Here, then, are the objections to this theory of the glacier-origin
of the Drift:

I. The glaciers do not produce striated stones.

II. The glaciers do not produce drift-clay.

III. The glaciers could not have formed continental sheets of "till."

IV. The glaciers could not have existed upon, and consequently could
not have striated, the mountain-tops.

V. The glaciers could not have reached to the great plains of the
continents far remote from valleys, where we still find the Drift and
drift-markings.

VI. The glaciers are limited in number and confined in their
operations, and were utterly inadequate to have produced the
thousands of square miles of drift-_débris_ which we find enfolding
the world.

[1. "The Great Ice Age," p. 373.]

{p. 23}

CHAPTER VI.

WAS IT CAUSED BY CONTINENTAL ICE-SHEETS?