then with a microscope.  You will be charmed with the exquisite finish of their most minute parts.  Nature glories in the artistic excellence of infinitesimal workmanship.  The most beautiful part of her handiwork is that which is seen through a microscope.  There is beauty, beauty everywhere; the crystals of the snow, the cell structure of the leaf, the scales of the butterfly’s wing, the pedicels, capsules and cilia of these mosses.  No wonder that many distinguished men have been led to give their whole lives to the study of mosses and have felt well repaid.

* * * * *

Here are Nature’s only two elementary forms of growth, the cell and the crystal, wrestling for the mastery over each other in a life and death struggle.  The moss is built up of cell, the rock of crystal forms.  Below this Devonian limestone, its crystals sparkling in the sunshine, with its coral fossils, its fragments of crinoids, and its broken shells of brachiopods, down through the Devonian, the Silurian, the Ordovician, and the Cambrian rocks, down to the original crust formed when first the earth began to cool, if any there be remaining; all these miles of rocks are inorganic, built up of crystals.  But here on the surface, the tender green mosses and the bright lichens have begun the struggle of the cellular system for supremacy.  These humble little rock-breakers will not rest until they have pulverized the rocks into soil sufficient to sustain higher forms of vegetable life.

Once before, many millions of years ago, the cell life had won a partial victory over the crystal.  In the great sub-tropical sea which once covered this spot, corals lived and flourished as they do now in similar seas.  Myriads of brachiopods lived, moved, and had their being.  Gigantic fish sported in the waters.  Meanwhile older rocks were being denuded and disintegrated.  Millions of tons of sediment were brought by the rivers and streams to the shores of the Devonian sea.  Upheaval, change, transformation followed, and the tide of battle turned.  Cell life was powerless before the vanquishing crystals of the infiltrating calcite.  Only the inorganic part of that vast world of organic life here remains in these fossils to tell the story—­the walls of the corals, the shells of the brachiopods, the teeth of the monster fishes.  Then came succeeding ages, and finally the great glaciers which brought down the drift, rounded the sharp ridges, filled up the deep valleys and gorges, and gave to Iowa her fertile and inexhaustible soil.  The earth was prepared to receive her king.  The glaciers receded.  Man came.

Now here, on this bit of limestone rock, the struggle is on again.  The mosses and the lichens have proceeded far enough in their work of disintegration to provide substance for the slender red stem of dogwood, which is growing out of the soil they have made.  The fallen leaves of the surrounding trees follow the pioneer work of the mosses.  The rain and the cracking frosts are other agencies.  By and by the organic will triumph over the inorganic, the cell over the crystal, the plant over the rock, and where now the fossils lie beautiful flowers will bloom.