THE following formulae are proposed to measure the maximum rate of progress of selection for dominant quantitative genes. To simplify the problem, certain assumptions are made: (1) Selection begins in the F2 generation of a cross between two pure lines. (2) All genes are dominant in the positive direction. (3) Environmental effects are ignored, selection always being for the phenotypic class of maximum expression. This determines the maximum rate of progress, which would never be attained in actual practice. (4) All genes have either equal additive effects, when data are treated arithmetically, or equal geometric effects, when data should be treated logarithmically.