H. Onslow 



289 



When the F^ hybrids were mated back to pure rustica, most of the 

 offspring were as pale as the rustica parent, and a few were slightly 

 tinged or flecked with buff or grey, lis may be seen from the colour 

 values in families 16 A and 19 B, Figs. 1 and 2. There should of course 

 be equal numbers of " pure rustica " DD and DR, but owing to the im- 

 possibility of separating the two forms of rustica except by breeding 



7 8 



Colour Units 



a <J ,^ parents of '19 D. b ^ parent of '19 C. 

 c Av. value of rustica ^ ^ parents of '19 A, E, H. 



Fig. 8 (cf. Fig. 7). Diagram showing the percentage frequency of the black values of 

 the jj (J, in the families of the cross (Fj) x type shown in the last figure. 



Totals 



60 



