370 Doubleuess in Stocks 



to the presence of the B factor, azure and light purple can never give 

 rose in the first generation, but in any mating with a 6-forni they will 

 presumably give it in F2. 



Rose is epistatic both to the deeper colours carmine and crimson, 

 and to the purer red shades flesh and terra-cotta. 



Lilac is a somewhat bluish pink form, the blue tinge becoming more 

 marked on fading. It occurs in ^2 from certain unions where flesh is 

 used, as, e.g. flesh x light purple or white incana. Its position in the 

 colour series has not yet been determined owing to the failure of the 

 crop in 1910. 



Terra-cotta (? Rothbraun of German catalogues) is a full pure colour. 

 So far it has only been obtained in F^ from matings between flesh and 

 sulphur-white or cream. It is recessive to flesh, and possibly stands at 

 the hypostatic end of the scale of the pure reds as copper probably does 

 of the impure series. 



Carmine and Crimson. These full red colours have hitherto been 

 spoken of collectively as " red." But carmine certainly includes three 

 distinct shades, and crimson probably more than one. The two colour 

 groups together form a very closely graduated series, and a full analysis 

 of these shades has not been attempted. When, as here, a considerable 

 deepening of the colour occurs between the unfolding and the fading 

 of the flower, the range of shades exhibited by individuals of a pale 

 grade may overlap those of an intermediate class, and so on up the 

 scale, thus increasing the difficulty of sorting. 



The same difficulty is met with among some grades in. the blue 

 series, but the three main classes, dark purple, light purple and azure 

 or very light purple, are easily distinguished. Marine blue is a larger- 

 flowered form, in range of tint between unfolding and fading covering 

 almost those of azure and light purple together. The two paler forms 

 azure and marine blue, differ from the more deeply coloured purple 

 types in having brown and not green seeds. 



Constitution of the sulphur -white race. 



All sulphur-whites were found to behave alike when self-fertilised, 

 in giving a mixture of white singles and cream doubles ; all probably 

 also give a small percentage of white doubles. When bred with other 

 glabrous forms the results varied according to the type of sulphur- 

 white employed. Seed supplied by Messrs Haage and Schmidt proved 

 to belong to the second type described above (p. 367, seeds yellow, large, 

 regular). The plants crossed with glabrous cream gave F^ all glabrous, 

 and either all cream or mixed white and cream, according as the 



