In his later paper (1909) Davenport gives fuller information in regard to some of the F₁ cases reported in his first paper, as well as the F₂ results. Thus, in the cross of Silky to Minorca, that gives black F₁ birds, the F₂ count gave 210 black, 57 game, and 95 white--approximately the expectation for two pairs of factors, one of them giving white (9:3:4). Silky by White Leghorn gave white F₁’s, but the males developed red on the wing bow and saddle when they became mature, and the female a faint blush of salmon (“red”) on the breast. In F₂ there were whites, games, and blacks, approximating to expectation for three pairs of factors, one being a dominant white (52:9:3). Silky by Buff Cochin gave a washed-out buff, but with the jungle coloration partly developed in the tail (black) and hackles and wing bow (redder buff). Davenport represents the Buff Cochin as having lost the jungle patterns and coloration, while the Silky retains it. The heterozygous condition of the genes for the wild-type color in F₁ is made responsible for the part development of color. The White Silky is represented as carrying the factor for black (N), hence in F₂ both black and game-colored birds are expected and they were obtained. When Black Cochin is crossed to Buff Cochin, the F₁ males are in general like the game (black and red) while the females are black (except for some red on the hackle). In this case Davenport represents the Black Cochin as showing a factor for jungle-fowl pattern, but lacking the color that is assumed in his other formulæ to go with this pattern. What is meant by this change is not quite clear to me, unless Davenport supposes there is an independent factor for the jungle-fowl pattern which may be filled in by other colors determined by other factors. But were there enough F₁ birds to exclude the possibility that jungle-fowl birds would not appear in this cross?
Davenport has reported a cross between a female White Cochin and a male Tosa (wild type) from which the daughters were Tosa, except that the shafting was broadened, and the saddle feathers and proximal secondaries were obscurely barred (black and buff); the sons were also like the Tosa, but every feather was repeatedly barred (see above). In F₂ there were 15 white, 25 game, and 16 barred birds. Davenport concludes that “barring is clearly heterozygous and confined to the male sex,” and in a footnote he adds that the sex-linked barring factor of the Plymouth Rock is different from that of this Cochin-Tosa cross, but Goodale informs me that the barring that appeared in this cross is probably the same as that in Barred Rocks.