IFFERENCES in sensitivity of oocytes to X-irradiation depending upon stage in meiosis when treatment occurred, have been shown for a number of organisms including Habrobracon (WHITING l938,1941,1945a, 1945b; ATWOOD, VON BORSTEL and WHITING 1956). Studies have also shown that death of Habrobracon embryos following irradiation of oocytes in late metaphase and in late prophase (diplotene) was attr...