SUMMARYEggs laid by 3 selected inbred queens producing brood of low survival rate were hatched in an incubator. Diploid larvae from worker cells and haploid larvae from drone cells were reared further under identical conditions in an incubator; 60% of 89 haploid larvae and 63% of 128 diploids reached the age of 5 days. About half the diploids were drones. Of the diploid drone larvae that reached 5 days, 43% lived to 9 days, compared with 36% of the haploids. The average weight of drone larvae at transference to pupation dishes was 357·7 mg. for diploids and 296·9 mg. for haploids. (The difference was not statistically significant, but might well be so with a greater number of larvae.) The viability of diploid drone larvae is certainly not lower, and may possibly be higher, than that of the haploids: by using right techniques for rearing, it should be possible to rear larger numbers of diploid drones to the imago.