etaining its hooked seeds,
would form an endemic species, having as useless an appendage as any
rudimentary organ,--for instance, as the shrivelled wings under the
soldered elytra of many insular beetles. Again, islands often possess
trees or bushes belonging to orders which elsewhere include only
herbaceous species; now trees, as Alph. de Candolle has shown, generally
have, whatever the cause may be, confined ranges. Hence trees would be
little likely to reach distant oceanic islands; and an herbaceous plant,
though it would have no chance of successfully competing in stature
with a fully developed tree, when established on an island and having to
compete with herbaceous plants alone, might readily gain an advantage
by growing taller and taller and overtopping the other plants. If so,
natural selection would often tend to add to the stature of herbaceous
plants when growing on an island, to whatever order they belonged, and
thus convert them first into bushes and ultimately into trees.

With respect to the absence of whole orders on oceanic islands, Bory St.
Vincent long ago remarked that Batrachians (frogs, toads, newts) have
never been found on any of the many islands with which the great oceans
are studded. I have taken pains to verify this assertion, and I have
found it strictly true. I have, however, been assured that a frog exists
on the mountains of the great island of New Zealand; but I suspect that
this exception (if the information be correct) may be explained through
glacial agency. This general absence of frogs, toads, and newts on
so many oceanic islands cannot be accounted for by their physical
conditions; indeed it seems that islands are peculiarly well fitted for
these animals; for frogs have been introduced into Madeira, the Azores,
and Mauritius, and have multiplied so as to become a nuisance. But as
these animals and their spawn are known to be immediately killed by
sea-water, on my view we can see that there would be great difficulty in
their transportal across the sea, and therefore why they do not exist on
any oceanic island. But why, on the theory of creation, they should not
have been created there, it would be very difficult to explain.

Mammals offer another and similar case. I have carefully searched the
oldest voyages, but have not finished my search; as yet I have not found
a single instance, free from doubt, of a terrestrial mammal (excluding
domesticated animals kept by the natives) inhab