206 



Bulletin No. 155. — 1913. 



In an actual mating of this sort, of 63 Fi individuals all were white. 

 Of this number, however, 5 showed one or more barred feathers. 

 Except in the case of one 9 the sex of these birds was not ascertained. 

 Many of the Fi generation, as chicks, showed patches of black down 

 feathers, but when the birds had matured all barred feathers had 

 disappeared and both sexes were pure white except for occasional 

 black ticks. It is thus evident that, even in Fi, pigment appeared 

 from some source, although the parent breeds were in appearance pure 

 white. This result is explainable on the ground of the dilution of 

 the // of the W. L. to li in the cross-breds. Better evidence is 

 however, to be derived from observations on the Fo individuals. 



In obtaining the F2, cross-bred cf 463A emploj-ed, was an almost 

 white bird, and may be assumed to form gametes of four sorts, as 

 follows: 



CBfl • CBfi ' cBfl • cBfi 

 while the cross-bred 99 (463 E, F, J; 464 K, 1, X, Q) may be 

 assumed to form gametes of eight sorts: 



CBfl • CBfi • cBfl ' cBfi 

 ChFI ■ CbFi • cbFI • chFi 



The mating may l)e represented as follows: 



9 CBfl ' CBfl ' cBfl ' cBfi • ChFI ■ CbFi • cbFI • cbFi X 

 d^ CBfl ' CBfi ' cBfl • cBfi — 



C^BbFfl. (1), white 

 C2BbFfIi (2), white 

 CcBbFflo (2), white 

 CcBbFfli (4), white 

 99 i coBbFfh (1), white 

 ciBhFfli (2), white 

 C2BbFfi2 (1), white 

 C^BbFfi^ (1), barred 

 I CcBbFfi2 (2), barred 



