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Darwin, Charles, 1809-1882

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

Therefore, the whole advantage of a cross with a
distinct stock is here confined to productiveness, and I have met with
no similar case.
8. RESEDACEAE.--Reseda lutea.
Seeds collected from wild plants growing in this neighbourhood were sown
in the kitchen-garden; and several of the seedlings thus raised were
covered with a net. Of these, some were found (as will hereafter be more
fully described) to be absolutely sterile when left to fertilise
themselves spontaneously, although plenty of pollen fell on their
stigmas; and they were equally sterile when artificially and repeatedly
fertilised with their own pollen; whilst other plants produced a few
spontaneously self-fertilised capsules. The remaining plants were left
uncovered, and as pollen was carried from plant to plant by the hive and
humble-bees which incessantly visit the flowers, they produced an
abundance of capsules. Of the necessity of pollen being carried from one
plant to another, I had ample evidence in the case of this species and
of R. odorata; for those plants, which set no seeds or very few as long
as they were protected from insects, became loaded with capsules
immediately that they were uncovered.
Seeds from the flowers spontaneously self-fertilised under the net, and
from flowers naturally crossed by the bees, were sown on opposite sides
of five large pots. The seedlings were thinned as soon as they appeared
above ground, so that an equal number were left on the two sides.


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