PLATE III. 



Figures 10-12 were drawn with a camera lucida, Bausch and 

 Lomb microscope, ocular 5, objective 16. Plate reduced to one-half. 



Fig. 10. Detail of section of eye of 25 mm embryo. 

 Fig. 11. Detail of section of eye of 80 mm embryo. 

 Fig. 12. Detail of section of eye of 35 mm embryo. 



