262 



THE NERVOUS SYSTEM 



portion of this lobe is occupied by the ascending frontal, or 

 the anterior central convolution, lying just in front of the 

 Rolandic fissure. 



(b) The parietal lobe is bounded anteriorly by the fissure 



FIG. 82. Median aspect of the right hemisphere. 



CC, corpus callosum divided longitudinally; Gf, gyrus fornicatus; H, gyrus 

 hippocampi; h, sulcus hippocampi; U, uncinate gyrus; cm, calloso-marginal fis- 

 sure; F, first frontal convolution; c, terminal portion of fissure of Rolando; A, 

 ascending frontal; B, ascending parietal convolution and paracentral lobule; P\' , 

 parecuneus or quadrate lobule; Os, cuneus; Po, parieto-occipital fissure; o', 

 transverse occipital fissure; oc, calcarine fissure; oc' , superior, oc" , inferior 

 ramus of the same; G' , gyrus descendens; T, gyrus occipito-temporalis lateralis 

 (lobulus fusiformis) ; T, gyrus occipito-temporalis medialis (lobulus lingualis). 

 (Landois.) 



of Rolando, internally by the longitudinal fissure, posteriorly 

 by the parieto-occipital fissure and below by the fissure of 

 Sylvius. Just behind the fissure of Rolando is the ascending 

 parietal, or posterior central convolution, above, this is con- 

 tinuous with the upper parietal convolution, below which is 

 the inferior parietal lobule separated from the preceding by 

 the intra-parietal sulcus. This inferior parietal lobule winds 

 around the posterior part of the fissure of Sylvius, and is 



