generations, if they were allowed to struggle together,
like like 1859 1860 1861 1866 1869 |
in the same manner as 1872 |
beings in a state of nature, and if the seed or young were not annually
sorted. sorted. 1859 1860 1861 1866 1869 |
preserved in due proportion. 1872 |
|
Struggle
Struggle
1869 |
Struggle
1866 1872 |
for
Life
most
severe
severe
1869 |
severe
1866 1872 |
between
between
1869 |
between
1866 1872 |
Individuals
Individuals
1869 |
Individuals
1866 1872 |
and
Varieties
Varieties
1869 |
Varieties
1866 1872 |
of
the
same
Species.
Species. 1869 |
Species.
1866 |
Species.
1872 |
|
As
species species 1859 1860 1861 1866 1869 | the species 1872 |
of the same genus
have usually, have usually, 1859 1860 1861 1866 1869 | usually have, 1872 |
though by no means invariably,
much much 1866 1869 1872 | some 1859 1860 1861 |
similarity in habits and constitution, and always in structure, the struggle will generally be more severe between
species of the same genus, when species of the same genus, when 1859 1860 1861 1866 1869 |
them, if 1872 |
they come into competition with each other, than between
species species 1859 1860 1861 1866 1869 | the species 1872 |
of distinct genera. We see this in the recent extension over parts of the United States of one species of swallow having caused the decrease of another species. The recent increase of the missel-thrush in parts of Scotland has caused the decrease of the song-thrush. How frequently we hear of one species of rat taking the place of another species under the most different
climates! In Russia the small Asiatic cockroach has everywhere driven before it its great congener. climates! In Russia the small Asiatic cockroach has everywhere driven before it its great congener. 1869 1872 |
climates! 1859 1860 1861 1866 |
↑1 blocks not present in 1869 1872; present in 1859 1860 1861 1866 | In Russia the small Asiatic cockroach has everywhere driven before it its great congener.
|
In Australia the imported hive-bee is rapidly exterminating the small, stingless native bee. One species of charlock
has been known to has been known to 1866 1869 1872 |
will 1859 1860 1861 |
supplant
another another 1866 1869 1872 | another, 1859 1860 1861 |
species; and species; and 1866 1869 1872 | and 1859 1860 1861 |
so in other cases. We can dimly see why the competition should be most severe between allied forms, which fill nearly the same place in the economy of nature; but probably in no one case could we precisely say why one species has been victorious over another in the great battle of life. |
|
A corollary of the highest importance may be deduced from the foregoing remarks, namely, that the structure of every organic being is related, in the most essential yet often hidden manner, to that of all
the other the other 1869 1872 | other 1859 1860 1861 1866 |
organic beings, with which it comes into competition for food or residence, or from which it has to escape, or on which it
|