| ↑ 2 blocks not present in 1869 1872; present in 1859 1860 1861 1866 |
| Some of these seedlings would probably
inherit the nectar-excreting power.
Those individual flowers which had the largest glands or nectaries, and which excreted most nectar, would be oftenest visited by insects, and would be oftenest crossed; and so in the long-run would gain the upper hand.
|
|
| → OMIT 1869 1872 |
| from flower to flower, 1859 1860 1861 1866 |
|
| → to be a 1869 1872 |
| a 1859 1860 1861 1866 |
|
| → and the 1869 |
| and those 1859 1860 1861 1866 |
| to be thus robbed; and the 1872 |
|
| → the above process long continued, 1869 1872 |
| this process of the continued preservation or natural selection of more and more attractive flowers, 1859 1860 1861 1866 |
|
| → OMIT 1869 1872 |
| can most effectually 1859 1860 1861 |
| can effectually 1866 |
|
| → one, 1869 1872 |
| one— not as a very striking case, but 1859 1860 1861 1866 |
|
|
vigorous seedlings, which consequently would have the best chance of flourishing and surviving. The plants which produced flowers with the largest glands or nectaries, excreting most nectar, would oftenest be visited by insects, and would oftenest be crossed; and so in the long-run would gain the upper hand and form a local variety. ↑
flowers, also, which had their stamens and pistils placed, in relation to the size and habits of the particular
which visited them, so as to favour in any degree the transportal of
→OMIT
would likewise be
We might have taken the case of insects visiting flowers for the sake of collecting pollen instead of nectar; and as pollen is formed for the sole
of fertilisation, its destruction appears
→to be a
simple loss to the plant; yet if a little pollen were carried, at first occasionally and then habitually, by the pollen-devouring insects from flower to flower, and a cross thus effected, although nine-tenths of the pollen were destroyed, it might still be a great gain to the
→and the
individuals which produced more and more pollen, and had larger
anthers, would be selected. |
|
| When our plant, by
→the above process long continued,
had been rendered highly attractive to insects, they would, unintentionally on their part, regularly carry pollen from flower to flower; and that they
→OMIT
do
could easily show by many striking
I will give only
→one,
as likewise illustrating one step in the separation of the sexes of
Some holly-trees bear only male flowers, which have four stamens producing
small quantity of pollen, and a rudimentary pistil; other
bear only female flowers; these have a full-sized pistil, and four stamens with shrivelled anthers, in which not a grain of pollen can be detected. Having found a female tree exactly
|
