stout pegs, as large around as a man's wrist protruding from
holes in the cliff into which they were driven. Es-sat's four handlike
members and his long, sinuous tail permitted him to move with
consummate ease whither he chose--a gigantic rat upon a mighty wall. As
he progressed upon his way he avoided the cave mouths, passing either
above or below those that lay in his path.

The outward appearance of these caves was similar. An opening from
eight to as much as twenty feet long by eight high and four to six feet
deep was cut into the chalklike rock of the cliff, in the back of this
large opening, which formed what might be described as the front
veranda of the home, was an opening about three feet wide and six feet
high, evidently forming the doorway to the interior apartment or
apartments. On either side of this doorway were smaller openings which
it were easy to assume were windows through which light and air might
find their way to the inhabitants. Similar windows were also dotted
over the cliff face between the entrance porches, suggesting that the
entire face of the cliff was honeycombed with apartments. From many of
these smaller apertures small streams of water trickled down the
escarpment, and the walls above others was blackened as by smoke.
Where the water ran the wall was eroded to a depth of from a few inches
to as much as a foot, suggesting that some of the tiny streams had been
trickling downward to the green carpet of vegetation below for ages.

In this primeval setting the great pithecanthropus aroused no jarring
discord for he was as much a part of it as the trees that grew upon the
summit of the cliff or those that hid their feet among the dank ferns
in the bottom of the gorge.

Now he paused before an entrance-way and listened and then, noiselessly
as the moonlight upon the trickling waters, he merged with the shadows
of the outer porch. At the doorway leading into the interior he paused
again, listening, and then quietly pushing aside the heavy skin that
covered the aperture he passed within a large chamber hewn from the
living rock. From the far end, through another doorway, shone a light,
dimly. Toward this he crept with utmost stealth, his naked feet giving
forth no sound. The knotted club that had been hanging at his back
from a thong about his neck he now removed and carried in his left hand.

Beyond the second doorway was a corridor running parallel with the
cliff face. In this corridor w