[Illustration: [Flower]]
I think flowers are “made of sugar and spice and everything nice.” At
least, if it is not that, it is something very like it, as I have good
reason to believe.
What flowers and all other parts of the plant are made of depends upon
protoplasm; and if protoplasm can make sugar and spice and build up
flowers that way, we should like to know it.
We _do_ know about sugar and how the little green chlorophyll people run
their starch factories in all the green parts of the plant,—under the
skin of stems sometimes as well as of leaves, for wherever a stem is
green, we may be sure chlorophyll is at work making starch in it. And we
know how the protoplasm in the different cells changes the starch into
sugar.
We know, too, how wood and other tough substances are made of starch.
But there is something else in plants as important as starch and very
different,—the protoplasm. Protoplasm itself is not made entirely of
starch; it requires materials not found in starch.
These materials are nitrogen, sulphur, and phosphorus.
Nitrogen is the most important, and this the plant gets chiefly through
the roots.
Nitrogen is found in the earth combined with hydrogen and other
substances. The protoplasm tears to pieces these nitrogenous substances
which the roots suck up, and so enables the plant to take the nitrogen.
The other two substances which the protoplasm needs, sulphur and
phosphorus, the plant gets partly from the air and partly from the
earth.
Sulphuric acid exists in _very_ small quantities in the air and goes in
through the stomata, attracted, no doubt, by the protoplasm inside. But
other sulphurous and phosphorous compounds are taken up by the roots.
So we see protoplasm is complicated. It contains carbon, hydrogen,
oxygen, nitrogen, sulphur, and phosphorus united in a very complicated
way.
Although protoplasm itself is made only of carbon, hydrogen, oxygen,
nitrogen, sulphur, and phosphorus, it can make use of a great many other
things. When the protoplasm of certain cells wants to build hard, tough
walls, it uses potash and soda or even silica, which you know glass is
made of. Just draw a blade of sedge grass through your fingers if you
want to feel the silica in it. You will probably cut your fingers, but
that will help make you remember about silica. Then the protoplasm uses
iron to color the petals and other parts of the plant. It uses magnesia,
too, and salt and lime and a number of other materials for building
walls or making dyes or something else.
Every material in our own bodies is found in plants, and sometimes the
plants have materials that we do not have.
Of course materials are put together differently in plants from what
they are in us. When Mother Nature combines her carbon, hydrogen,
oxygen, nitrogen, sulphur, phosphorus, magnesia, iron, and all the other
things to make a plant, she does not go to work as she would if she were
going to make an animal.
Just what the difference is it would be difficult to tell, but there
_is_ a difference.
Plants contain a good deal of sugar as a rule, and if you remember
cloves you will admit that at least _some_ flowers are made of spice,
for cloves are the dried flower buds of the clove tree.
Cinnamon is the bark of a plant, and if you are acquainted with orange
trees you will be willing to say they are “made of sugar and spice and
everything nice,” for the whole tree, wood, bark, stems, leaves,
flowers, and fruit, is fragrant and spicy.
Oil is another common substance in plants, and it is made from the
materials of starch which, as we know, are carbon, hydrogen, and oxygen;
cotton-seed oil, olive oil, and castor oil we are all familiar with.
All nuts contain a great deal of oil, and the skin of a fresh-picked
orange is so full of it that it runs down our fingers when we cut the
orange.
All the things in a plant—starch, sugar, oils, spices, wood,
bark—everything is made by the wonderful protoplasm in the cells.
Starch and the food taken up by the roots pass through all parts of the
plant by the sap tubes, and as the sap goes along, each living cell
draws into itself the substances from the sap that it needs, and these
it combines into the things it wants to make. Some of the cells in an
orange skin, for instance, attract out of the sap the materials to make
the fragrant, stinging oil that fills the fresh skin, while other cells
attract the materials to build the white cottony covering inside the
outer skin, and so the cells in each part of the plant take out what
they need to build with.
[Illustration: [Flower]]