vely little change took place in their forms or
habits. Of course, just in proportion as the islands got stocked I
noticed that the changes were less and less marked; for each new plant,
insect, or bird that established itself successfully tended to make the
balance of nature more similar to the one that obtained in the mainland
opposite, and so decreased the chances of novelty of variation.

Hence, it struck me that the oldest arrivals were the ones which
altered most in adaptation to the circumstances, while the newest,
finding themselves in comparatively familiar surroundings, had less
occasion to be selected for strange and curious freaks or sports of
form or colour.

The peopling of the islands with birds and animals, however, was to me
even a more interesting and engrossing study in natural evolution than
its peopling by plants, shrubs, and trees. I may as well begin,
therefore, by telling you at once that no furry or hairy quadruped of
any sort--no mammal, as I understand your men of science call them--was
ever stranded alive upon the shores of my islands. For twenty or thirty
centuries indeed, I waited patiently, examining every piece of
driftwood cast up upon our beaches, in the faint hope that perhaps some
tiny mouse or shrew or water-vole might lurk half drowned in some
cranny or crevice of the bark or trunk. But it was all in vain. I ought
to have known beforehand that terrestrial animals of the higher types
never by any chance reach an oceanic island in any part of this planet.
The only three specimens of mammals I ever saw tossed up on the beach
were two drowned mice and an unhappy squirrel, all as dead as
doornails, and horribly mauled by the sea and the breakers. Nor did we
ever get a snake, a lizard, a frog, or a fresh-water fish, whose eggs I
at first fondly supposed might occasionally be transported to us on
bits of floating trees or matted turf, torn by floods from those
prehistoric Lusitanian or African forests. No such luck was ours. Not a
single terrestrial vertebrate of any sort appeared upon our shores
before the advent of man with his domestic animals, who played havoc at
once with my interesting experiment.

It was quite otherwise with the unobtrusive small deer of life--the
snails, and beetles, and flies, and earthworms--and especially with the
winged things: birds, bats, and butterflies. In the very earliest days
of my islands' existence, indeed, a few stray feathered fowls of the
air wer