ings were all perfect.

Illustration of Plan of Zayi. (Bureau of Ethnology.)----

The plan of this mound and buildings is shown in the last cut. Ten rooms
on the north side of the second range presented a curious feature.
They were all filled up with a solid mass of stone and mortar, and this
filling up must have gone on as fast as the walls rose, and the
arched ceiling must have closed over a solid mass. A very reasonable
explanation is given of this state of things by Mr. Morgan.<52> He
considers that such was the rudeness of mechanical knowledge among these
people that the only way they could construct their peculiar arched roof
was to build it over an internal core of masonry. Once put together over
such a core, and carried up several feet, the down weight of the arch
would articulate and hold the mass together. Then the core of masonry
would be cleaned out, and the room was ready for use. If this be true,
it follows that these rooms were the last erected. They were not yet
cleared out when the operations of the Spaniards put an end to all
native building. We must notice the structures at Zayi are in as ruined
a condition as the others--thus strengthening the conviction that their
abandonment was at about the time of the conquest of the peninsula.

We have not space to follow Mr. Stephens in all his journey. Every few
miles he came across one of these peculiar structures. A common design
is apparent in all; but all are alike enveloped in mystery. At Labna
he found an extensive field of ruins, equal in importance to any in
Yucatan. The next illustration represents an arched gateway, which
reminds us of that in the "House of Nuns." Passing through this he
found himself in a ruined court-yard, fronting which were the remains of
buildings; but this was only one of many groups of ruins, and Labna
was but one of many places visited. At Labphak Mr. Stephens found "the
tottering remains of the grandest structure that now rears its ruined
head in the forests of Yucatan." This was a terraced mound, faced by
buildings on three sides, leaving an immense stair-way occupying the
fourth side.

Illustration of Gateway at Labna.----------------

Small interior stair-ways are mentioned in this building, but no
particular description is given of them. At two places sculptured
tablets were found. These tablets are worthy of notice. They were the
only ones Mr. Stephens found, except at Palenque. It will be seen, on
the map,