EMBRYO OF 24 MM. 



261 



cases they do not separate again until after birth, in which case the animals are 

 said to be " born blind." The ectoderm, Ec, of the cornea describes a wide, high 



L.sup. 



JV.3. N.op. 



~ an.ch. 



tu.v. 



Ret 



Pig. 



L.inf. 



Fig. 150.— Pig, 24.0 mm. Transverse Series 62, Section 428. 

 an.ch, Anterior chamber of eye. corn, Corneal mesoderm. Ec, Ectoderm (epidermis). Ep, Inner epithelium 

 of cornea. Ir, Mesodermal anlage of iris. U , Outer layer of lens. L", Inner layer of lens. L.inf, 

 Inferior eyelid. L.sup, Superior eyelid. N.j, Oculomotor nerve. N.op, Optic nerve. Pig, Pigment 

 layer. Ret, Retina. Schl, Canal of Schlemm. tu.v, Tunica vasculosa lentis. Vit, Vitreous humor. 

 X 5° diams. 



arch, underneath which is a broad band of embryonic connective tissue, corn, 

 which forms the main thickness of the cornea. Between the connective tissue 



