Abstract
After [3H]-thymidine injection to newly-hatching D. melanogaster females, the migration of labeled egg-chambers through the ovarioles was studied by autoradiographs of the ovaries at daily intervals. The growth duration of egg-chambers which progressed during the first 48 h was 24 h longer than the growth duration of chambers progressing thereafter. This temporary delay of ovarian activity was related to endocrine modifications occuring in the female during this period and particularly to a JH[juvenile hormone]-ecdysone interaction.