oo, winged species have stood at a great
advantage. To be sure, the earliest butterflies and bees that arrived
in the fern-clad period were starved for want of honey; but as soon as
the valleys began to be thickly tangled with composites, harebells, and
sweet-scented myrtle bushes, these nectar-eating insects established
themselves successfully, and kept their breed true by occasional
crosses with fresh arrivals blown to sea afterwards. The development of
the beetles I watched with far greater interest, as they assumed fresh
forms much more rapidly under their new conditions of restricted food
and limited enemies. Many kinds I observed which came originally from
Europe, sometimes in the larval state, sometimes in the egg, and
sometimes flying as full-grown insects before the blast of the angry
tempest. Several of these changed their features rapidly after their
arrival in the islands, producing at first divergent varieties, and
finally, by dint of selection, acting in various ways, through climate,
food, or enemies, on these nascent forms, evolving into stable and
well-adapted species. But I noticed three cases where bits of driftwood
thrown up from South America on the western coasts contained the eggs
or larvae of American beetles, while several others were driven ashore
from the Canaries or Madeira; and in one instance even a small insect,
belonging to a type now confined to Madagascar, found its way safely by
sea to this remote spot, where, being a female with eggs, it succeeded
in establishing a flourishing colony. I believe, however, that at the
time of its arrival it still existed on the African continent, but
becoming extinct there under stress of competition with higher forms,
it now survives only in these two widely separated insular areas.

It was an endless amusement to me during those long centuries, while I
devoted myself entirely to the task of watching my fauna and flora
develop itself, to look out from day to day for any chance arrival by
wind or waves, and to follow the course of its subsequent vicissitudes
and evolution. In a great many cases, especially at first, the
new-comer found no niche ready for it in the established order of
things on the islands, and was fain at last, after a hard struggle, to
retire for ever from the unequal contest. But often enough, too, he
made a gallant fight for it, and, adapting himself rapidly to his new
environment, changed his form and habits with surprising facility