PLATE 12 



EXPLANATION OF FIGURES 



40 A small portion of the adrenal of a 48/9.0 normal frog tadpole. Liver diet. 

 Fixed in osmium-bichromate 195 days after the operative stage. Babes' safranin 

 stain. Cortex black, medulla and nuclei red. X733. 



41 A small portion of the adrenal of a 54/0.2 albino frog tadpole. Same age, 

 diet, fixation, and stain as above. X733. 



136 



