On the whole,
there can be no doubt that the crossed plants exhibit a tendency to
flower before the self-fertilised, almost though not quite so strongly
marked as to grow to a greater height, to weigh more, and to be more
fertile.
A few other cases not included in the above three lists deserve notice.
In all three pots of Viola tricolor, naturally crossed plants the
offspring of crossed plants flowered before naturally crossed plants the
offspring of self-fertilised plants. Flowers on two plants, both of
self-fertilised parentage, of the sixth generation of Mimulus luteus
were intercrossed, and other flowers on the same plants were fertilised
with their own pollen; intercrossed seedlings and seedlings of the
seventh self-fertilised generation were thus raised, and the latter
flowered before the intercrossed in three out of the five pots. Flowers
on a plant both of Mimulus luteus and of Ipomoea purpurea were crossed
with pollen from other flowers on the same plant, and other flowers were
fertilised with their own pollen; intercrossed seedlings of this
peculiar kind, and others strictly self-fertilised being thus raised. In
the case of the Mimulus the self-fertilised plants flowered first in
seven out of the eight pots, and in the case of the Ipomoea in eight out
of the ten pots; so that an intercross between the flowers on the same
plant was very far from giving to the offspring thus raised, any
advantage over the strictly self-fertilised plants in their period of
flowering.
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