TROGLODYTES CORIITA 659 



formation are many bundles of myelinated fibers, the descending portion of 

 tlu' p\ rainidal tract as it is about to enter the sjjinal cord (X.Py). The 

 central gray matter by means oi a narrow isthmus-like extension is con- 



FIG. 298. GORILLA. LE\EL OF TIIF- DORSAL SENSORY NUCLEI. 

 CB, Column of Burdach; cen, (Central Gray (Jolumn; cc;. t^olumn of Goll; dt, Dt-iterso-spinal Tract; fle. 

 Dorsal Spinocerebellar Tract", cow, Ventral Spinocerebellar Tract; hel, Spino-olivary Tract of Ilelweg; 

 MF, Mesial Fillet; nb, Nucleus of Burdach; ng, Nucleus of Goll; nk, Nucleus of Rolando; pv. Pyramid; pvx. 

 Pyramidal Decussation; rii \ Reticular Formation; rst. Rubrospinal Tract; spt, Spinothalamic Tract; trd. 

 Descending Trigeminal Tract; xpv, Crossed Pyramidal Tract. [Accession No. J. D. Section 145. Actual Size 

 14 X 1 1 ram.] 



nccted witli ihrtT nuclear masses appearnig ni the dorsal sensory field. The 

 most mesial of these nuclei, and the most faintly dc\eloped, is the nucleus 



