294 DAVENPORT— NEW VIEWS ABOUT REVERSION. [April 23, 



what complex but perfectly clear. All fowl except the booted 

 races (which are of Asiatic origin and allied to the Aseel fowl) 

 contain the determiner — complex for the Jungle fowl color pattern. 

 We may call it J. This factor alone is impotent without a color- 

 producing enzyme (C). The Silkie fowl apparently lacks this in 

 the plumage and so remains colorless. The Spanish has it and so 

 produces the Jungle pattern of which the red portion is nearly 

 coincident with the glossy portion of the Spanish plumage. But 

 the Spanish has an additional factor, an additional black coat (N), 

 which turns the red part of the pattern black. Thus the Spanish 

 color factors are CJN whereas those of the White Silkie are cjn, 

 the small letters indicating the absence of the factors concerned. 

 When the germ cells of the two races fuse the fertilized egg con- 

 tains factors CcJoNn ; which means, the color enzyme is simplex, 

 the Jungle pattern is duplex and the supermelanic factor is simplex. 

 Since N is simplex it is insufficient to cover all of the red in the 

 male, where it is strongest and so the males show some red, only, 

 as Darwin says, it is darker than in the Jungle fowl. Now the 

 germ cells of these hybrids have their characters all simplex : and 

 they are consequently of four kinds: viz: CJN, CJn, cJN, cJn. If 

 two such hybrids be mated their germ cells unite at random. If two 

 germ cells of the first type unite a black bird results ; if two of the 

 second type Games result; if two of the other two types unite whites 

 result. I reared 362 offspring from the hybrids; the relation of 

 expected to observed birds of each type of color is shown on 

 Table I. 



Table I. 



Black. 



Expected 205 



Observed 210 



One sees that it is not hybridizing per sc that produces the 

 Game or Jungle coloration, else all would be so colored. It is the 

 union of the requisite ancestral factors one or more of which are 

 missing from the domesticated, fancy strains. 



Again, if a White Silkie be crossed with a White Leghorn, the 

 offspring are all white except that the males show some red in those 

 parts of the plumage that are red in the Jungle fowl. In the second 



