ine, in the ordinary sense, consists of a combination of smaller
"machines," that is to say, of wheels, systems of levers, &c., of a
simpler kind. And these sub-machines may in their turn consist of still
simpler ones, and so on. But ultimately a stage is reached when the
component parts are homogeneous, and cannot be analysed into simpler
machines. It is otherwise with the organism. According to Leibnitz it
consists of machines made up of other machines, and so on, into the
infinitely little. However far we can proceed in our analysis of the
parts, we shall still find that they are syntheses, made up of most
ingeniously complex component parts, and this as far as our powers of
seeing and distinguishing will carry us. That is to say: organisation is
continued on into the infinitely little.

Leibnitz's illustration of the fish-pond is well known. He could have no
better corroboration of his theory than the results of modern
investigation afford. His doctrine of the continuation of organisation
downwards into ever smaller expression is confirmed to a certain extent
even by anatomy. By analysing structural organisation down to cells a
definite point seemed to have been reached. But it now appears that at
that point the problem is only beginning. One organisation is made up of
other organisations--cells, protoplasm, nucleus, nucleolus, centrosomes,
and so on, according to the power of the microscope; and these structures,
instead of explaining the vital functions of growth, development,
multiplication by division, and the rest, simply repeat them on a smaller
scale, and are thus in their turn living units, the aggregation of which
is illustrated better by the analogy of a social organism than by that of
a mechanical structure.

In order to follow the mechanical explanation along the six lines we have
previously indicated, we shall, as we have already said, entrust ourselves
to the specialists who are on the opposite side. The difficulties and
objections which the mechanical theory has to face have forced themselves
insistently upon us even in the course of a short sketch such as has just
been given, but they will be clearly realised if we approach them from the
other side. But, first of all, a word as to the fundamental and, it is
alleged, unassailable doctrine on which the theory as a whole is based,
the "law of the conservation of energy." The appeal to this, at any rate
in the way in which it is usually made, is apt to b