NINTHLY.
Put pollen of a short-styled flower on a single long-styled stigma, and own-form
pollen on the other four stigmas; after twenty-four hours the one stigma was
somewhat discoloured and twisted, and penetrated by many long tubes: the other
four stigmas were quite straight and fresh; but on dissecting them I found that
three pollen-grains had protruded very short tubes into the tissue.
TENTHLY.
Repeated the experiment, with the same result after twenty-four hours, excepting
that only two own-form grains had penetrated the stigmatic tissue with their
tubes to a very short depth. The one stigma, which was deeply penetrated by a
multitude of tubes from the short-styled pollen, presented a conspicuous
difference in being much curled, half-shrivelled, and discoloured, in comparison
with the other four straight and bright pink stigmas.
I could add other experiments; but those now given amply suffice to show that
the pollen-grains of a short-styled flower placed on the stigma of a long-styled
flower emit a multitude of tubes after an interval of from five to six hours,
and penetrate the tissue ultimately to a great depth; and that after twenty-four
hours the stigmas thus penetrated change colour, become twisted, and appear
half-withered. On the other hand, pollen-grains from a long-styled flower placed
on its own stigmas, do not emit their tubes after an interval of a day, or even
three days; or at most only three or four grains out of a multitude emit their
tubes, and these apparently never penetrate the stigmatic tissue deeply, and the
stigmas themselves do not soon become discoloured and twisted.
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