Dominance in poultry feathered feet, rose comb, internal pigment and pile

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Abstract
In a previous report (Fisher 1935) I have described the results of an experiment with poultry, covering the years 1929-34, so far as these concerned the three factors for Crest, Polydactyly, and Barred plumage. It was hoped at that time that two further years’ experimentation would enable the conclusions to be demonstrated decisively by the production of parallel broods consisting exclusively of homozygotes and heterozygotes, in which the differences between these genotypes, and the variability of each, could be directly observed. This would require at least one male and several female homozygotes of the same kind, material which I have not succeeded in breeding in any line. Although the stock did well in 1934, the year in which in most lines intercrossing was first practised, the two following years were exceedingly unfavourable to propagation. In 1935, for example, from over fifty sittings of eggs, only fifteen chicks in all were reared to maturity. Little of consequence can, therefore, be added in respect of the three factors previously dealt with, and the present report will be given principally to the four remaining factors.