6. The ratio 15 orange : 1 white was secured in one ear resulting from a cross of Brazilian strains orange × white. The plants obtained from the orange seeds were selfed and in 46 ears the following results obtained:

Ears pure for orange 23
Ears segregating 3 orange : 1 white 14
Ears segregating 15 orange : 1 white 9

As the mutation from the recessive to the dominant condition is not probable and the ratio of ears obtained not in favor of two independent genes, some of the plants obtained from the ears segregating 15 : 1 were fixed and will be checked cytologically.