raggy, their croups more slanting,
their legs shorter; but their hoofs grew denser, hardier, their shorter
coupling gave them greater weight-carrying possibilities, the stout
bones and the clean lines of their legs meant speed, and above all they
kept the stout heart of the thoroughbred and they gained more than this,
an indomitable, bulldog persistence. The cheapest Western cow-pony may
look like the cartoon of a horse, but he has points which a judge will
note, and he will run a picture horse to death in three days.

Such were the horses which took the trail of Satan and they were chosen
specimens of their kind. Up the slope they stormed and there went Satan
skimming across the hollow beneath them. Their blood was his blood,
their courage his courage, their endurance his endurance. The difference
between them was the difference between the factory machine and the hand
made work of art. From his pasterns to his withers, from his hoofs to
his croup every muscle was perfectly designed and perfectly placed for
speed, tireless running; every bone was the maximum of lightness and
strength combined. A feather bloom on a steady wind, such was the gait
of Satan.

Down the hollow the posse thundered, and up the farther slope, and still
the black slipped away from them until Mark Retherton cursed deeply to
himself.

"Don't race your hosses, boys," he shouted. "Keep 'em in hand. That
devil is playing with us."

As a result, they checked their mounts to merely a fast gallup, and
Barry, looking back, laughed softly with understanding. Far different
the laborious pounding of the posse and the light stretch of Satan
beneath him. He leaned a little until he could catch the sound of the
breathing, big, steady draughts with comfortable intervals between.
He could run like that all day, it seemed, and Whistling Dan ran his
fingers luxuriously down the shining neck. Instantly the head tossed
up, and a short whinney whipped back to him like a question. Just before
them the Morgan Hills jutted up, like stiff mud chopped by the tread of
giants. "Now, partner," murmured Barry, "show 'em what you can do! Jest
lengthen out a bit."

The steady breeze from the running sharpened into a gale, whisking about
his face; there was no longer the wave-like rock of that swinging gallup
but a smooth, swift succession of impulses. Rocks, shrubs darted past
him, and he felt a gradual settling of the horse beneath him as the
strides lengthened, From beh