i 3 2 THE POCKET ANATOMY 



perforated spot, and is limited below by the calloso- 

 marginal sulcus, and behind by its upturned extremity . 



2. The parietal lohe : 



Convolutions and sulci : 

 On outer surface : 



The intra- parietal sulcus commences near posterior 

 limb of Sylvian fissure, passes upwards parallel to the 

 lower ha'f of the fissure of Rolando, and then turns 

 backwards to end near parieto-occipital fissure. 



The postcentral stilcus continues the line of the vertical 

 part of the intra-parietal sulcus. 



The ascending parietal convolution is bounded in front 

 by the fissure of Rolando, behind by the intra-parietal 

 and postcentral fissures, below by the fissure of Sylvius, 

 and above it joins the superior parietal convolution. 



The superior parietal convolution is bounded by the post- 

 central fissure in front, behind by the parieto-occipital 

 fissure, round which it is connected to the superior 

 occipital convolution by the first anncctant gyrus. 



Inferior parietal subdivided into : 



The supra-marginal convolution, bounded in front and 

 above by the intra-parietal fissure, round the lower 

 end of which it joins the ascending parietal convolu- 

 tion ; behind by the posterior limb of the Sylvian 

 fissure, round which it joins the superior temporo- 

 sphenoidal convolution. 



The angular convolution occupies the rest of the outer 

 surface of the parietal lobe. Above is the superior 

 parietal lobule, below the temporo-sphenoidal lobe, in 

 front the supra-marginal gyrus, and behind the occipital 

 lobe : it arches over the upturned end of the parallel 

 sulcus, and is continuous with the second temporo- 

 sphenoidal convolution. The postparietal convolution 

 curves over the upturned second temporal sulcus, and 

 is continued into the third temporo-sphenoidal con- 

 volution. 

 On the inner surface : 



The quadrate lobule lies anterior to the cuneate ; it is 

 bounded behind by the internal parieto-occipital fissure, 

 and in front by the ascending terminal limb of the 

 calloso-marginal sulcus. 



3. The occipital lobe : 



On outer surface three convolutions, an upper, a middle, and 

 an inferior, by two sulci. 



The superior occipital convolution is connected anteriorly to 

 the 6-H.perior parietal lobule by the first annectant gyrus. 



