THE NERVOUS SYSTEM. 



539 



from the stomodeeal epithelium and is connected with the latter by a stalk. 

 The pouch, which is at first a flat structure, develops two horns which envelop 



Ant. corp. quad. Pineal 

 (ant. colliculus) region 



Anterior 

 brachium 



Pallium 



Ant. I 



? olfact. lobe 

 Post. J 



Optic stalk 



Hypophyseal pouch 



Mammillary Lateral Tuber 

 region geniculate cinereum 

 body 



Fig. 462. — Lateral view of a model of the brain of a 10.2 mm. human embryo 

 (middle of 5th week). His. 



the infundibulum. The cavity of the end of the infundibular process becomes 

 nearly shut off from the rest of the infundibular cavity. The process penetrates 

 the upper part of the pouch and then bending reaches its posterior surface and 



Diencephalon Thalamus 



Pineal region 



Pallium 



Foramen of Monro 



Sulcus hypothal- 

 ami cus 



Ant. olfact. lobe 



Post, olfact. lobe 



Lamina terminalis 



Corpus striatum 



Mesencephalon 

 Tegmental swelling 



Mammillary region 

 Hypothalamus 

 Tuber cinereum 



Recessus Hypophyseal Recessus. 

 (pree ?) opticus pouch infundibuli 



Fig. 463. — Median view of the right half of a model of the brain of a 10.2 mm. human embryo 

 (middle of 5th week). Compare Fig. 462. His. 



ends blindly. In the second half of the second month epithelial sprouts, which 

 become very vascular, begin to appear, first in the lateral parts of the pouch, 



