X] The Silky Fowl 185 



Now if femaleness be a dominant factor and can repel 

 D, forminof a spurious allelomorphism with it in the way 

 suggested for the case of Ab^^axas grossulariata x lacticolor 

 and the Canaries, a system would be provided which would 

 fulfil all the chief conditions marked out by the experimental 

 data. 



Taking- then the following allelomorphs, the occurrences 

 in the three matings which have given clear results may be 

 represented in a tabular form. 



$, ^, presence and absence of femaleness, a dominant 

 factor without which the zygote developes into a 

 male. 



P, p, presence and absence of the black pigmentation. 



D, d, presence and absence of a factor which can sup- 

 press or mask the development of P, 



1. Silky $ X Brown Leghorn $ 

 composition PPdd^ $ ppDD ^ $ 



gametes |^^^ ^^^ 



F^ females slightly males slightly 



pigmented pigmented 



composition PpDd% $ PpDd $ S 



2. Brown Leghorn $ x Silky $ 

 composition ppDd^ $ PPdd$, $ 



gametes \^^^^ ^^ ^ 



F^ females deeply males slightly 



pigmented pigmented 



Ppdd^ cJ PpDdS 6 



3. Brown Leghorn ^ -/. F-^S 

 composition ppDd^ ^ PpDd $ $ 



<rametes [P^ ^ [PD$.Pd$ 



^<^^^^tes 1^^^^ \pD$pd$ 



Fcfnales Males 



offspring pd^.PD$ pD$.PD$ 



*pd^.Pd$ pD$.Pd$ 



pd^.pD$ pD$.pD$ 



pd^.pd$ pD^.pdS 



According to this analysis one bird in eight, namely the 



female marked *, will be of the deeply-pigmented type. 



ceived. It would, however, fail to represent the i deeply-pigmented $ in 

 8 birds from Brown Leghorn 9 x t^^ o , and woukl increase the expectation 

 to 2 9 in 8 birds, and this is negatived by the results of experiment. 



