For, save in places, the ground was sandy and firm, and, dark as it was, they had no difficulty in making out the watery spots by their faint gleam or the different character of the growth.
They shouted in turns and together, listening, going in different directions, and all to no purpose.

Not a sound could they get in reply; and at last, with a curious feeling of horror stealing over him, compounded of equal parts of superstition and dread lest the person whose cry they had heard had sunk in the mire of some hole, Dick reluctantly gave way to Tom's suggestion that they should go back to the boat.
"I knew it was something queer," whispered Tom.

"If we had gone on, we should have been led into some dangerous hole and lost." "Don't believe it," said Dick, as they trudged slowly back, utterly worn-out and hoarse with shouting.
"You're such a doubting fellow!" grumbled Tom.

"If it had been anybody in distress we should have found him." "Perhaps," said Dick sadly.

"It's so dark, though, that we might have passed him over." "Nonsense!" cried Tom; "we were sure to find him.