262 



THE NERVOUS SYSTEM 



the fissure of Sylvius, and is divided into the supra-marginal 

 convolution, embracing the short arm of this fissure, and the 

 angular convolution connecting below with the temporal lobe. 

 (c) The occipital lobe is situated posteriorly below the parieto- 



FIG. 82. Median aspect of the right hemisphere. 



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

 pocampi; h, sulcus hippocampi; U, uncinate gyrus; cm, calloso-marginal fissure; F, 

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

 frontal; B, ascending parietal convolution and paracentral lobule; Pi', parecuneus 

 or quadrate lobule; Oz, cuneus; Po, parieto-occipital fissure; o', transverse occipital 

 fissure; oc, calcarine fissure; pc', superior; oc", inferior ramus of the same; G, gyrus 

 descendens; T<, gyrus occipito-temporalis lateralis (lobulus fusiformis); Ta, gyrus 

 occipito-temporalis medialis (lobulus lingualis). (Landois.) 



occipital fissure and external to the median fissure. It presents 

 three convolutions, the superior, middle and inferior. 



(d) The temporo-sphenoidal lobe is below the fissure of Sylvius 

 in front of the occipital lobe. It likewise presents superior, 

 middle and inferior convolutions. 



(e) The central lobe, or island of Reil, presents the gyrus forni- 

 catus, a convolution curving around the corpus callosum; the 



