For instance, in the third generation the crossed and
self-fertilised plants produced capsules in the ratio of 100 to 38,
whilst the seeds in the capsules on the crossed plants were to those on
the self-fertilised plants only as 100 to 94. In the eighth generation
the capsules on two self-fertilised plants (not included in table 2/18),
grown in separate pots and thus not subjected to any competition,
yielded the large average of 5.1 seeds. The smaller number of capsules
produced by the self-fertilised plants may be in part, but not
altogether, attributed to their lessened size or height; this being
chiefly due to their lessened constitutional vigour, so that they were
not able to compete with the crossed plants growing in the same pots.
The seeds produced by the crossed flowers on the crossed plants were not
always heavier than the self-fertilised seeds on the self-fertilised
plants. The lighter seeds, whether produced from crossed or
self-fertilised flowers, generally germinated before the heavier seeds.
I may add that the crossed plants, with very few exceptions, flowered
before their self-fertilised opponents, as might have been expected from
their greater height and vigour.
The impaired fertility of the self-fertilised plants was shown in
another way, namely, by their anthers being smaller than those in the
flowers on the crossed plants. This was first observed in the seventh
generation, but may have occurred earlier.
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