. A history of birds . a red tail. The offspringof this cross, the mongrel Barb-fan-tail and Barb-spot, were thencrossed, and their offspring developed all the characteristics ofthe wild Rock-dove I This reversion, it is to be noted, wascomplete. That is to say, it was not merely blue colouredbirds that resulted—caused by a dilution of black pigment bythe mating of black-pigmented birds with birds in which pig-ment was practically absent—but birds that reproduced all thecharacteristic markings of the Rock-dove, among which are 22 338 A HISTORY OF BIRDS specially to be noted the two black bars
. A history of birds . a red tail. The offspringof this cross, the mongrel Barb-fan-tail and Barb-spot, were thencrossed, and their offspring developed all the characteristics ofthe wild Rock-dove I This reversion, it is to be noted, wascomplete. That is to say, it was not merely blue colouredbirds that resulted—caused by a dilution of black pigment bythe mating of black-pigmented birds with birds in which pig-ment was practically absent—but birds that reproduced all thecharacteristic markings of the Rock-dove, among which are 22 338 A HISTORY OF BIRDS specially to be noted the two black bars in the wings, whiterump and black-barred tail. Reversion of this kind seems to occur commonly wherebirds of remotely related races are mated. This, as Mr. Vernonhas suggested in his work Variation in Animals, is possibly dueto the fact that the characters built up by artificial selection,and superimposed upon the ancestral characters, are, in suchcases of reversion, too violently antagonistic to blend, and by this. III. 32.—Red Game Cockerel failure to combine allow the underlying ancestral characters tore-assert themselves. From the Wild Jungle-fowl {Gallus bankiva) man has suc-ceeded in building up a large number of domesticated varietieswhich, both in size, shape and coloration differ enormously onefrom another, and from the original, ancestral stock. Take,for example, such breeds as Plymouth-rocks, Wyandottes,Cochin-Chinas, Minorcas, Hamburgs, Spanish, Polish andSilkies, Game-fowls and Bantams. Here are black, white ARTIFICIAL SELECTION 330 and speckled breeds, breeds in which the comb and wattleshave been enormously increased—in some the comb is single,in others curiously complicated, giving rise to what are knownas rose, pea, and walnut combs—and breeds in which the combhas been replaced by a huge tuft of feathers which, falling down,covers the face so as to conceal the eyes! In some races thefeathering has been developed to a remarkable degree, so muchso that t
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbirds, bookyear1910
