128 SIRKS, THE COLOURFACTORS OF THE SEEDCOAT IN PHASEOLUS 
sidered to be very feeble. Most probably a blackseeded bean had 
functioned as pollenparent; the segregation fell into 11 phaenoty- 
pical groups: 
977 I black marbling upon greyish white groundcolour (28 indivi- 
duals); | 
II matblue marbling upon greyish white groundcolour (1 ind.); 
III darkblueviolet marbling upon yellowish white groundcolour 
(1 ind.); 
IV matblueviolet marbling upon yellowish white groundcolour 
(1 ind.); 
V greyish brown marbled, here and there somewhat violet 
(3 ind); 
VI reddish brown marbled, here and there somewhat violet 
(1 ind); 
VII red marbling, here and there somewhat violet (2 ind.); 
VIII yellowish brown marbling, here and there somewhat violet 
(2 ind.); 
IX selfcoloured black (9 ind.); 
X reddish brown selfcoloured (1 ind.); 
XI Wagenaar-type (1 ind; 
Such a complicated segregation with very little groupnumbers 
does not allow a detailed analysis of the factorial constitutions, 
if, as is here the case, only one Fo-family is available; the F3-cul- 
tures in this year will perhaps give the possibility of a decision. 
The results given above however are sufficient for argumenting a 
provisional hypothesis about the genotypic factors that are present 
in the parents and in the hybrid. There are types possessing the 
factor for black, Z, and other types without this factor; there are 
types with L, the factor for grey-brown and types missing this 
one; there are types with G, the factor yellow-brown and types, 
where this factor is failing and last types with K, the factor for 
Kievits-pattern besides types without K. The probable genotypic 
constitution of the Kievits-race can thus be supposed to be £11 
bl. bl.zzKK, while the black race had, in harmony with the 
suppositions in the foregoing cross GGLLBI. BL ZZkk as ge- 
notypic formula. The segregation will thus be that of a pentahete- 
rozygote and cannot be studied in detail in the few materials till 
now available. In some respects the numerical proportions are 

