240 SOUTH AND EAST AFRICA. Zaml>esc. But elsewhere nothing ia visible except thorny plants, scrub or even dreary wastes of sand. During the greater part of the year, Lake Ngarai discharges its overflow east- wards through the Zuga emissary, which, after flowing for some distance in that direction, trends to the south and again round to the east as far as the extensive saline tract known as the Makarakara, or Mukarikari, that is, the " Mirage." This shallow depression is occasionally flooded with a little water, which like Ngami, is constantly disi)lace<l by the prevailing and alternating winds. Between both basins, for a distance of no less than 240 miles west and east, Anderson's measurements could detect no difference of level, a few inches at the most probably representing the actual incline along this section of the ancient lacustrine depres- sion. Hence the least obstruction, the slightest change of barometric pressure, the smallest alternation between atmospheric dryness and moisture, the growth of a few tufts of reeds, suffice to affect the flow of the waters wandering with unde- cided course over the plain of the "thousand lakes." The whole region is tra- versed in every direction by fluvial beds alternately flooded or empty, by meres, swamps, and salines constantly displaced and restored. So intricate are the ramifying branches of the Indgten, that during the period of high water the natives venturing in their frail barks on the sluggish stneams often lose their way and spend days in searching for the right channel to cross the inundated plain. Even the Zuga, the only perennial river in this region of imperceptible slope, reverses its current, which in April and May sets steadily from Ngami,. but during the two following months flows back to the lake. During the floods the Mababe branch of the Zuga trends towards the north, and while a portion of its contents disappears amid the surrounding sands, another portion reaches the Chobe, which is itself a tributary of the Zambese. Thus the hydro- graphic systems of the Ku-Bango and Zumbese become periodically intermingled, and the original unity of the whole of this area of drainage is temporarily re-established. At this season the almost boundless watery horizon is relieved here and there by pleasant stretches of woodlands, clumps of -graceful palms, or gigantic isolated baobabs. A few eminences, assuming the aspect of lofty hills, appear as Islets and archipelagos in the midst of the ancient inland sea thus annually revived during the rainy period. The periphery of this level plain consists to a great extent of "volcanic formations. The Chobe. The Chobe or Kwa-ndo (Cuando), whose lower course connects the Ku-Bango with the Zumbese, rises like both of these rivers on the southern slope of the transverse waterparting, which stretches from the Bihe territory across the continent in an oblique direction to the region of the great equatorial lakes. The Chobe trickh s us a tiny brook from a swamp which fills a depression confined between two hills, and according to Serpa Pinto, standing at an elevation of
