a
centipede on your arm!' He pulled his Colt, and shot the blamed
centipede off as clean as a whistle. But the bullet hit a steer in the
leg; and would you believe it, the bullet carried so much poison that
in less than two hours the steer died of blood poisoning. Centipedes
are so poisonous they leave a blue trail on flesh just by crawling over
it. Look there!"

He bared his arm, and there on the brown-corded flesh was a blue trail
of something, that was certain. It might have been made by a centipede.

"This is a likely place for them," put in Wallace, emitting a volume of
smoke and gazing round the cave walls with the eye of a connoisseur.
"My archaeological pursuits have given me great experience with
centipedes, as you may imagine, considering how many old tombs, caves
and cliff-dwellings I have explored. This Algonkian rock is about the
right stratum for centipedes to dig in. They dig somewhat after the
manner of the fluviatile long-tailed decapod crustaceans, of the genera
Thoracostraca, the common crawfish, you know. From that, of course, you
can imagine, if a centipede can bite rock, what a biter he is."

I began to grow weak, and did not wonder to see Jim's long pipe fall
from his lips. Frank looked queer around the gills, so to speak, but
the gaunt Stewart never batted an eye.

"I camped here two years ago," he said, "An' the cave was alive with
rock-rats, mice, snakes, horned-toads, lizards an' a big Gila monster,
besides bugs, scorpions' rattlers, an' as fer tarantulers an'
centipedes--say! I couldn't sleep fer the noise they made fightin'."

"I seen the same," concluded Lawson, as nonchalant as a wild-horse
wrangler well could be. "An' as fer me, now I allus lays perfickly
still when the centipedes an' tarantulers begin to drop from their
holes in the roof, same as them holes up there. An' when they light on
me, I never move, nor even breathe fer about five minutes. Then they
take a notion I'm dead an' crawl off. But sure, if I'd breathed I'd
been a goner!"

All of this was playfully intended for the extinction of an unoffending
and impressionable tenderfoot.

With an admiring glance at my tormentors, I rolled out my sleeping-bag
and crawled into it, vowing I would remain there even if devil-fish,
armed with pikes, invaded our cave.

Late in the night I awoke. The bottom of the canyon and the outer floor
of our cave lay bathed in white, clear moonlight. A dense, gloomy black
shadow veiled the op