ce of a too precipitate advance in speculation, which led even
such a brilliant man as Prof. Huxley into an unfortunate error of
observation; for, beyond question, he would never have made such a
mistake had he not been dominated by his speculative theories as to the
nature of protoplasm.

But although Bathybias proved delusive, this did not materially affect
the advance and development of the doctrine of protoplasm. Simple forms
of protoplasm were found, although none quite so simple as the
hypothetical Bathybias. The universal presence of protoplasm in the
living parts of all animals and plants and its manifest activities
completely demonstrated that it was the only living substance, and as
the result of a few years of experiment and thought the biologist's
conception of life crystallized into something like this: Living
organisms are made of cells, but these cells are simply minute
independent bits of protoplasm. They may contain a nucleus or they may
not, but the essence of the cell is the protoplasm, this alone having
the fundamental activities of life. These bits of living matter
aggregate themselves together into groups to form colonies. Such
colonies are animals or plants. The cells divide the work of the colony
among themselves, each cell adopting a form best adapted for the special
work it has to do. The animal or plant is thus simply an aggregate of
cells, and its activities are the sum of the activities of its separate
cells; just as the activities of a city are the sum of the activities of
its individual inhabitants. The bit of protoplasm was the unit, and this
was a chemical compound or a simple mixture of compounds to whose
combined physical properties we have given the name vitality.

==The Decline of the Reign of Protoplasm.==--Hardly had this extreme
chemical theory of life been clearly conceived before accumulating facts
began to show that it is untenable and that it must at least be vastly
modified before it can be received. The foundation of the chemical
theory of life was the conception that protoplasm is a definite though
complex chemical compound. But after a few years' study it appeared that
such a conception of protoplasm was incorrect. It had long been
suspected that protoplasm was more complex than was at first thought. It
was not even at the outset found to be perfectly homogeneous, but was
seen to contain minute granules, together with bodies of larger size.
Although these bodies were seen