POLLEN AND THE BEE
POPULAR beliefs as to the ways of the honey-bee, unlike those relating to
many other insects, are surprisingly accurate, so far as they go. But,
dealing with such a complex thing as hive-life, it is well-nigh
impossible to have understanding on any single point without going very
much farther than the ordinary tabloid-method of knowledge can carry us.
This is especially true with regard to pollen, and the uses to which it
is put within the hive. The hand-books on bee-keeping usually tell us
that pollen is employed with honey as food for the young bees when in the
larval state; but this is so wide a generalisation that it amounts to
almost positive error.
[Picture: “A rarity in hive life: a honeycomb built upward”]
As a matter of fact, the pollen in its raw condition is given only to the
drone-larva, and this only towards the end of its life as a grub. For
the first three days of the drone-larva’s existence, and in the case of
the young worker-bee for the whole five days of the larval period, the
pollen is administered by the nurse-bees in a pre-digested state. After
partial assimilation, both the pollen and the nectar are regurgitated by
these nurse-bees, and form together a pearly-white fluid—veritable
bee-milk—on which the young grubs thrive in an extraordinary way.
There are few things more fascinating than to watch a hive of bees at
work on a fine June morning, and to note how the pollen is carried in.
With a prosperous stock, thousands of bees must pass within the space of
a few minutes, each bee dragging behind her a double load of this
substance. Very often, in addition to the half-globes of pollen which
she carries on her thighs, the bee will be smothered in it from head to
foot, as in gold-dust. If you track her into the hive, one curious point
will be noted. No matter how fast she may go, or what frantic spirit of
labour may possess the entire colony, the pollen-laden bee is never in a
hurry to get rid of her load. She will waste precious time wandering
over the crowded combs, continually shaking herself, as though showing
off her finery to her admiring relatives; and it may be some minutes
before she finally selects a half-filled pollen-cell and proceeds to kick
off her load. The different kinds of pollen are packed into the cells
indiscriminately, the bee using her head as a ram to press each pellet
home. When the cell is full it is never sealed over with a waxen
capping, as in the case of the honey-stores, but is left open or covered
with a thin film of honey, apparently to preserve it from the air. The
nurse-bees, who are the young workers under a fortnight old, help
themselves from these pollen-bins. They also frequently stop a
pollen-bearer as she hurries through the crowd, and nibble the pollen
from her thighs.
Throughout the season there is hardly an imaginable colour or shade of
colour which is not represented in the pollen carried into a beehive; and
with the aid of a microscope it is not difficult to identify the source
of each kind. In May, before the great field-crops have come into bloom,
the pollen is almost entirely gathered from wild flowers, and consists of
various rich shades of yellow and brown. By far the heaviest burdens at
this time are obtained from the dandelion. The pollen from this flower
is a peculiarly bright orange, and is easily recognised under a strong
glass by its grains, which are in the form of regular dodecahedrons,
thickly covered all over with short spikes.
It is well known that the honey-bee confines herself during each journey
to one species of flower, and this is proved by the microscope. It is
not easy to intercept a homing bee laden with pollen. On alighting
before the hive she runs in so quickly that the keenest eye and deftest
hand are necessary to effect her capture. But with the aid of a
miniature butterfly-net and a little practice it can generally be done;
and then the pellet of pollen will be found to consist almost invariably
of one kind of grain. But it is not always so. The honey-bee, as a
reasoning creature, does not and cannot be expected to do anything
invariably. Among some hundreds of these pollen-lumps examined under the
microscope I have occasionally found grains of pollen differing from the
bulk. Perhaps there are no two species of flower which have
pollen-grains exactly alike in colour, shape, and size, and in most the
differences are very striking. In the cases mentioned the bulk of the
pollen was made up of long oval yellow grains divided lengthwise into
three lobes or gores, which were easily identifiable as coming from the
figwort. The isolated grains were very minute spheres thickly studded
with blunt spikes—obviously from the daisy. The figwort is a famous
source of bee-provender in spring time, and its pollen can be seen
flowing into the hives at that time in an almost unbroken stream of
brilliant chrome-yellow. The brownish-gold masses that are also being
constantly carried in are from the willow; and where the hives are near
woodlands the bluebells yield the bees enormous quantities of pollen of a
dull yellowish white.
It is interesting that all these various materials, so carefully kept
asunder when gathered, are for the most part inextricably mingled within
the hive. Obviously the system of visiting only one species of flower on
each foraging journey can have no relation to pollen-gathering; nor does
it seem to apply to the nectar obtained at the same time. It cannot be
inferred that the contents of each honey-cell are brewed from only one
source, because it has been proved that bees do blend the various nectars
together when several crops are simultaneously in flower. A honey-judge
can easily detect the flavours of heather and white-clover in the same
sample of honey by taste alone. But there is another and much more
conclusive way of deciding the source from which a particular sample of
honey has been obtained. In the purest and most mature honeys there are
always a few accidental grains of pollen, invisible to the eye, yet
easily detected under a strong glass. And these may be taken as almost
infallible guides to the species of flowers visited by the foraging bees.
The only explanation which seems possible, therefore, of the honey-bee’s
care to visit only one kind of blossom on each journey is that it is done
for the sake of the plant itself, cross-fertilisation being thus rendered
extremely improbable.
When once the bee-man has succumbed to the fascination of the microscope,
there is very little chance that he will ever return to his old panoramic
view of things. He goes on from wonder to wonder, and the horizon of the
new world he has entered continually broadens with each marvelling step.
To the old rule-of-thumb bee-keepers pollen was mere bee-bread; and the
fact that the bees preferred one kind to another did not greatly concern
them. But at a time when the small-holder is beginning to feel his feet,
and the question of the feasibility of planting for bee-forage is certain
to arise, it is necessary to know why bees gather this important part of
their diet from particular kinds of flowers, while leaving severely alone
others which appear to be equally attractive. To this question the
microscope supplies a sufficient answer.
Chemists have determined that nectar is the heat and force-producer in
the food of the bee, while pollen supplies its nitrogenous
tissue-building qualities. It is evident that bees select certain
pollens for their superior nutritive powers, just as in bread-making we
prefer wheat to any other species of grain. In the kinds of pollen most
in favour with bees a good microscope will reveal the fact that the
pollen-grains are often accompanied by a certain amount of true farina,
as well as essential oils, which must greatly enhance their food-value.
And in those crops generally neglected by bees, such as daisies and
buttercups, those accompaniments appear to be absent. The dandelion is
especially rich in a thick yellow oil, which the bees carry away with the
pollen; while two plants in particular of which the bees are especially
fond—the crocus and the box—have a large amount of this farina mingled
with the true pollen.
It is only within the last century or so that the real uses of pollen in
the economy of the hive have been ascertained. Until comparatively
recent times the pollen was supposed to be crude wax, which the bees
refined and purified into the white ductile material of the new combs;
and a few old-fashioned bee-keepers still hold this view, and refuse to
believe that the wax used in comb-building is entirely a secretion from
the bee’s own body. Pollen, indeed, seems to have very little to do with
wax, hardly any nitrogenous food being consumed while the wax is being
generated.