1 



Constitution of the White Leghorn Breed. 203 



It is at once apparent that there is close relation between the 

 actual and the expected results in these cases, thus verifying the 

 constitution of 325E as C2b2FfIi. It is therefore clear that neither 

 325A nor 325E could be used in further matings to produce a barred 

 strain. This purpose was served, however, by the barred 99, 

 daughters of 325B, secured in the 1912 matings from the black 

 mothers. These were mated in 1913, not with 325B, but with one of 

 his sons, 477V, a bird which possessed a somewhat clearer pattern, 

 and was chosen as one which might be homozygous for barring. The 

 details of these crosses are as follows : 



I (White Leghorn X Black Minorca) d^ 



1 { 



Case 5. — cf { [ Black Minorca 9 



9 Black Java 



bred 99, heterozygous for barring (Table 16, p. 177). Since the d^ 

 477V and the barred 9 9 are homozygous for both C and i, these sym- 

 bols now may conveniently be left out of the mating formulae, which 

 may be given as follows: 



The zygotic constitution of the cT" 477V is 



Bbf2 



forming gametes 



The constitution of the 9 9 is 

 forming gametes 



cf 



X Cross- 



Bf' bf 

 BbFf 



bF ' Bf 



The mating may therefore be represented: 



9 Bf bF X ■ 

 cf Bf bf = 

 d^ Bbf2, barred 

 cf -62/2, barred 

 9 b2Ff, black 

 9 BbFf, barred 



