Decay and disintegration in the inorganic world often lead to the production of beautiful forms. In life the reverse is true; the vital forces build up varied and picturesque forms which when pulled down are shapeless and displeasing. The immense layers of sandstone and limestone out of which the wonderful forms that fill the Grand Canon of the Colorado are carved were laid down in wide uniform sheets; if the waters had deposited their material in the forms which we now see, it would have been a miracle. We marvel and admire as we gaze upon them now; we do more, we have to speculate as to how it was all done by the blind, unintelligent forces. Giant stairways, enormous alcoves, dizzy, highly wrought balustrades, massive vertical walls standing four-square like huge foundations--how did all the unguided erosive forces do it? The secret is in the structure of the rock, in the lines of cleavage, in the unequal hardness, and in the impulsive, irregular, and unequal action of the eroding agents. These agents follow the lines of least resistance; they are active at different times and seasons, and from different directions; they work with infinite slowness; they undermine, they disintegrate, they dislodge, they transport; the hard streaks resist them, the soft streaks invite them; water charged with sand and gravel saws down; the wind, armed with fine sand, rounds off and hollows out; and thus the sculpturing goes on. But after you have reasoned out all these things, you still marvel at the symmetry and the structural beauty of the forms. They look like the handiwork of barbarian gods. They are the handiwork of physical forces which we can see and measure and in a degree control. But what a gulf separates them from the handiwork of the organic forces! VI