Hence we have the truly wonderful fact, that in James Island, of the
thirty-eight Galapageian plants, or those found in no other part of the
world, thirty are exclusively confined to this one island; and in
Albemarle Island, of the twenty-six aboriginal Galapageian plants,
twenty-two are confined to this one island, that is, only four are at
present known to grow in the other islands of the archipelago; and so
on, as shown in the above table, with the plants from Chatham and
Charles Islands. This fact will, perhaps, be rendered even more
striking, by giving a few illustrations:--thus, Scalesia, a remarkable
arborescent genus of the Compositae, is confined to the archipelago: it
has six species: one from Chatham, one from Albemarle, one from Charles
Island, two from James Island, and the sixth from one of the three
latter islands, but it is not known from which: not one of these six
species grows on any two islands. Again, Euphorbia, a mundane or
widely distributed genus, has here eight species, of which seven are
confined to the archipelago, and not one found on any two islands:
Acalypha and Borreria, both mundane genera, have respectively six and
seven species, none of which have the same species on two islands, with
the exception of one Borreria, which does occur on two islands. The
species of the Compositae are particularly local; and Dr. Hooker has
furnished me with several other most striking illustrations of the
difference of the species on the different islands. He remarks that
this law of distribution holds good both with those genera confined to
the archipelago, and those distributed in other quarters of the world:
in like manner we have seen that the different islands have their
proper species of the mundane genus of tortoise, and of the widely
distributed American genus of the mocking-thrush, as well as of two of
the Galapageian sub-groups of finches, and almost certainly of the
Galapageian genus Amblyrhynchus.
The distribution of the tenants of this archipelago would not be nearly
so wonderful, if, for instance, one island had a mocking-thrush, and a
second island some other quite distinct genus,--if one island had its
genus of lizard, and a second island another distinct genus, or none
whatever;--or if the different islands were inhabited, not by
representative species of the same genera of plants, but by totally
different genera, as does to a certain extent hold good: for, to give
one instance, a large berry-bearing tree at James Island has no
representative species in Charles Island. But it is the circumstance,
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