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Darwin, Charles, 1809-1882

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

I repeated this experiment on another flower,
and in eighteen hours the stigmas were penetrated by a multitude of long pollen-
tubes. This is what might have been expected, as the union is a legitimate one.
The converse experiment was likewise tried, and pollen from a long-styled flower
was placed on the stigmas of a short-styled flower, and in twenty-four hours the
stigmas were discoloured, twisted, and penetrated by numerous pollen-tubes; and
this, again, is what might have been expected, as the union was a legitimate
one.
SECONDLY.
Pollen from a long-styled flower was placed on all five stigmas of a long-styled
flower on a separate plant: after nineteen hours the stigmas were dissected, and
only a single pollen-grain had emitted a tube, and this was a very short one. To
make sure that the pollen was good, I took in this case, and in most of the
other cases, pollen either from the same anther or from the same flower, and
proved it to be good by placing it on the stigma of a short-styled plant, and
found numerous pollen-tubes emitted.
THIRDLY.
Repeated last experiment, and placed own-form pollen on all five stigmas of a
long-styled flower; after nineteen hours and a half, not one single grain had
emitted its tube.
FOURTHLY.
Repeated the experiment, with the same result after twenty-four hours.


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