About two o’clock, having rested sufficiently, we once more forged ahead, bearing more to the north-east than in the direction we had hitherto followed. We encountered the same soft crumbling brown earth, with loose stones on the surface. Aloes, morio trees, and thorn trees were the only vegetation, and even they were only sparsely distributed. The country was formed of long rolling ridges, which we traversed at right angles. It was a weary and tiresome march. Each time we climbed a ridge we looked eagerly forward for a sight of the longed-for Waso Nyiro. Again and again we were disappointed, each ridge exactly resembling the last. At four o’clock in the afternoon we entered a small belt of thorn trees and dodged a couple of rhinos who were love-making just inside, and would no doubt have resented being disturbed. When we once more emerged from the thorn belt we gazed over a broad plain which sloped gently down to a range of dun-coloured hills some miles away. The Waso Nyiro, we knew, flowed at the foot of these hills, and once more we pressed forward, momentarily forgetting our fatigue in our eagerness to reach the desired goal. I was walking with my Martini over my shoulder, when I was considerably startled by a noise from my left, which caused me to hurriedly bring my rifle to the ready. It was a long-drawn growling grunt, and my first thought was of lions. Closer attention, however, solved the mystery. It was the cry of a zebra, one of a herd of Grevy’s beautiful zebra which were congregated over half a mile away. The cry of the zebra is very like a long-drawn growling whistle, and in the distance, when too far off to hear the whistle, the growl very much resembles that of a lion. There were large herds of oryx in sight, and a few rhinoceros and water-buck. The sun sank gradually lower in the western heavens, and we were still apparently no nearer the range of hills we were making for, so deceptive are the apparent distances in the clear atmosphere. But just as dusk had fallen, our eyes were gladdened by the sight of a large clump of Doum palms growing in the centre of an open green space a mile away. We made towards them, and feasted our weary eyes on the beautiful green expanse stretching out before us.