reason why the trees are not large is because all the spaces we passed
over were formerly garden ground before the Makondé had been thinned
by the slave-trade. As soon as a garden is deserted, a thick crop of
trees of the same sorts as those formerly cut down springs up, and
here the process of woody trees starving out their fellows, and
occupying the land without dense scrub below, has not had time to work
itself out. Many are mere poles, and so intertwined with climbers as
to present the appearance of a ship's ropes and cables shaken in among
them, and many have woody stems as thick as an eleven-inch hawser. One
species may be likened to the scabbard of a dragoon's sword, but along
the middle of the flat side runs a ridge, from which springs up every
few inches a bunch of inch-long straight sharp thorns. It hangs
straight for a couple of yards, but as if it could not give its thorns
a fair chance of mischief, it suddenly bends on itself, and all its
cruel points are now at right angles to what they were before.
Darwin's observation shows a great deal of what looks like instinct in
these climbers. This species seems to be eager for mischief; its
tangled limbs hang out ready to inflict injury on all passers-by.
Another climber is so tough it is not to be broken by the fingers;
another appears at its root as a young tree, but it has the straggling
habits of its class, as may be seen by its cords stretched some fifty
or sixty feet off; it is often two inches in diameter; you cut it
through at one part and find it reappear forty yards off.

[Illustration: Tomahawk and Axe.]

Another climber is like the leaf of an aloe, but convoluted as
strangely as shavings from the plane of a carpenter. It is dark green
in colour, and when its bark is taken off it is beautifully striated
beneath, lighter and darker green, like the rings of growth on wood;