PLATE 2 



EXPLANATION OP FIGURES 



6 and 7 Photomicrographs of sections at moi-e posterior levels of the same 

 embryo, o.s., dissociated optic cup substance in the oral cavity; ui, the last 

 trace of the right eye; 02, the second optic cup of the right side; I., lentoids; p., 

 ])lasma in pericardium; e.v., ear-vesiole. X 150. 



366 



