ries, the Lachlan and Murrumbidgee, are lasting streams; but the Darling, a river of considerable size, flowing into the Murray from the north, has the Australian peculiarity of disappearing into quicksands and marshes. With the exception of the Murray, all the other permanent streams of Australia are short, and of little consequence; and, like the rivers of New Zealand, they have been clogged with water-cress, which was introduced from England in the expectation that it would be a great luxury."
A WATERLESS REGION.
"You have hit exactly upon the obstacle which has baffled Australian explorers," said the Doctor. "All who have sought to penetrate the interior have suffered terribly from thirst, and some expeditions that have never been heard from are supposed to have perished from the same cause. The rainfall in the interior of the continent is slight, the heat in summer is intense, and even in winter the thermometer sometimes runs to a high figure."
"Then it is fair to suppose that the interior of Australia is practically of no use," Frank remarked.
"It is fair to suppose so," was the reply; "but some scientists
