p pigment layer of retina. 
187 
This result suggested the experiment of turning the optic vesicle 
around making the normally inner pole lie outwards. 
Embryo 314, 3 mm long. The ectoderm over the right optic 
vesicle was removed, the vesicle cut loose from the brain and turned 
Fig. 1. Embryo 121. 
Left half of brain through intracranial eye. 
R regenereted brain wall. 
xX 270. 
ch chorioid. 
rc layer of rods and cones. 
around so that its ventricular attachment was directed outwards. The 
optic vesicle was held in position by gentle pressure with the side of a 
small lance until the ectoderm had covered the margins of the wound. 
