Coming down the Zouga, we had now time to look at its banks.  These are very beautiful, resembling closely many parts of the River Clyde above Glasgow.  The formation is soft calcareous tufa, such as forms the bottom of all this basin.  The banks are perpendicular on the side to which the water swings, and sloping and grassy on the other.  The slopes are selected for the pitfalls designed by the Bayeiye to entrap the animals as they come to drink.  These are about seven or eight feet deep, three or four feet wide at the mouth, and gradually decrease till they are only about a foot wide at the bottom.  The mouth is an oblong square (the only square thing made by the Bechuanas, for every thing else is round), and the long diameter at the surface is about equal to the depth.  The decreasing width toward the bottom is intended to make the animal wedge himself more firmly in by his weight and struggles.  The pitfalls are usually in pairs, with a wall a foot thick left uncut between the ends of each, so that if the beast, when it feels its fore legs descending, should try to save itself from going in altogether by striding the hind legs, he would spring forward and leap into the second with a force which insures the fall of his whole body into the trap.  They are covered with great care.  All the excavated earth is removed to a distance, so as not to excite suspicion in the minds of the animals.  Reeds and grass are laid across the top; above this the sand is thrown, and watered so as to appear exactly like the rest of the spot.  Some of our party plumped into these pitfalls more than once, even when in search of them, in order to open them to prevent the loss of our cattle.  If an ox sees a hole, he carefully avoids it; and old elephants have been known to precede the herd and whisk off the coverings of the pitfalls on each side all the way down to the water.  We have known instances in which the old among these sagacious animals have actually lifted the young out of the trap.

The trees which adorn the banks are magnificent.  Two enormous baobabs (’Adansonia digitata’), or mowanas, grow near its confluence with the lake where we took the observations for the latitude (20d 20’ S.).  We were unable to ascertain the longitude of the lake, as our watches were useless; it may be between 22 Deg. and 23 Deg.  E. The largest of the two baobabs was 76 feet in girth.  The palmyra appears here and there among trees not met with in the south.  The mokuchong, or moshoma, bears an edible fruit of indifferent quality, but the tree itself would be a fine specimen of arboreal beauty in any part of the world.  The trunk is often converted into canoes.  The motsouri, which bears a pink plum containing a pleasant acid juice, resembles an orange-tree in its dark evergreen foliage, and a cypress in its form.  It was now winter-time, and we saw nothing of the flora.  The plants and bushes were dry; but wild indigo abounded, as indeed it does over large tracts of Africa.  It is called mohetolo, or the “changer”, by the boys, who dye their ornaments of straw with the juice.  There are two kinds of cotton in the country, and the Mashona, who convert it into cloth, dye it blue with this plant.