As they went forward the next day they were all amazed at the remarkable tameness of the herds which passed on every side. A drove of at least a hundred zebra paused within fifty yards of them, gazing curiously, and not until Bakari flourished a spear did they whirl and dash away. At another time a group of slender-horned impalla bunched together not a hundred yards away, watching fearlessly as the wagon passed. "That looks mighty queer," declared Charlie. "Seems like they don't get hunted much up here." "Remember what that letter o' Mowbray's said?" interjected Jack quickly. "How he never met any natives, I mean? Bet a cookie you were right, General, about the slavers." "What's worrying me," returned Schoverling, "is where that lake can be. There seems to be hills ahead, and to the right, but I can see no sign of a lake." "I tell you," cried Charlie. "If we strike another drift, it's a good guess that it comes from a lake, isn't it?" "Yes," rumbled von Hofe, smiling. "That is right, my boy. We will follow the next river to which we come." Plainly enough, the country was a desert as far as human life was concerned. But the animal life was far too abundant to suit them. That day they passed a rhinoceros, standing to one side and watching them from a distance of fifty yards. With his ears cocked forward he looked like a gigantic pig, but the hunters kept their heavy rifles cocked, for at any moment the beast might take it into his head to charge, and they had had one experience with these huge beasts. "He's two-horned!" exclaimed Jack, watching intently. It was their first meeting with one of the two-horned variety, and they were relieved when he turned and slowly trotted off, the tick-birds on his back settling down again. That night Schoverling issued orders that with each halt the Masai should construct a thorn zareba for the oxen, while big fires should be kept blazing all night. Lions were very plainly in abundance, and they could afford to run no risk of losing the cattle, or horses either. Toward dawn they were aroused by Guru, on guard, to find the horses shivering with fear and the glowing eyes of lions shining from the undergrowth around the camp. A shot seemed to have no effect, until with a well-placed bullet Schoverling killed one of the beasts and the rest disappeared with threatening rumbles. "That shows what we can expect, in this no-man's country," he said. "We'll have worse than that later on, I'm afraid." And his words were to prove true, though not exactly as he had intended, before two days more had passed. Shortly before noon they came upon lower ground, with the high hills rising some ten miles farther on. A stream trickled through beds of reeds and swamp-grass, and it was decided that they should follow the high ground upstream, in the hope of being thus led to their hard-sought goal.