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more diversified in habits and structure the descendants of our carnivorous
the more places they
be enabled to occupy. What applies to one animal will apply throughout all time to all animals— that is, if they vary— for otherwise natural selection can
nothing. So it will be with plants. It has been experimentally proved, that if a plot of ground be sown with one species of grass, and a similar plot be sown with several distinct genera of grasses, a greater number of plants and a greater weight of dry herbage can
be
→raised. The same has been found to hold good when
one variety and
several mixed varieties of wheat have been sown on equal spaces of ground. Hence, if any one species of grass were to go on varying, and
varieties were continually selected which differed from each other in
the same
→as
distinct species and genera of
→differ from each other,
a greater number of individual plants of this
including its modified descendants, would succeed in living on the same piece of ground. And we
know that each species and each variety of grass is annually sowing almost countless
and
→thus,
as it may be said,
→is striving its
utmost to increase
→OMIT
in the course of many
generations, the most distinct varieties of any one species of grass would
have the best chance of succeeding and of increasing in numbers, and thus of supplanting the less distinct varieties; and varieties, when rendered very distinct from each other, take the rank of species. |
