454 



THE JNTERNAL STRUCTURE 



stated, the Convolutions that are thus brought into 

 relation in the two hemispheres are precisely those with 

 which the ' radiating fibres ' of the Crus are also in 



relation. The 

 names of these 

 Convolutions 

 have been al- 

 ready given (p. 

 444). 



The Anterior 

 Commissure is 

 a distinct band 

 of w^hite fibres 

 which crosses 

 the anterior 

 part of the 

 * third ventricle' 

 and on each 

 side penetrates 

 the substaiice 

 of the Corpus 

 Striatum (fig. 

 164, 6). It is 

 not, however, 

 as it seems to 

 be, a Commis- 

 sure connecting 

 these bodies. 

 Careful dissec- 

 tion suffices to 

 show that its fibres merely pass through the Corpus 

 Striatum on each side (where they lie in a distinct groove 

 or canal), that they emerge on the under and outer surface 

 of these bodies, and that they are thence distributed 



Fin. 163. —Horizontal Section throiigli the Cranium and 

 Cerebral Hemisphere just above the level of the Corpus 

 Callosum, showing the so called 'centrum ovale ' of Vieus 

 sens. (Sappey, after Vicq d'Azyr.) 1, 1, Median furrow of 

 the upi^er face of the Corpus Callosum ; 2, 2, longitudinal 

 fasiculi of this face ('nerves of Lancisi'); 3, the transverse 

 fasiculi of its main body ; 3', section of the medullary sub- 

 stance at the level of the border of the Corpus Callosum ; 

 4, 4, grey layer of the Convolutions forming an irregular 

 festoon around the ' centrum ovale ' of Vicus.scns ; 5, ante- 

 rior part of the great longitudinal fissure of the Cerebrum ; 

 6, posterior part of this longitudinal fissure ; 7, 7, section of 

 the walls of the Skull. 



