204* 



HUMAN PHYSIOLOGY. 



Convolutions. Frontal Lobe. 



The ascending frontal or precentral convolution, situated in front 

 of the fissure of Rolando runs downward and forward ; it is con- 



FIG. .24. DIAGRAM SHOWING FISSURES AND CONVOLUTIONS OF THE LEFT SIDE 

 OF THE HUMAN BRAIN. (Landois' "Physiology.") 



F. Frontal. P. Parietal. O. Occipital. T. Temporosphenoid lobe. S. Fis- 

 sure of Sylvius. S'. Horizontal. S". Ascending ramus of S. c. Sulcus 

 centralis, or fissure of Rolando. A. Ascending frontal, and B. Ascending 

 parietal convolutions. FI. Superior, F 2 . Middle, and F 3 . Inferior frontal 

 convolutions. f 2 . Superior, f 2 . Inferior frontal fissures. f 3 . Sulcus praecen- 

 tralis. PI. Superior parietal lobule. P 2 . Inferior parietal lobule, con- 

 sisting of P 2 . Supramarginal gyrus. and P/. Angular gyrus. ip. Sulcus 

 interparietalis. cm. Termination of callosomarginal fissure. Oi. First, 

 O 2 . Second, O 3 . Third occipital convolutions, po. Parieto-occipital fissure. 

 o. Transverse occipital fissure. o 2 . Inferior longitvidinal occipital fissure. 

 T . First, T 2 . Second, T 3 . Temporosphenoid, convolutions, ti, t 2 . First, t 2 . 

 Second, temporosphenoid fissures. 



