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; still another is a thin string with a succession of large knobs, and another has its bark pinched up all round at intervals so as to present a great many cutting edges.

One sort need scarcely be mentioned, in which all along its length are strong bent hooks, placed in a way that will hold one if it can but grapple with him, for that is very common and not like those mentioned, which the rather seem to be stragglers from the carboniferous period of geologists, when Pachydermata wriggled unscathed among tangled masses worse than these.
We employed about ten jolly young Makonde to deal with these prehistoric plants in their own way, for they are accustomed to clearing spaces for gardens, and went at the work with a will, using tomahawks well adapted for the work.

They whittled away right manfully, taking an axe when any trees had to be cut.