| → acknowledged variations 1869 |
| variation 1859 1860 1861 1866 |
| the production of varieties 1872 |
|
| → so-called specific differences. 1869 |
| so-called specific forms. 1859 1860 1861 1866 |
| distinct species. 1872 |
|
| → some direct and definite effect, but how much we cannot say. 1869 1872 |
| but little direct effect; yet when varieties enter any zone, they occasionally assume some of the characters of the species proper to that zone. 1859 1860 1861 1866 |
|
| → hybrids! 1859 1860 1861 1866 1869 |
| hybrids! How simply is this fact explained if we believe that these species are all descended from a striped progenitor, in the same manner as the several domestic breeds of the pigeon are descended from the blue and barred rock-pigeon! 1872 |
|
| → the pigeon are 1869 |
| pigeon have 1859 1860 1861 1866 |
|
|
daughters; at ichneumonidæ feeding within the
bodies of caterpillars;
at other such cases. The wonder indeed is, on the theory of natural selection, that more cases of the want of absolute perfection have not been
|
|
| The complex and little known laws governing
→acknowledged variations
are the same, as far as we can
with the laws which have governed the production of
→so-called specific differences. In both cases physical conditions seem to have produced
→some direct and definite effect, but how much we cannot say.
when varieties enter any new station, they occasionally assume some of the characters proper to the species of that station.
both varieties and species, use and disuse seem to have produced
effect; for it is
to resist this
when we look, for instance, at the logger-headed duck, which has wings incapable of flight, in nearly the same condition as in the domestic duck; or when we look at the burrowing
which is occasionally blind, and then at certain moles, which are habitually blind and have their eyes covered with skin; or when we look at the blind animals inhabiting the dark caves of America and Europe.
varieties and
seems to have played
important part, so that when one part has been modified other parts
necessarily modified.
both varieties and
reversions to long-lost characters
How inexplicable on the theory of creation is the
appearance of stripes on the
and legs of the several species of the horse-genus and
their
→hybrids! How simply is this fact explained if we believe that these species
from a striped progenitor, in the same manner as the several domestic breeds of
→the pigeon are
descended from the blue and barred rock-pigeon!
|
