FLOWER AND SEED COLOUR IN LUPINUS 341 


areas, which would have been expected had the quantity of the pig- 
ment been the same and only the distribution of it unequal. The non- 
marbled type has exactly the same intensity of colour as the marbled 
areas of the other type. Thus it is clear that the marbled form is 
a type weaker in colour than the non-marbled variety. This is of a 
certain interest, as the marbled type dominates over the non-marbled, 
according to the results obtained. Thus the M-factor, assumed to be 
responsible for the marbling, exhibits the character of an inhibiting 
factor. Its effect, however, is limited to the seed; it has no weakening 
effect on the flower. The marbling factor operates probably quite 
independent of the flower colour factors. Earth-brown and rust- 
brown segregate in cross 2 in addition to the marbling character. The 
di-hybrid segregation is quite normal, and the following values have 
been obtained: 
162 earth-brown, marbled : 47 earth-brown, non-marbled : 53 rust- 
brown, marbled : 16 rust-brown, non-marbled. 

expected 156,4 Hate > 52,1 ae 
5,6 Er NE IN ze a 
D/M 5: Ei 0,67 en 0,78 En 0,14 oe 0,35. 
DISCUSSION OF THE LINKAGE CASES. 
The results of the analysis have proved that linkage occurs in 
two crosses (crosses 8 and 9); the third case of linkage is not abso- 
lutely proven (cross 10, bluish red X tinged blue). The factors in- 
volved are B, V and F. The factors coupled in cross 8 are B and F, 
in cross 9, Band V. In cross 10 the factors V and F are segregating: 
linkage is thus to be expected also in this case, and the results of the 
segregation go to show that this view is correct. . They do not offer 
any proof when considered separately, but the fact that each of the 
factors involved is coupled with a third is conclusive. This being so, 
theory and the results obtained claim coupling between V and F as 
well; the results of the segregation agree well with this assumption, 
and coupling must be considered proven between the factors V and F. 
The factors B, V and F are then situated in the same chromosome, 
according to the chromosome theory, and their location is assumed 
to be the following. 
According to cross 8 there is very close linkage between the fac- 
tors B and F, as in a large material no crossovers (tinged violet) have 
been obtained. Furthermore, it is very improbable that a continued 
