I'k;. 1 shows that the plane of sc[)aratioii ol llic 

 dividing germinal nuclei is at riglit angles to the 

 limiting membrane of the retina, loth day hog 

 embryo Xl50(). lùuly stages of mitosis exhibited 

 on the right. 



Fig. 2 is a section of the retinal wall in a IDth 

 day frog-embryo. The neuroblast-nuclei will be ob- 

 served to lie for the most part with their long axes 

 at right angles to the limiting membranes. 

 p.c.l. — pigment cell layer. 

 i.l.m. — -internal limiting n.endjrane. 



