rtistic character
of the pottery and other products of handicraft found in them seem to
indicate that the ancient population was both denser and more highly
cultured than that which the Europeans finally ousted. In the Gulf
States there is perhaps not much evidence that there was a denser
population at an earlier period, but the excellence of the pre-Columbian
handicrafts and the existence of a decadent sun worship illustrate the
way in which the civilization of the past was higher than that of
later days. The Aztecs, who figure so largely in the history of the
exploration and conquest of Mexico, were merely a warlike tribe which
had been fortunate in the inheritance of a relatively high civilization
from the past. So, too, the civilization found by the Spaniards at
places such as Mitla, in the extreme south of Mexico, could not compare
with that of which evidence is found in the ruins. Most remarkable of
all is the condition of Yucatan and Guatemala. In northern Yucatan the
Spaniards found a race of mild, decadent Mayas living among the relics
of former grandeur. Although they used the old temples as shrines, they
knew little of those who had built these temples and showed still
less capacity to imitate the ancient architects. Farther south in
the forested region of southern Yucatan and northern Guatemala the
conditions are still more surprising, for today these regions are almost
uninhabitable and are occupied by only a few sickly, degraded natives
who live largely by the chase. Yet in the past this region was the scene
of by far the highest culture that ever developed in America. There
alone in this great continent did men develop an architecture which, not
only in massiveness but in wealth of architectural detail and sculptural
adornment, vies with that of early Egypt or Chaldea. There alone did the
art of writing develop. Yet today in those regions the density of
the forest, the prevalence of deadly fevers, the extremely enervating
temperature, and the steady humidity are as hostile to civilization as
are the cold of the far north and the dryness of the desert.

The only explanation of this anomaly seems to be that in the past the
climatic zones of the world have at certain periods been shifted
farther toward the equator than they are at present. Practically all
the geographers of America now believe that within the past two or three
thousand years climatic pulsations have taken place whereby places like
the dry So