I wished, therefore, to ascertain whether a
cross between two flowers on the same plant would give to the offspring
any superiority over the offspring from flowers fertilised with their
own pollen. I procured some fresh seed and raised two plants, which were
covered with a net; and several of their flowers were crossed with
pollen from a distinct flower on the same plant. Twenty-nine capsules
thus produced contained on an average 4.86 seeds per capsule; and 100 of
these seeds weighed 36.77 grains. Several other flowers were fertilised
with their own pollen, and twenty-six capsules thus produced contained
on an average 4.42 seeds per capsule; 100 of which weighed 42.61 grains.
So that a cross of this kind appears to have increased slightly the
number of seeds per capsule, in the ratio of 100 to 91; but these
crossed seeds were lighter than the self-fertilised in the ratio of 86
to 100. I doubt, however, from other observations, whether these results
are fully trustworthy. The two lots of seeds, after germinating on sand,
were planted in pairs on the opposite sides of nine pots, and were
treated in every respect like the plants in the previous experiments.
The remaining seeds, some in a state of germination and some not so,
were sown on the opposite sides of a large pot (Number 10); and the four
tallest plants on each side of this pot were measured. The result is
shown in Table 2/12.
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