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Darwin, Charles, 1809-1882

"The Different Forms of Flowers on Plants of the Same Species"

And as in these cases the male organs were manifestly
deteriorated, it is by far the most probable conclusion that the female organs
were in some cases likewise affected, and that this was the cause of the reduced
number of seeds.
With respect to the six plants in these three classes which yielded a very high
percentage of seeds, the thought naturally arises that the normal standard of
fertility for the long-styled and short-styled forms (with which alone we are
here concerned) may have been fixed too low, and that the six legitimate plants
are merely fully fertile. The standard for the long-styled form was deduced by
counting the seeds in twenty-three capsules, and for the short-styled form from
twenty-five capsules. I do not pretend that this is a sufficient number of
capsules for absolute accuracy; but my experience has led me to believe that a
very fair result may thus be gained. As, however, the maximum number observed in
the twenty-five capsules of the short-styled form was low, the standard in this
case may possibly be not quite high enough. But it should be observed, in the
case of the illegitimate plants, that in order to avoid over-estimating their
infertility, ten very fine capsules were always selected; and the years 1865 and
1866, during which the plants in the three latter classes were experimented on,
were highly favourable for seed-production.


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