LEMUR MONGOZ 57 



cal and physiological reasons for tliis inference are not far to seek. Such fibers 

 as constitute the transverse fasciculi of the pons have their origin in the 

 cerebral cortex of the frontal, parietal, occipital and temporal lobes. Descend- 



FIG. 29. LEMUR MONGOZ. LEVEL OF CAUDAL EXTREMITY OF PONS VAROLIL 



CEN, Central Gray Matter; Gow, Ventral Spinocerebellar Tract; mcp. Middle Cerebellar Peduncle; nbe, 

 Nucleus of Bechterew; nr, Nucleus of Rolando; N5, Trigeminal Nerve; n6, Abducens Nerve; N7, Facial 

 Nerve; pd, Predorsal Bundle; pl. Posterior Longitudinal Fasciculus; pn. Pontile Nuclei; pns. Pons; py, 

 Pyramid; ref, Reticular Formation; rst, Rubrospinal Tract; scp, Superior Cerebellar Peduncle; so, 

 Superior Olive; spt, Spinothalamic Tract; trd, Descending Trigeminal Tract; trp, Trapezoid Body; tur, 

 Tractus Uncinatus of Russel (Hook Bundle); ver, Vermis. [Accession No. 147. Section 188. Actual Size, 

 15X7 mm.] 



ing from these origins they make their entrance into the cerebral peduncle 

 and ultimately reach the pons. At this point they alter their direction from 

 the vertical to the horizontal plane, thereafter pursuing a transverse course. 

 Many of these fibers end in the pontile nuclei of the same side for a relay 

 here. The relaying axons then undergo decussation across the midline and 

 eventualh' enter the middle cerebellar peduncle (Mcp). Some pallio- 



