B. MiYAZAWA 15 



Summary. 



1. The light magenta colour in F^ is produced when both G and D 

 are in heterozygous condition ; and the bluing-factor B and the modifying 

 factor M are brought in from the parent A. 



2. Reciprocal hybrids are similar to each other in all respects. 



3. D produces dark-red colours when G is present in a homozygous 

 condition, but it produces red-colours (magenta and scarlet) when G is 

 present in a heterozygous condition or altogether absent. Such an inter- 

 relation between G and D was found only in the hybrids between A and 

 B, and it does not exist in other hybrids, though (7, for instance, has 

 colours closely related to those of B. 



4. The fact that D has such a character may be seen closely from 

 the results in which all three families of the offspring of (10 — 1) x (16 — 9) 

 which is green, white and yellow, deep scarlet, respectively, produced 

 dark-red colours. 



5. The effects of B are not manifested in the individuals which are 

 in a homozygous condition with respect to G. 



6. The magenta colour appears in plants which have the con- 

 stitution DB, either Gg or gg being present at the same time. On the 

 contrary, the scarlet colour appears only in plants which are in the 

 condition Db. 



7. The white colour appears in the individuals when D is altogether 

 absent, and then G, B, and M may be in any condition. So that there 

 are various genetic constitutions among white-flowered plants. 



8. The interrelations between D and M are as follows : 



DdM light colour 



DDM medium colour 



DDmm) , , 



^ , \ deep colour 



Ddmm | ^ 



9. The magenta colour is dominant over both scarlet and dark-red, 

 and scarlet is dominant over dark-red. 



10. There may exist homozygous plants, at least with respect to 

 flower-colour, with medium and deep tones of magenta, scarlet, and 

 dark-red ; but we could find no individuals with light tones of each 

 colour. 



EXPLANATION OF PLATE I. 



Figs. 1, 2, 3. Light, medium, and deep magenta. 

 Figs. 4, 5, C. „ ,, ,, scarlet. 



Figs. 7, 8, 9. ,, ,, ,, dark-red. 



