THE CEREBRUM. 



123 



Horizontal Section of the Hemispheres at the Level of the Cerebral Ganglia : 1, great 

 longitudinal fissure between frontal lobes: 2, great longitudinal fissure between 

 occipital lobes : 3, anterior part of corpus callosum ; 4, fissure of Sylvius ; 5, convolu- 

 tions of the insula; 6, caudate nucleus of corpus striatum; 7, lenticular nucleus of 

 corpus striatum; 8, optic thalamus; 9, internal capsule; 10, external capsule; 11, 

 claustrum. 



(5) The Central Lobe, or Mand of Reil, is within the fissure of 

 Sylvius and covered by the convolutions of the frontal and parietal 

 lobes. (See 5 in Fig. 34.) 



Besides these well-defined lobes, the portion of the cerebral sur- 



