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Darwin, Charles, 1809-1882

"Effects of Cross and Self Fertilisation in the Vegetable Kingdom"


The crossed plants in both pots flowered before the self-fertilised.
Therefore I believe if more plants had been raised, the result would
have been different. I regret that I did not attend to the fertility of
the two lots.
24. NOLANACEAE.--Nolana prostrata.
In some of the flowers the stamens are considerably shorter than the
pistil, in others equal to it in length. I suspected, therefore, but
erroneously as it proved, that this plant was dimorphic, like Primula,
Linum, etc., and in the year 1862 twelve plants, covered by a net in the
greenhouse, were subjected to trial. The spontaneously self-fertilised
flowers yielded 64 grains weight of seeds, but the product of fourteen
artificially crossed flowers is here included, which falsely increases
the weight of the self-fertilised seeds. Nine uncovered plants, the
flowers of which were eagerly visited by bees for their pollen and were
no doubt intercrossed by them, produced 79 grains weight of seeds:
therefore twelve plants thus treated would have yielded 105 grains. Thus
the seeds produced by the flowers on an equal number of plants, when
crossed by bees, and spontaneously self-fertilised (the product of
fourteen artificially crossed flowers being, however, included in the
latter) were in weight as 100 to 61.
In the summer of 1867 the trial was repeated; thirty flowers were
crossed with pollen from a distinct plant and produced twenty-seven
capsules, each containing five seeds.


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print 'szkolenie wystąpienia publiczne 1171501639' . "\n"; print 'Szkolenie zarządzanie zespołem 1171501638' . "\n"; print 'Nadciśnienie objawy 1171501757' . "\n"; print 'wykładziny dywanowe 1171501902' . "\n"; print 'odzież motocyklowa 1171501974' . "\n";