PITHECUS RHESUS, MACACUS RHESUS 



367 



expansive dorsal field in which, however, there is as yet no sign of those 

 great sensory nuclei which serve as relays for the sensory pathways trom 

 the extremities. The broad expanse of this dorsal sensory field indicates the 



FIG. 172. MACACUS. LEVEL OF CAUDAL LIMIT OF DORSAL SENSORY NUCLEI. 



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

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

 NB, Nucleus of Burdach; ng, Nucleus of Goll; nr. Nucleus of Rolando; py. Pyramid; pyx. Pyramidal Decus- 

 sation; REF, Reticular Formation; rst, Rubrospinal Tract; spt. Spinothalamic Tract; trd. Descending 

 Trigeminal Tract; ven. Ventral Gray Column. [Accession No. 149. Section 35. Actual Size 12X8 mm.] 



capacity of the central axis for the conduction of sensory impulses concerned 

 in discriminative sensibility. The faint indenture on the dorsal aspect of the 

 section indicates the position of the dorsal paramedian sulcus which sepa- 

 rates the column of Goll (CG) fVom the column of Burdach (CB), thus 

 furnishing some idea as to the relative dimensions of these two tracts. 



