THE BRAIN 



331 



Telencephalon 



Cervical flexure 



-Myelencephalon 



Melencephalon 

 Myelencephalon 



FIG. 333. Brains of human embryos, from reconstructions by His: A, 4.2 mm. embryo 

 (X2o); B, 6.9 mm. embryo (X 16); C, 18.5 mm. embryo (X 4). o, Optic vesicle; in, infun- 

 dibulum; m, mammillary body; pf, pontine flexure; ol, olfactory^Jobe; b, basilar artery; 

 p, Rathke's pouch (American Text-Book of Obstetrics). 



In the table on page 332 are given the primitive subdivisions of the 

 neural tube and the parts derived from them: 



