of his presence is blown to the prey; and he will skulk
across an open plain, stealing from hollow to hollow and stalking from
bush to bush, so that the wariest are taken by surprise. As for Black
Bart, he knew the kind of going which the stallion liked as well,
almost, as he knew his own preferences, and he picked out a course which
a surveyor with line and spirit-level could hardly have bettered. He
wove across the country in loosely thrown semicircles, and came back in
view of the master at the proper point. There was hardly much point in
such industry in a country as smooth as this, not much more difference,
say, than the saving of distance which the horse makes who hugs the
fence on the turn and on account of that sticks his head under the
finish wire a nose in front; and Bart clung to his work with scrupulous
care.

Sometimes he ran back with lolling, red tongue, when the course lay
clear even to the duller sense of a human, and frisked under the nose
of Satan until a word from Barry sent him scurrying away like a pleased
child. His duties comprehended not only the selection of the course but
also an eagle vigilance before and behind, so that when he came again
with a peculiar whine, Barry leaned a little from the saddle and spoke
to him anxiously.

"D'you mean to say that they been gainin' ground on us old boy?"

Black Bart leaped sidewise, keeping his head toward the master, and he
howled in troubled fashion.

"Whereaway are they now?" muttered Barry, and looked back again.

A great distance behind, hardly distinguishable now, the dust of the
posse was blending into the landscape and losing itself against a gray
background.

"If they's nothin' wrong behind, what's bitin' you, Bart. You gettin'
hungry, maybe? Want to hurry home?"

Another howl, still louder, answered him.

"Go on, then, and show me where they's trouble."

Black Bart whirled and darted off almost straight ahead, but bearing up
a hill slightly south of their course. Toward the top of this eminence
he changed his lope for a skulking trot that brought his belly fur
trailing on the ground.

"They's somethin' ahead of us, Satan!" cried the master softly. "What
could that be? It's men, by the way Bart sneaks up to look at 'em.
They's nothin' else that he'd do that way for. Easy, boy, and go soft!"

The stallion cut his gallop into a slinking trot, his head lowered,
even his ears flat back, and glided up the hillside. Barry swung to
the gr