But as I did not measure their actual height I cannot give
the exact ratio, but it must have been at least as 100 to 75. A similar
trial was subsequently made with two other peas from a different cross,
and the result was nearly the same. For instance, a crossed seedling
between the Maple and Purple-podded pea was planted in poor soil and
grew to the extraordinary height of 116 inches; whereas the tallest
plant of either parent variety, namely, a Purple-podded pea, was only 70
inches in height; or as 100 to 60.
Sarothamnus scoparius.
Bees incessantly visit the flowers of the common Broom, and these are
adapted by a curious mechanism for cross-fertilisation. When a bee
alights on the wing-petals of a young flower, the keel is slightly
opened and the short stamens spring out, which rub their pollen against
the abdomen of the bee. If a rather older flower is visited for the
first time (or if the bee exerts great force on a younger flower), the
keel opens along its whole length, and the longer as well as the shorter
stamens, together with the much elongated curved pistil, spring forth
with violence. The flattened, spoon-like extremity of the pistil rests
for a time on the back of the bee, and leaves on it the load of pollen
with which it is charged. As soon as the bee flies away, the pistil
instantly curls round, so that the stigmatic surface is now upturned and
occupies a position, in which it would be rubbed against the abdomen of
another bee visiting the same flower.
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