Every day the boys watched their buds and seeds bursting into life.
It was slow work; but, as winter passed slowly away and they were able
to go out for walks more often, they had much to amuse them. They
brought home all sorts of curious things, and soon had quite a host of
living things to watch.
[Illustration: Four Stages in the opening of Horse-Chestnut Buds.]
Three weeks passed before the horse-chestnut buds showed any signs of
opening. By this time they had swelled out very much. First the sticky
scales moved apart, then folded themselves backwards out of the way, and
at last fell off altogether.
This moving apart of the scales was caused by the shoot or branch inside
the bud, which was growing rapidly.
Before the scales fell off, it had burst its way through them. It was
now a large mass of thick leaves all folded together, and covered all
over with a sort of wool.
Soon these thick leaves moved apart, the woolly covering came off, and
what a month ago was a little woolly body, so tiny that it had to be
picked apart with a needle, was now a large stout branch, smooth and
green, and bearing beautiful broad leaves.
Some of the buds brought forth small clusters of little green balls.
These the boys at first thought were berries, but they afterwards found
out that they were flowers.
After all the buds had quite opened out, they began slowly to wither.
Uncle George told them the reason of this. It was because the branch had
been cut away from the mother-tree, which drew its food from the soil
and air.
The growing buds had used up all the sap which the cut branch contained.
But by the time their twigs had withered, the buds outside had began to
open—for spring was now at hand.
The hedges were becoming greener every day. The birds were heard singing
in the woods, and little green shoots were springing up everywhere under
foot.
Frank and Tom brought home opening buds of all kinds, and watched the
hedges and trees as they walked daily to school.
Two of the bean seeds were dug up out of the sawdust every second or
third day. In this way the boys were able to see exactly how a bean
plant grows from seed.
[Illustration: Stages in the Germination of the Runner Bean.
In 1 and 4, inside of seed, growing baby plant is shown.]
First the seed swells out; then the skin bursts, and the little plant in
between the two masses of plant-food begins to grow.
The root always grows down straight. The little shoot always grows
upwards.
After the root has grown about an inch it begins to branch; and in about
two weeks these branch branch-roots are searching the soil for food all
around the main root.
The shoot meanwhile is growing in length and thickness. It remains
folded up until it reaches the air and light. Then its leaves open out
and turn from a creamy colour to bright green.
One small box of seeds was placed in a dark cupboard. These beans grew
much more quickly than those grown in the light; but they were pale,
lank, and sickly. They never turned green.
From this the boys learned that the green colour of leaves and stems is
due to the action of light.
Uncle George took a few grains of wheat and placed them upon wet
blotting-paper. A tumbler turned upside down was placed over them.
In a few days the children saw that a few small roots had grown out from
the end of each grain.
When these roots had grown to about half an inch in length, great tufts
of long slender hairs sprang out all round them near their tips. These,
their uncle told them, were “root-hairs.”
The root-hairs of a plant are so fine that they are always torn off when
we dig or pull a plant out of the ground. It is by means of these
slender root-hairs that the plant is able to suck water out of the soil;
and this water always contains a very little plant-food in it.
The boys noticed that the wheat grain did not sprout in the same way as
the bean seed. Instead of one stout little root, three usually came out.
The tiny shoot seemed to grow from the _outside_ of the grain, and the
two large masses of plant-food were missing.
[Illustration: Stages in the Germination of Wheat.]
Some wheat seeds were soaked and cut down the middle. With the aid of
the glass, the boys saw that in the wheat seed the baby plant is
attached to _one_ large mass of plant-food, made up of flour with an
outside layer of bran.
Their uncle then told them that all the flowering plants in the world
are of two great families, namely, those whose seeds have only one food
store, like the wheat grain, and those whose seeds have two, like the
bean.
Exercises on Lesson V.
1. Explain all that happens when a horse-chestnut bud opens.
2. Why do the buds which you force indoors wither after they open?
3. What changes come over your bean seeds as they grow?
4. Do the young plants draw any food from the sawdust? If not, what
feeds them?
5. What three things does a seed need in order to start growing?
[Illustration]
1. Magnified sections of Maize and Wheat Seeds, showing Young Plant,
Food Store, etc.
2. Germination of Maize.
3. Maize growing in Sawdust.
4. Maize growing in Tap Water.
5. Bean growing in Bottle over Water.