tually crossed,
no doubt through the agency of bees, and in the autumn blue and white
peas were found within the same pods. Wiegmann made an exactly similar
observation in the present century. The same result has followed
several times when a variety with peas of one colour has been
artificially crossed by a differently-coloured variety.[929] These
statements led Gaertner, who was highly sceptical on the subject,
carefully to try a long series of experiments: he selected the most
constant varieties, and the result conclusively showed that the colour
of the skin of the pea is modified when pollen of a differently
coloured variety is used. This conclusion has since been confirmed by
experiments made by the Rev. J. M. Berkeley.[930]

Mr. Laxton of Stamford, whilst making experiments on peas for the
express purpose of ascertaining the influence of foreign pollen on the
mother-plant, has recently[931] observed an important additional fact.
He fertilised the Tall Sugar pea, which bears very thin green pods,
becoming {398} brownish-white when dry, with pollen of the
Purple-podded pea, which, as its name expresses, has dark-purple pods
with very thick skin, becoming pale reddish-purple when dry. Mr. Laxton
has cultivated the tall sugar-pea during twenty years, and has never
seen or heard of it producing a purple pod; nevertheless, a flower
fertilised by pollen from the purple-pod yielded a pod clouded with
purplish-red, which Mr. Laxton kindly gave to me. A space of about two
inches in length towards the extremity of the pod, and a smaller space
near the stalk, were thus coloured. On comparing the colour with that
of the purple-pod, both pods having been first dried and then soaked in
water, it was found to be identically the same; and in both the colour
was confined to the cells lying immediately beneath the outer skin of
the pod. The valves of the crossed pod were also decidedly thicker and
stronger than those of the pods of the mother-plant, but this may have
been an accidental circumstance, for I know not how far their thickness
in the Tall Sugar-pea is a variable character.

The peas of the Tall Sugar-pea, when dry, are pale greenish-brown,
thickly covered with dots of dark purple so minute as to be visible
only through a lens, and Mr. Laxton has never seen or heard of this
variety pro