t; the folded and compressed leaves of
the plant, like a man's fist, had pushed against the hard but flexible
concrete till it had bulged up and then split, and let the irrepressible
plant through. The force exerted must have been many pounds. I think it
doubtful if the strongest man could have pushed his fist through such a
resisting medium. If it was not life which exerted this force, what was
it? Life activities are a kind of explosion, and the slow continued
explosions of this growing plant rent the pavement as surely as powder
would have done. It is doubtful if any cultivated plant could have
overcome such odds. It required the force of the untamed hairy plant of
the plains to accomplish this feat.

That life does not supply energy, that is, is not an independent source
of energy, seems to me obvious enough, but that it does not manifest
energy, use energy, or "exert force," is far from obvious. If a growing
plant or tree does not exert force by reason of its growing, or by
virtue of a specific kind of activity among its particles, which we name
life, and which does not take place in a stone or in a bar of iron or in
dead timber, then how can we say that any mechanical device or explosive
compound exerts force? The steam-engine does not create force, neither
does the exploding dynamite, but these things exert force. We have to
think of the sum total of the force of the universe, as of matter
itself, as a constant factor, that can neither be increased nor
diminished. All activity, organic and inorganic, draws upon this force:
the plant and tree, as well as the engine and the explosive--the winds,
the tides, the animal, the vegetable alike. I can think of but one
force, but of any number of manifestations of force, and of two distinct
kinds of manifestations, the organic and the inorganic, or the vital and
the physical,--the latter divisible into the chemical and the
mechanical, the former made up of these two working in infinite
complexity because drawn into new relations, and lifted to higher ends
by this something we call life.

We think of something in the organic that lifts and moves and
redistributes dead matter, and builds it up into the ten thousand new
forms which it would never assume without this something; it lifts lime
and iron and silica and potash and carbon, against gravity, up into
trees and animal forms, not by a new force, but by an old force in the
hands of a new agent.

The cattle move about t