ich we
append in abstract.

DARWIN. (1) Everything organic is capable of variation. Variations arise
in part from internal, in part from external causes. They are slight,
inconspicuous, individual differences.

KORSCHINSKY AND THE MODERNS. (1) Everything organic is capable of
variation. This capability is a fundamental, inherent character of living
forms in general, and is independent of external conditions. It is usually
kept latent by "heredity," but occasionally breaks forth in sudden
variations.

DARWIN. (2) The struggle for existence. This combines, increases, fixes
useful variations, and eliminates the useless. All the characters and
peculiarities of a finished species are the results of long-continued
selection; they must therefore be adapted to the external conditions.

KORSCHINSKY AND THE MODERNS. (2) Saltatory variations.--These are, under
favourable circumstances, the starting-point of new and constant races.
The characters may sometimes be useful, sometimes quite indifferent,
neither advantageous nor disadvantageous. Sometimes they are not in
harmony with external circumstances.

DARWIN. (3) The species is subject to constant variation. It is
continually subject to selection and augmentation of its characters. Hence
again the origin of new species.

KORSCHINSKY AND THE MODERNS. (3) All fully developed species persist, but
through heterogenesis a splitting up into new forms may take place, and
this is accompanied by a disturbance of the vital equilibrium. The new
state is at first insecure and fluctuating, and only gradually becomes
stable. Thus new forms and races arise with gradual consolidation of their
constitution.

DARWIN. (4) The sharper and more acute the effect of the environment, the
keener is the struggle for existence, and the more rapidly and certainly
do new forms arise.

KORSCHINSKY AND THE MODERNS. (4) Only in specially favourable conditions,
only when the struggle for existence is weak, or when there is none, can
new forms arise and become fixed. When the conditions are severe no new
forms arise, or if they do they are speedily eliminated.

DARWIN. (5) The chief condition of evolution is therefore the struggle for
existence and the selection which this involves.

KORSCHINSKY AND THE MODERNS. (5) The struggle for existence simply
decimates the overwhelming abundance of possible forms. Where it occurs it
prevents the establishment of new variations, and in reality stands in the
way