hese
little beings grows and feeds itself independently. It assimilates
juices from without, absorbing them from the surrounding fluid. Each
separate cell is also able to reproduce itself and to increase. This
increase generally takes place by simple division, the nucleus parting
first, by a contraction round its circumference, into two parts; after
which the protoplasm likewise separates into two divisions. The single
cell is able to move and creep about; from its outer surface it sends
out and draws back again finger-like processes, thereby modifying its
form. Finally, the young cell has feeling, and is more or less
sensitive. It performs certain movements on the application of chemical
and mechanical irritants."

[Sidenote: The Will of the Cell]

The single living cell moves about in search of food. When food is found
it is enveloped in the mass of protoplasm, digested and assimilated.

The single cell has the _power of choice_, for it refuses to eat what is
unwholesome and extends itself mightily to reach that which is
nourishing.

[Sidenote: The Cell and Organic Evolution]

Moebius and Gates are convinced that the single cell possesses _memory_,
for having once encountered anything dangerous, it knows enough to avoid
it when presented under similar circumstances. And having once found
food in a certain place, it will afterwards make a business of looking
for it in the same place.

And, finally, Verwoern and Binet have found in a single living cell
manifestations of _the emotions of surprise and fear_ and the rudiments
of _an ability to adapt means to an end_.

Let us now consider pluricellular organisms and consider them
particularly from the standpoint of organic evolution. The pluricellular
organism is nothing more nor less than a later development, a
confederated association of unicellular organisms. Mark the development
of such an association.

[Sidenote: Evolutionary Differentiation]

Originally each separate cell performed all the functions of a separate
life. The bonds that united it to its fellows were of the most transient
character. Gradually the necessities of environment led to a more and
more permanent grouping, until at last the bonds of union became
indissoluble.

Meanwhile, the great laws of "adaptation" and "heredity," the basic
principles of evolution, have been steadily at work, and slowly there
has come about a differentiation of cell function, an apportionment
among the different