Arabella B. Buckley.

The Fairy-Land of Science online

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dust from flower to flower, and therefore there was no need of
coloured flowers to attract them. But little by little, as
flies, butterflies, moths and bees began to live in the world,
flowers too began to appear, and plants hung out these gay-
coloured signs, as much as to say, "Come to me, and I will give
you honey if you will bring me pollen-dust in exchange, so that
my seeds may grow healthy and strong."

We cannot stop to inquire to-day how this all gradually came
about, and how the flowers gradually put on gay colours and
curious shapes to tempt the insects to visit them; but we will
learn something about the way they attract them now, and how you
may see it for yourselves if you keep your eyes open.

For example, if you watch the different kinds of grasses, sedges
and rushes, which have such tiny flowers that you can scarcely
see them, you will find that no insects visit them. Neither will
you ever find bees buzzing round oak-trees, nut-trees, willows,
elms or birches. But on the pretty and sweet-smelling apple-
blossoms, or the strongly scented lime-trees, you will find bees,
wasps, and plenty of other insects.

The reason of this is that grasses, sedges, rushes, nut-trees,
willow, and the others we have mentioned, have all of them a
great deal of pollen-dust, and as the wind blows them to and fro,
it wafts the dust from one flower to another, and so these plants
do not want the insects, and it is not worth their while to give
out honey, or to have gaudy or sweet-scented flowers to attract
them.

But wherever you see bright or conspicuous flowers you may be
quite sure that the plants want the bees or some other winged
insect to come and carry their pollen for them. Snowdrops
hanging their white heads among their green leaves, crocuses with
their violet and yellow flowers, the gaudy poppy, the large-
flowered hollyhock or the sunflower, the flaunting dandelion, the
pretty pink willow-herb, the clustered blossoms of the mustard
and turnip flowers, the bright blue forget-me-not and the
delicate little yellow trefoil, all these are visited by insects,
which easily catch sight of them as they pass by and hasten to
sip their honey.

Sir John Lubbock has shown that bees are not only attracted by
bright colours, but that they even know one colour from another.
He put some honey on slips of glass with coloured papers under
them, and when he had accustomed the bees to find the honey
always on the blue glass, he washed this glass clean, and put the
honey on the red glass instead. Now if the bees had followed
only the smell of the honey, they would have flown to the red
glass, but they did not. They went first to the blue glass,
expecting to find the honey on the usual colour, and it was only
when they were disappointed that they went off to the red.

Is it not beautiful to think that the bright pleasant colours we
love so much in flowers, are not only ornamental, but that they
are useful and doing their part in keeping up healthy life in our
world?

Neither must we forget what sweet scents can do. Have you never
noticed the delicious smell which comes from beds of mignonette,
thyme, rosemary, mint, or sweet alyssum, from the small hidden
bunches of laurustinus blossom, or from the tiny flowers of the
privet? These plants have found another way of attracting the
insects; they have no need of bright colours, for their scent is
quite as true and certain a guide. You will be surprised if you
once begin to count them up, how many white and dull or dark-
looking flowers are sweet-scented, while gaudy flowers, such as
tulip, foxglove and hollyhock, have little or no scent. And
then, just as in the world we find some people who have
everything to attract others to them, beauty and gentleness,
cleverness, kindliness, and loving sympathy, so we find some
flowers, like the beautiful lily, the lovely rose, and the
delicate hyacinth, which have colour and scent and graceful
shapes all combined.

But we are not yet nearly at an end of the contrivances of
flowers to secure the visits of insects. Have you not observed
that different flowers open and close at different times? The
daisy receives its name day's eye, because it opens at sunrise
and closes at sunset, while the evening primrose (Aenothera
biennis) and the night campion (Silene noctiflora) spread out
their flowers just as the daisy is going to bed.

What do you think is the reason of this? If you go near a bed of
evening primroses just when the sun is setting, you will soon be
able to guess, for they will then give out such a sweet scent
that you will not doubt for a moment that they are calling the
evening moths to come and visit them. The daisy opens by day,
because it is visited by day insects, but those particular moths
which can carry the pollen-dust of the evening primrose, fly only
by night, and if this flower opened by day other insects might
steal its honey, while they would not be the right size or shape
to touch its pollen-bags and carry the dust.

It is the same if you pass by a honeysuckle in the evening; you
will be surprised how much stronger its scent is than in the day-
time. This is because the sphinx hawk-moth is the favourite
visitor of that flower, and comes at nightfall, guided by the
strong scent, to suck out the honey with its long proboscis, and
carry the pollen-dust.

Again, some flowers close whenever rain is coming. The pimpernel
(Anagallis arvensis) is one of these, hence its name of the
"Shepherd's Weather-glass." This little flower closes, no doubt,
to prevent its pollen-dust being washed away, for it has no
honey; while other flowers do it to protect the drop of honey at
the bottom of their corolla. Look at the daisies for example
when a storm is coming on; as the sky grows dark and heavy, you
will see them shrink up and close till the sun shines again.
They do this because in each of the little yellow florets in the
centre of the flower there is a drop of honey which would be
quite spoiled if it were washed by the rain.

And now you will see why cup-shaped flowers so often droop their
heads - think of the harebell, the snowdrop, the lily-of-the-
valley, the campanula, and a host of others; how pretty they look
with their bells hanging so modestly from the slender stalk!
They are bending down to protect the honey-glands within them,
for if the cup became full of rain or dew the honey would be
useless, and the insects would cease to visit them.



Week 29

But it is not only necessary that the flowers should keep their
honey for the insects, they also have to take care and keep it
for the right kind of insect. Ants are in many cases great
enemies to them, for they like honey as much as bees and
butterflies do, yet you will easily see that they are so small
that if they creep into a flower they pass the anthers without
rubbing against them, and so take the honey without doing any
good to the plant. Therefore we find numberless contrivances for
keeping the ants and other creeping insects away. Look for
example at the hairy stalk of the primrose flower; those little
hairs are like a forest to a tiny ant, and they protect the
flower from his visits. The Spanish catchfly (Silene otites), on
the other hand, has a smooth, but very gummy stem, and on this
the insects stick, if they try to climb. Slugs and snails too
will often attack and bite flowers, unless they are kept away by
thorns and bristles, such as we find on the teazel and the
burdock. And so we are gradually learning that everything which
a plant does has its meaning, if we can only find it out, and
that even very insignificant hair has its own proper use, and
when we are once aware of this a flower-garden may become quite a
new world to us if we open our eyes to all that is going on in
it.

But as we cannot wander among many plants to-day, let us take a
few which the bees visit, and see how they contrive not to give
up their honey without getting help in return. We will start
with the blue wood-geranium, because from it we first began to
learn the use of insects to flowers.

More than a hundred years ago a young German botanist, Christian
Conrad Sprengel, noticed some soft hairs growing in the centre of
this flower, just round the stamens, and he was so sure that
every part of a plant is useful, that he set himself to find out
what these hairs meant. He soon discovered that they protected
some small honey-bags at the base of the stamens, and kept the
rain from washing the honey away, just as our eyebrows prevent
the perspiration on our faces from running into our eyes. This
led him to notice that plants take great care to keep their honey
for insects, and by degrees he proved that they did this in order
to tempt the insects to visit them and carry off their pollen.

The first thing to notice in this little geranium flower is that
the purple lines which ornament it all point directly to the
place where the honey lies at the bottom of the stamens, and
actually serve to lead the bee to the honey; and this is true of
the veins and marking of nearly all flowers except of those which
open by night, and in these they would be useless, for the
insects would not see them.

When the geranium first opens, all its ten stamens are lying flat
on the corolla or coloured crown, as in the left-hand flower in
Fig. 58, and then the bee cannot get at the honey. But in a
short time five stamens begin to raise themselves and cling round
the stigma or knob at the top of the seed-vessel, as in the
middle flower. Now you would think they would leave their dust
there. But no! the stigma is closed up so tight that the dust
cannot get on to the sticky part. Now, however, the bee can get
at the honey-glands on the outside of the raised stamens; and as
he sucks it, his back touches the anthers or dust-bags, and he
carries off the pollen. Then, as soon as all their dust is gone,
these five stamens fall down, and the other five spring up.
Still, however, the stigma remains closed, and the pollen of
these stamens, too, may be carried away to another flower. At
last these five also fall down, and then, and not till then, the
stigma opens and lays out its five sticky points, as you may see
in the right-hand flower, Fig. 58.

But its own pollen is all gone, how then will it get any? It
will get it from some bee who has just taken it from another and
younger flower; and thus you see the blossom is prevented from
using its own pollen, and made to use that of another blossom, so
that its seeds may grow healthy and strong.

The garden nasturtium, into whose blossom we saw the humble-bee
poling his head, takes still more care of its pollen-dust. It
hides its honey down at the end of its long spur, and only sends
out one stamen at a time instead of five like the geranium; and
then, when all the stamens have had their turn, the sticky knob
comes out last for pollen from another flower.

All this you may see for yourselves if you find geraniums* in the
hedges, and nasturtiums in you garden. But even if you have not
these, you may learn the history of another flower quite as
curious, and which you can find in any field or lane even near
London. The common dead-nettle (Fig. 59) takes a great deal of
trouble in order that the bee may carry off its pollen. When you
have found one of these plants, take a flower from the ring all
round the stalk and tear it gently open, so that you can see down
its throat. There, just at the very bottom, you will find a
thick fringe of hairs, and you will guess at once that these are
to protect a drop of honey below. Little insects which would
creep into the flower and rob it of its honey without touching
the anthers of the stamens cannot get past these hairs, and so
the drop is kept till the bee comes to fetch it. (*The scarlet
and other bright geraniums of our flower-gardens are not true
geraniums, but pelargoniums. You may, however, watch all these
peculiarities in them if you cannot procure the true wild
geranium.)

Now look for the stamens; there are four of them, two long and
two short, and they are quite hidden under the hood which forms
the top of the flower. How will the bee touch them? If you were
to watch one, you would find that when the bee alights on the
broad lip and thrusts her head down the tube, she first of all
knows her back against the little forked tip. This is the sticky
stigma, and she leaves there any dust she has brought from
another flower; then, as she must push far in to reach the honey,
before she comes out again has carried away the yellow powder on
her back, ready to give it to the next flower.

Do you remember how we noticed at the beginning of the lecture
that a bee always likes to visit the same kind of plant in one
journey? You see now that this is very useful to the flowers.
If the bee went from a dead-nettle to a geranium, the dust would
be lost, for it would be of no use to any other plant but a dead-
nettle. But since the bee likes to get the same kind of honey
each journey, she goes to the same kind of flowers, and places
the pollen-dust just where it is wanted.

There is another flower, called the Salvia, which belongs to the
same family as our dead-nettle, and I think you will agree with
me that its way of dusting the bee's back is most clever. The
Salvia (Fig. 60) is shaped just like the dead-nettle, with a hood
and a broad lip, but instead of four stamens it has only two, the
other two being shrivelled up. The two that are left have a very
strange shape, for the stalk or filament of the stamen is very
short, while the anther, which is in most flowers two little bags
stuck together, has here grown out into a long thread, with a
little dust-bag at one end only. In 1, Fig. 60, you only see
one of these stems, because the flower is cut in half, but in the
whole flower, one stands on each side just within the lip. Now,
when the bee puts her head into the tube to reach the honey, she
passes right between these two swinging anthers, and knocking
against the end pushes it before her and so brings the dust-bag
plump down on her back, scattering the dust there! you can
easily try this by thrusting a pencil into any Salvia flower, and
you will see the anther fall.

You will notice that all this time the be does not touch the
sticky stigma which hangs high above her, but after the anthers
are empty and shrivelled the stalk of the stigma grows longer,
and it falls lower down. By-and-by another bee, having pollen on
her back, comes to look for honey, and as she goes into No. 3,
she rubs against the stigma and leaves upon it the dust from
another flower.

Tell me, has not the Salvia, while remaining so much the same
shape as the dead-nettle, devised a wonderful contrivance to make
use of the visits of the bee?

The common sweet violet (Viola odorata) or the dog violet (Viola
canina), which you can gather in any meadow, give up their
pollen-dust in quite a different way from the Salvia, and yet it
is equally ingenious. Everyone has noticed what an irregular
shape this flower has, and that one of its purple petals has a
curious spur sticking out behind. In the tip of this spur and in
the spur of the stamen lying in it the violet hides its honey,
and to reach it the bee must press past the curious ring of
orange-tipped bodies in the middle of the flower. These bodies
are the anthers, Fig. 61, which fit tightly round the stigma, so
that when the pollen-dust, which is very dry, comes out of the
bags, it remains shut in by the tips as if in a box. Two of
these stamens have spurs which lie in the coloured spur of the
flower, and have honey at the end of them. Now, when the bee
shakes the end of the stigma, it parts the ring of anthers, and
the fine dust falls through upon the insect.

Let us see for a moment how wonderfully this flower is arranged
to bring about the carrying of the pollen, as Sprengel pointed
out years ago. In the first place, it hangs on a thin stalk, and
bends its head down so that the rain cannot come near the honey
in the spur, and also so that the pollen-dust falls forward into
the front of the little box made by the closed anthers. Then the
pollen is quite dry, instead of being sticky as in most plants.
This is in order that it may fall easily through the cracks.
Then the style or stalk of the stigma is very thin and its tip
very broad, so that it quivers easily when the bee touches it,
and so shakes the anthers apart, while the anthers themselves
fold over to make the box, and yet not so tightly but that the
dust can fall through when they are shaken. Lastly, if you look
at the veins of the flower, you will find that they all point
towards the spur where the honey is to be found, so that when the
sweet smell of the flower has brought the bee, she cannot fail to
go in at the right place.

Two more flowers still I want us to examine together, and then I
hope you will care to look at every flower you meet, to try and
see what insects visit it, and how its pollen-dust is carried.
These two flowers are the common Bird's-foot trefoil (Lotus
corniculatus), and the Early Orchis (Orchis mascula), which you
may find in almost any moist meadow in the spring and early
summer.

The Bird's-foot trefoil, Fig. 62, you will find almost anywhere
all through the summer, and you will know it from other flowers
very like it by its leaf, which is not a true trefoil, for behind
the three usual leaflets of the clover and the shamrock leaf, it
has two small leaflets near the stalk. The flower, you will
notice, is shaped very like the flower of a pea, and indeed it
belongs to the same family, called the Papilionaceae or butterfly
family, because the flowers look something like an insect flying.

In all these flowers the top petal stands up like a flag to catch
the eye of the insect, and for this reason botanists call it the
"standard". Below it are two side-petals called the "wings," and
if you pick these off you will find that the remaining two petals
are joined together at the tip in a shape like the keel of a
boat. For this reason they are called the "keel". Notice as we
pass that these two last petals have in them a curious little
hollow or depression, and if you look inside the "wings" you will
notice a little knob that fits into this hollow, and so locks the
two together. We shall see by-and-by that this is important.



Week 30

Next let us look at the half-flower when it is cut open, and see
what there is inside. There are ten stamens in all, enclosed
with the stigma in the keel; nine are joined together and one is
by itself. The anthers of five of these stamens burst open while
the flower is still a bud, but the other stamens go on growing,
and push the pollen-dust, which is very moist and sticky, right
up into the tip of the keel. Here you see it lies right round
the stigma, but as we saw before in the geranium, the stigma is
not ripe and sticky yet, and so it does not use the pollen
grains.

Now suppose that a bee comes to the flower. The honey she has to
fetch lies inside the tube, and the one stamen being loose she is
able to get her proboscis in. but if she is to be of any use to
the flower she must uncover the pollen-dust. See how cunningly
the flower has contrived this. In order to put her head into the
tube the bee must stand upon the wings, and her weight bends them
down. but they are locked to the keel by the knob fitting in the
hole, and so the keel is pushed down too, and the sticky pollen-
dust is uncovered and comes right against the stomach of the bee
and sticks there! As soon as she has done feeding and flies
away, up go the wings and the keel with them, covering up any
pollen that remains ready for next time. Then when the bee goes
to another flower, as she touches the stigma as well as the
pollen, she leaves some of the foreign dust upon it, and the
flower uses that rather than its own, because it is better for
its seeds. If however no bee happens to come to one of these
flowers, after a time the stigma becomes sticky and it uses its
own pollen: and this is perhaps one reason why the bird's-foot
trefoil is so very common, because it can do its own work if the
bee does not help it.

Now we come lastly to the Orchis flower. Mr. Darwin has written
a whole book on the many curious and wonderful ways in which
orchids tempt bees and other insects to fertilize them. We can
only take the simplest, but I think you will say that even this
blossom is more like a conjuror's box than you would have
supposed it possible that a flower could be.

Let us examine it closely. It has sic deep-red covering leaves,
Fig. 62, three belonging to the calyx or outer cup, and three
belonging to the corolla or crown of the flower; but all six are
coloured alike, except that the large on in front, called the
"lip", has spots and lines upon it which will suggest to you at
once that they point to the honey.

But where are the anthers, and where is the stigma? Look just
under the arch made by those three bending flower-leaves, and
there you will see two small slits, and in these some little
club-shaped bodies, which you can pick out with the point of a
needle. One of these enlarged is shown. It is composed of
sticky grains of pollen held together by fine threads on the top
of a thin stalk; and at the bottom of the stalk there is a little
round body. This is all that you will find to represent the
stamens of the flower. When these masses of pollen, or pollinia
as they are called, are within the flower, the knob at the bottom
is covered by a little lid, shutting them in like the lid of a
box, and just below this lid you will see two yellowish lumps,
which are very sticky. These are the top of the stigma, and they
are just above the seed-vessel, which you can see in the lowest
flower in the picture.

Now let us see how this flower gives up its pollen. When a bee
comes to look for honey in the orchis, she alights on the lip,
and guided by the lines makes straight for the opening just in
front of the stigmas. Putting her head into this opening she
pushes down into the spur, where by biting the inside skin she
gets some juicy sap. Notice that she has to bite, which takes
time.

You will see at once that she must touch the stigmas in going in,
and so give them any pollen she has on her head. but she also
touches the little lid and it flies instantly open, bringing the
glands at the end of the pollen-masses against her head. These
glands are moist and sticky, and while she is gnawing the inside
of the spur they dry a little and cling to her head and she
brings them out with her. Darwin once caught a bee with as many
as sixteen of these pollen-masses clinging to her head.

But if the bee went into the next flower with these pollinia
sticking upright, she would simply put them into the same slits
in the next flower, she would not touch them against the stigma.
Nature, however, has provided against this. As the bee flies
along, the glands sticking to its head dry more and more, and as
they dry they curl up and drag the pollen-masses down, so that
instead of standing upright, as in 1, Fig. 63, they point
forwards, as in 2.

And now, when the bee goes into the next flower, she will thrust
them right against the sticky stigmas, and as they cling there
the fine threads which hold the grains together break away, and
the flower is fertilized.

If you will gather some of these orchids during your next spring
walk in the woods, and will put a pencil down the tube to
represent the head of the bee you may see the little box open,
and the two pollen-masses cling to the pencil. Then if you draw
it out you may see them gradually bend forwards, and by thrusting
your pencil into the next flower you may see the grains of pollen
bread away, and you will have followed out the work of a bee.

Do not such wonderful contrivances as these make us long to know
and understand all the hidden work that is going on around us
among the flowers, the insects, and all forms of life? I have
been able to tell you but very little, but I can promise you that
the more you examine, the more you will find marvellous histories
such as these in simple field-flowers.

Long as we have known how useful honey was to the bee, and how it
could only get it from flowers, yet it was not till quite lately
that we have learned to follow out Sprengel's suggestion, and to
trace the use which the bee is to the flower. But now that we
have once had our eyes opened, every flower teaches us something
new, and we find that each plant adapts itself in a most


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