The fact that diploid male tissue could exist in honey bees was later demonstrated by Rothenbuhler (1957) in gynandromorph or mosaic bees. Then, Woyke (1962, 1963, 1965) successfully hatched in an incubator all the eggs from imbred queens that had each been mated to one drone and that were laying eggs of wich only 50% seemed to hatch in colonies; and he reared them to maturity in the laboratory.