Comparison with 1860 |
|
From looking at species as only strongly-marked and well-defined varieties, I was led to anticipate that the species of the larger genera in each country would oftener present varieties, than the species of the smaller genera; for wherever many closely related species
(
I. e.
(
I. e.
1860 1861 |
(
i
.
e
.
1859 |
(
i. e.
1866 |
(
i.e.
1869 1872 |
species
of the same genus) have been formed, many varieties or incipient species ought, as a general rule, to be now forming. Where many large trees grow, we expect to find saplings. Where many species of a genus have been formed through variation, circumstances have been favourable for variation; and hence we might expect that the circumstances would generally be still favourable to variation. On the other hand, if we look at each species as a special act of creation, there is no apparent reason why more varieties should occur in a group having many species, than in one having few. |
|
To test the truth of this anticipation I have arranged the plants of twelve countries, and the coleopterous insects of two districts, into two nearly equal masses, the species of the larger genera on one side, and those of the smaller genera on the other side, and it has invariably proved to be the case that a larger proportion of the species on the side of the larger genera
present present 1859 1860 1861 1866 | presented 1869 1872 |
varieties, than on the side of the smaller genera. Moreover, the species of the large genera which present any varieties, invariably present a larger average number of varieties than do the species of the small genera. Both these results follow when another division is made, and when all the
smallest smallest 1859 1860 1861 | least 1866 1869 1872 |
genera, with from only one to four species, are absolutely
excluded from the tables. These facts are of plain signification on the view that species are only
strongly marked strongly marked 1859 1860 1861 | strongly-marked 1866 1869 1872 |
and permanent varieties; for wherever many species of the same genus have been formed, or where, if we may use the expression, the manufactory of species has been active,
|
From looking at species as only strongly-marked and well-defined varieties, I was led to anticipate that the species of the larger genera in each country would oftener present varieties, than the species of the smaller genera; for wherever many closely related species
(
i.e.
(
i.e.
1869 1872 |
(
i
.
e
.
1859 |
(
I. e.
1860 1861 |
(
i. e.
1866 |
species species 1859 1860 1861 1866 1869 | , species 1872 |
of the same genus) have been formed, many varieties or incipient species ought, as a general rule, to be now forming. Where many large trees grow, we expect to find saplings. Where many species of a genus have been formed through variation, circumstances have been favourable for variation; and hence we might expect that the circumstances would generally be still favourable to variation. On the other hand, if we look at each species as a special act of creation, there is no apparent reason why more varieties should occur in a group having many species, than in one having few. |
|
To test the truth of this anticipation I have arranged the plants of twelve countries, and the coleopterous insects of two districts, into two nearly equal masses, the species of the larger genera on one side, and those of the smaller genera on the other side, and it has invariably proved to be the case that a larger proportion of the species on the side of the larger genera
presented presented 1869 1872 | present 1859 1860 1861 1866 |
varieties, than on the side of the smaller genera. Moreover, the species of the large genera which present any varieties, invariably present a larger average number of varieties than do the species of the small genera. Both these results follow when another division is made, and when all the
least least 1866 1869 1872 | smallest 1859 1860 1861 |
genera, with from only one to four species, are
absolutely absolutely 1859 1860 1861 1866 1869 | altogether 1872 |
excluded from the tables. These facts are of plain signification on the view that species are only
strongly-marked strongly-marked 1866 1869 1872 | strongly marked 1859 1860 1861 |
and permanent varieties; for wherever many species of the same genus have been formed, or where, if we may use the expression, the manufactory of species has been active,
|