110 sIRKS, THE COLOURFACTORS OF THE SEEDCOAT IN PHASEOLUS 
cations for a certain race as being the fatherplant sought after. In 
these cases the results of spontaneous crosses are taken together 
with those of artificial hybrids. | 
1. Cross oF CITROEN X WAGENAAR. 
The hybrid obtained between these two races showed the same 
phaenotype as the Wagenaar: brown navelring and soon colour- 
changing into brown of the remainder of the seedcoat were do- 
minant. Two families obtained from artificial crossings and one 
from a spontaneous hybrid came into cultivation; in all cases the 
Citroen-race was the mother. The segregations in the Fo-families 
gave the following numbers of frequency: 





| : € Proportion in 
Family W agenaar-type | Citroen-type | Totals it 
997 | Artif. hybr. 33 8 41 3.21 : 0.79 
1033 | Artif. hybr. 25 9 34 | 2.99 : 1.01 
1034 | Spont. hybr. 41 13 54 3.03 : 0.97 
Total 99 30 129 | 3.06 : 0.94 

The segregation follows in a sufficient way the scheme of a 
monohybrid; the difference between the two races depends upon 
the presence of a single factor in the Wagenaar, perhaps the same 
factor, as that indicated by Kooıman as D. 
2. Cross OF WAGENAAR X BRUINE. 
The yellowish brown colour of the „Bruine” showed to dominate 
over the yellow Wagenaar-seedcoat; the F;-individuals could not 
be discerned from the brown race. Two Fo-families were grown: 
one originated from an artificial cross, made by Mr. C. J. DROOGEN- 
DIJK, the other from a spontaneous hybrid, found as such in a 
culture of Wagenaar-beans. Some F3 families, that came from the 
firstmentioned Fo-plant and showed the same segregation, may — 
also be taken into consideration and tabulated together: 
(Cf table page 111). 
Three more F3-posterities, grown frown Fo-individuals after arti- 
ficial hybridization, contained only brownseeded plants (34, 23 and 
46); the two Wagenaar-like Fo-plants gave only Wagenaarseeded 
