Page:Mendel's principles of heredity; a defence.pdf/81

Rh From the angular yellow seeds 96 resulting plants bore seed, of which:

From 108 round green seeds 102 resulting plants fruited, of which:

The angular green seeds yielded 30 plants which bore seeds all of like character; they remained constant ab.

The offspring of the hybrids appeared therefore under nine different forms, some of them in very unequal numbers. When these are collected and co-ordinated we find:

The whole of the forms may be classed into three essentially different groups. The first embraces those with the signs AB, Ab, aB, and ab: they possess only constant characters and do not vary again in the next generation. Each of these forms is represented on the average thirty-three times. The second group embraces the signs ABb, aBb, AaB, Aab: these are constant in one character and hybrid in another, and vary in the next generation only as regards the hybrid character. Each of these appears on