348 



THE MORPHOGENESIS OF THE CENTRAL NERVOUS SYSTEM 



central sulcus, or fissure of Rolando, which forms the dorso-lateral boundary line 

 between the frontal and parietal lobes (Fig. 337); (2) the parieto-occipital fissure, 

 which, on the median wall of the cerebrum, is the line of separation between the 



Median olfactory 

 gyrus 



Middle olfactory 



gyrus 



Diagonal gyrus 



Insula 



Lai. olfactory gyrus 



Gyrus ambiens 

 Gyrus semilunaris 



Oliva 



FIG. 336. Ventral view of the brain of a 100 mm. embryo showing development of the rhinencephalon 



(Kollmann). 



Sulcus postcentralis Sulcus centralis 



Lobus 



parietalis 



superior 



Supra- 

 marginal 

 and an- 

 gular gyri 



Post. 



ramus 



of lateral 



fissure 



Middle 



temporal 



sulcus 



Occipital 

 pole 



Inferior 



frontal 



sulcus 



Temporal 

 lobe 



Superior temporal gyrus Middle temporal gyrus 

 FIG. 337. Lateral view of the right cerebral hemisphere, from a seven months' fetus (Kollmann). 



