Many have tried to explain it by imagining them swept away by a flood when camped on flat country, but this is scarcely likely, for even then, on the subsidence of the waters, the blacks would have found something of their belongings. Thirst was most likely the agent of their destruction, and fire completed the work. Once across the waters that wend their sluggish way into the lake district of South Australia, Leichhardt and his followers would be in the great region of fragmentary watercourses; rivers and creeks, when met with, pursuing no definite courses--now lost in miles of level country, now reforming again for a brief existence, but always delusive and disappointing. Here they would one day find themselves in a position that left them no other chance but the slender one of still pushing forward into the unknown. Probably it was during one of the cycles of rainless years that periodically visit the continent. Led on mile after mile, following the dry bed of one creek, to lose it in some barren flat, whereon the withered stalks of blue-bush alone told of a time of past vegetation; again picking up another creek, to lose it in like manner, knowing that to retrace their steps was impossible; making at last for a hazy, blue line in the distance that turned out to be spinifex and stunted forest; trusting still that this might indicate a change that would lead them to higher country and to water, they would struggle forward, weak and disorganised. Then would come the beginning of the end. As they pressed on, the forest became scantier, and the spinifex higher, spikier, and harder to march through. One by one their animals had fallen and died, and the desperate resort of drinking the blood had been tried by some. What little water they had in their canteens was fast evaporating. Still some of them would keep heart. The ground was getting stonier, and bare patches of rock were constantly passed; surely they must be getting on higher country; they were doubtless ascending the gradual rise of one of the inland watersheds, and suddenly they hoped the ground would break away at their feet in deep gullies and ravines; below they would see the tops of green trees, shading some quiet waterhole. How anxiously they looked out for any sign of life that might be a good augury of this, but none could be seen.