MYCETES SENICULUS 211 



LEVEL OF THE PYRAMIDAL DECUSSATION (FIG. II7) 



At the level of the pyramidal decussation the chief feature is the crossing 

 of the pyramidal bundles and the effect which these crossing fibers have upon 



FIG. 117. MYCETES SENICULUS. LEVEL OF THE PYRAMIDAL DECUSSATION. 

 CB, Column of Burdach; cen, Central Gray Matter; CG, Column of Goll; dt, Deiterso-spinal Tract; fle. 

 Dorsal Spinocerebellar Tract; cow. Ventral Spinocerebellar Tract; hel, Spino-olivary Tract of Helweg; 

 NR, Nucleus of Rolando; pv. Pyramid; p\-x. Pyramidal Decussation; rst. Rubrospinal Tract; spt, Spino- 

 thalamic Tract; trd. Descending Trigeminal Tract; ven, Ventral Gray Column; xpv, Crossed Pyramidal 

 Tract. [Accession No. 148. Section 15. Actual size 8X7 mm.] 



the arrangement of the gray matter. The decussation is shown at Pyx. Its 

 final accompHshment and the formation of a crossed pyramidal tract about 



