LEMUR MONGOZ 6i 



and the central gray matter (Cen), immediately beneath the floor of 

 the fourth ventricle, is a small collection of medium-sized nerve ceUs con- 

 stituting the nucleus of von Bechterew (NBe) which is one of the group of 



FIG. 31. LEMUR MONGOZ. LEVEL OF EMERGENCE OF TROCHLEAR NERVE. 



CEN, Central Gray Matter; ctt. Central Tegmental Tract; lf, Lateral Fillet; mf. Mesial Fillet; N4, Trochlear 

 Nerve; PL, Posterior Longitudinal Fasciculus; pn, Pontile Nuclei; pns. Pons; py, Pyrarnid; ref, Reticular 

 Formation; rst. Rubrospinal Tract; scp, Superior Cerebellar Peduncle; scpx. Crossing of the Superior 

 Cerebellar Peduncle; spt, Spinocerebellar Tract. [Accession No. 147. Section 245. Actual Size, 11X6 mm.] 



vestibular nuclei. Ventral to this nucleus are the ascending root fibers of 

 the trigeminal nerve known as the tractus mesencephalici trigemini. A 

 large collection of small nerve cells lies at the border of the tegmentum 

 opposite the middle cerebellar peduncle. This is the dorsal nucleus of the 

 lateral fillet. 



