BASE OF THE CEREBRUM. 



741 



commissure the corpus callosum. In their lower half the hemi- 

 spheres are united by other commissures, as well as by several united by 

 connecting parts at the under surface. The under part of each JJ^rts" 1 

 hemisphere is divided into two by the deep transverse cleft the 

 jl-i-nu'i' of Sylvius. 



UNDER SURFACE, OR BASE, OP THE CEREBRUM (He. 268). The Under 



surface of 

 cerebrum 



FIG. 268. UNDER SUIIFACK OF THE BRAIN. 



a. -Medulla oblongata. 



b. Hemisphere of cerebellum. 



c. Flocculus. 



d. Pons. 



e. Corpus albicans. 



f. Cms cerebri. 



g. Posterior perforated space. 

 h. Tuber cinereum. 



i. Optic commissure. 

 I. Vallecula Sylvii and anterior 

 perforated space. 



iii. Lamina cinerea. 



n. Rostrum of corpus callosum : on 

 each side of m, is a narrow white 

 band the peduncle of the corpus 

 callosum. 



o. Olfactory bulb. 



p. Frontal lobe of the cerebral 

 hemisphere. 



r. Temporal, separated from the 

 foregoing by the fissure of Sylvius. 



under surface of the cerebrum is irregular, in consequence of its 

 fitting into inequalities in the base of the skull ; and on this aspect 

 the separation into hemisphere is not so complete as on the upper. 

 The main objects to be recognised along the median part of the base 

 of the brain have already been enumerated (pp. 725 and 726). 



The PEDUNCLE OF THE CEREBRUM or CRUS CEREBRI (/). This is a Cms 



large, white, stalk-like body, which reaches from the upper border 



