抄録
The number of first spermatocytes per cyst in 5 iso-female strains of Drosophila virilis was studied with regard to fertility. The cysts involving 8cells were dominantly seen in TK and B33, and 9cells in A12 and A13 strains. But B12 strain had a highest mode of 12cells. Meioses could be assumed to proceed in every strain. The analysis of variance for the number of spermatids per bundle showed great difference between B12 and any other strain. The male fertility was also significantly different between TK and B12. The mean progeny numbers per male were 2300.1 in TK and 243.1 in B12, respectively. No significant difference was detected in female fertility.