EFFECTS OF HYDROCORTISONE ON HIND-LIMB REGENERATION IN THE TADPOLES OF TOAD, BUFO-ANDERSONII

Hind limb regeneration was studied in the tadpoles of toad, Bufo ander sonii of developmental stages IX, X and XI according to the normal tab le of Taylor and Kollros(1) for Rana pipiens. Following amputation thr ough thigh, shank and ankle levels, the control were reared in water a nd the experimental groups in 5, 7.5, 10, 15, 20, 30, 40, and 50 mu g/ ml concentrations of hydrocortisone. Legs regenerated at various level s showed a decline of regenerative capacity at thigh, shank and ankle levels. It is manifested in production of progressively increasing num ber of oligodactylous and defective regenerates. Frequency of regenera tes depends on the levels of amputation, stage of development of tadpo les and on the concentrations of hydrocortisone in the medium. High co ncentrations of the hormone are inhibitory and destructive. Hydrocorti sone treatment improved the quality of regenerates but the subsequent processes of differentiation and growth are inhibited.