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Darwin, Charles, 1809-1882

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


Plants of Papaver vagum were raised from seeds sent me from Antibes
through the kindness of Dr. Bornet. Some little time after the flowers
had expanded, several were fertilised with their own pollen, and others
(not castrated) with pollen from a distinct individual; but I have
reason to believe, from observations subsequently made, that these
flowers had been already fertilised by their own pollen, as this process
seems to take place soon after their expansion. (4/3. Mr. J. Scott found
'Report on the Experimental Culture of the Opium Poppy' Calcutta 1874
page 47, in the case of Papaver somniferum, that if he cut away the
stigmatic surface before the flower had expanded, no seeds were
produced; but if this was done "on the second day, or even a few hours
after the expansion of the flower on the first day, a partial
fertilisation had already been effected, and a few good seeds were
almost invariably produced." This proves at how early a period
fertilisation takes place.) I raised, however, a few seedlings of both
lots, and the self-fertilised rather exceeded the crossed plants in
height.
Early in the following year I acted differently, and fertilised seven
flowers, very soon after their expansion, with pollen from another
plant, and obtained six capsules. From counting the seeds in a
medium-sized one, I estimated that the average number in each was at
least 120.


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