→ such as the cardoon, and a tall thistle, now most numerous 1866 1869 |
now most numerous 1859 |
such as the cardoon and a tall thistle, now most numerous 1860 1861 |
such as the cardoon and a tall thistle, which are now the commonest 1872 |
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→ In such cases the 1859 1860 1861 1866 1869 |
Their 1872 |
|
→ of naturalised productions 1859 1860 1861 1866 1869 |
OMIT 1872 |
|
→ plant 1859 1860 1861 1866 1869 |
full-grown plant annually 1872 |
|
→ forget 1859 1860 1861 1866 1869 |
do not keep in mind 1872 |
|
in
and latterly in Australia, had not been well authenticated, they would have been
incredible. So it is with
cases could be given of introduced plants which have become common throughout whole islands in a period of less than ten years. Several of the
→such as the cardoon, and a tall thistle, now most numerous
over the wide plains of La Plata, clothing square leagues of surface almost to the exclusion of
other
have been introduced from Europe; and there are plants which now range in India, as I hear from Dr. Falconer, from Cape Comorin to the Himalaya, which have been imported from America since its discovery. In such cases, and endless
could be given, no one
that the fertility of
animals or plants has been suddenly and temporarily increased in any sensible degree. The obvious explanation is that the conditions of life have been
favourable, and that there has consequently been less destruction of the old and young, and that nearly all the young have been enabled to breed.
→In such cases the
geometrical ratio of increase, the result of which never fails to be surprising, simply explains
extraordinarily rapid increase and wide diffusion
→of naturalised productions
in their new homes. |
|
In a state of nature almost every
→plant
produces seed, and amongst animals there are very few which do not annually pair. Hence we may confidently assert, that all plants and animals are tending to increase at a geometrical
all would
rapidly stock every station in which they could any how
that
geometrical tendency to increase must be checked by destruction at some period of life. Our familiarity with the larger domestic animals tends, I think, to mislead us: we see no great destruction falling on them,
we
→forget
that thousands are annually slaughtered for food,
|