onges, and while they
absorb moisture readily, are yet as particular about getting what they
think nice to eat as any dainty little boy or girl; looking for it
everywhere, and turning angry and sulky if they don't get it.

10. But the root has, it seems to me, one more function, the most important
of all. I say, it seems to me, for observe, what I have hitherto told you
is all (I believe) ascertained and admitted; this that I am going to tell
you has not yet, as far as I know, been asserted by men of {33} science,
though I believe it to be demonstrable. But you are to examine into it, and
think of it for yourself.

There are some plants which appear to derive all their food from the
air--which need nothing but a slight grasp of the ground to fix them in
their place. Yet if we were to tie them into that place, in a framework,
and cut them from their roots, they would die. Not only in these, but in
all other plants, the vital power by which they shape and feed themselves,
whatever that power may be, depends, I think, on that slight touch of the
earth, and strange inheritance of its power. It is as essential to the
plant's life as the connection of the head of an animal with its body by
the spine is to the animal. Divide the feeble nervous thread, and all life
ceases. Nay, in the tree the root is even of greater importance. You will
not kill the tree, as you would an animal, by dividing its body or trunk.
The part not severed from the root will shoot again. But in the root, and
its touch of the ground, is the life of it. My own definition of a plant
would be "a living creature whose source of vital energy is in the earth"
(or in the water, as a form of the earth; that is, in inorganic substance).
There is, however, one tribe of plants which seems nearly excepted from
this law. It is a very strange one, having long been noted for the
resemblance of its flowers to different insects; and it has recently been
proved by Mr. Darwin to be dependent on insects for its existence. Doubly
strange therefore, it seems, that in some cases this race of plants all but
reaches the independent life of {34} insects. It rather _settles_ upon
boughs than roots itself in them; half of its roots may wave in the air.

11. What vital power is, men of science are not a step nearer knowing than
they were four thousand years ago. They are, if anything, farther from
knowing now than then, in that they imagine themselves nearer. But they
know more abo