an appearance
of kinship. While the animal evolved, not without accidents along the
way, toward a freer and freer expenditure of discontinuous energy, the
plant perfected rather its system of accumulation without moving. We
shall not dwell on this second point. Suffice it to say that the plant
must have been greatly benefited, in its turn, by a new division,
analogous to that between plants and animals. While the primitive
vegetable cell had to fix by itself both its carbon and its nitrogen, it
became able almost to give up the second of these two functions as soon
as microscopic vegetables came forward which leaned in this direction
exclusively, and even specialized diversely in this still complicated
business. The microbes that fix the nitrogen of the air and those which
convert the ammoniacal compounds into nitrous ones, and these again into
nitrates, have, by the same splitting up of a tendency primitively one,
rendered to the whole vegetable world the same kind of service as the
vegetables in general have rendered to animals. If a special kingdom
were to be made for these microscopic vegetables, it might be said that
in the microbes of the soil, the vegetables and the animals, we have
before us the _analysis_, carried out by the matter that life found at
its disposal on our planet, of all that life contained, at the outset,
in a state of reciprocal implication. Is this, properly speaking, a
"division of labor"? These words do not give the exact idea of
evolution, such as we conceive it. Wherever there is division of labor,
there is _association_ and also _convergence_ of effort. Now, the
evolution we are speaking of is never achieved by means of association,
but by _dissociation_; it never tends toward convergence, but toward
_divergence_ of efforts. The harmony between terms that are mutually
complementary in certain points is not, in our opinion, produced, in
course of progress, by a reciprocal adaptation; on the contrary, it is
complete only at the start. It arises from an original identity, from
the fact that the evolutionary process, splaying out like a sheaf,
sunders, in proportion to their simultaneous growth, terms which at
first completed each other so well that they coalesced.

Now, the elements into which a tendency splits up are far from
possessing the same importance, or, above all, the same power to evolve.
We have just distinguished three different kingdoms, if one may so
express it, in the organized