196 Bulletin No. 155.— 1913. 



Since both d^ and 9 are now homozygous for C and ?', these symbols- 

 may be left out of the mating formulae: 



& Bf ■ hi X 

 9 hF - hf = 



9 fesFf— black 

 9 B6Ff — barred 

 cf 62/*2 — black 

 cf Bhfo — barred 



In other words, provided cf 325B was actually heterozygous for 

 barring, this mating should give equal numbers of barred and black 

 birds, equally divided between the sexes. WTien we compare with 

 these theoretical deductions the experimental results presented in 

 Table 11, p. 175, it is apparent that there is close correspondence. 

 Similar results were obtained from mating of 6^ 325B with Black 

 Java 9 9 (Case 3f ) and Black Hamburg 9 9 . These matings served 

 to give a number of 99 heterozygous for the barred plumage- 

 pattern, and freed from the pigment -inhibiting factor; and these 

 fowls as described in Case 5 w^re mated in the season of 1913 \Nith 

 cf 477 V, a bird which show^ed better barring than325B. The data 

 on the results of these crosses are reported on p. 180. 



( (White Leghorn d^ X Black Minorca 9 ) d^ ) 



Case 3d.— d^ ] ■ - X 



( Black Minorca 9 ) 



(White Leghorn d" X Black Minorca 9) 9 .—(Table 12, p. 176). 

 Another method of testing the heterozygous nature of d^ 325B for 

 the barring factor was to mate this bird with (W. L. X B. M.) 

 Fi 99. These we assume are, themselves, heterozygous for the 

 barring factor and have the zygotic constitution C^BhFfli, a formula 

 compatible with barred plumage rendered obscure by the presence 

 of inhibiting factor /. These birds form gametes 



ChFi ' CbFI ' CBfl ■ CBfi 

 In this case the presence of the inliibiting factor 7, in a heterozy- 

 gous condition, would interfere with the manifestation of the barred 

 color-pattern in one-half the progeny which would therefore be white. 



