114 SIRKS, THE COLOURFACTORS OF THE SEEDCOAT IN PHASEOLUS 
der is missing this factor; a part of them have a brown navelring 
(D) the others have not; some show the presence of the factor 
for a totally yellowish brown seedcoat (G), in the others this fac- 
tor is absent. Thus the F‚-individuals had as genotypic formula 
G $ D d L 1 and the Fo-generations would thereby be composed 
of 8 types of individuals (when homozygotic or heterozygotic 
presence of a factor is supposed to give the same phaenotype): 
1) 27.G°D L, 2):9 GDL 3) 9:G d L 4) 9 SED EN ES EN 
6) 3 6 D1, 7) 3 g d L and 8) 1 $ d L. On the supposition, that 
the three factors mentioned (G for the yellowish brown seedcoat, 
D for the brown colour ot the navelring, and L for the grey colour) 
segregate independently from each other, the numbers observed 
in the Fo-families give a very strong indication for the hypothesis, 
that the G-factor can become visible only if the D-factor is also 
present;in other cases the G-factor may be present but remains in 
cryptomeric (latent) position. If this may be supposed, the 
phaenotypes of group 1 (27/64 of the whole number) would be reddish- 
brown (type I), of group 2 yellowbrown (type IV), of groups 3 and 
7 grey with uncoloured navelring (type III), group 4 grey-brown 
{type II), groups 5 and 8 lemoncoloured (type VI) and group 
6 Wagenaar-type (type V). 
A comparison of the numbers observed with the proportions 
that were expected on this hypothesis, may be given here: 




| | 
Genotypes G DL g DL GdLandsdL GDI gDI Gdl and gdl. 
Theoret. | Ele 
Brosortion | a7 /ea | Sea | leni Tia ba 9/ea | Sea Sea cr Lot 
Expected 47.25 | 15.75 21.0 15.75 |5.25 7.0 
Observed | 46 | 14. | 23 Dees 12 



The phaenotypic differences, by which group I a could be 
discerned from group I b, as also Il a from II b, have probably 
their ground in the incomplete dominance of the L-factor; if LL- 
individuals would show a darker intensity of colour than the 
heterozygous Ll-plants, this difference will be observable among : 
the individuals of types I, II and III, so that these groups can be 
