FLOWER AND SEED COLOUR IN LUPINUS 337 

(crosses 4, 5, 8 and 10). That the F-factor also influences the bluish 
red colour (RRBB) is seen from cross 10, where tinged red originates 
as a product of recombination. It is true, no tinged form of violet 
has yet been found, but this is probably due to close linkage. It is, 
therefore, a difficult task to succeed in obtaining this form from the 
material at hand, although probably not unreälizable. The relation of 
the F-factor to the pure red factor is not yet known. 
I have succeeded in determining the Ff-plants in the case of blue 
colour, as all F,-generations involving the F-factor have showed a weak 
dilution of the blue colour. This dilution is so weak, however, that 
it is observed only in an F,-plot, where all plants have the same diluted 
shading contrasting with the next, fully coloured plot. However, 
great difficulties are experienced in separating the different types in 




TABLE 6. 
FF Ff 
f Constant |Mono-hybrid,| Di-hybrid |Mono-hybrid, 
u blue without dil. | segregation | without dil. 
| cross 5 À 6 4 1 
LU... cross 10 2 4 3 
total a 10 9 
x : cross 5 0 0 6 2 
Sligthly diluted | eross 10 0 0 6 1 
Blue: 22.02; 
total 0 0 12 | 3 




F;, where homo- and heterozygotically blue individuals are mixed. 
They have been listed with the pure blue type for this reason, when 
examined. I have classified the individuals as accurately as possible 
in blue and slightly diluted blue in the taking out of the parent 
plants for the F;-families in crosses 5 and 10. The relation between 
the phenotype and the genotype in this case is shown in table 6. 
The result is significant. Individuals with the full colour factor in 
duplex stage have in no case been listed as slightly diluted blue but 
always as blue, but the Ff-individuals have been listed in 10 cases 
as blue and in 15 cases as slightly diluted blue. Presuming complete 
dominance of the F-factor these facts would be explained by the 
assumption that the FF-plants do not become modified towards di- 
luted blue, while the Ff-individuals do become modified in this way. 
If the F-factor predominates only, the facts become explained by the 
