animals probably took for some new species of enemy? These were
questions which the boys waited anxiously to have answered. Nor did
they have to wait long.

The foremost of the steers came within a few feet of the rattlers.
Then something seemed to stiffen the cattle. They tried to stop short,
but the press of the beasts behind them would not permit of this. For
a few seconds it looked as if the impetus of the cattle in the rear
would shove the others on, in spite of their desire to stop.

But now more of the foremost steers became aware of the den of snakes.
Their instinct, their sense of smell, and, above all, hearing the
rattling, told them the terrible danger that was in their path. More
of the animals braced their forelegs to bring themselves to a stop,
and all bellowed in terror. Then, almost as though an order had been
given by some one in command, the ranks of steers parted, right at the
point where the snakes were reared ready to strike.

To right and left the cattle passed, increasing their speed as they
became aware of the danger they were escaping. The boys and the
professor stood on the little eminence of land, as if they were on an
island in a sea of cattle. The angry snakes hissed and rattled, but
did not glide away, or what had proved a source of safety for the
travelers, might have been instrumental in their death.

Right past them rushed the cattle, raising a dust that was choking.
The four were enveloped in a yellow haze, as they stood huddled
together. Then, the last of the steers galloped past, with a band of
excited cowboys in the rear, vainly endeavoring to understand the
cause of the stampede, and halt it. As they rode on like the wind,