RECONSTRUCTION OF PITHECUS RHESUS 



395 



nucleus appears somewhat above this level, dorsolateral to the ventral 

 accessory olive where it is a pHcated fold of gray matter, its fundus 

 directed toward the vcntrohueral angle of the brain stem. It presents a 



FIG. 105 



DORSAL SURFACE OF GRAY MATTER OF BRAIN STEM, 

 PITHECUS RHESUS. 



Key to Diagram, dors, cochl., Dorsal Cochlear Nucleus; inf. coll., Inferior Colliculus; nucl. of burd. and 

 NUCL. of burdach, Nucleus of Burdach; nucl. of deiters. Nucleus of Deiters; nucl. of goll. Nucleus of 

 Goll; RET. form., Reticular Formation; subst. gel. rolando. Substantia Gelatinosa of Rolando; sup. 

 coll., Superior Colliculus; vent. coch. and vent, cochlear. Ventral Cochlear Nucleus. 



tendency toward plication, an undulating strand of gray matter showing a 

 number of bends and folds. The ventral lamina is almost devoid of redupli- 

 cations, whereas the dorsal lamina shows an increased irregularity produced 

 by the appearance of numerous redupHcations. At a level somewhat above 

 the appearance of the main mass of the inferior olivary nucleus, the dorsal 

 accessory olivary nucleus appears as a flat, narrow strand of gray matter 

 placed almost in the lateral meridian of the brain stem and overlying the 

 hihis of the inferior oHvary nucleus. It extends upward as a ilat band in this 



