hile a sickening odour
arose. Although the sun was still far above the horizon, the rapidity
with which it was descending showed that the short night of less than
five hours would soon be upon them; and though short it might be very
dark, for they were in the tropics, and the sun, going down
perpendicularly, must also pass completely around the globe, instead
of, as in northern latitudes on earth in summer, approaching the
horizon obliquely, and not going far below it. A slight and diffused
sound here seemed to rise from the ground all about them, for which
they could not account. Presently it became louder, and as the sun
touched the horizon, it poured forth in prolonged strains. The large
trumpet-shaped lilies, reeds, and heliotropes seemed fairly to throb as
they raised their anthem to the sky and the setting 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 doctor.

They soon gave up the