[Illustration: [Flower]]
In the beginning flowers seem to have had their petals all separate from
each other. Some do still, and these we call polypetalous, because
“poly-” means many, and they have many petals. But other flowers, like
our morning-glory, have no separate petals; all are grown together into
a tube with a bright border.
But this tube and border tell us a little story if we are able to hear
it.
They tell us of the time when the morning-glory had several petals. More
than this, they tell us just how many it had. If we were to guess we
should probably say five, because it seems so fond of the number five,
with its five nectaries, five nectar guides, five stamens, and five
sepals.
If we guessed five we should guess just right. There is no doubt but
that once upon a time the plants from which our morning-glories are
descended had five separate petals. The morning-glories themselves
manage it differently now, but it took them a long time to do it. They
were working away, long before the great pyramids of Egypt were built,
to get their five petals united into one piece. But it is done, and they
have learned how to twist the flower up tightly in the bud and then
unroll it in all its glory.
[Illustration: [Flower]]
They never have five petals now, but they still bear traces of it.
Look at the little notch on the border, halfway between two nectar
guides. Does that tell us anything?
Count the notches. Five, you see.
Look at the line that runs from the notch down to the bottom of the
flower.
The corolla looks as though it had been folded along those lines. You
can easily see five long creases ending in a notch. The flower is folded
along these lines in the bud, but we think the lines have yet another
meaning.
Carefully tear the corolla down the lines; you see, a very little
pressure does it. Now we have the corolla in five parts, like five
petals, only it is so weak it can no longer hold itself up. Once upon a
time we think it grew this way, with five separate petals, only the
petals stood up then, for they must have been stiffer and perhaps were
not so long. It was long, long ago, oh, very long ago, that it had its
five petals. Then the edges of the petals began to grow together, and
they kept on doing this until, in course of time, the whole length of
each petal had grown fast to the next one, all except that little tiny
spot where the notch is.
We are glad our morning-glory kept this little notch and the line where
the sides of the petals grew together, for that is what tells us the
story of long, long ago when all the petals were separate.
When finally they were grown together, the corolla did not need to be so
stiff, for its shape helped to make it firm, and then it no longer used
good material to make stiffening for the petals, for that would have
been a waste of plant sap, and plants do not like to waste materials.
When they find they can get along without something they have been used
to having, they stop making it. Life is too short and too precious to
waste a bit of it. Our flower only kept the stiffening in the corolla
along the paths where it wished the bees to go to its honey cups and
where, when folded, it could best protect the bud.
The morning-glory, you see, is as wise as it is beautiful.
[Illustration: [Flower]]