pil

"The triangular tip (Figs. 73-80) consists of one from the pliers protruding triangular, double-edged leaf. This blade is usually provided with two rearward barbs (Figs. 75-80) or two shallow barbs (Fig. 74). At some point, the triangular blade lacks of barbs (Fig. 73). The pliers are also usually fitted with barbs (Figs. 73, 77 and 79). If there are none, it is adorned with notches or carved ornaments (figs. 75 and 76), which are probably arranged so that the arrow poison will stick more easily when used. Arrows with a triangular tip are exceptionally provided with guide springs (Figs. 78 and 79); some are poisoned (Figs. 78 and 80).
The arrow poison is prepared from seeds of Strophantus Welwitschii. The seeds are crushed and mixed with flour and water to a dough. This dough is smeared on the tip of the arrow head, where it is let to harden. The poison is extremely powerful and has a paralyzing effect on the heart.
In figs. 79 and 80, a wooden stick tied to the pliers is seen immediately in front of the forward end of the arrow tube. This small crossbar has the task of prevent the arrow from cutting through reeds or grass blades in the event of a boom shot and disappearing into the dunes. If an arrow fitted with a crossbar strikes a reed, it gets stuck and can then be recovered. Transverse loans are always placed so far from the cape that the arrow, if fired at animals or humans, can still have the intended effect. The swamps always carve a few small lines on the crossbar so that they can "get lucky with the arrow". I have also seen this depicted device with a crossbar on the arrow in use in babisa, baushi and balenge; according to an oral statement from Dr. G. Lindblom, it also occurs here and there in East Africa, but is not previously described in the literature."
(pp. 186 - 189, von Rosen, 1916, translated from Swedish).