Abstract
Admn. of 0.25 mg. of cortisone intramusc. to mice daily for 14 days after their exposures to the LD 60 and 25/14 days of X-rays resulted in increased mortality rates produced by these doses. There was no increase in mortality in the cortisone-treated mice exposed to the minimal lethal dose of X-rays but as in the higher X-ray doses, cortisone treatment produced a shortening of the latent period between irradiation and onset of death, indicating an adverse effect even at this low radiation level. Simultaneous treatment of irradiated mice with cortisone and vit. C did not modify the enhancement of the radiation-induced mortality rate produced by the cortisone admn.