PLUMAGE COLOR. 



73 



derived from the Silkie. Certain it is that the ordiuary Jungle pattern 

 develops pigment on the belly and on the wings, as well as on other parts 

 of the plumage. The hybrid chicks may be said to have the extended pig- 

 mentation dominant over interrupted pigmentation. In the adult hybrids 

 a difference appears between the coloration of the male and female, even 

 as Darwin pointed out. For the latter retains its uniform blackness, 

 while the former gains red on the wing-bar, and saddle and hackle lacing 

 (plate 4) . Now, since all the factors present in the Minorca, and none 

 others, are present in the hybrids, why should the male hybrids show red, 

 and why should the males show red and not the females? The answer to 

 the first question is, I think, clear. While the Jungle pattern of black and 

 red is completely obscured by the undiluted A'^ factor of the Minorca, it is 

 only incompletely covered by the diluted, heterozygous A'' factor of the 

 hybrid. Hence the red appears in greatly reduced amount, as compared 

 with the Jungle-fowl. In the female Jungle-fowl there is little red and 

 consequently none shows in the female hybrid. Thus the difference in the 

 sexes of the hybrids corresponds to the sexual dimorphism of the Jungle- 

 fowl; but the hybrids are, as indicated, very unhke the Jungle-fowl in 

 coloration (c/. plates 1 and 2). 



Since segregation takes place in the gametes of these heterozygotes, 

 4 kinds of gametes are possible, namely, CJN, CJn, cJN, cJn. On mating 

 heterozygotes together, zygotes of 16 types will be formed, as in table 57. 



Table 57. Zygotes in F^ of Silkie X Minorca hybrids and their corresponding somatic colors. 



In the foregoing table there is given after each combination a letter: 

 N standing for black, the appearance of the soma; G standing for Game- 

 colored, and W standing for white. No distinction is made between pure 

 blacks and those that, while black as chicks, subsequently show some red 

 in the male. Such a distinction was impracticable because most of the color 



Table 58. 



determinations are made on the young chicks. It appears that in 16 

 progeny expectation is 9 black, 4 white, and 3 Game-colored. Actually 

 362 offspring were obtained, with the results shown in table 58. Nothing 



