will have been will have been 1866 |
were 1859 1860 1861 1869 1872 |
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
the northern hemisphere, the northern hemisphere, 1866 1869 1872 |
Europe, 1859 1860 1861 |
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. 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.
Before the Glacial period, no doubt Before the Glacial period, no doubt 1866 |
Something of the same kind must have occurred on 1859 1860 1861 |
Before the last great Glacial period, no doubt 1869 1872 |
the intertropical
mountains mountains 1866 1869 1872 | mountains: 1859 1860 1861 |
...OMIT 1866 1869 1872 |
no doubt before the Glacial period they 1859 1860 1861 |
were stocked with endemic Alpine forms; but these have almost
every-where every-where 1866 | everywhere 1859 1860 1861 1869 1872 |
....... 1866 1869 1872 | largely 1859 1860 1861 |
yielded to the more dominant forms, generated in the larger areas and more efficient workshops of the north. In many islands the native productions are nearly
equalled, equalled, 1866 1869 1872 | equalled 1859 1860 1861 |
or even
out-numbered, out-numbered, 1866 | outnumbered 1859 1860 1861 | outnumbered, 1869 1872 |
by
those which have become naturalised there; those which have become naturalised there; 1866 |
the naturalised; 1859 1860 1861 |
those which have become naturalised; 1869 1872 |
and if the natives have not been actually exterminated, their numbers have been greatly reduced, and
this is the first stage towards extinction. A
mountain
is an
island
on the land;
and
the intertropical mountains before the Glacial period must have been completely isolated; and I believe that the inhabitants of these islands on the land 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 |
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 |
their inhabitants have 1869 1872 |
have yielded have yielded 1866 | yielded 1859 1860 1861 1869 1872 |
to those produced within the larger areas of the north, just in the same way as the productions
of real islands have everywhere
yielded to continental forms lately yielded to continental forms lately 1866 |
lately yielded to continental forms, 1859 1860 1861 |
yielded and are still yielding to continental forms 1869 1872 |
naturalised
there through there through 1866 | by 1859 1860 1861 | through 1869 1872 |
man's man's 1859 1861 1866 1872 | mans 1860 1869 |
agency. ↑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.
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