292 



EYE FIELD OPERATIONS 



EYE FIELD OPERATIONS 



NEURAL FOLD jd ■. > ; cW 







ANURAH STAGE 13-14 



NEURAL OR 

 MEDULLARY PLATE 



NEURAL FOLD 



OPTIC VESICLE 

 FIELD 



LENS FIELD 



MESENCHYME 



SECTION THROUGH 

 PRESUMPTIVE FOREBRAIN 



VESICLE FIELD 

 -LENS FIELD 



HOT NEEDLE 



HOT NEEDLE 



PRIMORDIA OF OPTICO - OCULAR APPARATUS 



(REDRAWN FROM SPEMANN '38) 



TRANSPLANT ■ ARCHENTERIC ROOF 



STAGE 12 STAGE 10 



INDUCTION OF EYE FIELD 



(Eedrawn from Spemann 1958) 



