3SO 



THE MORPHOGENESIS OF THE CENTRAL NERVOUS SYSTEM 



Median olfactory 

 gyms 



Middle olfactory 

 gyrus 

 ' gyrus 



Cerebelhcm 



Insula 



Lat. olfactory gyrus 



Gyrus ambiens 

 Gyrus semilunaris 



Oliva 



Fig. 354,— Ventral view of the brain of a 100 mm. fetus, 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 



-i scend- 



i_ "'S 

 ramus 



Lateral 

 fissure 

 (Sylvii) 



Temporal 

 lobe 



Superior temporal gyrus Middle temporal g wus 

 Fig. 355.-Lateral view of the right cerebral hemisphere from a seven months' fetus (KoUmann). 



frontal lobe. These are not approximated over the insula until after birth. The 

 frontal operculum is included between the anterior limbs of the Sylvian fissure and 

 the extent of its development, which is variable, determines tlie form of these Hmbs. 



