Settling themselves comfortably in their bed of dry reeds and grass, the two hunters now concentrated their attention upon these indistinct and stealthily moving objects, with the result that, as their eyes gradually adapted themselves to the new conditions of light--or darkness, rather-- it became possible for them to form some sort of opinion as to the species of the different animals there congregated together. They appeared to be chiefly bucks of various kinds, with a zebra or two, none of which the sportsmen thought worth a cartridge; they were therefore permitted to pass to and fro unmolested. Gradually the number of animals coming down to drink grew less and less, until at length no more came at all, and the spot seemed to be completely deserted. And then, with the cessation of the coming and going, the vigilance of the watchers gradually relaxed, and the thought occurred to Mildmay that they might as well be getting back to the ship. He made the suggestion to von Schalckenberg, but the latter pleaded so earnestly for an hour or two longer, urging the possibility of a visit from the unicorns, that the good-natured sailor readily gave way, with the remark-- "All right, Professor. `In for a penny, in for a pound;' I don't mind. Only--I suppose a fellow mustn't smoke?" "Smoke! oh no," answered the professor, in keen distress at thus being obliged to deny his companion the solace of a pipe. "Do you think I am not pining for a smoke, too?" argued the scientist. "But were we to do so, the smell of the burning tobacco would scare everything away. Nothing would come near us. We will fill ourselves up with smokes when by-and-by we walk back to the ship." So Mildmay settled himself down as comfortably as he could once more, and never knew when sleep overtook him. As for the professor, he was quite determined to remain where he was until daylight, if need were. He told himself that the unicorns _must_ drink somewhere, and why not here? It was as likely a place as any, and quite worth watching, and-- and--yes--um! The professor's eyes closed, his thoughts wandered, and presently he, too, was asleep. The grey light of dawn was in the sky when the slumbering pair were startled into instant and broad wakefulness by the sound of a curious barking kind of neigh. They had heard it but once in their lives before this, but they both recognised it in a moment. "By Jove!" gasped the professor, laying his hand upon Mildmay's arm and compressing it in a vice-like grasp, "the unicorns!"