Lecture X
BEES AND FLOWERS
Whatever thoughts each one of you may have brought to the
lecture to-day, I want you to throw them all aside and fancy
yourself to be in a pretty country garden on a hot summer's
morning. Perhaps you have been walking, or reading, or playing,
but it is getting too hot now to do anything; and so you have
chosen the shadiest nook under the old walnut-tree, close to the
flower-bed on the lawn, and would almost like to go to sleep if
it were not too early in the day.
As you lie there thinking of nothing in particular, except how
pleasant it is to be idle now and then, you notice a gentle
buzzing close to you, and you see that on the flower-bed close
by, several bees are working busily among the flowers. They do
not seem to mind the heat, nor to wish to rest; and they fly so
lightly and look so happy over their work that it does not tire
you to look at them.
That great humble-bee takes it leisurely enough as she goes
lumbering along, poking her head into the larkspurs, and
remaining so long in each you might almost think she had fallen
asleep. The brown hive-bee on the other hand, moves busily and
quickly among the stocks, sweet peas, and mignonette. She is
evidently out on active duty, and means to get all she can from
each flower, so as to carry a good load back to the hive. In
some blossoms she does not stay a moment, but draws her head back
directly she has popped it in, as if to say "No honey there."
But over the full blossoms she lingers a little, and then
scrambles out again with her drop of honey, and goes off to seek
more in the next flower.
Let us watch her a little more closely. There are plenty of
different plants growing in the flower-bed, but, curiously
enough, she does not go first to one kind and then to another;
but keeps to one, perhaps the mignonette, the whole time till she
flies away. Rouse yourself up to follow her, and you will see
she takes her way back to the hive. She may perhaps stop to
visit a stray plant of mignonette on her way, but no other flower
will tempt her till she has taken her load home.
Then when she comes back again she may perhaps go to another kind
of flower, such as the sweet peas, for instance, and keep to them
during the next journey, but it is more likely that she will be
true to her old friend the mignonette for the whole day.
We all know why she makes so many journeys between the garden and
the hive, and that she is collecting drops of honey from each
flower, and carrying it to be stored up in the honeycomb for
winter's food. How she stores it, and how she also gathers
pollen-dust for her bee-bread, we saw in the last lecture; to-day
we will follow her in her work among the flowers, and see, while
they are so useful to her, what she is doing for them in return.
We have already learnt from the life of a primrose that plants
can make better and stronger seeds when they can get pollen-dust
from another plant, than when they are obliged to use that which
grows in the same flower; but I am sure you will be very much
surprised to hear that the more we study flowers the more we find
that their colours, their scent, and their curious shapes are all
so many baits and traps set by nature to entice insects to come
to the flowers, and carry this pollen-dust from one to the other.
So far as we know, it is entirely for this purpose that the
plants form honey in different parts of the flower, sometimes in
little bags or glands, as in the petals of the buttercup flower,
sometimes in clear drops, as in the tube of the honeysuckle.
This food they prepare for the insects, and then they have all
sorts of contrivances to entice them to come and fetch it.
You will remember that the plants of the coal had no bright or
conspicuous flowers. Now we can understand why this was, for
there were no flying insects at that time to carry the pollen-
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.