THE CORPUS STRIATDM. 



L33 



of white substance (internal capsule), but is united with it in front, where it is 

 pierced, as just stated, by the fibres passing to the frontal lobe. The lenticular 

 nucleus is only seen in sections of the hemisphere. Its horizontal section (fig. 99, n.l) 



Fig. 97. VIEW FROM BEHIND OF A FRONTAL SECTION OF THE HEMISPHERES PASSING THROUGH THE 



MIDDLE OF THE ANTERIOR COMMISSURE. (E. A. S. ) From a photograph. 



c.c., corpus callosum ; fo., anterior pillars of the fornix with the anterior extremity of the third 

 ventricle between them ; v.l. , lateral ventricles ; a. c. , anterior commissure ; n. c. , nucleus caudatus ; 

 gl,p., globus pallidus and pu., putamen, of nucleus lenticularis ; c.i., between the nucleus caudatus 

 and nucleus lenticularis, the internal capsule; cl., claustrum ; i. R., insula ; c. m.s., sulcus calloso- 

 marginalis ; s.fr.s., sulcus frontalis superior; s.pr.s., sulcus precentralis superior; tr.nlf., tractus 

 olfactorius passing to the anterior perforated space and giving off its mesial, lateral, and middle roots. 



somewhat resembles that of a biconvex lens, being wider in the centre than at either 

 end, but larger anteriorly than posteriorly. It is less extensive than the caudate 

 nucleus, which projects beyond it at either end. The antero-posterior diameter 

 corresponds closely with that of the central lobe of the hemisphere, or island of Reil, 

 and the greatest width is opposite the anterior edge of the , optic thalamus. On a 



