RECONSTRICTIOX 01" TROGLODYTES GORILLA 6yi 



In gorilla the mesencephalic reticular iorination \ iewecl from above pre- 

 sents an arranucincnt similar to that loiind in the chimpanzee. It presents a 

 median luielear mass which extends to the midline, there to become contig- 



FIG. 314. LAKEKAL SURFACE OF GRAY MATTER OF BRAIX STEM, 



IROGLODYTES GORILLA. 

 Key to Diagram, im-. coli ., Inl'irior Colliculus; inf. olive. Inferior Olive; ivter-ped. c. Interpeduncular 

 Gray Matter; lat. gen. body. Lateral Geniculate Body; lat. gray coi.., Lateral Gray Column; meso-cen. 

 BODY', .Mesial Geniculate Body; nlcl. of bihdach, Nucleus of Burdach; nicl. of deiters, Nucleus of 

 Deitcrs; n. of g., Nucleus of Goll; ret. form.. Reticular Formation; roof of folrtii yen., Roof of Fourth 

 Ventricle; slbst. gel. roI-Ando, Substantia Gelatinosa of Rolando; sl'p. coll., Superior Colliculus; ve.st. 

 cocnL., N'entral Cochlear Nucleus; vent, gray col.. Ventral Gray Column. 



nous with its fellow of the opposite side. The lateral surface of this median 

 mass is serrated and covered In the superior cerebellar peduncle. Lateral to 

 the superior cerebellar peduncle is the dorsal extension ol the main niiiss of 

 the reticular formation which, as the peduncle continues in its course toward 

 Its decussation, becomes more extensive. 



From the lateral extremity of the inferior colliculus there arises a mass of 

 libers which produces a hiatus in the formatio reticularis, separating its more 

 ventral jjortion from contact with the superior colliculus. This hiatus is lilled 



