This paper deals with the ratios in which bi-parental [male][male], [female][female], and haploid [male][male] occur. Previous work is summarized and the effect of temperature upon these ratios is reported. Crosses between related stocks produce biparental [male][male] while outcrossing fails to produce them. Ratios of [male][male] among biparental offspring are negatively correlated with ratios of total biparentals. Male biparentalism can not be explained b}- loss of a sex chromosome during gametogenesis, but, if such loss occurs, it must be at the time of or subsequent to fertilization. It is considered that fertilization by a related sperm has a lethal effect by causing chromosome elimination. Recessive [female][female] mated with dominant related [male][male] produce fewer biparental offspring but more [male][male] among the biparentals if they are kept at 30[degree]C. than if kept at 20[degree]C. Transfer of young to other temps, appears to have no effect on ratios except that the ratio of biparentals is increased if transfers are made from low, 20[degree], to higher, 30[degree] and 35[degree], temps. This can probably be explained by a differential lethal effect on the [male][male] in general.