542 



TEXT-BOOK OF EMBRYOLOGY. 



a portion of these two projections takes place, forming the commissure, mollis 

 or massa intermedia. The condition at this stage is shown in Fig. 467. Later 



Ant. corp. quad. Diencephalon 



Tegmental 

 swelling 



Mammillary 

 .body 



Tuber 

 cinereum 



Pallium 



Beginning of 

 fossa Sylvii 



Ant. 

 Post. ). 



olfact. 

 lobe 



Optic stalk 



Infundibulum Hypophyseal pouch. 



FIG. 465. Lateral view of the model of the brain of a 13.6 mm. human embryo (beginning of 6th 

 week). F, Beginning of frontal lobe; T, beginning of temporal lobe. His. 



this protrusion thrusts the lateral structures above described (the pulvinar, 

 geniculate bodies and brachia) to the side, the cavity of the lateral geniculate 



Lplthalamus (Corpus pineale) Metathalanuis (Corpora geniculata; 



Rhinence 



Cor 

 Sulcus hypotlia 



rpora quadrigeniina 



Peduneulus cerebri 



FIG. 466. From a model of the brain of a 13.6 mm. human embryo, right half, 

 seen from the left side. His, Spalteholz. 



body being obliterated. The prominence itself extends to the tegmental swell- 

 ing (see Figs. 467-8) and there thus arises the possibility of direct connections 



