Consequently my anticipation that the plants with longer
pistils, rougher stigmas, shorter stamens and smaller pollen-grains, would prove
to be more feminine in nature, is exactly the reverse of the truth.
In 1860 a few umbels on some plants of both the long-styled and short-styled
form, which had been covered by a net, did not produce any seed, though other
umbels on the same plants, artificially fertilised, produced an abundance of
seed; and this fact shows that the mere covering in itself was not injurious.
Accordingly, in 1861, several plants were similarly covered just before they
expanded their flowers; these turned out as follows:--
TABLE 1.5.
Column 1: Plant.
Column 2: Number of Plants.
Column 3: Number of Umbels produced.
Column 4: Product of Seed.
Short-styled : 6 : 24 : 1.3 grain weight of seed, or about 50 in number.
Long-styled : 18 : 74 : Not one seed.
Judging from the exposed plants which grew all round in the same bed, and had
been treated in the same manner, excepting that they had been exposed to the
visits of insects, the above six short-styled plants ought to have produced 92
grains' weight of seed instead of only 1.3; and the eighteen long-styled plants,
which produced not one seed, ought to have produced above 200 grains' weight.
The production of a few seeds by the short-styled plants was probably due to the
action of Thrips or of some other minute insect.
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