6o6 



THE HIGHER ANTHROPOIDS 



with the cerebral peduncles form the lateral hoiindary of the optico-pedun- 

 cular space. The optic thalanii provide the iinj:)()rtant relay stations in 

 the patiiway of all types of sensibility w ith the exce|)tion of the olfactory 



FIG. 2~0. CHIMPANZEE. LEVEL OF THE OPTIC CHIASM. 

 riN, Internal CJapsulc; idi', Descending Pillars of Fornix; n>H, Corpus Ilypothalamicum; olp. Globus 

 Pallidus; nl. Lateral Nucleus of Thalamus; mi. Internal Lateral Nucleus of Thalamus; oi'X, Optic Chiasm; 

 PUT, Pulamcn; vy, Fasciculus of Vicq D'Azyr. [Accession No. 157. Section 813. Actual Size 45 X 25 mm.) 



sense. The specializations withm this poition ol the brain stem are too exten- 

 sive to jjermit ol discussion at this timr and properly belong to a treatise in 

 which e\clusi\e attention ina\ be ck'Noted to their structure and e\()lutional 

 significance. The globus pallidus (Glp), a portion of the corpus stria- 

 tum, likewise is a structure presenting a highdegreeol s|)ccializat ion. Bcinga 

 part of the endbrain it should propeilN be considered with other constituents 

 of this division of the encephalon rather than as related to the brain stem. 



