, till finally in the microscopically small masses, which are
now called cells, division into two parts always appears, after these
masses have grown to perhaps double their original size. After division
the two halves separate from each other and represent independent
individuals.

In the further course of phylogeny the division of the cells into two
parts takes place regularly. But the cells remain united to each other
and form multicellular individuals, which increase by cell division and
which at times in the lowest stages are divided at regular intervals
into smaller individuals, perhaps even at last into single cells, but
from which there are periodically given off cells that develop as germ
cells into new multicellular individuals.

_B._ Another phenomenon which appears in the primordial plasma or its
immediate offspring is the death of the greater part of the plasma under
certain unfavorable conditions of nutrition, while the smaller part
continues to be nourished at its expense and in that case remains viable
during the dormant period.

In the offspring this phenomenon gradually becomes free cell formation,
which takes place before the resting stage or before the death of many
unicellular and multicellular organisms, and which forms germ cells from
a part of the contents of the parent cells.

The formation of germ cells by cell division (_A_), or by free cell
formation (_B_) is reproduction of the organism. The germ cells are the
elements in which the life and growth of the parental individual are
continued.

5. MORPHOLOGY OF THE IDIOPLASM IN GENERAL.

The larger part of the unarranged, soft and homogenous primordial
plasma, which grows by intussusception, becomes watery soma-plasm, with
unarranged and easily movable micellae. The smaller part is converted in
the course of phylogeny into idioplasm, in which at certain favorable
points the micellae that are being stored up under the influence of
molecular forces arrange themselves into groups by similar orientations,
and hence form bodies of less water content and greater solidity. Each
body of idioplasm consists originally of only one group of micellae,
which, however, necessarily breaks up with increasing additions into
several groups. On account of the dynamic influence of the groups of
micellae upon their own growth, they become in part more distinct and
more definitely separated, in part again differentiated by new irregular
intussusception. This p