Such ill-placed flowers would not yield any
seed or leave descendants; and the plants bearing them would thus tend to be
eliminated through natural selection.
The seeds produced by the cleistogamic and perfect flowers do not differ in
appearance or number. On two occasions I fertilised several perfect flowers with
pollen from other individuals, and afterwards marked some cleistogamic flowers
on the same plants; and the result was that 14 capsules produced by the perfect
flowers contained on an average 9.85 seeds; and 17 capsules from the
cleistogamic ones contained 9.64 seeds,--an amount of difference of no
significance. It is remarkable how much more quickly the capsules from the
cleistogamic flowers are developed than those from the perfect ones; for
instance, several perfect flowers were cross-fertilised on April 14th, 1863, and
a month afterwards (May 15th) eight young cleistogamic flowers were marked with
threads; and when the two sets of capsules thus produced were compared on June
3rd, there was scarcely any difference between them in size.
Viola odorata (WHITE-FLOWERED, SINGLE, CULTIVATED VARIETY).
The petals are represented by mere scales as in the last species; but
differently from in the last, all five stamens are provided with diminutive
anthers. Small bundles of pollen-tubes were traced from the five anthers into
the somewhat distant stigma.
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