sun, while the air grew dark with clouds of birds that gradually
alighted on the ground, until, as the chorus grew fainter and
gradually ceased, they flew back to their nests. The three
companions had stood astonished while this act was played. The
doctor then spoke:

"This is the most marvellous development of Nature I have seen,
for its wonderful divergence from, and yet analogy to, what takes
place on earth. You know our flowers offer honey, as it were, as
bait to insects, that in eating or collecting it they may catch
the pollen on their legs and so carry it to other flowers,
perhaps of the opposite sex. Here flowers evidently appeal to
the sense of hearing instead of taste, and make use of birds, of
which there are enormous numbers, instead of winged insects, of
which I have seen none, one being perhaps the natural result of
the other. The flowers have become singers by long practice, or
else, those that were most musical having had the best chance to
reproduce, we have a neat illustration of the 'survival of the
fittest.' The sound is doubtless produced by a shrinking of the
fibres as the sun withdraws its heat, in which case we may expect
another song at sunrise, when the same result will be effected by
their expanding."

Searching for a camping-place in which to pass the coming hours,
they saw lights flitting about like will-o'-the-wisps, but
brighter and intermittent.

"They seem to be as bright as sixteen-candle-power lamps, but the
light is yellower, and appears to emanate from a comparatively
large surface, certainly nine or ten inches square," said the