In such a cross the classes resembling the two original parents tend to be produced in excess, while the other two combinations are produced much more rarely. Nevertheless, the ratio of dark to light axil, and of fertile to sterile anthers, is, in each case, a simple 3:1 ratio. [Sidenote: M 7a] Example of association of +characters in heredity+. Purple flower colour is dominant to red in the sweet pea, and the old-fashioned erect form of standard with the central notch is dominant to the hooded. In families where these characters are involved, the nature of the F_{2} generation depends upon the manner in which the cross was made. (A) When one dominant character goes in with each parent. Purple} {Red hood} × {erect | Purple erect +--------+-------+-------+ | | | | Purple Purple Red [*]Red erect hood erect hood Approximate ratio 2 1 1 * Not yet found in this mating, but probably occurs very rarely. [Sidenote: M 7b] (B) When the two dominants enter, from one parent, they tend to remain associated in the F_{2} generation. Purple} {Red erect} × {hood | +--------+----+------+--------+ | | | | Purple Purple Red Red erect hood erect hood Approximate \-------+--------/ ratio 3 | 1 These two classes are only found very rarely _i.e._, about once in each 300 plants of the F_{2} generation. [Sidenote: N & N 1] Exhibited by the Utah Agricultural College. * * * * * Mr. E. G. Titus. * * * * *