of this chapter, since it follows as a direct corollary from the law of
the Conservation of Energy. Indeed, we might even term it the biological
aspect of that law.

As we have seen, we can neither create energy nor destroy it; though we
can _lose it_,--so far as this earth is concerned. The vast fund of
energy that daily comes streaming to us from the sun is transmuted back
and forth in a thousand ways, though little by little it is dissipated
off into space, and we are dependent upon a fresh supply from the ever
replenished fountain.

Just so, though in a somewhat idealistic sense, is it with what we may
term vital energy. Cells, organisms, even whole races, are subject to
degeneration and decay. They cannot acquire higher powers, though they
may gradually lose what they already have; as Bateson has recently told
us that whatever evolution there is must be by loss and not by gain.
Water very easily runs down hill; but cannot go up hill in and of
itself. Just so with the types of organic life. It was not merely an
idle sneer of the witty Frenchman, that science has not yet explained
how an ancestor can transmit what he has not got himself. He cannot
always transmit all that he himself actually possesses of nature's
gifts. Vitality becomes lowered, and the type degenerates. Weismann has
emphasized this idea in his doctrine of "panmixia," or the withdrawal of
selection, which always results in degeneration. Selection, artificial
or natural, may serve to counteract this universal tendency of organic
life, but only approximately. As Sir William Dawson says, "All things
left to themselves tend to degenerate." Little by little the endowment
of vitality bestowed upon our world at the beginning has, like radiant
energy, been returned to God who gave it; but, unlike the case of
radiant energy, the Creator has not established any regular source of