446 



Warren Harmon Leivis. 



Plate II. 



Fig. 7. Experiment MF2. Lens and part of optic cup removed shortly after the separation of the 

 lens from the skin. Embryo killed 14 days after the operation. Figure from section through right 

 eye region, shows the regular reformed optic cup with small cavity and pupil, and overlying cornea 

 with its endothelium. X 80 diameters. 



Fig. 8. Experiment MG4. Right optic cup removed shortly after separation of lens from skin, 

 but before corneal formation. Embryo killed 13 days after the operation. Figure from section through 

 the right eye region, shows a lens smaller than normal pressed close against the skin, where there is 

 distinct corneal clearing, but no endothelial formation. X 80 diameters. 



Fig. 9. Experiment Mai. Operation as above except that the lens was disturbed. Embryo killed 

 13 days after the operation. Figure shows the small lens separated from the skin by mesenchyme. 

 There are no corneal changes in this region nor endothelial formation. A small mass of eye-cells lies 

 medial to the lens. X 80 diameters. 



Fig. 10. Experiment XV3G2. Epidermis from over the entire right eye cut off before traces of 

 corneal formation present. Embryo killed 1 1 days after the operation. Figure from a transverse 

 section of the right eye region shows how new skin has completely covered the eye and become trans- 

 formed into cornea. X 80 diameters. 



Fig. II. Experiment XVsor,. All of the skin over the eye and a portion of the optic cup removed. 

 Embryo killed 1 1 days after the operation. Figure shows small eye with irregular lens and corneal 

 formation from the new skin. X 80 diameters. 



Fig. 12. Experiment XVII310. All of the skin over the eye, the lens and part of the optic cup cut 

 away before corneal formation. Embryo killed 1 1 days after the operation. Figure shows deep optic 

 cup without pupil or cavity separated from skin by mesenchyme. There are no traces of corneal 

 formation in the new ectoderm. X 80 diameters. 



