746 



DISSECTION OF THE BRAIN. 



has three 

 branches. 



As soon as it reaches the outer surface, it gives off one small branch i 

 forwards, the anterior limb (fig. 270, s'), and another upwards, the 

 ascending limb(s"), which project into the inferior frontal convolution, 



FIG. 270.- SOLCI AND CONVOLUTIONS OF THE OUTER SURFACE OF THE 

 HEMISPHERE. 



Fissures and Sulci. 



s. Fissure of Sylvius ; s', its an- 

 terior, s" its ascending, and s", its 

 posterior branch. 



r. Sulcus of Rolando. 



po. Parieto-occipital fissure. 



sf. Superior, and 



if. Inferior frontal sulcus. 

 pr.c. Priecentral sulcus. 



ip. Intraparietal. 

 pt. c. Postcentral (superior). 



cm. End of calloso-marginal sulcus. 



s 1 .. First temporal or parallel sul- 

 cus, and 



nit. Second temporal sulcus. 



Convolutions: 



SF. Superior. 

 MF. Middle, and 



IF. Inferior frontal. 



AF. Ascending frontal. 



AP. Ascending parietal. 

 SPL. Superior parietal lobule. 

 S.M. Supramarginal convolution. 

 Ant/. Angular. 



so. Superior. 



MO. Middle, and 



10. Inferior occipital. 



ST. First. 



MT. Second, and 



IT. Third temporal. 



Note. The inferior parietal lobule is commonly described as consisting of 

 these parts : 



sulcus. 



3. The postparietal surrounding 

 the upturned end of the second 

 temporal sulcus. 



1. The supra-marginal surround- 

 ing the upturned end of the fissure of 

 Sylvius. 



2. The angular surrounding the 

 upturned end of the first temporal 



Only the first two of these are represented on the figure. The upturned, 

 posterior, part of the second temporal sulcus is often separate from the 

 anterior part. 



and then continues backwards as the posterior limb (s'") through 

 about the middle third of the hemisphere. The posterior limb 

 separates the temporal from the frontal and parietal lobes ; it ascends 



