in any one region. Many of them are very rare, others extremely local, while a
considerable number inhabit the more arid regions of Africa and India, in which
tropical vegetation does not exhibit itself in its usual luxuriance. Fine and varied
foliage, rather than gay flowers, is more characteristic of those parts where
tropical vegetation attains its highest development, and in such districts each
kind of flower seldom lasts in perfection more than a few weeks, or sometimes a
few days. In every locality a lengthened residence will show an abundance of
magnificent and gaily-blossomed plants, but they have to be sought for, and are
rarely at any one time or place so abundant as to form a perceptible feature in the
landscape. But it has been the custom of travellers to describe and group together
all the fine plants they have met with during a long journey, and thus produce the
effect of a gay and flower-painted landscape. They have rarely studied and
described individual scenes where vegetation was most luxuriant and beautiful,
and fairly stated what effect was produced in them by flowers. I have done so
frequently, and the result of these examinations has convinced me that the bright
colours of flowers have a much greater influence on the general aspect of nature
in temperate than in tropical climates. During twelve years spent amid the
grandest tropical vegetation, I have seen nothing comparable to the effect
produced on our landscapes by gorse, broom, heather, wild hyacinths, hawthorn,
purple orchises, and buttercups.
The geological structure of this part of Celebes is interesting. The limestone
mountains, though of great extent, seem to be entirely superficial, resting on a
basis of basalt which in some places forms low rounded hills between the more
precipitous mountains. In the rocky beds of the streams basalt is almost always
found, and it is a step in this rock which forms the cascade already described.
From it the limestone precipices rise abruptly; and in ascending the little
stairway along the side of the fall, you step two or three times from one rock on
to the other—the limestone dry and rough, being worn by the water and rains
into sharp ridges and honeycombed holes—the basalt moist, even, and worn
smooth and slippery by the passage of bare-footed pedestrians. The solubility of
the limestone by rain-water is well seen in the little blocks and peaks which rise
thickly through the soil of the alluvial plains as you approach the mountains.
They are all skittle-shaped, larger in the middle than at the base, the greatest
diameter occurring at the height to which the country is flooded in the wet
season, and thence decreasing regularly to the ground. Many of them overhang
considerably, and some of the slenderer pillars appear to stand upon a point.
When the rock is less solid it becomes curiously honeycombed by the rains of
successive winters, and I noticed some masses reduced to a complete network of