rine of the Struggle for Existence. It is a probable
hypothesis, that what the world is to organisms in general, each
organism is to the molecules of which it is composed. Multitudes of
these, having diverse tendencies, are competing with one another for
opportunity to exist and multiply; and the organism, as a whole, is as
much the product of the molecules which are victorious as the Fauna,
or Flora, of a country is the product of the victorious organic beings
in it.

On this hypothesis, hereditary transmission is the result of the
victory of particular molecules contained in the impregnated germ.
Adaptation to conditions is the result of the favouring of the
multiplication of those molecules whose organizing tendencies are
most in harmony with such conditions. In this view of the matter,
conditions are not actively productive, but are passively permissive;
they do not cause variation in any given direction, but they permit
and favour a tendency in that direction which already exists.

It is true that, in the long run, the origin of the organic molecules
themselves, and of their tendencies, is to be sought in the external
world; but if we carry our inquiries as far back as this, the
distinction between internal and external impulses vanishes. On the
other hand, if we confine ourselves to the consideration of a single
organism, I think it must be admitted that the existence of an
internal metamorphic tendency must be as distinctly recognized as
that of an internal conservative tendency; and that the influence of
conditions is mainly, if not wholly, the result of the extent to which
they favour the one, or the other, of these tendencies.

III. There is only one point upon which I fundamentally and entirely
disagree with Professor Haeckel, but that is the very important one
of his conception of geological time, and of the meaning of the
stratified rocks as records and indications of that time. Conceiving
that the stratified rocks of an epoch indicate a period of depression,
and that the intervals between the epochs correspond with periods
of elevation of which we have no record, he intercalates between the
different epochs, or periods, intervals which he terms "Ante-periods."
Thus, instead of considering the Triassic, Jurassic, Cretaceous, and
Eocene periods, as continuously successive, he interposes a
period before each, as an "Antetrias-zeit," "Antejura-zeit,"
"Antecreta-zeit," "Antecocen-zeit," &c. And he conceives