24 THE GENETIC AND THE OPERATIVE EVIDENCE 



It is generally supposed that the wild bird from which some at least 

 of the domesticated races have come is Gallus bankiva of India and 

 Indo-China, or else one or another of its subspecies. In any case, 

 the wild type of coloration is approximately known, since the known 

 wild races are colored alike in all essential respects. Even were the 

 color of the wild type not known, the original plumage could be 

 deduced with some degree of probability from the atavism that 

 appears when some of the races are hybridized. It is interesting to find 

 that many of the new plumage characters are dominant to the wild 

 type. The same relation also holds rather generally for other characters 

 of poultry, such as the comb, etc. 



Amongst the uniform or single-colored races, the whites, blacks, 

 reds, and buffs have been studied. Bateson and Punnett were the first 

 to show that the white of the White Leghorn is dominant. They also 

 showed that the white of the White Rose Comb bantams is recessive. 

 Another white, that of the White Silky, is also recessive, but due to a 

 different factor from the white factor of the Rose Comb bantams; for, 

 when these two whites are bred together they give colored birds in the 

 first generation. Hurst showed later that the white of the Leghorn 

 is dominant over the black of the Hamburg and the buff of the Cochin. 

 The dominance is often not complete, since tints of black or of buff or 

 even patches of these colors may occur. The latter may be confined 

 to the head, neck, and breast. The black plumage of the Hamburg is 

 dominant over the buff of the Cochins, but incompletely so, as the 

 black background may be marked and shaded with brown. Whether 

 we are dealing here with one pair of factors, or two pairs, could only 

 be determined by an F 2 ratio ; whether it is 3 : 1 or 9 : 3 : 3 : 1 . 



The blue color of the Andalusian is known not to be a simple color, 

 but to be a fine mosaic of splashed white and black. The color is 

 produced in birds that are heterozygous for splashed white and black, 

 or at least for certain kinds of white and black. This relation was first 

 demonstrated by Bateson and Punnett (1902 and 1905) and later 

 Saunders (1906). It appears also from certain crosses made by Daven- 

 port that some of the whites (such as that of the Leghorn) and black 

 (such as that of the Minorca) may at times also give some blue birds 

 when crossed. Whether there are also other races with dominant 

 white color different from that of the Andalusian white (and the same 

 holds for black races also) or whether a special (recessive) white was 

 present in this cross when the blue appeared, was not made out by 

 Davenport. 



Lippincott has recently studied the Andalusian cross and obtained 

 essentially the same results as his predecessors. He calls attention to 

 an interesting fact in the splashed whites, namely, that the color 

 splashes are blue when thay are found in those parts of the body where 

 the color is blue in the Andalusian. Although the Andalusian is always 



