8o MENDELISM CHAP. 



in a complete reversion to the purple colour characteris- 

 tic of the wild Sicilian form (PL IV.)- In this particular 

 instance subsequent breeding from the purples resulted 

 in the production of six different colour forms in addi- 

 tion to whites. The proportion of the coloured forms to 

 the whites was 9 : 7 (cf. p. 44), but it is with the relation 

 of the six coloured forms that we are concerned here. 

 Of these six forms three were purples and three were 

 reds. The three purple forms were (i) the wild bicolor 

 purple with blue wings known in cultivation as the 

 Purple Invincible (PL IV., 4); (2) a deep purple with 

 purple wings (PL IV., 5) ; and (3) a very dilute purple 

 known as the Pico tee (PL IV., 6). Corresponding to these 

 three purple forms were three reds: (i) a bicolor red 

 known as Painted Lady (PL IV., 7) ; (2) a deep red with 

 red wings known as Miss Hunt (PL IV., 8) ; and (3) a very 

 pale red which we have termed Tinged White 1 (PL IV., 9). 

 In the F 2 generation the total number of purples bore to 

 the total number of reds the ratio 3:1, and this ratio was 

 maintained for each of the corresponding classes. Purple, 

 therefore, is dominant to red, and each of the three classes 

 of red differs from its corresponding purple in not possess- 

 ing the blue factor (B) which turns it into purple. Again, 



1 The reader who searches florists' catalogues for these varieties will 

 probably experience disappointment. The sweet pea has been much 

 "improved" in the past few years, and it is unlikely that the modern 

 seedsman would list such unfashionable forms. 



