this while the
globe was in process of condensation. It grew smaller in mathematical
measurements at the same time that it grew heavier by the accretion of
matter. At last the surface was formed, and in time that surface was
sufficiently cooled to allow the vapors around it to condense into
seas and oceans and rivers. There were ages of superficial
softness--vast epochs of mud--in which the living beings that had now
appeared wallowed and sprawled.

We cannot trace the world-growth through all its stages but can only
indicate them as it were in a sketch. The more important thing to be
noted is the relation of our planet in process of formation to the
great fact called life. Here the New Astronomy comes in again to
indicate, theoretically at least, the philosophy of planetary
evolution. Each planet seems to pass through a vast almost
inconceivable period in which its condition renders life on its
surface or in its structure impossible. Heat is at once the favoring
and the prohibitory condition of life. Without heat life cannot exist;
with too great heat life cannot exist. With an intermediate and
moderate degree of heat many forms of animate and inanimate existence
may be promoted.

These facts tend to show that every world has in its career an
intermediate period which may be called the epoch of life. Before the
epoch of life begins there is in the given world no such form of
existence. There is matter only. Then at a certain stage the epoch of
life begins. The epoch of life continues for a vast indeterminate
period. No doubt in some of the worlds an epoch of life has been
provided ten times as great, possibly a thousand times as great, as in
other planets. After the epoch of life begins only certain forms of
existence are for a while possible. Then other and higher forms
succeed them, and then still higher. Thus the process continues until
the highest--that is, the conscious and moral form of existence
becomes possible, and that highest, that conscious, that moral form of
being is ourselves.

This is not all. The epoch of life seems to be terminable at the
further extreme by a planetary condition in which life is no longer
possible. The New Astronomy indicates the coming of a condition in all
the worlds when life must disappear therefrom and be succeeded by a
lifeless state of worldhood. This may be called the epoch of
death--that is, of world-death. It seems to be almost established by
investigation and right re