Abstract
Life span of adult Sarcophaga peregrina became short after X-irradiation given in early pupal stage. It also inhibited imago formation of irradiated pupae. Shortening of life was adequately explained by upward shift of age specific mor-tality curve. In a range between zero and a single dose of about 2, 000 roentgen which inhibited 90 per cent of imago formation, there was a possible correla-tion of short-term and long-term effects and two kinds of injuries reduced when a dose was fractionated. Mitotic inhibition of disc cells induced by radiation plays some role in these effects.
