The Effects of Cross & Self-Fertilisation in the Vegetable KingdomDarwin, Charles
Science
The Effects of Cross & Self-Fertilisation in the Vegetable Kingdom
Darwin, Charles
Fertilization of plants; Plants -- Variation; Pollination
Column 2: Crossed Plants.
Column 3: Self-fertilised Plants.
Pot 1 : 8 2/8 : 0 2/8.
Pot 1 : 7 4/8 : 2 4/8.
Pot 1 : 5 : 1 2/8.
Pot 2 : 5 : 6.
Pot 2 : 4 : 4.
Pot 2 : 4 4/8 : 3 1/8.
Pot 3 : 9 4/8 : 3 1/8.
Pot 3 : 3 3/8 : 1 7/8.
Pot 3 : 8 4/8 : 0 5/8.
Pot 4 : 4 7/8 : 2 1/8.
Pot 4 : 4 2/8 : 1 6/8.
Pot 4 : 4 : 2 1/8.
Pot 5 : 6 : 3.
Pot 5 : 3 3/8 : 1 4/8.
Total : 78.13 : 33.25.
The average height of the fourteen crossed plants is here 5.58 inches,
and that of the fourteen self-fertilised 2.37; or as 100 to 42. In four
out of the five pots, a crossed plant flowered before any one of the
self-fertilised; as likewise occurred with the pair raised during the
previous year. These plants without being disturbed were now turned out
of their pots and planted in the open ground, so as to form five
separate clumps. Early in the following summer (1869) they flowered
profusely, and being visited by humble-bees set many capsules, which
were carefully collected from all the plants on both sides. The crossed
plants produced 167 capsules, and the self-fertilised only 17; or as 100
to 10. So that the crossed plants were more than twice the height of the
self-fertilised, generally flowered first, and produced ten times as
many naturally fertilised capsules.
By the early part of the summer of 1870 the crossed plants in all the
five clumps had grown and spread so much more than the self-fertilised,
that any comparison between them was superfluous. The crossed plants
were covered with a sheet of bloom, whilst only a single self-fertilised
plant, which was much finer than any of its brethren, flowered. The
crossed and self-fertilised plants had now grown all matted together on
the respective sides of the superficial partitions still separating
them; and in the clump which included the finest self-fertilised plant,
I estimated that the surface covered by the crossed plants was about
nine times as large as that covered by the self-fertilised plants. The
extraordinary superiority of the crossed over the self-fertilised plants
in all five clumps, was no doubt due to the crossed plants at first
having had a decided advantage over the self-fertilised, and then
robbing them more and more of their food during the succeeding seasons.
But we should remember that the same result would follow in a state of
nature even to a greater degree; for my plants grew in ground kept clear
of weeds, so that the self-fertilised had to compete only with the
crossed plants; whereas the whole surface of the ground is naturally
covered with various kinds of plants, all of which have to struggle
together for existence.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account