Independent Development of the Lens. 409 
EXTREMELY DEFrEcTIVE Optic Cup-Like Bopies ASSOCIATED WITH PERFECT 
LENSES 
Fig. 21. An anterior section, as is indicated by its size, of a nineteen-day em- 
bryo. A free lens is shown on the left while on the right a very small defective 
eye contains a small lens. ; 
Fig. 22. Asmall lensnear a vesicle-like structure, E, in the brain which might 
represent an abortive optic body. F 
Fias. 23 and 24 Sections through the embryo shown in fig. 2. In the diagram, 
fig. 25, is shown approximately the planes of the sections. The large well-formed 
lenses are associated with defective optic cups which lack any sign of differentia- 
tion. 
