Comparison with 1861 |
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be advantageous to a plant to produce stamens alone in one flower or on one whole plant, and pistils alone in another flower or on another plant. In plants under culture and placed under new conditions of life, sometimes the male organs and sometimes the female organs become more or less impotent; now if we suppose this to occur in ever so slight a degree under nature,
then then 1859 1860 1861 | then, 1866 1869 1872 |
as pollen is already carried regularly from flower to flower, and as a more complete separation of the sexes of our plant would be advantageous on the principle of the division of labour, individuals with this tendency more and more increased, would be continually favoured or selected, until at last a complete separation of the sexes would
be effected. ↑1 blocks not present in 1859 1860 1861; present in 1866 1869 1872 | It would take up too much space to show the various steps, through dimorphism and other means, by which the separation of the sexes in plants of various kinds is apparently now in progress; but I may add that some of the species of holly in North America
are, according to Asa Gray, in an intermediate
condition, or, as he expresses himself, the flowers
are more or less diœciously polygamous.
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Let us now turn to the nectar-feeding insects
in our imaginary case:
we may suppose the plant
of which we have been slowly increasing the nectar by continued selection, to be a common plant; and that certain insects depended in main part on its nectar for food. I could give many facts,
showing how anxious bees are to save
time; time; 1859 1860 1861 | time: 1866 1869 1872 |
for instance, their habit of cutting holes and sucking the nectar at the bases of certain flowers, which they can, with a very little more trouble,
enter by the mouth. Bearing such facts in mind,
I can see no reason to doubt that an accidental deviation I can see no reason to doubt that an accidental deviation 1859 1860 1861 |
it may be believed that an accidental deviation 1866 |
it may be believed that under certain circumstances individual differences 1869 1872 |
in the size and form
of the body, or in the curvature and length of the
proboscis, &c., far
too slight to be appreciated by us, might profit a bee or other insect, so
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be advantageous to a plant to produce stamens alone in one flower or on one whole plant, and pistils alone in another flower or on another plant. In plants under culture and placed under new conditions of life, sometimes the male organs and sometimes the female organs become more or less impotent; now if we suppose this to occur in ever so slight a degree under nature,
then, then, 1866 1869 1872 | then 1859 1860 1861 |
as pollen is already carried regularly from flower to flower, and as a more complete separation of the sexes of our plant would be advantageous on the principle of the division of labour, individuals with this tendency more and more increased, would be continually favoured or selected, until at last a complete separation of the sexes
would would 1859 1860 1861 1866 | might 1869 1872 |
be effected. It would take up too much space to show the various steps, through dimorphism and other means, by which the separation of the sexes in plants of various kinds is apparently now in progress; but I may add that some of the species of holly in North
America America 1866 1869 | America, 1872 |
are, according to Asa Gray, in an
intermediate intermediate 1866 1869 | exactly intermediate 1872 |
condition, or, as he expresses
himself, the flowers himself, the flowers 1866 |
it, 1869 1872 |
are more or less diœciously polygamous. |
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Let us now turn to the nectar-feeding
insects insects 1859 1860 1861 1866 | insects: 1869 | insects; 1872 |
in our imaginary case: in our imaginary case: 1859 1860 1861 1866 |
OMIT 1869 1872 |
we may suppose the
plant plant 1859 1860 1861 1866 | plant, 1869 1872 |
of which we have been slowly increasing the nectar by continued selection, to be a common plant; and that certain insects depended in main part on its nectar for food. I could give many
facts, facts, 1859 1860 1861 1866 1869 | facts 1872 |
showing how anxious bees are to save
time: time: 1866 1869 1872 | time; 1859 1860 1861 |
for instance, their habit of cutting holes and sucking the nectar at the bases of certain flowers, which
they can, with a very little more trouble, they can, with a very little more trouble, 1859 1860 1861 1866 1869 |
with a very little more trouble, they can 1872 |
enter by the mouth. Bearing such facts in mind,
it may be believed that an accidental deviation it may be believed that an accidental deviation 1866 |
I can see no reason to doubt that an accidental deviation 1859 1860 1861 |
it may be believed that under certain circumstances individual differences 1869 1872 |
in the
size and form size and form 1859 1860 1861 1866 |
curvature or length 1869 1872 |
of the
body, or in the curvature and length of the body, or in the curvature and length of the 1859 1860 1861 1866 |
OMIT 1869 1872 |
proboscis, &c.,
far far 1859 1860 1861 1866 | far 1869 1872 |
too slight to be appreciated by us, might profit a bee or other insect, so
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