The Different Forms of Flowers on Plants of the Same SpeciesDarwin, Charles
Science
The Different Forms of Flowers on Plants of the Same Species
Darwin, Charles
Fertilization of plants; Heterostylism; Plant physiology; Plants -- Variation; Pollination
I now determined to observe more carefully during successive seasons some bushes
growing in another place about a mile distant. As the female bushes were so
highly productive, I marked only two of them with the letters A and B, and five
polleniferous bushes with the letters C to G. I may premise that the year 1865
was highly favourable for the fruiting of all the bushes, especially for the
polleniferous ones, some of which were quite barren except under such favourable
conditions. The season of 1864 was unfavourable. In 1863 the female A produced
“some fruit;” in 1864 only 9; and in 1865, 97 fruit. The female B in 1863 was
“covered with fruit;” in 1864 it bore 28; and in 1865 “innumerable very fine
fruits.” I may add, that three other female trees growing close by were
observed, but only during 1863, and they then bore abundantly. With respect to
the polleniferous bushes, the one marked C did not bear a single fruit during
the years 1863 and 1864, but during 1865 it produced no less than 92 fruit,
which, however, were very poor. I selected one of the finest branches with 15
fruit, and these contained 20 seeds, or on an average 1.33 per fruit. I then
took by hazard 15 fruit from an adjoining female bush, and these contained 43
seeds; that is, more than twice as many, or on an average 2.86 per fruit. Many
of the fruits from the female bushes included four seeds, and only one had a
single seed; whereas not one fruit from the polleniferous bushes contained four
seeds. Moreover when the two lots of seeds were compared, it was manifest that
those from the female bushes were the larger. The second polleniferous bush, D,
bore in 1863 about two dozen fruit,--in 1864 only 3 very poor fruit, each
containing a single seed,--and in 1865, 20 equally poor fruit. Lastly, the three
polleniferous bushes, E, F, and G, did not produce a single fruit during the
three years 1863, 1864, and 1865.
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