|The Fairy-Land of Science|
|by Arabella Buckley|
|Introduction to the wonders of the physical world: sunbeams and the work they do, the aerial ocean in which we live, a drop of water on its travels, the two great sculptors—water and ice, the voices of nature and how we hear them, the life of a primrose, the history of a piece of coal, bees in the hive, and bees and flowers. Ages 10-13 |
THE LIFE OF A PRIMROSE
HEN the dreary days of winter and the early damp days of
spring are passing away, and the warm bright sunshine has
begun to pour down upon the grassy paths of the wood, who
does not love to go out and bring home posies of violets,
and bluebells, and primroses? We wander from one plant to
another picking a flower here and a bud there, as they
nestle among the green leaves, and we make our
rooms sweet and gay with the tender and lovely blossoms.
But tell me, did you ever stop to think, as you added flower
after flower to your nosegay, how the plants which bear
them have been building up their green leaves and their
fragile buds during the last few weeks? If you had visited
the same spot a month before, a few of
last year's leaves,
withered and dead, would have been all that you would have
found. And now the whole wood is carpeted with delicate
green leaves, with nodding bluebells, and pale-yellow
primroses, as if a fairy had touched the ground and covered
it with fresh young life. And our fairies have been at work
here; the fairy "Life," of whom we know so
lit-  tle, though we
love her so well and rejoice in the beautiful forms she can
produce; the fairy sunbeams with their invisible influence
kissing the tiny shoots and warming them into vigor and
activity; the gentle rain-drops, the balmy air, all these
have been working, while you or I passed heedlessly by; and
now we come and gather the flowers they have made, and too
often forget to wonder how these lovely forms have sprung
up around us.
Our work during the next hour will be to consider this
question. You were asked last week to bring with you to-day
a primrose-flower, or a whole plant if possible, in order
the better to follow out with me the "Life of a Primrose."
This is a
very different kind of subject from those of our former
lectures. There we took world-wide histories; we
traveled up to the sun, or round the earth, or into the
air; now I only ask you to fix your attention on one little
plant, and inquire into its history.
There is a beautiful little poem by Tennyson, which says—
"Flower in the crannied wall,
I pluck you out of the crannies;
Hold you here, root and all, in my hand,
Little flower; but if I could understand
What you are, root and all, and all in all,
I should know what God and man is."
 We cannot learn all about this little flower, but we can
learn enough to understand that it has a real separate life
of its own, well worth knowing. For a plant is born,
breathes, sleeps, feeds, and digests just as truly as an
animal does, though in a different way. It works hard both
for itself to get its food, and for others in making the
air pure and fit for animals to breathe. It often lays by
provision for the winter. It sends young plants out, as
parents send their children, to fight for themselves in the
world; and then, after living sometimes to a good old age,
it dies, and leaves its place to others.
We will try to follow out something of this life to-day; and
first, we will begin with the seed.
I have here a packet of primrose-seeds, but they are so
small that we cannot examine them; so I have also had given
to each one of you an almond-kernel, which is the seed of
the almond-tree, and which has been soaked, so that it
splits in half easily. From this we can learn about seeds
in general, and then apply it to the primrose.
Half an almond, showing the plantlet.
a, rudiment of stem. b, beginning of root.
If you peel the two skins off your almond-seed
(the thick, brown, outside skin, and the thin, transparent
one under it), the two halves of the almond will slip apart
quite easily. One of these halves will have a small dent at
the pointed end, while in the other half you will see a
 lump, which fitted into the dent when the two halves
were joined. This little lump (a b) is a young
plant, and the two halves of the almond are the seed-leaves
which hold the plantlet, and feed it till it can feed
itself. The rounded end of the plantlet (b) sticking out of
the almond, is the beginning of the root, while the other
end (a) will in time become the stem. If you look
carefully, you will see two little points at this end,
which are the tips of future leaves. Only think how minute
this plantlet must be in a primrose, where the whole seed
is scarcely larger than a grain of sand! Yet in this tiny
plantlet lies hid the life of the future plant.
When a seed falls into the ground, so long as the earth is
cold and dry, it lies like a person in a trance, as if it
were dead; but as soon as the warm, damp spring comes, and
the busy little sun-waves pierce down into the earth, they
wake up the plantlet and make it bestir itself. They agitate
to and fro the particles of matter in this tiny body, and
cause them to seek out for other particles to seize and
join to themselves.
But these new particles cannot come in at the
roots, for the seed has none; nor through the leaves, for
they have not yet grown up; and so the plantlet begins by
helping itself to the store
 of food laid up in the thick
seed-leaves in which it is buried. Here it finds starch,
oils, sugar, and substances called albuminoids,—the
sticky matter which you notice in wheat-grains when you
chew them is one of the albuminoids. This food is all ready
for the plantlet to use, and it sucks it in, and works
itself into a young plant with tiny roots at one end, and a
growing shoot, with leaves, at the other.
But how does it grow? What makes it become larger? To answer
this you must look at the second thing I asked you to
bring—a piece of orange. If you take the skin off a piece of
orange, you will see inside a number of long-shaped
transparent bags, full of juice. These we call cells, and
the flesh of all plants and animals is made up of cells
like these, only of various shapes. In the pith of elder
they are round, large, and easily seen; in the
stalks of plants they are long, and lap over each other,
so as to give the stalk strength to stand upright.
Sometimes many cells growing one on the top of the other
break into one tube and make vessels.
But whether large or
small, they are all bags growing one against the other.
Juicy cells in a piece of orange.
In the orange-pulp these cells contain only sweet juice, but
in other parts of the orange-tree
 or any other
plant they contain a sticky substance with little grains in
it. This substance is called "protoplasm," or the first
form of life, for it is alive and active, and under a
microscope you may see in a living plant streams of the
little grains moving about in the cells.
Now we are prepared to explain how our plant grows. Imagine
the tiny primrose plantlet to be made up of cells filled
with active living protoplasm, which drinks in starch and
other food from the seed-leaves. In this way each cell will
grow too full for its skin, and then the protoplasm divides
into two parts and builds up a wall between them, and so one
cell becomes two. Each of these two cells again breaks up
into two more, and so the plant grows larger and larger,
till by the time it has used up all the food in the
seed-leaves, it has sent roots covered with fine hairs
downwards into the earth, and a shoot with beginnings of
leaves up into the air.
Sometimes the seed-leaves themselves come above ground,
as in the mustard-plant, and sometimes they are left empty
behind, while the plantlet shoots through them.
And now the plant can no longer afford to be idle
and live on prepared food. It must work for itself. Until
now it has been taking in the same kind of food that you
and I do; for we too find many seeds very pleasant to eat
and useful to nourish us. But now this store is exhausted.
 Upon what then is the plant to live? It is cleverer than we
are in this, for while we cannot live unless we have food
which has once been alive, plants can feed upon gases and
water and mineral matter only. Think over the substances
you can eat or drink, and you will find they are nearly all
made of things which have been alive: meat, vegetables,
bread, beer, wine, milk; all these are made from living
matter, and though you do take in such things as water and
salt, and even iron and phosphorus, these would be quite
useless if you did not eat and drink prepared food which
your body can work into living matter.
But the plant, as soon as it has roots and leaves, begins to
make living matter out of matter that has never been alive.
Through all the little hairs of its roots it sucks in
water, and in this water are dissolved more or less of the
salts of ammonia, phosphorus, sulphur, iron, lime, magnesia,
and even silica, or flint. In all kinds of earth there is
some iron, and we shall see presently that this is very
important to the plant.
Suppose, then, that our primrose has begun to drink in water
at its roots. How is it to get this water up into the stem
and leaves, seeing that the whole plant is made of closed
bags or cells? It does it in a very curious way, which you
can prove for yourselves. Whenever two fluids, one thicker
than the other, such as treacle and water for
example, are only separated by a skin or any
substance, they will always mix, the thinner one oozing
through the skin into the thicker one. If you tie a piece
of bladder over a glass tube, fill the tube half-full of
treacle, and then let the covered end rest in a bottle of
water, in a few hours the water will get in to the treacle
and the mixture will rise up in the tube till it flows over
the top. Now, the saps and juices of plants are thicker than
water, so, directly the water enters the cells at the root
it oozes up into the cells above, and mixes with the sap.
Then the matter in those cells becomes thinner than in the
cells above, so it too oozes up, and in this way cell by
cell the water is pumped up into the leaves.
When it gets there it finds our old friends the sunbeams
hard at work. If you have ever tried to grow a plant in a
cellar, you will know that in the dark its leaves remain
white and sickly. It is only in the sunlight that a
beautiful delicate green tint is given to them, and you will
remember from Lecture II. that this green tint shows that
the leaf has used all the sun-waves except those which make
you see green; but why should it do this only when it has
grown up in the sunshine?
The reason is this: when the sunbeam darts into the leaf and
sets all its particles quivering, it divides the protoplasm
into two kinds, collected into different cells. One of
 white, but the other kind near the surface,
is altered by the sunlight and by the help of the iron
brought in by the water. This particular kind of
protoplasm, which is called "chlorophyll," will
have nothing to do with the green waves and throws them
back, so that every little grain of this protoplasm looks
green and gives the leaf its green color.
It is these little green cells that by the help of the
sun-waves digest the food of the plant and turn the water
and gases into useful sap and juices. We saw in Lecture
III. that when we breathe-in air, we use up the oxygen in
it and send back out of our mouths carbonic acid, which is a
gas made of oxygen and carbon.
Now, every living thing wants carbon to feed upon, but
plants cannot take it in by itself, because carbon is solid
(the blacklead in your pencils is pure carbon), and a plant
cannot eat, it can only drink-in fluids and gases. Here the
little green cells help it out of its difficulty. They take
in or absorb out of the air carbonic acid gas which we have
given out of our mouths and then by the help of the
sun-waves they tear the
 carbon and oxygen apart. Most of
the oxygen they throw back into the air for us to use, but
the carbon they keep.
Oxygen-bubbles rising from laurel-leaves in water.
If you will take some fresh laurel leaves and put them into
a tumbler of water turned upside-down in a saucer of water,
and set the tumbler in the sunshine, you will soon see
little bright bubbles rising up and clinging to the glass.
These are bubbles of oxygen gas, and they tell
you that they have been set free by the green cells which
have torn from them the carbon of the carbonic acid in the
But what becomes of the carbon? And what use is made of the
water which we have kept waiting all this time in the
leaves? Water, you already know, is made of hydrogen and
oxygen, but perhaps you will be surprised when I tell you
that starch, sugar, and oil, which we get from plants, are
nothing more than hydrogen and oxygen in different
quantities joined to carbon.
It is very difficult at first to picture such a black thing
as carbon making part of delicate leaves and beautiful
flowers, and still more of pure white sugar. But we can
make an experiment by which we can draw the hydrogen and
oxygen out of common loaf sugar, and then you will see the
carbon stand out in all its blackness. I have here a plate
with a heap of white sugar in it. I pour upon it first some
hot water to melt
 and warm it, and then some strong
sulphuric acid. This acid does nothing more than simply draw
the hydrogen and oxygen out. See! in a few moments a black
mass of carbon begins to rise, all of which has come out of
the white sugar you saw just now.
You see, then, that from
the whitest substance in plants we can get this black
carbon; and in truth, one-half of the dry part of every
plant is composed of it.
Carbon rising up from white sugar.
Now look at my plant again, and tell me if we have not
already found a curious history? Fancy that you see the
water creeping in at the roots, oozing up from cell to cell
till it reaches the leaves, and there meeting the carbon
which has just come out of the air, and being worked up with
it by the sun-waves into starch, or sugar, or oils.
But meanwhile, how is new protoplasm to be formed? for
without this active substance none of the work can go on.
Here comes into use a lazy gas we spoke of in Lecture III.
 thought that nitrogen was of no use except to
float oxygen in the air, but here we shall find it very
useful. So far as we know, plants cannot take up nitrogen
out of the air, but they can get it out of the ammonia
which the water brings in at their roots.
Ammonia, you will remember, is a strong-smelling gas, made
of hydrogen and nitrogen, and which is often almost
stifling near a manure-heap. When you manure a plant you
help it to get this ammonia, but at any time it gets some
from the soil and also from the rain-drops which bring it
down in the air. Out of this ammonia the plant takes the
nitrogen and works it up with the three elements, carbon,
oxygen, and hydrogen, to make the substances called
albuminoids, which form a large part of the food of the
plant, and it is these albuminoids which go to make
protoplasm. You will notice that while the starch and other
substances are only made of three elements, the
active protoplasm is made of these three added to a fourth,
nitrogen, and it also contains phosphorus and sulphur.
And so hour after hour and day after day our primrose goes
on pumping up water and ammonia from its roots to its
leaves, drinking in carbonic acid from the air, and using
the sun-waves to work them all up into food to be sent to
all parts of its body. In this way these leaves act, you
see, as the stomach of the plant, and digest its food.
 Sometimes more water is drawn up into the leaves than can be
used, and then the leaf opens thousands of little mouths in
the skin of its under surface, which let the drops out just
as drops of perspiration ooze through our skin when we are
overheated. These little mouths, which are called stomates
are made of two flattened cells, fitting
against each other. When the air is damp and the plant has
too much water these lie open and let it out, but when the
air is dry, and the plant wants to keep as much water as it
can, then they are closely shut. There are as many as a
hundred thousand of these mouths under one apple-leaf, so
you may imagine how small they often are.
Stomates of a leaf.
Plants which only live one year, such as mignonette, the
sweet pea, and the poppy, take in just enough food to
supply their daily wants and to make the seeds we shall
speak of presently. Then, as soon as their seeds are ripe
their roots begin to shrivel, and water is no
longer carried up. The green cells can no longer get food
to digest, and they themselves are broken up by the
sunbeams and turn yellow, and the plant dies.
But many plants are more industrious than the stock and
mignonette, and lay by store for another year, and our
primrose is one of these. Look at
 this thick solid mass
below the primrose leaves, out of which the roots
spring. This is really the stem of the primrose
hidden underground, and all the starch, albuminoids, etc.,
which the plant can spare as it grows, are sent down into
this underground stem and stored up there, to lie quietly in
the ground through the long winter, and then when the warm
spring comes this stem begins to send out leaves for a new
We have now seen how a plant springs up, feeds itself,
grows, stores up food, withers, and dies; but we have said
nothing yet about its beautiful flowers or how it forms its
seeds. If we look down close to the bottom of the leaves in
a primrose root in spring-time, we shall always find three
or four little green buds nestling in among the leaves, and
day by day we may see the stalk of these buds lengthening
till they reach up into the open sunshine, and then the
flower opens and shows its beautiful pale-yellow crown.
We all know that seeds are formed in the flower, and that
the seeds are necessary to grow into new plants. But do we
know the history of how they are formed, or what is the use
of the different parts of the bud? Let us examine them all,
and then I think you will agree with me that
this is not the least wonderful part of the plant.
Remember that the seed is the one important
 thing and then
notice how the flower protects it. First, look at the
outside green covering, which we call the calyx. See how
closely it fits in the bud, so that no insect can creep in
to gnaw the flower, nor any harm come to it from cold or
blight. Then, when the calyx opens, notice that the yellow
leaves which form the crown or corolla, are each alternate
with one of the calyx leaves, so that anything which got
past the first covering would be stopped by the second.
Lastly, when the delicate corolla has opened out, look at
those curious yellow bags just at the top of the tube.
What is their use?
a, Stigma or sticky head of the seed-vessel. b, Anthers of the stamens. c, Corolla or crown of the flower. d, Calyx or outer covering. sv, Seed-vessel. A, enlarged pistil, with pollen-grain resting on the stigma and growing down to the ovule. o, Ovules.
But I fancy I see two or three little questioning
which seem to say, "I see no yellow bags at the
top of the tube." Well, I cannot tell whether you can or
not in the specimen you have in your hand; for one of the
most curious things about primrose flowers is, that some of
them have these yellow bags at the top of the tube and some
of them hidden down right in the middle. But this I can
tell you: those of you who have got no yellow bags at the
top will have a round knob there (1 a), and will
find the yellow bags (b) buried in the tube. Those, on the
other hand, who have the yellow bags (2 b) at the
top will find the knob (a) half way down the tube.
Now for the use of these yellow bags, which are called the
anthers of the stamens, the stalk on which they grow being
called the filament or thread. If you can manage to split
them open you will find that they have a yellow powder in
them, called pollen, the same as the powder which sticks to
your nose when you put it into a lily; and if you look with
a magnifying glass at the little green knob in the centre
of the flower, you will probably see some of this yellow
dust sticking on it (A). We will leave it there
for a time, and examine the body called the pistil, to which
the knob belongs. Pull off the yellow corolla (which will
come off quite easily), and turn back the green leaves. You
will then see that the knob stands on the top of a column,
and at the bottom of this column there is a round ball
 (sv), which is a vessel for holding the seeds. In this diagram
(A) I have drawn the whole of this curious ball
and column as if cut in half, so that we may see what is in
it. In the middle of the ball, in a cluster,
there are a number of round transparent little bodies,
looking something like round green orange-cells full of
juice. They are really cells full of protoplasm, with one
little dark spot in each of them, which by-and-by is to
make our little plantlet that we found in the seed.
"These, then, are seeds," you will say. Not yet; they are
only ovules, or little bodies which may become seeds. If
they are left as they are they would all wither and die.
But those little grains of pollen, which we saw sticking to
the knob at the top, are coming down to help them. As soon
as these yellow grains touch the sticky knob or stigma, as
it is called, they throw out tubes, which grow down the
column until they reach the ovules. In each one of these
they find a tiny hole, and into this they creep, and then
they pour into the ovule all the protoplasm from the
pollen grain which is sticking above, and this enables it
to grow into a real seed, with a tiny plantlet inside.
This is how the plant forms its seed to bring up new little
ones next year, while the leaves and the roots are at work
preparing the necessary food. Think sometimes when you walk
 woods, how hard at work the little plants and big
trees are all around you. You breathe in the nice fresh
oxygen they have been throwing out, and little think that it
is they who are making the country so fresh and pleasant,
and that while they look as if they were doing nothing but
enjoying the bright sunshine, they are really fulfilling
their part in the world by the help of this sunshine;
earning their food from the ground; working it
up; turning their leaves where they can best get light (and
in this it is chiefly the violet sun-waves that help them),
growing even at night, by making new cells out of the food
they have taken in the day; storing up for the winter;
putting out their flowers and making their seeds, and all
the while smiling so pleasantly in quiet nooks and sunny
dells that it makes us glad to see them.
But why should the primroses have such golden crowns? Plain
green ones would protect the seed quite as well. Ah! now we
come to a secret well worth knowing. Look at the two
primrose flowers, 1 and 2, p. 181, and tell me how
you think the dust gets on to the top of the sticky knob or
stigma. No. 2 seems easy enough to explain, for it looks as
if the pollen could fall down easily from the stamens on to
the knob, but it cannot fall up, as it would have to do in
No. 1. Now the curious truth is, as Mr. Darwin has shown,
that neither of these flowers can get the dust
 easily for
themselves, but of the two No. 1 has the least difficulty.
Look at a withered primrose, and see how it holds its head
down, and after a little while the yellow crown falls off.
It is just about as it is falling that the anthers or bags
of the stamens burst open, and then, in No. 1, they
are dragged over the knob and some of the grains stick
there. But in the other form of primrose, No. 2, when the
flower falls off, the stamens do not come near the knob, so
it has no chance of getting any pollen; and while the
primrose is upright the tube is so narrow that the dust does
not easily fall. But, as I have said, neither kind gets it
very easily, nor is it good for them if they do.
The seeds are much stronger and better if the dust or
pollen of one flower is carried away and left on
 the knob
or stigma of another flower; and the only way this can be
done is by insects flying from one flower to another and
carrying the dust on their legs and bodies.
Corolla of Primrose falling off
1, Primrose with long pistil, and stamens in the tube. 2, Primrose with short pistil, and stamens at mouth of tube.
If you suck the end of the tube of the primrose flower you
will find it tastes sweet, because a drop of honey has been
lying there. When the insects go in to get this honey, they
brush themselves against the yellow dust-bags, and some of
the dust sticks to them, and then when they go to the next
flower they rub it off on to its sticky knob.
Look at No. 1 and No. 2 (page 185) and you will see at once
that if an insect goes into No. 1 and the pollen sticks to
him, when he goes into No. 2 just that part of his body on
which the pollen is will touch the knob; and so
the flowers become what we call "crossed," that is, the
pollen-dust of the one feeds the ovule of the other. And
just the same thing will happen if he flies from No. 2 to
No. 1. There the dust will be just in the position to touch
the knob which sticks out of the flower.
Therefore, we can see clearly that it is good for the
primrose that bees and other insects should come to it, and
anything it can do to entice them will be useful. Now, do
you not think that when an insect once knew that the
pale-yellow crown showed where honey was to be found, he
would soon spy these crowns out as he flew along? or
they were behind a hedge, and he could not see them, would
not the sweet scent tell him where to come and look for
them? And so we see that the pretty sweet-scented corolla is
not only delightful for us to look at and to smell, but it
is really very useful in helping the primrose to make
strong healthy seeds out of which the young plants are to
grow next year.
And now let us see what we have learned. We began with a tiny
seed, though we did not then know how this seed had been
made. We saw the plantlet buried in it, and learned how it
fed at first on prepared food, but soon began to make
living matter for itself out of gases taken from the water
and the air. How ingeniously it pumped up the water
through the cells to its stomach—the leaves! And how
marvelously the sun-waves entering there formed the little
green granules, and then helped them to make food and
living protoplasm! At this point we might have
gone further, and studied how the fibres and all the
different vessels of the plant are formed, and a wondrous
history it would have been. But it was too long for one
hour's lecture, and you must read it for yourselves in books
on botany. We had to pass on to the flower, and learn the
use of the covering leaves, the gaily colored crown
attracting the insects, the dust-bags holding the pollen,
the little ovules each
 with the germ of a new plantlet,
lying hidden in the seed-vessel, waiting for the
pollen-grains to grow down to them. Lastly, when the pollen
crept in at the tiny opening we learned that the ovule had
now all it wanted to grow into a perfect seed.
And so we came back to a primrose seed, the point from which
we started; and we have a history of our primrose from its
birth to the day when its leaves and flowers wither away
and it dies down for the winter.
But what fairies are they which have been at work here?
First, the busy little fairy Life in the active protoplasm;
and secondly, the sun-waves. We have seen that it was by
the help of the sunbeams that the green granules were made,
and the water, carbonic acid, and nitrogen worked up into
the living plant. And in doing this work the sun-waves were
caught and their strength used up, so that they could no
longer quiver back into space. But are they gone for ever?
So long as the leaves or the stem or the root of the plant
remain they are gone, but when those are destroyed we can
get them back again. Take a handful of dry withered plants
and light them with a match, then as the leaves burn and
are turned back again to carbonic acid,
nitrogen, and water, our sunbeams come back again in the
flame and heat.
And the life of the plant? What is it, and why is this
protoplasm always active and busy? I
 cannot tell you. Study
as we may, the life of the tiny plant is as much a mystery
as your life and mine. It came, like all things, from the
bosom of the Great Father, but we cannot tell how it came
nor what it is. We can see the active grains moving under
the microscope, but we cannot see the power that moves
them. We only know it is a power given to the plant, as to
you and to me, to enable it to live its life, and to do its
useful work in the world.
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