viii WILD AND DOMESTIC VARIETIES 81 



the proportion in which the three classes of purples ap- 

 peared was 9 bicolors, 3 deep purples, 4 picotees. We 

 are, therefore, concerned here with the operation of two 

 factors : (1) a light wing factor, which renders the bicolor 

 dominant to the dark winged form; and (2) a factor 

 for intense colour, which occurs in the bicolor and in 

 the deep purple, but is lacking in the dilute picotee. 

 And here it should be mentioned that these conclusions 

 rest upon an exhaustive set of experiments involving the 

 breeding of many thousands of plants. In this cross, 

 therefore, we are concerned with the presence or absence 

 of five factors, which we may denote as follows : — 



A colour base, R. 



A colour developer, C. 



A purple factor, B. 



A light wing factor, L. 



A factor for intense colour, I. 



On this notation our six coloured forms are : — 



(1) Purple bicolor . . . CRBLI. 1 



(2) Deep purple . . . CRBII. 



(3) Picotee .... CRBLi or CRBli. 



(4) Red bicolor ( = Painted Lady) CRbLI. 



(5) Deep red ( = Miss Hunt) . CRUL 



(6) Tinged white . . . CRbLi or CRbli. 



It will be noticed in this series that the various coloured 



1 It is to be understood that wherever a given factor is present the 

 plant may be homozygous or heterozygous for it without alteration in 

 its colour. 



G 



