with a thin layer of rocks. Upon these lifeless rocks the
rain descended in endless torrents, wearing out the hard
granite and carrying the dust to the valleys that lay hidden between
the high cliffs of the steaming earth.

Finally the hour came when the sun broke through the
clouds and saw how this little planet was covered with a few
small puddles which were to develop into the mighty oceans of
the eastern and western hemispheres.

Then one day the great wonder happened. What had been
dead, gave birth to life.

The first living cell floated upon the waters of the sea.

For millions of years it drifted aimlessly with the currents.
But during all that time it was developing certain habits that
it might survive more easily upon the inhospitable earth. Some
of these cells were happiest in the dark depths of the lakes and
the pools. They took root in the slimy sediments which had
been carried down from the tops of the hills and they became
plants. Others preferred to move about and they grew
strange jointed legs, like scorpions and began to crawl along
the bottom of the sea amidst the plants and the pale green things
that looked like jelly-fishes. Still others (covered with scales)
depended upon a swimming motion to go from place to place
in their search for food, and gradually they populated the ocean
with myriads of fishes.

Meanwhile the plants had increased in number and they had