618 



HAXDBOOK OF PHYSIOLOGY. 



sulcus. The inferior parietal lobule (pli courbe) is situated at the pos- 

 terior and upper end of the fissure of Sylvius; it consists of (a) an 

 anterior part (supra-marginal convolution} which hooks round the end 

 of the fissure of Sylvius, and joins the superior temporal convolution, 

 and a posterior part (b) (angular gyrus) which hooks round into the 

 middle temporal convolution. 



3. Temporal contains three well-marked convolutions, parallel to 

 each other, termed the superior, middle, and inferior temporal. The 

 superior and middle are separated by the parallel fissure. 



4. Occipital. This lobe lies behind the external perpendicular 



Fig. 371. The cerebrum, from above. (After Eberstaller.) f 



or parieto-occipital fissure, and contains three convolutions, termed the 

 superior, middle, and inferior occipital. They are often not well marked. 

 In man, the external parieto-occipital fissure is only to be distinguished 

 as a notch in the inner edge of the hemisphere; below this it is quite 

 obliterated by the four annectaut gyri (plis de passage) which run nearly 

 horizontally. The upper two connect the parietal, and the lower two 

 the temporal with the occipital lobe. 



5. Central lobe, or island of Eeil, which contains a number of radiat- 

 ing convolutions (gyri operti). 



The fig. 372 shows the following gyri and sulci: 



Gyrus fornicatus, a long curved convolution, parallel to and curving 



