338 



THE MORPHOGENESIS OF THE CENTRAL NERVOUS SYSTEM 



network of blood-vessels and produce an important internal secretion. Pari 

 passu with the differentiation of the anterior lobe the infundibular anlage of the 



Diencephalt 

 (Inter-braiu) 



l pkZs 



Pitted body epiihalamus 



Cerebral pedu nek 

 Cerebral aqueduct 



Mesencephalon 

 " <») 



RkombemxphaHc 



isthmus 

 Cerebellum 



Metencephaloti 

 {Hind-brain) 



Rhomboid 



fossa 

 Myelentepkalon 

 [Ajler-bmin) 



Spinal card 

 Central canal 



Fig. 324. — Median sagittal section of the brain from a fetus of the third month 

 l^His from Sobotta's Atlas). 



Foramen Monro i 



Third ventricle 



Optic vesicle 

 Lens vesicle: 



Infundibulum 



JfathfCe's pocket- . 



Fig. 325. — Oblique transverse section through the diencephalon and telencephalon of a 10 mm. embryo. 



X 61. 



posterior lobe loses its cavity, but the walls of the infundibulum persist as its 

 solid permanent stalk. The lobe enlarges and its cells are differentiated into a 



