The collisions of the gathered fragments caused a revival of the heat, and the resulting planet was for a long time a mass of glowing gas.

Little by little it cooled once more, until it became fit to be the theatre of life such as ours.

Thus were all the planets formed.
Almost all the matter of those interpenetrating worlds was by this time concentrated into the newly formed planets.

Each of them was and is composed of all those different kinds of matter.

The earth upon which we are now living is not merely a great ball of physical matter, built of the atoms of that lowest world, but has also attached to it an abundant supply of matter of the sixth, the fifth, the fourth and other worlds.