for several minutes, listening. No other howl reached their ears, and the only sounds were that of the rushing stream as it tumbled over some rocks, and the cries of the night birds and the humming of the insects.
"Let us set up a yell," suggested Dan. "That may scare them off."
They called out at the top of their lungs several times. One distant howl answered them, then all became as silent as before.
"We may as well go on," said the older brother. "We'll be as safe moving as standing still. But keep your eyes peeled, Ralph."
They moved on slowly, with eyes turned to the right and the left, and keeping as far as possible from the brushwood and the low-hanging boughs of the trees. The mustangs seemed to realise that all was not right, and pricked up their ears and smelled the air.
