ducing a purple pea; but in the crossed pod one of the peas
was of a uniform beautiful violet-purple tint, and a second was
irregularly clouded with pale purple. The colour lies in the outer of
the two coats which surround the pea. As the peas of the purple-podded
variety when dry are of a pale greenish-buff, it would at first appear
that this remarkable change of colour in the peas in the crossed pod
could not have been caused by the direct action of the pollen of the
purple-pod: but when we bear in mind that this latter variety has
purple flowers, purple marks on its stipules, and purple pods; and that
the Tall sugar-pea likewise has purple flowers and stipules, and
microscopically minute purple dots on the peas, we can hardly doubt
that the tendency to the production of purple in both parents has in
combination modified the colour of the peas in the crossed pod. After
having examined these specimens, I crossed the same two varieties, and
the peas in one pod, but not the pods themselves, were clouded and
tinted with purplish-red in a much more conspicuous manner than the
peas in the uncrossed pods produced at the same time by the same
plants. I may notice as a caution that Mr. Laxton sent me various other
crossed peas slightly, or even greatly, modified in colour; but the
change in these cases was due, as had been suspected by Mr. Laxton, to
the altered colour of the cotyledons, seen through the transparent
coats of the peas; and as the cotyledons are parts of the embryo, these
cases are not in any way remarkable.

Turning now to the genus Matthiola. The pollen of one kind of stock
sometimes affects the colour of the seeds of another kind, used as the
mother-plant. I give the following case the more readily, as Gaertner
doubted similar statements with respect to the stock previously made by
other observers. A well-known horticulturist, Major Trevor Clarke,
informs me[932] that the seeds of the large red-flowered _biennial_
stock {399} (_Matthiola annua_; _Cocardeau_ of the French) are light
brown, and those of the purple branching Queen stock (_M. incana_) are
violet-black; and he found that, when flowers of the red stock were
fertilised by pollen from the purple stock, they yielded about fifty
per cent. of _black_ seeds. He sent me four pods from a red-flowered
plant, two of which had