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Darwin, Charles, 1809-1882

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


In the four previous classes, plants raised from the three forms fertilised with
pollen from either the longer or shorter stamens of the same form, but generally
not from the same plant, have been described. Six other illegitimate unions are
possible, namely, between the three forms and the stamens in the other two forms
which do not correspond in height with their pistils. But I succeeded in raising
plants from only three of these six unions. From one of them, forming the
present Class 5, twelve plants were raised; these consisted of eight short-
styled, and four long-styled plants, with not one mid-styled. These twelve
plants never attained quite their full and proper height, but by no means
deserved to be called dwarfs. The anthers in some of the flowers were
contabescent. One plant was remarkable from all the longer stamens in every
flower and from many of the shorter ones having their anthers in this condition.
The pollen of four other plants, in which none of the anthers were contabescent,
was examined; in one a moderate number of grains were minute and shrivelled, but
in the other three they appeared perfectly sound. With respect to the power of
producing seed, five plants (Numbers 21 to 25) were observed: one yielded
scarcely more than half the normal number; a second was slightly infertile; but
the three others actually produced a larger average number of seeds, with a
higher maximum, than the standard.


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