530 ExiDerimental Studies on the Origin of the Lens in Amphibia 



vesicle must have reached the skin and stimulated lens formation. The 

 lens over this side is about 110 micro mm. and the normal one about 

 180 micro mm. in diameter. 



Series II. 



The experiments of series II differ from those of series DF and IV in 

 that the optic vesicle was destroyed and not transplanted after it was 

 cut off. 



Fig. 40. Fig. 41. 



Fig. 40. Experiment Iln. Outline of tadpole killed 9 days after operation. Drawn in 

 xylol. X 8 diameters. 

 Fig. 41. Experiment IIi,,. Outline of tadpole. X 8 diameters. 



Fig. 43. E.vperiment IIio. Section through about the center of both eyes. X 45 diameters. 



Experiment 11^^. 



As in experiment IV^o, the optic vesicle was cut off close to the brain 

 of E. palustris, stage II. The skin flap was uninjured and turned back 

 into place, where it readily adhered and healed. Five days after the 

 operation a large reformed optic vesicle with what appeared to be a lens 

 was visible and 9 days after the operation the tadpole was killed. Fig. 



