The Inheritance of Peloria in Foxgloves. 73 
Assuming the constitution of plant F to be Ww MM, the cross 
F x E=Ww MM x ww mm. 
The gametes produced by plant F=WM and wM, by plant E= 
wm, and the zygotes of Fj=l Ww Mm : 1 ww Mm. 
=1 white : 1 magenta. 
On the other hand, if the second alternative be adopted, viz., 
that plant F is heterozygous for W and M, i.e., is Ww Mm, then 
plant F x plant E=Ww Mm x ww mm : gametes of plant F= 
WM, Wm, wM and wm : gametes of plant E=wm. So that F t 
will contain:— 
1 Ww Mm : 1 Ww mm : 1 ww mm : 1 ww Mm. 
3 white : 1 magenta. 
The numbers actually obtained, viz., 15 white, 25 magenta, 
indicate fairly conclusively that the gametic constitution of plant F 
is Ww MM and not Ww Mm. Plant F is pure for magenta factor 
and heterozygous for dominant white factor. 
Dark Magenta Flower Colour. Plant A, (see Table I.), bearing 
a deep magenta (purple) coloured flower yields an F x composed of 
11 deep magenta (purple), 6 magenta, 5 white. If we assume the 
presence of a darkening factor (D) which may change magenta to 
purple, but which is without effect on white (i.e., one which is 
epistatic to magenta) then a fairly close fit between expectation and 
realisation is obtained by ascribing to plant A a constitution of 
Mm Dd, i.e., one heterozygous for magenta colour factor M and 
darkening factor D. A plant of such a constitution produces when 
selfed an Fj composed of:— 
9 MD : 3 Md : 3 mD : 1 nul 
v_ ^ 
9 purple : 3 magenta : 4 white, 
as compared with the numbers obtained, 
11 purple : 6 magenta : 5 white, 
calculated on 9 : 3 : 3 : 1 ratio, 
12*4 purple : 4-1 magenta : 5 5 white. 
Spot Factor. Yellow, brown, or red spots occur generally in 
the corollas of Foxgloves. The spots vary considerably in size, 
contour and frequency. In white flowers the spots may be of any 
one of the three colours ; and so far as our observations go, no 
Foxglove, no matter what the ground colour of the corolla may he, 
is altogether devoid of spots, which may, however, be so faint as to 
be only just distinguishable. It is not improbable that the colours, 
yellow and brown, of these spots are due to one and the same cause, 
