SUMMARYHomozygous cordovan queens and homozygous chartreuse queens (from crosses of heterozygous mutant mothers with mutant fathers) were each inseminated from a single wild-black brother. After tests for survival rate of brood had been carried out, four queens producing low-survival brood were chosen, and the eggs they laid in both worker and drone cells were hatched in an incubator. The 321 young larvae were reared further in the incubator.Drone pupae grafted as larvae from worker cells and originating from the cordovan queen showed some characters of the father. Stronger evidence is supplied by brood produced by the chartreuse queens. Drone prepupae and pupae reared in the incubator from eggs they laid in drone cells showed only the genetic character of the mother, as expected. But drone prepupae and pupa from eggs in worker cells laid by the same queens, and reared from the egg stage in an incubator, showed the genetic character of the father, as did the female offspring of these queens. This proves that drone larvae from eggs laid in worker cells by inbred queens producing low-survival brood develop from fertilized eggs.