gent directions in which
vegetables and animals have taken their course. It is a remarkable fact
that the fungi, which nature has spread all over the earth in such
extraordinary profusion, have not been able to evolve. Organically they
do not rise above tissues which, in the higher vegetables, are formed in
the embryonic sac of the ovary, and precede the germinative development
of the new individual.[52] They might be called the abortive children of
the vegetable world. Their different species are like so many blind
alleys, as if, by renouncing the mode of alimentation customary amongst
vegetables, they had been brought to a standstill on the highway of
vegetable evolution. As to the Drosera, the Dionaea, and insectivorous
plants in general, they are fed by their roots, like other plants; they
too fix, by their green parts, the carbon of the carbonic acid in the
atmosphere. Their faculty of capturing, absorbing and digesting insects
must have arisen late, in quite exceptional cases where the soil was too
poor to furnish sufficient nourishment. In a general way, then, if we
attach less importance to the presence of special characters than to
their tendency to develop, and if we regard as essential that tendency
along which evolution has been able to continue indefinitely, we may say
that vegetables are distinguished from animals by their power of
creating organic matter out of mineral elements which they draw directly
from the air and earth and water. But now we come to another difference,
deeper than this, though not unconnected with it.

The animal, being unable to fix directly the carbon and nitrogen which
are everywhere to be found, has to seek for its nourishment vegetables
which have already fixed these elements, or animals which have taken
them from the vegetable kingdom. So the animal must be able to move.
From the amoeba, which thrusts out its pseudopodia at random to seize
the organic matter scattered in a drop of water, up to the higher
animals which have sense-organs with which to recognize their prey,
locomotor organs to go and seize it, and a nervous system to coordinate
their movements with their sensations, animal life is characterized, in
its general direction, by mobility in space. In its most rudimentary
form, the animal is a tiny mass of protoplasm enveloped at most in a
thin albuminous pellicle which allows full freedom for change of shape
and movement. The vegetable cell, on the contrary, is surround