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. 



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

 diet, fixation, and stain as above. X733. 



13b" 



