18 THE CHILDHOOD OF PLANTS.

with a bent neck begins to struggle upwards. This is the
plumule, and is the small beginning of the future bean.
plant. Some children I was teaching once used to say:

“The radicle is the reot
And the plumule is the shoot.”

That helped them to remember, you see.

But how is it that the plumule grows upwards? Does
not the earth pull it too? Ah! this is one of the secrets of
Nature. We do not know how the little plant finds strength
to grow upwards in spite of the earth’s attraction; but we
know that the whisper which prompts it to do so is a wise
one, for sunlight and air are indispensable to its life. You
know already that the sun is the great fire, and the green
leaves the kitchen where all the plant’s food is prepared.

But until the green leaves are old enough to do the cook-
ing, what does the baby bean live upon ?

I have told you before of the two thick seed-leaves, with
their store of prepared food. They have no cooking to do,
for the food is ready for use, stored up in their thick sides ;
so they do not need sunlight or air, and may be content to
stay below, unless they should be dragged up out of the
ground by the efforts of that little arching neck which is
trying to uplift the plumule. We call that little bent white
stalk the caulicle.

Why does it arch so?

Think. If you have ever played in a hay-field and been
buried in the hay, how did you get out? Did you push
your way out nose first? I expect not. I expect you
protected the delicate skin of your face by a bent neck
and back, as the little seedling protects its delicate plumule.

How does it straighten itself? Well, the underneath
part of the curved stem sets to work to grow much faster
than the upper part of the curve, and so the stem is soon
straight. How, and why it does this, I may be able fully to