| → recently have been 1859 1860 1861 1866 |
| have been recently 1869 1872 |
|
| → of level in our continents; 1859 1860 1861 1866 |
| in the level of the land or sea; 1869 1872 |
|
| → as 1859 1860 1861 1866 |
| of our continents, as 1869 1872 |
|
| → migration. In the coral-producing oceans such sunken islands are now marked, as I believe, by rings of coral or atolls standing over them. 1860 |
| migration. 1859 1861 1866 1869 1872 |
|
| → Whenever it is fully admitted, 1860 |
| In the coral-producing oceans such sunken islands are now marked, 1859 |
| In the coral-producing oceans such sunken islands are now marked 1861 1866 1869 1872 |
|
| → as I believe 1860 |
| as I believe, 1859 |
| OMIT 1861 1866 1869 1872 |
|
| → it will some day be, that each species has proceeded from a single birthplace, and when in the course of time we know something definite about the means of distribution, we shall be enabled to speculate with security on the former extension of the land. 1860 |
| by rings of coral or atolls standing over them. 1859 1861 1866 1869 1872 |
|
| ↑ 1 blocks not present in 1860; present in 1859 1861 1866 1869 1872 |
| Whenever it is fully admitted, as I believe
it will some day be, that each species has proceeded from a single birthplace, and when in the course of time we know something definite about the means of distribution, we shall be enabled to speculate with security on the former extension of the land.
|
|
|
possibly even continents together, and thus have allowed terrestrial productions to pass from one to the other. No geologist
that great mutations of
have occurred within the period of existing organisms. Edward Forbes insisted that all the islands in the Atlantic must
→recently have been
connected with Europe or Africa, and Europe likewise with America. Other authors have thus hypothetically bridged over every ocean, and
united almost every island to some mainland. If indeed the arguments used by Forbes are to be trusted, it must be admitted that scarcely a single island exists which has not recently been united to some continent. This view cuts the Gordian knot of the dispersal of the same species to the most distant points, and removes many a
but to the best of my judgment we are not authorized in admitting such enormous geographical changes within the period of existing species. It seems to me that we have abundant evidence of great oscillations
→of level in our continents;
but not of such vast changes in
position and
→as
to have united them within the recent period to each other and to the several intervening oceanic islands. I freely admit the former existence of many islands, now buried beneath the sea, which may have served as
for plants and for many animals during their
→migration. In the coral-producing oceans such sunken islands are now marked, as I believe, by rings of coral or atolls standing over them.
→Whenever it is fully admitted,
→as I believe
→it will some day be, that each species has proceeded from a single birthplace, and when in the course of time we know something definite about the means of distribution, we shall be enabled to speculate with security on the former extension of the land.
↑
But I do not believe that it will ever be proved that within the
|
