X-RAY INDUCED DOMINANT LETHALS IN DIFFERENT STAGES OF SPERMATOGENESIS IN DROSOPHILA

T is a well known fact that in Drosophila melanogaster the number I of eggs that hatch is decreased when the sperm used in fertilizing the females has been previously X-ray irradiated.This decrease is not only due to the dose but also to the age of the males at treatment (DEMPSTER, 1941; STROMNZS, 1949) and the time between treatment and fertilization (BONNIER and L ~~N I N G , 1950).Possible ,explanations were given in the latter publication.The pres'ent paper deals with th,e forces :it work altering the percentage of hatchability when increasing the time between treatment and insemination.