PLATE .I 



EXPLANATION OF FIGURES 



22 The pigmentary system of a 4(1 o.l albino frog tadpole, 'light and heat' 

 adapted. This tadpole was supplied with a posterior-lobe diet for 4}4 months. 

 Prior to fixation it had been on a liver diet for one week. Fixed 4J4 months after 

 epithelial hypophysectomy. X226. 



23 The pigmentary system of a 43/0.1 albino frog tadpole, 'light and heat' 

 adapted. This tadpole was supplied with a posteriordobe diet for 3}£ months. 

 It had been on a liver diet for 5 weeks prior to fixation. Fixed by dropping into 

 ETelly's fluid 4'_; months after epithelial hypophysectomy. X226. 



L22 



