| Comparison with 1861 |
|
were
enabled to beat the less powerful
southern forms. Just in
the same manner as we see
at the present day, that
very many European productions cover the ground in La Plata, and in
a lesser degree in Australia, and have to a certain extent
beaten the natives; whereas extremely few southern forms have become naturalised in any part of Europe,
though hides, wool, and other objects likely to carry seeds have been largely imported into Europe during the last two or three centuries from La Plata, and during the last thirty
or forty
years from Australia. ↑| 1 blocks not present in 1859 1860 1861; present in 1866 1869 1872 | | The Neilgherrie mountains in India, however, offer a partial exception; for here, as I hear from Dr. Hooker, Australian forms are rapidly sowing themselves and becoming naturalised.
|
| man's 1859 1861 1866 1872 | | mans 1860 1869 |
| 2 blocks not present in 1859 1860 1861 1866; present in 1869 1872 | | The same principles apply to the distribution of terrestrial animals and of marine productions, in the northern and southern temperate zones, and on the intertropical mountains.
When
during the height of the Glacial period
the ocean-currents were widely different to what they now are, some of the inhabitants of the temperate seas might have reached the equator; of these a few would perhaps at once be able to migrate southward, by keeping to the cooler currents, whilst others might remain and survive in the cooler
depths,
until the southern hemisphere was in its turn subjected to a glacial climate and permitted of
their further progress; in nearly the same manner as, according to Forbes, isolated spaces inhabited by Arctic productions exist to the present day in the deeper parts of the temperate
seas.
|
|
|
I am far
from supposing that all difficulties are removed on the view here given
in regard to the range
and affinities of the allied
species
which live
in the northern
and southern temperate zones and
on the mountains of the intertropical regions.
↑| 3 blocks not present in 1859 1860 1861 1869 1872; present in 1866 | | It is extremely difficult to understand how a vast number of peculiar forms confined to the tropics could have been therein preserved during the coldest part of the Glacial period.
The number of forms in Australia, which are related to European temperate forms, but which differ so greatly that it is impossible to believe that they could have been modified since the Glacial period, perhaps indicates some much more ancient cold period, even as far back as the miocene age, in accordance with the recent speculations of certain geologists.
So again, as I am informed by Mr. Bates, the strongly marked character of several species of Carabus, inhabiting the southern parts of America, indicates that their common progenitor must have been introduced at some early period; and other analogous facts could be given.
|
| 1 blocks not present in 1859 1860 1861; present in 1866 1869 1872 | | The exact lines and means
of migration during the recent Glacial period
cannot be indicated;
nor the reason why certain species and not others have migrated; why certain species have been modified and have given rise to new nor the reason why certain species and not others have migrated; why certain species have been modified and have given rise to new groups of forms, and others have remained unaltered. others have remained unaltered.
|
|
were | were 1859 1860 1861 1869 1872 |
| will have been 1866 |
| enabled to beat the less powerful 1859 1860 1861 1866 |
| the more powerful and were able to hold their places on the mountains, and afterwards to migrate southward with the 1869 1872 |
| forms. 1859 1860 1861 1866 |
| forms; but not so the southern in regard to the northern forms. 1869 1872 |
| Just in 1859 1860 1861 1866 | | In 1869 1872 |
| as we see 1859 1860 1861 1866 |
| we see 1869 |
| OMIT 1872 |
| that 1859 1860 1861 1866 1869 |
| we see that 1872 |
| and in 1859 1860 1861 1866 |
| New Zealand, and to 1869 1872 |
| to a certain extent 1859 1860 1861 1866 |
| OMIT 1869 1872 |
| Europe, 1859 1860 1861 |
| the northern hemisphere, 1866 1869 1872 |
| thirty 1859 1860 1861 1866 1869 | | forty 1872 |
| forty 1859 1860 1861 1866 1869 | | fifty 1872 |
| 1 blocks not present in 1859 1860 1861; present in 1866 1869 1872 | | The Neilgherrie mountains in India, however, offer a partial exception; for here, as I hear from Dr. Hooker, Australian forms are rapidly sowing themselves and becoming naturalised.
|
| Something of the same kind must have occurred on 1859 1860 1861 |
| Before the Glacial period, no doubt 1866 |
| Before the last great Glacial period, no doubt 1869 1872 |
| mountains: 1859 1860 1861 | | mountains 1866 1869 1872 |
| no doubt before the Glacial period they 1859 1860 1861 |
| OMIT 1866 1869 1872 |
| everywhere 1859 1860 1861 1869 1872 | | every-where 1866 |
| largely 1859 1860 1861 | largely 1866 1869 1872 |
| equalled 1859 1860 1861 | | equalled, 1866 1869 1872 |
| outnumbered 1859 1860 1861 | | out-numbered, 1866 | | outnumbered, 1869 1872 |
| the naturalised; 1859 1860 1861 |
| those which have become naturalised there; 1866 |
| those which have become naturalised; 1869 1872 |
| if the natives have not been actually exterminated, their numbers have been greatly reduced, and 1859 1860 1861 1866 |
| OMIT 1869 1872 |
| extinction. 1859 1860 1861 1866 | | their extinction. 1869 1872 |
| A 1859 1860 1861 1866 | A 1869 1872 |
| mountain 1859 1860 1861 1866 | | Mountains 1869 1872 |
| is an 1859 1860 1861 1866 | | are 1869 1872 |
| island 1859 1860 1861 1866 | | islands 1869 1872 |
| land; 1859 1860 1861 1866 | | land, 1869 1872 |
| the intertropical mountains before the Glacial period must have been completely isolated; and I believe that the productions of these islands on the land 1859 1860 1861 |
| the intertropical mountains before the Glacial period must have been completely isolated; and I believe that the inhabitants of these islands on the land 1866 |
| their inhabitants have 1869 1872 |
| yielded 1859 1860 1861 1869 1872 | | have yielded 1866 |
| productions 1859 1860 1861 1866 | | inhabitants 1869 1872 |
| lately yielded to continental forms, 1859 1860 1861 |
| yielded to continental forms lately 1866 |
| yielded and are still yielding to continental forms 1869 1872 |
| by 1859 1860 1861 | | there through 1866 | | through 1869 1872 |
| mans 1860 1869 | | man's 1859 1861 1866 1872 |
|
|
I am
far | far 1859 1860 1861 1869 1872 | | very far 1866 |
| difficulties are removed on the view here given 1859 1860 1861 |
| difficulties 1866 1869 |
| the difficulties 1872 |
| range 1859 1860 1861 | | distribution 1866 1869 1872 |
| allied 1859 1860 1861 1866 |
| identical and allied 1869 1872 |
| species 1859 1860 1861 | | species, 1866 1869 1872 |
| live 1859 1860 1861 1866 |
| now live so widely separated 1869 1872 |
| northern 1859 1860 1861 1866 | | north 1869 1872 |
| southern temperate zones and 1859 1860 1861 |
| southern tem- perate zones and 1866 |
| south, and sometimes 1869 1872 |
| mountains of the intertropical regions. 1859 1860 1861 |
| mountains of the intertropical regions, are removed on the views above given. 1866 |
| intermediate mountain-ranges, are removed on the views above given. 1869 1872 |
| I do not pretend to indicate the exact lines and means of migration, or the reason 1859 1860 1861 |
| We cannot say 1869 |
|
