Sometimes the whole set appeared to bounce up at once; and the white canvas of the tent, which had got loosened, was flapping up and down, as her body rose and fell.
The boys looked on for a moment, with feelings of curiosity, not unmingled with fear.

"It might be Indians," thought they.
"No," said Basil.

"It is wolves--she is attacked by wolves! Let us hasten to her rescue!" All three spurred their horses into a gallop, and soon got within a few hundred yards.

They could now see the ground by the mule's feet, which was covered, not with wolves, but with animals of a far different species.

They were hog-shaped, with small, dark bodies, and long pointed snouts.