Abstract:
Evidence has been presented in the literature on the mode of inheritance of shank colour in various breeds of chickens, but little has hitherto been known about the same aspect in an Australian breed, the Black Australorp. Observations on the incidence of shank colour in different types of crosses between yellow-shanked White Leghorns and black-shanked Australorps are reported in this paper. According to the observations made by other workers on White Leghorn and other breeds, a hypothesis is advanced regarding the genes involved in determining shank colour in the White Leghorn and Australorp. A genetical analysis of the observations made by the authors on 847 single crosses, 71 backcrosses, and 31 zig-zag crosses is presented and shows close statistical agreement with the hypothesis. A genetical formula, including four autosomal and two sex-linked genes, is suggested which would explain the mode of inheritance of shank colour in White Leghorns and Australorps.