grass, which was six or seven feet above the water and blocked all outlook.

The water at this point being more than five or six feet deep, we had great difficulty in paddling, poling, and pushing the canoes through. We felt absolutely lost in this trackless wilderness of grass, and could only follow the course of the river by going against the current, the bank being completely hidden. After several miles of this unpleasant travelling we found an open stretch of water about forty yards wide, which led us up to the village of Angoma. It has been suggested that, by the growth of this rank grass and other vegetation, together with the debris deposited in it by the percolating water, the Lukuga is sometimes dammed, and that this may be a cause for the extraordinary variation of the level which has been noticed on Tanganyika.