow, Ventral Spinocerebellar Tract; 10, Inferior Olive; mf, Mesial Fillet; nb, Nucleus of Bur- 

 dach; ng, Nucleus of Goll; nhy, Hypoglossal Nucleus; nr, Nucleus of Rolando; nvd, Dorsal Vagal Nucleus; 

 Nio, Vagus Nerve; N12, Hypoglossal Nerve; pd, Predorsal Fasciculus; pl. Posterior Longitudinal Fasciculus; 

 PY, Pyramid; ref. Reticular Formation; rst. Rubrospinal Tract; spt, Spinothalamic Tract; trd, Descending 

 Trigeminal Tract. |Acccssion No. 2 to. Section 95. Actual Size 6X3 mm.) 



outline. Its diminutive size as compared with that of other primates is also 

 notable. Mesial to the olive is the pyramid (Py) which likewise is 

 small. Dorsomesial to the pyramid is the mesial fillet (Mf), still receiv- 



