378 



THE PERIPHERAL NERVOUS SYSTEM 



Mesenchyma Lens vesicle Vitreous body Optic stalk Optic recess of brain 



Epithelium of cornea Pigment layer of retina Nervous layer of retina 



FIG. 376. A transverse section through the optic cup, stalk and lens of a ro mm. human 



embryo. X 100. 



'Epithelial layer of lens Pigment layer of the retina 

 Ectoderm 



Nervous layer of retina 



horioid fissure 



'Central artery 

 Vitreous body 

 Layer of lens fibers 



Mesenchyme 



FIG. 377. Transverse section passing through the optic cup at the level of the chorioid 

 fissure. The central artery of the retina is seen entering the fissure and sending a branch to 

 the proximal surface of the lens; from a 12.5 mm. human embryo. X 105. 



