VULGARIS L. AND IN PH. MULTIFLORUS WILLD. 103 
3 P y Z = selfcoloured, the other marbling factor being latent. 
WP aide — selfcoloured, both marbling factors being absent. 
5 p Y Z = white, with both marbling factors latent. 
6 p Y z = white, with one latent marbling factor. 
Z 
Z 
TED white, the other marbling factor being latent. 
Spey white, without any marbling factor. 
In this hypothesis of SPILLMAN both types of marbling are taken 
together; one possessing both absolutely linked factors X and Y 
in a permanent state, giving thus by their collaboration a constant 
marbling and pretending the presence of only one dominant factor; 
the other, inconstant type of marbling would result after crossing 
two selfcoloured races (or a white race with a selfcoloured one), 
each of which possesses one of these two factors X or Y. 
EMERSON did not emphasize the absolute repulsion, that must take 
action in these crossings, a supposition necessary for an explana- 
tion of the numerical proportions (1:2: 1) resulting in the Fo-ge- 
neration. This supposition however seems to be very well tolerable 
if the cases known from other researches about coupling and 
repulsion are taken into consideration. 
To this seemingly very plausible hypothesis KooıMAN has ob- 
jected, that by it the numerical proportions in some of his F3- 
families cannot be explained (he observed sometimes 66.60/, of 
marbled, in other cases 53.3°/) of marbled individuals in the 
whole of coloured F3-plants). The firstmentioned proportion was 
apparent in families, that gave a great number of whites; the 
segregation followed almost along 1 selfcoloured: 2 marbled: 1 
white. The families with 53.30/) of marbled individuals showed a 
segregation of 8 marbled: 7 selfcoloured: 1 white. From these 
results, KOOIMAN has derived as his opinion, that inconstant mar- 
bling may be caused by a special chromogenic factor in a hetero- 
zygotic state. He calls A the groundfactor for pigmentation, that 
alone causes a white seedcoat, but is necessary for the apparence 
of other colour factors, that remain invisible, if A is absent. A 
chromogenic factor B gives in collaboration with A a coloured _ 
seedcoat, with exception of a small ring around the navel. If only 
A and B are present, the seedcoat is light lemoncoloured. This 
chromogenic factor Bin KooïMANSs opinion would cause in heterozy- 
gotic state the inconstant marbling. The Fo-generations from a 
