These tables yield several points of interest. First, although the proportions of normal and extra toe in table 12, a and c, are not Mendelian, yet the average increase, from F1 to F2 in the proportion of the recessive (4-toed) type is almost exactly what is called for by Mendel's law. That law calls for an increase of 25 per cent. The actual average increase is 23.3 per cent (20.1 and 26.5 in the two cases). It seems fair to conclude, consequently, that Mendel's law does hold here, and that the 4-toed individuals of F1 are heterozygotes with imperfect dominance. The feet of most of the 4-toed Silkies of this generation belong, indeed, to the reduced 5-toed type (table 10, B), and the reduced condition is prima facie evidence of heterozygotism. In F1 Silkies of the first hybrid generation, 20 per cent of the feet exhibit "reduced" types of toes, but in F2 only 5 per cent; and . . . Read More