Overwintering females of the Culex pipiens complex from Memphis, Tennessee, were acclimated to laboratory conditions and allowed to oviposit. Egg rafts were reared as individual progenies. The DV/D ratios of the male offspring of 23 progenies were determined. The authors compared the results, utilizing the generally accepted interpretation of the DV/D ratio with a suggested more "strict" interpretation, the use of which markedly alters the dynamics of the study population. Further evidence is given that the forms of the complex should be regarded as infraspecific and that a self-sustaining intermediate population exists in the area.