CEREBRAL CONVOLUTIONS. 



605 



and above the occipital lobe, (3) the occipital lobe, and (4) the temporo- 

 sphenoidal lobe. The parietal lobe is bounded in front by the fissure of 



FIG. 221. Diagram of the external surface of the left cerebral hemisphere (modified from Ecker). 



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

 (shown in Fig. 222). The occipital lobe lies below the parieto-occipital fis- 



Temp f 

 FIG. 222. Diagram of the internal surface of the right cerebral hemisphere, shown in a longitudinal 



section in the median line (modified from Ecker). 



40 



