problem, which is after all the fundamental one, namely, to ask whether
we can tell anything of nature's method of building the protoplasmic
machine. The building of the higher animal and plant, as we have seen,
is the result of the powers of protoplasm; but protoplasm itself is a
machine. What has been its history?

We must first notice that no notion of _chemical evolution_ helps us
out. It has been a favourite thought with some that the origin of the
first living thing was the result of chemical evolution. As the result
of physical forces there was produced, from the original nebulous mass,
a more and more complicated system until the world was formed. Then
chemical phenomena became more and more complicated until, with the
production of more and more complicated compounds, protoplasm was
finally produced. A few years ago, under the impulse of the idea that
protoplasm was a compound, or at least a simple mixture of compounds,
this thought of protoplasm as the result of chemical evolution was quite
significant. _Physical forces_, _chemical forces_, and _vital forces_,
explain successively the origin of _worlds_, _protoplasm_, and
_organisms_. This conception has, however, no longer much significance.
We know of no such living chemical compound apart from cell machinery. A
new conception of protoplasm has arisen which demands a different
explanation of its origin. Since it is a machine rather than a compound,
mechanical rather than chemical forces are required for its explanation.

Have we then any suggestion as to the method of the origin of this
protoplasmic machine? Our answer must, at the present, be certainly in
the negative. The complexity of the cell tells us plainly that it can
not be the ultimate living substance which may have arisen from chemical
evolution. It is made up of parts delicately adapted to act in harmony
with each other, and its activity depends upon the relation of these
parts. Whatever chemical forces may have accomplished, they never could
have combined different bodies into linin, centrosomes, chromosomes,
etc., which, as we have seen, are the basis of cell life. To account for
this machine, therefore, we are driven to assume either that it was
produced by some unknown intelligent power in its present condition of
complex adjustment, or to assume that it has had a long history of
building by successive steps, just as we have seen to be the case with
the higher organisms. The latter assumpti