POLLEN
“IN a few days, even in a few hours, a flower withers. Pistils, stamens,
calyx, fade and die. Only one thing survives: the ovary, which will
become fruit.
“Now, in order to outlive the other parts of the flower and remain on
its stem when all the rest dries up and falls, the ovary, at the moment
when blossoming is at its greatest vigor, receives a supplement of
strength, I should almost say a new life. The magnificence of the
corolla, its sumptuous colorings, its perfumes, serve to celebrate the
solemn moment when this new vitality comes to the ovary. This great act
accomplished, the flower has had its day.
[Illustration: Grains of Pollen]
“Well, it is the pollen, the yellow dust of the stamens, that gives this
increase of energy without which the nascent seeds would perish in the
ovary, itself withered. It falls from the stamens on to the stigma,
always coated with a stickiness apt to hold it; and from the stigma, it
makes its mysterious action felt in the depths of the ovary. Animated
with new life, the nascent seeds develop rapidly, while the ovary swells
so as to give them necessary room. The final result of this
incomprehensible travail is the fruit, with its contents of seeds ready
to germinate and produce new plants. Do not question me further about
these wonderful things concerning which even the keenest observer ceases
to see clearly. God only, the wisest of beings, knows how a grain of
pollen can give birth to something that was not before, and can cause
the ovary to feel the stirring of the vital principle.
“I will tell you now how we know that the falling of the pollen on to
the stigma is indispensable to the development of the ovary into fruit.
“Most flowers have both stamens and pistils. All those we have just
looked at are in that class. But there are plants that have some flowers
with stamens and others with pistils. Sometimes the flowers with stamens
only and those with pistils only are found on the same plant; sometimes
they are found on separate plants.
“Did I not fear to overcharge your memory, I would tell you that plants
having flowers with stamens only and flowers with pistils only on the
same plant are called monœcious plants. This expression means ‘living in
one house.’ In a word, the flowers with stamens and those with pistils
live together in the same house, since they are found on the same plant.
The pumpkin, cucumber, melon, are monœcious plants.
“Vegetables whose flowers with stamens and flowers with pistils are
found on different plants are termed diœcious; that is to say, plants
with a double house. By this is meant that the ovary and pollen are not
found in the same plant. The locust, date, and hemp are diœcious.
[Illustration: Flowering branch of Locust Tree]
“The locust is a tree of extreme southern France. Its fruit grows in
pods similar to those of the pea, but brown, very long, and plump. This
fruit, in addition to seeds, has a sugary flesh. Supposing we took a
notion, if the climate permitted, to grow locust seeds in our garden.
What locust tree must we plant? Evidently the tree with pistils, because
it alone possesses the ovaries which become fruit. But that is not
enough. Planted by itself, the locust tree with pistils will be able to
blossom abundantly every year, without ever producing any fruit; for its
flowers would fall without leaving a single ovary on the branches. What
is wanting? The action of the pollen. Close to the locust with pistils
let us plant one with stamens. Now fructification proceeds as we wish.
Wind and insects carry the pollen from the stamens to the stigmas; the
torpid ovaries spring to life, and in time the locust pods grow and
ripen perfectly. With pollen, fruit; without pollen, no fruit. Are you
convinced, Jules?”
“Without doubt, Uncle; only, unfortunately, we do not know the locust. I
should prefer a plant of our own region.”
[Illustration: Date-palm]
“I will tell you of one that will permit you to prove what I have told
you; but first of all let me mention a second example.
“The date-tree, like the locust, is diœcious. Arabs cultivate it for its
fruit,—dates, their chief food.”
“Dates are those long fruits of a very sweet taste, preserved dry in
boxes,” said Jules. “A Turk was selling some at the last fair. The
kernel is long and split all along one side from one end to the other.”
“That is it. In the country of the date-tree, a sandy country burnt by
the sun, spots of watered and fertile earth are rare. These spots are
called oases. It is necessary to utilize them as much as possible. So
the Arabs plant only date-trees with pistils, the only ones that will
produce dates. But when they are in flower, the Arabs go long distances
to seek bunches of flowers with stamens on wild date-trees, to shake the
dust on the trees they have planted. Without this precaution there is no
harvest.”
“Uncle will tell us so much,” Emile interposed, “that I shall have as
much regard for the pollen as I have for the ovary. Without it, I should
not have tasted the dates of the Turk who smoked such a long pipe;
without it, no apricots and no cherries.”
“In the garden there is a long pumpkin-vine that will soon blossom. I
will give it to you for the following experiment.
“The pumpkin is monœcious; flowers with stamens and flowers with pistils
inhabit the same house, the same plant. Before they are full-blown they
can easily be distinguished from each other. The flowers with pistils
have under the corolla a swelling almost as large as a nut. This
swelling is the ovary, the future pumpkin. The blossoms with stamens
have not this swelling.
“Cut off all the blossoms with stamens before they are full-blown, and
leave those with pistils. For greater surety, wrap each one of these in
a piece of gauze before it is in full-bloom. The covering must be large
enough to permit the flower to open. Do you know what will happen? Not
being able to receive the pollen, since the flowers with stamens are cut
off, and since, also, the gauze wrapping keeps out the insects from the
neighboring gardens, the pistillate flowers will wither after
languishing a while, and the plant will not produce any pumpkins.
“Would you, on the contrary, like such and such blossoms, at your
choice, to produce pumpkins in spite of their gauze prison and the
suppression of the staminate blossoms? With the tip of your finger take
a little pollen from one of the blossoms you have cut off, and put the
yellow dust on the stigma of a pistillate flower. Then replace the gauze
wrapping. That is enough, the pumpkin will come.”
“You will let us try that delightful experiment?” asked Jules.
“I will, I give the pumpkin-vine over to you.”
“I have some gauze,” volunteered Claire.
“And I some string to tie it with,” added Emile.
“Come along,” cried Jules.
And, gay as larks, the three children ran to the garden to get
everything ready for the experiment.
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