The notion of a rainy zone, in which the clouds deposit their treasures in perpetual showers, has received no confirmation from my observations. In 1866-7, the rainfall was 42 inches. In 1867-8, it amounted to 53 inches: this is nearly the same as falls in the same latitudes on the West Coast. In both years the rains ceased entirely in May, and with the exception of two partial thunder showers on the middle of the watershed, no rain fell till the middle and end of October, and then, even in November, it was partial, and limited to small patches of country; but scarcely a day passed between October and May without a good deal of thunder. When the thunder began to roll or rumble, that was taken by the natives as an indication of the near cessation of the rains. The middle of the watershed is the most humid part: one sees the great humidity of its climate at once in the trees, old and young, being thickly covered with lichens; some flat, on the trunks and branches; others long and thready, like the beards of old men waving in the wind. Large orchids on the trees in company with the profusion of lichens are seen nowhere else, except in the mangrove swamps of the sea-coast. I cannot account for the great humidity of the watershed as compared with the rest of the country, but by the prevailing winds and the rains being from the south-east, and thus from the Indian Ocean: with this wind generally on the surface one can observe an upper strong wind from the north-west, that is, from the low humid West Coast and Atlantic Ocean. The double strata of winds can easily be observed when there are two sheets of clouds, or when burning grass over scores of square miles sends up smoke sufficiently high to be caught by the upper or north-west wind. These winds probably meet during the heavy rains: now in August they overlap each other. The probability arises from all continued rains within the tropics coming in the opposite direction from the prevailing wind of the year. Partial rains are usually from the south-east. The direction of the prevailing wind of this region is well marked on the islands in Lake Bangweolo: the trunks are bent away from the south-east, and the branches on that side are stunted or killed; while those on the north-west run out straight and make the trees appear lopsided. The same bend away from the south-east is seen on all exposed situations, as in the trees covering the brow of a hill. At Kizinga, which is higher than the Lake, the trees are covered with lichens, chiefly on the south-east sides, and on the upper surfaces of branches, running away horizontally to or from the north-west. Plants and trees, which elsewhere in Africa grow only on the banks of streams and other damp localities, are seen flourishing all over the country: the very rocks are covered with lichens, and their crevices with ferns.