2 3 8 



THE NERVOUS SYSTEM 



THE MEDIAN AND BASAL SURFACES 



The occipital lobe comes more nearly being a structural and functional 

 entity than any of the other lobes. It corresponds in a general way to the 

 "regio occipitalis" as outlined by Brodman (Figs. 216, 217), and it is probably 

 all concerned directly or indirectly with visual processes. We have seen that 

 it forms a small convex area on the lateral surface near the occipital pole; 

 and we now note that it is continued on to the medial surface of the hemi- 

 sphere, where it forms a somewhat larger triangular field between the parieto- 

 occipital and anterior portion of the calcarine fissure dorsorostrally and the 



Sulcus cinguli 

 Sulcus of corpus callosum 



Sup. fronta 



gyrus'-- 



Frontal par. of 



stilcus cinguli 



Frontal pole 



Genu of corp. cat.' 



Septum pellucidum 

 Rost. of corpus callosum 

 Anterior parolfactory sulcus / / / ^ 

 Par olfactory area < I 



Temporal pole jUncus 

 Anterior commissure Fimbria 



Hippocampal gyms 



J3ody of corpus callosum 

 ' Paracentral lobule 

 -' ' / Central sulcus 



Marginal portion of sulcus cinguli 

 Precuneus 

 'Column of fornix 

 -'Subparietal sulcus 

 '.Cms of fornix 



..- Parieto-occip. fis. 



Splen. of corp. cal. 

 \.,-lsth. of gyms 

 fornicatus 

 j Cuneus 



Calcarine 

 Ussure 



'Occipital pole 



' Lingual gyms 

 Inferior temporal gyrus 

 Inferior temporal sulcus 

 Fusiform gyrus 



Collateral fissure 

 Fasciola cinerea 



Fig. 170. Human cerebral hemisphere seen from the medial side. The brain has been 

 divided in the median plane and part of the thalamus has been removed along with the mesen- 

 cephalon and rhombencephalon. (Sobotta-McMurrich.) 



collateral fissure ventrally. On this aspect of the brain it includes two constant 

 and well-defined convolutions: the cuneus and the lingual gyrus (Figs. 170, 

 171). 



The calcarine fissure begins ventrally to the splenium of the corpus callosum 

 and extends toward the occipital pole, arching at the same time somewhat 

 dorsally. It consists of two portions. The rostral part, the calcarine fissure 

 proper, is deeper, more constant in form and position, and phylogenetically 

 much older than the rest, and produces the elevation on the wall of the lateral 

 ventricle known as the calcar avis (Fig. 181). This part terminates at the point 



