y.

And then, to gain a better view, the ape-man ascended to the topmost
branches of a tall tree where he overlooked the nearer wall. From
this point of vantage he saw that the city was long and narrow, and
that while the outer walls formed a perfect rectangle, the streets
within were winding. Toward the center of the city there appeared
to be a low, white building around which the larger edifices of
the city had been built, and here, in the fast-waning light, Tarzan
thought that between two buildings he caught the glint of water,
but of that he was not sure. His experience of the centers of
civilization naturally inclined him to believe that this central
area was a plaza about which the larger buildings were grouped
and that there would be the most logical place to search first for
Bertha Kircher and her companion.

And then the sun went down and darkness quickly enveloped the
city--a darkness that was accentuated for the ape-man rather than
relieved by the artificial lights which immediately appeared in
many of the windows visible to him.

Tarzan had noticed that the roofs of most of the buildings were
flat, the few exceptions being those of what he imagined to be the
more pretentious public structures. How this city had come to exist
in this forgotten part of unexplored Africa the ape-man could not
conceive. Better than another, he realized something of the unsolved
secrets of the Great Dark Continent, enormous areas of which have
as yet been untouched by the foot of civilized man. Yet he could
scarce believe that a city of this size and apparently thus well
constructed could have existed for the generations that it must
have been there, without intercourse with the outer world. Even
though it was surrounded by a trackless desert waste, as he knew
it to be, he could not conceive that generation after generation
of men could be born and die there without attempting to solve the
mysteries of the world beyond the confines of their little valley.

And yet, here was the city surrounded by tilled land and filled
with people!

With the coming of night there arose throughout the jungle the cries
of the great cats, the voice of Numa blended with that of Sheeta,
and the thunderous roars of the great males reverberated through
the forest until the earth trembled, and from within the city came
the answering roars of other lions.

A simple plan for gaining entrance to the city had occurred to
Tarzan, and now that darkne