of formations, and sunken a thousand feet into the solid granite. The section of the rocks in the gorge shows above the granite two or three thousand feet of paleozoic sandstones, shales, and limestones, one thousand feet of subcarboniferous limestones, and twelve hundred feet of carboniferous sandstone and limestone. Higher up the stream the section extends up through the Triassic and Cretaceous systems.

What æons have rolled by while this unparalleled riverwork has been in progress! And yet this work must have been limited to the later ages, since the gorge cuts through Cretaceous strata. There was a time, during the Cenozoic ages, before yet the ridges of the Rocky Mountains had been elevated to their present altitudes, when this vast desert had just become dry land-upheaved from the recent bottom of the Cretaceous sea. Now the Colorado began to gather its forces and to irrigate the surface of the new-formed land. Now began the great cañon; but for many ages the surface features of the region were normal; and not improbably it was clothed with a soil, and watered by streams which sustained a luxuriant growth of vegetation. But man was slumbering in the voiceless future, and lazy reptiles held possession of the fair domain. Vast, then, as is the work, and vast as must have been its duration, its commencement can date back but to the end, or, at farthest, to the beginning of Cenozoic Time.

Who can tell but similar gorges have been cut in the strata of more eastern states. Here was land-permanent land-covered with vegetation, while yet the great desert was but ocean-slime. Here, too, were rivers-rivers like the Ohio and the Mississippi-with their numerous tributaries. What prevented these streams from scoring the strata to the depth of ten thousand feet? We know that during this interval the Niagara cut an ancient

gorge. We

know that an ancient river-bed stretches from Lake Michigan down through the valley of the Illinois. The subterranean explorations of the well-borer's auger have disclosed multitudes of ancient gorges which are now filled up with drift. If such tremendous gorges were ever cut, they were filled up and obliterated by the great glacier. And may not this reparation of the surface have been one of the beneficent operations of the glacier? We are told no glacial action is detected west of the Rocky Mountains. Had the great glacier been moved over the deep-cut gorges of the great desert, they must have been filled and blotted out, and the new-formed streams, on the advent of man, would have been just in the act of surveying new channels for themselves. The bare rock would have been clothed with soil, and the "desert" might have been the garden of the continent.

THE

CHAPTER XXXII.

PRIMEVAL MAN.

HE history of our race, traced back a few thousand years, loses itself in traditions and myths. We come down out of a cloud of obscurity, in which we can just discern the rude forms of men clad in skins, frequenting the caves of wild beasts, fashioning rude pottery, and practicing in the chase with the primeval bow and arrow. Out of the haze which hangs over the verge of antiquity come sounds of conflict in arms, pæans of peace, hymns to relig ion, and the hum of barbaric industry.

Our written history does not extend back to the origin of man. The Mosaic records, which are undoubtedly the oldest of our authentic documents, represent the western portion of Asia as swarming with a population tolerably advanced in the arts at a period two or three thousand years antecedent to our era. There was, consequently, a long interval of human history still anterior to this date. What destinies befell our race-how did they live, whither did they wander, during that prolonged infancy of whichRevelation aside-we have no other information than such as we have gleaned of the Mastodon, the Megatherium, or the Zeuglodon?

The quickened intellectual activity of the modern age has started new and interesting inquiries in this direction. There are no questions which more profoundly interest us than the history of primeval man. The investigation has been pushed far beyond the limits of the most ancient written documents. It has passed over the remoter domain of