the dark forms of a range of low hills were outlined upon
the horizon. I concluded to push on and gain their shelter. Once within
their protecting shadow, I could pursue my course more leisurely, and
without the fear of immediate detection. My grand anxiety was to hide
or blind the trail, and by this means baffle the sleuth hounds, who were
by this time in full pursuit.

I had not proceeded far when the pony came to a sudden halt, which
almost unseated me. I tried to urge him forward by word and action, but
it was of no avail; he refused to move, and stood trembling like an
aspen. Leaning forward and peering over his neck, I discovered, to my
dismay, a wide chasm, which fully explained why the mustang had refused
to be urged forward. The banks on either side were quite level, and no
indentations or ruggedness marked the line of separation. One could ride
up to its very brink without being aware of a break in the prairie
level. I had thus come upon one of those _barancas_, the result of
volcanic action, that are so frequently met with in this country. There
was no alternative but to ride along its edge until I came to a point
where its sides were depressed to the level of the plain. This, of
course, involved a long detour, and a consequent loss of valuable time.
My only consolation was in the reflection that my enemies, in following
the trail, would be compelled to resort to the same tactics.

I had journeyed down its banks about three miles, before I found an
opportunity to cross. As I reached the opposite side, I turned and
looked back. Away to my right, and in the direction from whence I came,
I discerned a number of dark specks on the horizon, which filled me with
the direst apprehensions. These dark objects were, doubtless, the forms
of my pursuers, who had, it would seem, traveled with a celerity almost
equaling my own. The chase now assumed a desperate aspect; before me lay
life, hope, and freedom; behind was a nemesis that represented
captivity, torture, and death. I plied the whip vigorously to the flank
of my jaded steed, in the frantic endeavor to reach the cover of the
mountain. I had not proceeded far on my course, when my pony showed
unmistakable signs of giving out. Indeed, I had not made more than a
mile on my course, when the animal stopped abruptly. I could feel him
tremble under my weight; and dropping on his knees, I had scarcely time
to leap to the ground before he fell, and drawing a deep sigh, he t