nt, and
Kirby asked no questions.

Once he thought he saw a group of gorilla creatures parallelling their
course back amongst the forest growth, but if Naida observed the
animals, she paid no attention. The one thing which had any effect upon
the company was the appearance, presently, of two vast, birdlike
creatures. As these things approached, Naida signaled to all to crouch
beneath the shelter of a tall rock beside the path.

Enormous, the birds had bat wings, and carried with them, as they
approached, the stink of putrid flesh. The long beaks were overfull of
sharp teeth. The heads, set upon bodies of glistening white-grey, were
black. Reddish grey eyes searched the jungle as the creatures flapped
along. But, the Pterodactyls--if they were that--passed above Naida's
band without offering attack, and presently Naida gave the command to
advance again.

* * * * *

In time, they came to a chasmlike gorge across which was suspended
a slender long thread of a bridge. Not far above the bridge, a
considerable river emptied itself into the gorge in a mirrorlike
ribbon. Kirby could not hear the torrent fall--or rather could not
hear it strike any solid bottom. But from somewhere in the unlighted,
unfathomed depths of the abyss rose strange bubbling and whistling
sounds.

At the bridge, Naida paused and pointed to the land across the river.
And as Kirby looked in the direction indicated, he beheld a rocky
eminence rising for several hundred feet straight up from the expanse of
a level, tree and grass covered plain. Atop of the plateau, glimmered
the complex towers and turrets, the crenellated walls of a castle which,
in its grey antiquity, seemed as old as the race of men.

"It is behind those walls that the caciques dwell," Naida said quickly.
"It is behind the castle, in a series of separate houses, that the older
members of the race dwell. We shall go and look upon them presently. But
first we will force an interview with the caciques."

In silence Kirby took her hand, and, with the others following, they
moved out upon the swaying, perilous causeway which hung above the
chasm. After that, the trip across the plain to the foot of the plateau
cliffs was quickly accomplished.

Here, however, Kirby thought they must face trouble, for he found that
the great walls, of a sparkling, almost glassy smoothness, shot up to a
height of at least three hundred feet, and that no path of any sort wa