tions of foreign elements; that
is, they are peculiarly liable to be modified by disturbing forces.
Hence then it follows, _a priori_, that a homogeneous aggregate of these
unstable molecules will have an excessive tendency to lose its
equilibrium. It will have a quite special liability to lapse into a
non-homogeneous state. It will rapidly gravitate towards heretogeneity.

Moreover, the process must repeat itself in each of the subordinate
groups of organic units which are differentiated by the modifying
forces. Each of these subordinate groups, like the original group, must
gradually, in obedience to the influences acting on it, lose its balance
of parts--must pass from a uniform into a multiform state. And so on
continuously.

Thus, starting from the general laws of things, and the known chemical
attributes of organic matter, we may conclude deductively that the
homogeneous germs of organisms have a peculiar proclivity towards a
non-homogeneous state; which may be either the state we call
decomposition, or the state we call organization.

* * * * *

At present we have reached a conclusion only of the most general nature.
We merely learn that _some_ kind of heterogeneity is inevitable; but as
yet there is nothing to tell us _what_ kind. Besides that _orderly_
heterogeneity which distinguishes organisms, there is the _disorderly_
or _chaotic_ heterogeneity, into which a loose mass of inorganic matter
lapses; and at present no reason has been given why the homogeneous germ
of a plant or animal should not lapse into the disorderly instead of the
orderly heterogeneity. But by pursuing still further the line of
argument hitherto followed we shall find a reason.

We have seen that the instability of homogeneous aggregates in general,
and of organic ones in particular, is consequent on the various ways and
degrees in which their constituent parts are exposed to the disturbing
forces brought to bear on them: their parts are differently acted upon,
and therefore become different. Manifestly, then, a rationale of the
special changes which a germ undergoes, must be sought in the particular
relations which its several parts bear to each other and to their
environment. However it may be masked, we may suspect the fundamental
principle of organization to be, that the many like units forming a germ
acquire those kinds and degrees of unlikeness which their respective
positions entail.

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