LOBES AND GYRI OF THE CONVEX SURFACE. 



central sulcus, and by the fronto-parietal part of the operculum, 

 below it. The anterior central gyms, together with the para- 

 central lobule constitutes the emissive motor zone of the human 

 cerebrum. 



(2) The parietal lobe (lobus parietalis) is situated behind 

 the central sulcus and above the posterior limb of the lateral 

 fissure of the cerebrum (Figs. 22 and 28). From the curve near 

 the posterior end of the latter to the occipito-parietal sulcus the 

 lobe is separated from the temporal, below, and the occipital, 

 behind, by an imaginary line. This imaginary line runs back- 

 ward parallel with the infero-lateral border of the hemisphere 

 to the boundary of the occipital lobe; and then, obliquely upward 

 toward the supero-medial border in a line drawn from the pre- 

 occipital notch to the occipito-parietal sulcus. Extending over 

 the supero-medial border, the lobe on the medial surface is inclosed 

 between the occipito-parietal sulcus behind and the marginal 

 part of the sulcus cinguli in front, and is bounded antero-inferiorly 

 by the subparietal sulcus. 



On the convex surface of the hemisphere the parietal lobe 

 possesses the following sulci and gyri (Figs. 23 and 24). 



Interparietal (s. interparietalis) four parts 

 Inferior post -central (s. post-centralis inferior; 

 Superior post -central (s. post-centralis superior) 

 Horizontal limb (ramus horizontalis) 

 Occipital limb (ramus occipitalis). 



Sulci 



Gyri 



Upturned ends of 



Lateral fissure (f. cerebri lateralis) 



Superior temporal sulcus (s. temporalis superior) 



Middle temporal sulcus (s. temporalis medius). 



Posterior central (g. centralis posterior) 

 Superior parietal lobule (1. parietalis superior) 

 Inferior parietal lobule (1. parietalis inferior) 



Supramarginal (g. supramarginalis) 



Angular (g. angularis) 



Postparietal (g. postparietalis). 



The interparietal sulcus (Figs. 20 and 23) is the only one 

 belonging to the parietal lobe. The inferior and superior post- 



