c-stricken struggles to hold back; and it was the
pressure of this battling mass that was creating the horrible,
bulging undulation on the plain.

Grom's quick intelligence took in the situation on the instant.
The naked brown surface beneath the feet of the tribe was nothing
more than a thin crust overlying a lake of some dense, dark,
strange-smelling liquid.

His first impulse, naturally, was to turn back--and A-ya, with wide
eyes of terror, was already dragging fiercely at his elbow. But to
turn back was utterly impossible. That way lay the long strip of
engulfing pitch, swallowing up insatiably the ranks of the groaning
and kicking sambur. There was but one possible way of escape left
open, and that was straight ahead.

But would the crust continue to uphold them? Already, under the weight
of the whole tribe pressing together, it was beginning to sag
hideously. With furious words and blows he tried to make the tribe
scatter to right and left, so as to spread the pressure as widely as
possible. Perceiving his purpose, A-ya and Loob, and several of the
leading warriors, seconded his efforts with frantic vehemence; till in
a few minutes the whole tribe, amazed and quaking with awe, was
extended like a fan over a front of three or four hundred yards.
Seeing that the perilous sagging of the crust was at once relieved,
Grom then ordered the tribe to advance cautiously, keeping the same
wide-open formation, while he himself brought up the rear.

But in a few minutes every one, from Grom downwards, came to a halt
irresistibly, in order to watch the monstrous drama unfolding behind
them.

For nearly half a mile to either side of their immediate rear, between
the still unbroken surface of the dust-brown expanse and the edge of
the trampled grassy plain, stretched a sort of canal, perhaps ten
paces wide, of brown-black, glistening pitch, beaten up with thrashing
antlers, and tossing heads that whistled despairingly through wide
nostrils, and heaving, agonizing bulks that went down slowly to their
doom. After several ranks of the herd had been engulfed those next
behind turned about in terror and fought madly to force their way back
from the fatal brink. But the inexorable masses behind them rolled
them on backwards, and slowly they too were thrust down into the
pitch, till the canal was filled to the brink, and writhed horribly
along its whole length. By this time, however, the alarm had spread
through the rest of the s