having been satisfactorily explained. Long ago Buffon sought to account
for the hexagonal form of the cells by an hypothesis of mutual pressure.
Supposing the bees to have a tendency to build tubular cells, if a
greater number of bees were to build in a given space than could admit
of all the parallel tubes being completed, tubes with flat sides and
sharp angles might result, and if the mutual pressure were exactly equal
in all directions, these sides and angles would assume the form of
hexagons. This hypothesis of Buffon was sustained by such physical
analogies as the blowing of a crowd of soap-bubbles in a cup, the
swelling of moistened peas in a confined space, &c. The hypothesis,
however, as thus presented was clearly inadequate; for no reason is
assigned why the mutual pressure, even if conceded to exist, should
always be so exactly equal in all directions as to convert all the
cylinders into perfect hexagons--even the analogy of the soap-bubbles
and the moistened peas failing, as pointed out by Brougham and others,
to sustain it, seeing that as a matter of fact bubbles and peas under
circumstances of mutual pressure do not assume the form of hexagons,
but, on the contrary, forms which are conspicuously irregular. Moreover,
the hypothesis fails to account for the particular prismatic shape
presented by the cell base. Therefore it is not surprising that this
hypothesis should have gained but small acceptance. Kirby and Spence
dispose of it thus:--'He (Buffon) gravely tells us that the boasted
hexagonal cells of the bee are produced by the reciprocal pressure of
the cylindrical bodies of these insects against each other!!'[59] The
double note of admiration here may be taken to express the feelings with
which this hypothesis of Buffon was regarded by all the more
sober-minded naturalists. Yet it turns out to have been not very wide of
the mark. As is often the case with the gropings of a great mind, the
idea contains the true principle of the explanation, although it fails
as an explanation from not being in a position to take sufficient
cognizance of all the facts. Safer it is for lesser minds to restrain
their notes of exclamation while considering the theories of a greater;
however crude or absurd the latter may appear, the place of their birth
renders it not impossible that some day they may prove to have been
prophetic of truth revealed by fuller knowledge. Usually in such cases
the final explanation is eventually reached by the working of a yet
greater mind, and in this case the undivided credit of solving the
problem is to be assigned to the genius of Darwin.
Mr. Waterhouse pointed out 'that the form of the cell stands in close
relation to the presence of adjoining cells.' Starting from this fact,
Mr. Darwin says,--
Let us look to the great principle of gradation, and
see whether Nature does not reveal to us her method of
work. At one end of a short series we have
humble-bees, which use their old cocoons to hold
honey, sometimes adding to them short tubes of wax,
and likewise making separate and very irregular
rounded cells of wax. At the other end of the series
we have the cells of the hive-bee, placed in a double
layer. . . . In the series between the extreme perfection
of the cells of the hive-bee and the simplicity of
those of the humble-bee we have the cells of the
Mexican _Melipona domestica_, carefully described and
figured by Pierre Huber. . . . It forms a nearly regular
waxen comb of cylindrical cells, in which the young
are hatched, and, in addition, some large cells of wax
for holding honey. These latter cells are nearly
spherical and of nearly equal sizes, and are
aggregated into an irregular mass. But the important
thing to notice is, that these cells are always made
at that degree of nearness to each other that they
would have intersected or broken into each other if
the spheres had been completed; but this is never
permitted, the bees building perfectly flat cells of
wax between the spheres which thus tend to intersect.
Hence each cell consists of an outer spherical
portion; and of two, three, or more flat surfaces,
according as the cell adjoins two, three, or more
other cells. When one cell rests on three other cells,
which, from the spheres being nearly of the same size,
is very frequently and necessarily the case, the three
flat surfaces are united into a pyramid; and this
pyramid, as Huber has remarked, is manifestly a gross
imitation of the three-sided pyramidal base of the
cell of the hive-bee. . . .
Reflecting on this case, it occurred to me that if the
Melipona had made its spheres at some given distance
from each other, and had made them of equal sizes, and
had arranged them symmetrically in a double layer, the
resulting structure would have been as perfect as the
comb of the hive-bee. Accordingly I wrote to Prof.
Miller of Cambridge, and this geometer has kindly read
over the following statement, drawn up from his
information, and tells me that it is strictly correct.
This statement having fully borne out his theory, Mr. Darwin
continues:--
Hence we may safely conclude that, if we could
slightly modify the instincts already possessed by the
Melipona, and in themselves not very wonderful, this
bee would make a structure as wonderfully perfect as
that of the hive-bee. We must suppose the Melipona to
have the power of forming her cells truly spherical,
and of equal sizes; and this would not be very
surprising, seeing that she already does so to a
certain extent, and seeing what perfectly cylindrical
burrows many insects make in wood, apparently by
turning round on a fixed point. We must suppose the
Melipona to arrange her cells in level layers, as she
already does her cylindrical cells; and we must
further suppose--and this is the greatest
difficulty--that she can somehow judge accurately at
what distance to stand from her fellow-labourers when
several are making their spheres; but she is already
so far able to judge of distance that she always
describes her spheres so as to intersect to a certain
extent; and then she unites the points of intersection
by perfectly flat surfaces. By such modifications of
instinct, which in themselves are not very
wonderful--hardly more wonderful than those which
guide a bird to make its nest,--I believe that the
hive-bee has acquired through natural selection her
inimitable architectural powers.[60]
Mr. Darwin next tested this theory by the experiment of introducing into
beehives plates of wax, and observing that the bees worked upon these
plates just as the theory required. That is to say, they made their
cells by excavating a number of little circular pits at equal distances
from one another, so that by the time the pits had acquired the width of
an ordinary cell, the sides of the pits intersected. As soon as this
occurred the bees ceased to excavate, and instead began to build up flat
walls of wax on the lines of intersection. Other experiments with very
thin plates of vermilion-coloured wax showed that the bees all worked at
about the same rate, and on opposite sides of the plates, so that the
common bottoms of any two opposite pits were flat. These flat bottoms
'were situated, as far as the eye could judge, exactly along the planes
of imaginary intersection between the basins on the opposite sides of
the ridge of wax;' so that if the plate of wax had been thick enough to
admit of the opposite basins being deepened (and widened) into cells,
the mutual intersection of _adjacent_ as well as _opposite_ bottoms
would have given rise, as in the first experiment with the thick plate
of wax, to the pyramidal bottoms. Experiments with the vermilion wax
also showed, as Huber had previously stated, that a number of individual
bees work by turns at the same cell; for by covering parts of growing
cells with vermilion wax, Mr. Darwin--
Invariably found that the colour was most delicately
diffused by the bees--as delicately as a painter could
have done it with his brush--by atoms of the coloured
wax having been taken from the spot on which it had
been placed, and worked into the growing edges of the
cells all round.
Such, omitting details, is the substance of Mr. Darwin's theory. In
summary he concludes,--
The work of construction seems to be a sort of balance
struck between many bees, all instinctively standing
at the same relative distance from each other, all
trying to sweep equal spheres, and then building up,
or leaving ungnawed, the planes of intersection
between these spheres.
This theory, while serving as a full and simple explanation of all the
facts, has, as we have seen, been so fully substantiated by observation
and experiment, that it deserves to be regarded as raised to the rank of
a completed demonstration. It differs from the theory of Buffon in two
important particulars: it embraces all the facts, and supplies a cause
adequate to explain them. This cause is natural selection, which
converts the random 'pressure' in Buffon's theory into a precisely
regulated principle. Random pressure alone could never produce the
beautifully symmetrical form of the hexagonal cell with the pyramidal
bottom; but it could and must have produced the intersection of
cylindrical cells among possibly many extinct species of bees, such as
the Melipona. Whenever this intersection occurred in crowded nests, it
must clearly have been of great benefit in securing economy of precious
wax; for in every case where a flat wall of partition between two
adjacent cells did duty instead of a double cylindrical wall of
separate cells, there wax should have been saved. Thus we can see how
natural selection would have worked towards the developing of an
instinct to excavate cells near enough together to produce intersection;
and once begun, there is no reason why this instinct should not have
been perfected by the same agency, till we meet with its ideal
perfection in the hive-bee. For as Mr. Darwin observes,--
With respect to the formation of wax, it is known that
bees are often hard pressed to get sufficient nectar;
and I am informed by Mr. Tegetmeier that it has been
experimentally proved that from twelve to fifteen
pounds of dry sugar are consumed by a hive of bees for
the secretion of a pound of wax; so that a prodigious
quantity of fluid nectar must be collected and
consumed by the bees in a hive for the secretion of
the wax necessary for the construction of their combs.
Moreover, many bees have to remain idle for many days
during the process of secretion. . . . Hence it would
continually be more and more advantageous to our
humble-bees if they were to make their cells more and
more regular, nearer together, and aggregated into a
mass, like the cells of Melipona; for in this case a
large part of the bounding surface of each cell would
serve to bound the adjoining cell, and much labour and
wax would be saved. Again, from the same cause, it
would be advantageous to the Melipona if she were to
make her cells closer together, and more regular in
every way than at present; for then, as we have seen,
the spherical surfaces would wholly disappear and be
replaced by plane surfaces; and the Melipona would
make a comb as perfect as that of the hive-bee. Beyond
this stage of perfection in architecture, natural
selection could not lead; for the comb of the
hive-bee, as far as we can see, is absolutely perfect
in economising labour and wax.
The problem, then, as to the origin and perfection of the cell-making
instinct appears thus to have been fully and finally solved. I shall now
adduce a few facts to show that while the general instinct of building
hexagonal cells has doubtless been acquired by natural selection in the
way just explained, it is nevertheless an instinct not wholly of a blind
or mechanical kind, but is constantly under the control of intelligent
purpose. Thus Mr. Darwin observes,--
It was really curious to note in cases of difficulty,
as when two pieces of comb met at an angle, how often
the bees would pull down and rebuild in different ways
the same cell, sometimes recurring to a shape which
they had at first rejected.[61]
Again, Huber saw a bee building upon the wax which had already been put
together by her comrades. But she did not arrange it properly, or in a
way to continue the design of her predecessors, so that her building
made an undesirable corner with theirs. 'Another bee perceived it,
pulled down the bad work before our eyes, and gave it to the first in
the requisite order, so that it might exactly follow the original
direction.' Similarly, to quote Büchner,--
All the cells have not the same shape, as would be the
case if the bees in building worked according to a
perfectly instinctive and unchangeable plan. There are
very manifold changes and irregularities. Almost in
every comb irregular and unfinished cells are to be
found, especially where the several divisions of a
comb come together. The small architects do not begin
their comb from a single centre, but begin building
from many different points, so as to progress as
rapidly as possible, and so that the greatest number
may work simultaneously; they therefore build from
above downwards, in the shape of flat truncated cones
or hanging pyramids, and these several portions are
afterwards united together during the winter budding.
At these lines of junction it is impossible to avoid
irregular cells between the pressed together or
unnaturally lengthened ones. The same is true more or
less of the passage cells, which are made to unite the
large cells of the so-called drone wax with the
smaller ones of the working bees, and which are
generally placed in two or three rows. The cells also
which they usually build from the combs to the glass
walls of their hives, in order to hold them up, show
somewhat irregular forms. Finally, in places where
special conditions of the situation do not otherwise
permit, it may be observed that the bees, far from
clinging obstinately to their plan, very well
understand how to accommodate themselves to
circumstances not only in cell-building, but also in
making their combs. F. Huber tried to mislead their
instinct, or rather to put to the proof their reason
and cleverness in every possible way, but they always
emerged triumphant from the ordeal. For instance, he
put bees in a hive the floor and roof of which were
made of glass, that is of a body which the bees use
very unwillingly for the attachment of their combs, on
account of its smoothness. Thus the possibility of
building as usual from above downwards, and also from
below upwards, was taken away from them; they had no
point of support save the perpendicular walls of their
dwelling. They thereupon built on one of these walls a
regular stratum of cells, from which, building
sideways, they tried to carry the comb to the opposite
side of the hive. To prevent this Huber covered that
side also with glass. But what way out of the
difficulty was found by the clever insects? Instead of
building further in the projected direction, they bent
the comb round at the extreme point, and carried it at
a right angle towards one of the inner sides of the
hive which was not covered with glass, and there
fastened it. The form and dimensions of the cells must
necessarily have been altered thereby, and the
arrangement of their work at the angle must have been
quite different from the usual. They made the cells of
the convex side so much broader than those of the
concave that they had a diameter two or three times as
great, and yet they managed to join them properly with
the others. They also did not wait to bend the comb
until they came to the glass itself, but recognised
the difficulty beforehand,[62] which had been
interposed by Huber while they were building with a
view to overcome the first difficulty.
_Special Habits._
_The Mason-Bee._--This insect closes the roof of its larval cell with a
kind of mortar, which sets as hard as stone. A little hole, closed only
with soft mud, is, however, left in one part of the roof as a door of
exit for the matured insect. It is said that when a mason-bee finds an
old and deserted nest, it saves itself the trouble of making a new
one--utilising the ready-made nest after having well cleaned it. In
Algiers the mason-bees have been observed in this way to utilise empty
snail-shells. According to Blanchard, some individuals avoid the labour
of making their own nests or houses for their young, by possessing
themselves of their neighbours' houses either by craft or by force.
'Does the mason-bee act like a machine,' says E. Menault, 'when it
directs its work according to circumstances, possesses itself of old
nests, cleanses and improves them, and thereby shows that it can fully
appreciate the immediate position? Can one believe that no kind of
reflection is here necessary?'
_The Tapestry-Bee._--The so-called tapestry-bee digs holes for her larvæ
three or four inches deep in the earth, and lines the walls and floor of
the chamber with petals of the poppy laid perfectly smooth. Several
layers of petals are used, and when the eggs are introduced the chamber
is closed by drawing all the leaves together at the top. Loose earth is
then piled over the whole structure in order to conceal it. The
so-called rose-bee (_Megachile centuncularis_) displays very similar
habits.[63]
_The Carpenter-Bee._--This was first observed and described by
Réaumur.[64] It makes a long cylindrical tube in the wood of beams,
palings, &c. This it divides into a number of successive chambers by
partitions made of agglutinated saw-dust built across the tube at right
angles to its axis. In each chamber there is deposited a single egg,
together with a store of pollen for the nourishment of the future larva.
The larvæ hatch out in succession and in the order of their age--_i.e._
the dates at which they were deposited. To provide for this, the bee
bores a hole from the lower cell to the exterior, so that each larva,
when ready to escape from its chamber, finds an open way from the tube.
The larvæ have to cut their own way out through the walls of their
respective chambers, and it is remarkable that they always cut through
the wall that faces the tubular passage left by the parent; they never
bore their way out in the opposite direction, which, were they to do so,
would entail the destruction of all the other and immature larvæ.
_The Carding-Bee._--This insect surrounds its nest with a layer of wax,
and then with a thick covering of moss. For this purpose a number of
bees co-operate, and in order to save time each bee does not find and
carry its own moss, but, with a division of labour similar to that
which we have already noticed in the case of certain ants, a row of bees
is formed, and the bits of moss passed from one to another along the
line. There is a long passage to the nest, through which the moss has to
be passed, and it is said that at the mouth of the tunnel a guard is
stationed to drive away ants or other intruders.
_Wasps._--These usually construct their nests of wood-dust, which they
scrape off the weather-worn surfaces of boards, palings, &c., and work
into a kind of paper with their saliva. If they happen to find any real
paper, they perceive that it so much resembles the product of their own
manufacture that they utilise it forthwith. The wasps do not require any
special cells or chambers for the storage of honey, as they do not lay
up any supply for the winter. The cells which they construct are
therefore used exclusively for the rearing of larvæ. In form these cells
are sometimes cylindrical or globular, but more usually hexagonal, like
those of the hive-bee. Although the mode of building is different from
that employed by the bees, there can be little doubt that if it were as
carefully investigated Mr. Darwin's theory of transition from the
cylindrical to the hexagonal form would be found to apply here also,
seeing that both forms so frequently occur in the same nest.
_The Mason-Wasp._--The habits of this insect are described by Mr. Bates.
It constructs its nest of clay. Each pellet that the insect brings it
lays on the top of its nest-wall, and then spreads it out with its jaws,
and treads it smooth with its feet. The nest, which is suspended on the
branch of a tree, is then stocked with spiders and insects paralysed by
stinging. The victims, not being wholly deprived of life, keep fresh
until required as food of the developing larvæ.
_The Butcher-Wasps._--These also paralyse their prey in a similar
manner, and for a similar purpose. Fabre removed from a so-called
sphex-wasp a killed grasshopper, which it was conveying to its nest and
had momentarily laid down at the mouth of the burrow--as these insects
always do on returning with prey, in order to see that nothing has
intruded into the burrow during their absence. Fabre carried the dead
or paralysed grasshopper to a considerable distance from the hole. On
coming out the insect searched about until it found its prey. It then
again carried it to the mouth of its burrow, and again laid it down
while it once more went in to see that all was right at home. Again
Fabre removed the grasshopper, and so on for forty times in
succession--the sphex never omitting to go through its fixed routine of
examining the interior of its burrow every time that it brought the prey
to its mouth.
Mr. Mivart, in his 'Lessons from Nature,' points to the instinct of this
animal in the stinging of the ganglion of its prey as one that cannot be
explained on Mr. Darwin's theory concerning the origin of instincts. In
my next work, which will have to deal with this theory, I shall consider
Mr. Mivart's difficulty, and also the difficulty first pointed out by
Mr. Darwin himself as to why neuter insects, separated as they appear to
be from the possibility of communicating by heredity any instinctive
acquirements of the individual to the species, should present any
instincts at all.
_General Intelligence._
Beginning with Sir John Lubbock's observations on this head, I shall
first quote his statements with regard to way-finding:--
I have found, he says, that some bees are much more
intelligent in this respect than others. A bee which I
had fed several times, and which had flown about in
the room, found its way out of the glass in a quarter
of an hour, and when put in a second time came out at
once. Another bee, when I closed the postern door,
used to come round to the honey through an open
window.
Bees seem to me much less clever in finding things
than I had expected. One day (April 14, 1872), when a
number of them were very busy on some barberries, I
put a saucer with some honey between two bunches of
flowers; these were repeatedly visited, and were so
close that there was hardly room for the saucer
between them, yet from 9.30 to 3.30 not a single bee
took any notice of the honey. At 3.30 I put some
honey on one of the bunches of flowers, and it was
eagerly sucked by the bees; two kept continually
returning till past five in the evening.
One day when I came home in the afternoon I found that
at least a hundred bees had got into my room through
the postern and were on the window, yet not one was
attracted by an open jar of honey which stood in a
shady corner about 3 feet 6 inches from the window.
One day (29th April, 1872) I placed a saucer of honey
close to some forget-me-nots, on which bees were
numerous and busy; yet from 10 A.M. till 6 only one
bee went to the honey.
I put some honey in a hollow in the garden wall
opposite the hives at 10.30 (this wall is about five
feet high and four feet from the hives); yet the bees
did not find it during the whole day.
On the 30th March, 1873, a fine sunshiny day, when the
bees were very active, I placed a glass containing
honey at 9 in the morning on the wall in front of the
hives; but not a single bee went to the honey the
whole day. On April 20 I tried the same experiment,
with the same result.
September 19.--At 9.30 I placed some honey in a glass
about four feet from and just in front of the hive;
but during the whole day not a bee observed it.
As it then occurred to me that it might be suggested
that there was something about this honey which
rendered it unattractive to the bees, on a following
day I placed it again on the top of the wall for three
hours, during which not a single bee came, and then
moved it close to the alighting-board of the hive. It
remained unnoticed for a quarter of an hour, when two
bees observed it; and others soon followed in
considerable numbers. . . . On the whole, wasps seem to
me more clever in finding their way than bees. I tried
wasps with the glass mentioned on p. 124 [_i.e._ the
bell-jar], but they had no difficulty in finding their
way out.
We shall now conclude this _résumé_ of Sir John Lubbock's observations
by quoting two other passages bearing on the general intelligence of
bees and wasps:--
The following fact struck me as rather remarkable. The
wasp already mentioned at the foot of p. 135 one day
smeared her wings with syrup, so that she could not
fly. When this happened to a bee, it was only
necessary to carry her to the alighting-board, when
she was soon cleaned by her comrades. But I did not
know where this wasp's nest was, and therefore could
not pursue a similar course with her. At first, then,
I was afraid that she was doomed. I thought, however,
that I would wash her, fully expecting, indeed, to
terrify her so much that she would not return again. I
therefore caught her, put her in a bottle half full of
water, and shook her up well till the honey was washed
off. I then transferred her to a dry bottle and put
her in the sun. When she was dry I let her out, and
she at once flew to her nest. To my surprise, in
thirteen minutes she returned, as if nothing had
happened, and continued her visits to the honey all
the afternoon.
This experiment interested me so much that I repeated
it with another marked wasp, this time, however,
keeping the wasp in the water till she was quite
motionless and insensible. When taken out of the water
she soon recovered; I fed her; she went quietly away
to her nest as usual, and returned after the usual
absence. The next morning this wasp was the first to
visit the honey.
I was not able to watch any of the above-mentioned
wasps for more than a few days; but I kept a specimen
of _Polistes Gallica_ for no less than nine months.
This is the wasp which has already been alluded to under the heading
'Memory;' but it is evident that the capacity which the insect displayed
of becoming tamed implies no small degree of general intelligence; its
hereditary instincts were conspicuously modified by the individual
experiences incidental to its domestication.
The remaining passages that deserve quotation are the following:--
It is sometimes said of bees that those of one hive
all know one another, and immediately recognise and
attack any intruder from another hive. At first sight
this certainly implies a great deal of intelligence.
It is, however, possible that the bees of particular
hives have a particular smell. Thus Langshaft, in his
interesting 'Treatise on the Honey-Bee,' says:
'Members of different colonies appear to recognise
their hive companions by the sense of smell; and I
believe that if colonies are sprinkled with scented
syrup, they may generally be safely mixed. Moreover, a
bee returning to its own hive with a load of treasure
is a very different creature from a hungry marauder;
and it is said that a bee, if laden with honey, is
allowed to enter any hive with impunity.' Mr.
Langshaft continues, 'There is an air of roguery about
a thieving bee which, to the expert, is as
characteristic as are the motions of a pickpocket to a
skilful policeman. Its sneaking look, and nervous,
guilty agitation, once seen, can never be mistaken.'
It is, at any rate, natural that a bee which enters a
wrong hive by accident should be much surprised and
alarmed, and would thus probably betray herself.
On the whole, then, I do not attach much importance to
their recognition of one another as an indication of
intelligence.
Since their extreme eagerness for honey may be
attributed rather to their anxiety for the common weal
than to their desire for personal gratification, it
cannot fairly be imputed as greediness; still the
following scene, one which most of us have witnessed,
is incompatible surely with much intelligence. The sad
fate of their unfortunate companions does not in the
least deter others who approach the tempting lure from
madly alighting on the bodies of the dying and dead,
to share the same miserable end. No one can understand
the extent of their infatuation until he has seen a
confectioner's shop assailed by myriads of hungry
bees. I have seen thousands strained out from the
syrup in which they had perished; thousands more
alighting even upon the boiling sweets, the floor
covered and windows darkened with bees, some crawling,
others flying, and others still, so completely
besmeared as to be able neither to crawl nor fly, not
one in ten able to carry home its ill-gotten spoils,
and yet the air filled with new hosts of thoughtless
comers.
Passing on now to the statements of other observers, Huber first noticed
the remarkable fact that when beehives are attacked by the death's-head
moth the bees close the entrance of their hive with wax and propolis to
keep out the marauder. The barricade, which is built immediately behind
the gateway, completely stops it up--only a small hole being left large
enough to admit a bee, and therefore of course too small to admit the
moth. Huber specially states that it was not until the beehives had been
_repeatedly_ attacked and robbed by the death's-head moth, that the bees
closed the entrance of their hive with wax and propolis. _Pure_ instinct
would have induced the bees to provide against the first attack. Huber
also observed that a wall built in 1804 against the death's-head
hawk-moth was destroyed in 1805. In the latter year there were no
death's-head moths, nor were any seen during the following. But in the
autumn of 1807 a large number again appeared, and the bees at once
protected themselves against their enemies. The bulwark was destroyed
again in 1808.
Again, Huber (_loc. cit._, tom. ii., p. 280) gives a case of apparent
exercise of reason, or power of inference from a particular case to
other and general cases. A piece of comb fell down and was fixed in its
new position by wax. The bees then strengthened the attachments of all
the other combs, clearly because they inferred that they too might be in
danger of falling. This is a very remarkable case, and leads Huber to
exclaim, 'I admit that I was unable to avoid a feeling of astonishment
in the presence of a fact from which the purest reason seemed to shine
out.'
A closely similar, and therefore corroborative case of an even more
remarkable kind is thus narrated in Watson's 'Reasoning Power of
Animals' (p. 448):--
Dr. Brown, in his book on the bee, gives another
illustration of the reasoning power of bees, observed
by a friend of his. A centre comb in a hive, being
overburdened with honey, had parted from its
fastenings, and was pressing against another comb, so
as to prevent the passage of the bees between them.
This accident excited great bustle in the colony, and
as soon as their proceedings could be observed, it was
found that they had constructed two horizontal beams
between the two combs, and had removed enough of the
honey and wax above them to admit the passage of a
bee, while the detached comb had been secured by
another beam, and fastened to the window with spare
wax. But what was most remarkable was, that, when the
comb was thus fixed, they removed the horizontal beams
first constructed, as being of no further use. The
whole occupation took about ten days.
Again, Mr. Darwin's MS. quotes from Sir B. Brodie's 'Psychological
Inquiries' (1854, p. 88) the following case, which is analogous to the
above, except that the supports required had to be made in a vertical
instead of in a horizontal direction:--
On one occasion, when a large portion of the honeycomb
had been broken off, they pursued another course. The
fragment had somehow become fixed in the middle of the
hive, and the bees immediately began to erect a new
structure of comb on the floor, so placed as to form a
pillar supporting the fragment, and preventing its
further descent. They then filled up the space above,
joining the comb which had become detached to that
from which it had been separated, and they concluded
their labours by removing the newly constructed comb
below, thus proving that they had intended it to
answer a merely temporary purpose.
Similarly, Dr. Dzierzon, an experienced keeper of bees, and the observer
who first discovered the fact of their parthenogenesis, makes the
general remark,--
The cleverness of the bees in repairing perfectly
injuries to their cells and combs, in supporting on
pillars pieces of their building accidentally knocked
down by a hasty push, in fastening them with rivets,
and bringing everything again into proper unity,
making hanging bridges, chains, and ladders, compels
our astonishment.
Lastly, as still further corroboration of such facts, I shall quote the
following from Jesse's 'Gleanings:'[65]--
Bees show great ingenuity in obviating the
inconvenience they experience from the slipperiness of
glass, and certainly beyond what we can conceive that
mere instinct would enable them to do. I am in the
habit of putting small glass globes on the top of my
straw hives, for the purpose of having them filled
with honey; and I have invariably found that before
the bees commence the construction of combs, they
place a great number of spots of wax at regular
distances from each other, which serve as so many
footstools on the slippery glass, each bee resting on
one of these with its middle pair of legs, while the
fore claws were hooked with the hind ones of the bee
next above him; thus forming a ladder, by means of
which the workers were enabled to reach the top, and
begin to make their combs there.
Herr Kleine, in his pamphlet on Italian Bees and Bee-keeping (Berlin,
1855), says that on substituting during the absence of the bees a hive
filled with empty comb for their own hive, the returning bees exhibit
the utmost perplexity. As the substituted hive stands in the exact spot
previously occupied by their own hive, the returning bees fly into it
without observing the change. But finding only empty combs inside, 'they
stop, do not know where they are, come out of the hole again without
depositing their loads, fly off, look most carefully round the stand to
assure themselves that they have made no mistake, and go in once more
when convinced that they are at the right place. The same thing is
repeated over and over again, until the bees at last bow to the
incomprehensible and unavoidable, lay down their loads, and set to work
at those tasks made necessary by the new circumstances of the hive. But
as all the newly arriving bees behave in similar fashion, the
disturbance lasts till late in the evening, and the uncertainty and
anxiety of the bees is so great that the bee-master cannot contemplate
it without deep sympathy.' Under such circumstances the bees take
quickly to a substituted queen; 'for the feeling of the first comers
that they have no right to the new dwelling, having, as they suppose,
made some inexplicable mistake which they cannot remedy, prevents them
from feeling any hostility to the new queen which they find; they
probably consider themselves as merely on sufferance, and feel that they
should be grateful that no action is taken against them for their
illegal entry, as generally happens in bee-experience.' Hence the writer
adopts this device when he desires to exchange or substitute queens.
Büchner, after alluding to this case, supplements it with the
following:--
The wind threw down from the stand of a bee-master--a
friend of the author's, whose name will soon become
known--a straw beehive, the inmates of which were
surprised in full work, and no small disorder in the
interior was the result. The owner repaired the hive,
put the loose comb back in its place, and replaced it
in such a manner that the wind could not again catch
it, hoping that the accident would have no further
results. But when he examined the hive a few days
later, he found that the bees had left their old home
in the lurch, and had tried to enter other hives,
clearly because they could no longer trust the
weather, and feared that the terrible accident might
again befall them.
Dr. Erasmus Darwin, in his 'Zoonomia,' asserts that bees, when
transported to Barbadoes, where there is no winter, cease to lay up
honey. In contradiction to this statement, however, Kirby and Spence
say, 'It is known to every naturalist acquainted with the fact, that
many different species of bees store up honey in the hottest climates,
and that there is no authentic instance on record of the hive-bees
altering in any age or climate their peculiar operations.'
On the other hand, more recent observation has shown that Dr. Darwin's
statement is probably correct. For, according to a note in _Nature_,[66]
European bees, when transported to Australia, retain their industrious
habits only for the first two or three years. After that time they
gradually cease to collect honey till they become wholly idle. In a
subsequent number of the same periodical (p. 411) a correspondent writes
that the same fact is observable with bees transported to California,
but is obviated by abstracting honey as the bees collect it.
There seems to be no doubt that bees and wasps are able to distinguish
between persons, and even to recognise those whom they are accustomed to
see, and to regard as friends. Bee-masters who attend much to their
bees, so as to give the insects a good chance of knowing them, are
generally of the opinion that the insects do know them, as shown by the
comparatively sparing use of their stings. Again, many instances might
be quoted, such as that given by Guerinzius,[67] who allowed a species of
wasp native to Natal to build in the doorposts of his house, and who
observed that although he often interfered with the nest, he was only
once stung, and this by a young wasp; while no Caffre could venture to
approach the door, much less to pass through it.[68] This power of
distinguishing between persons indicates a higher order of intelligence
than we might have expected to meet with among insects; and, according
to Bingley, bees will not only learn to distinguish persons, but even
lend themselves to tuition by those whom they know. For he says, 'Mr.
Wildman, whose remarks on the management of bees are well known,
possessed a secret by which he could at any time cause a hive of bees to
swarm upon his head, shoulders, or body, in a most surprising manner. He
has been seen to drink a glass of wine with the bees all over his head
and face more than an inch deep; several fell into the glass, but did
not sting him. He could even act the part of a general with them, by
marshalling them in battle array on a large table. Then he divided them
into regiments, battalions, and companies, according to military
discipline, waiting only for his word of command. The moment he uttered
the word _march!_ they began to march in a very regular manner in rank
and file, like soldiers. To these, his Lilliputians, he also taught so
much politeness that they never attempted to sting any of the numerous
company which, at different times, resorted to admire this singular
spectacle.'
Huber's observation, since amply confirmed, of bees biting holes through
the base of corollas in order to get at the honey which the length of
the corollas prevent them from reaching in the ordinary way, also seems
to indicate a rational adjustment to unusual circumstances. For the bees
do not resort to this expedient until they find from trial that they
cannot reach the nectar from above; but having once ascertained this,
they forthwith proceed to pierce the bottoms of all the flowers of the
same species. From an interesting account by Mr. Francis Darwin[69]
(unfortunately too long to quote) it appears that, even when the nectar
may be reached from above, bees may still resort to the expedient of
biting through corollas in order to save time.
In connection with biting holes in corollas I may quote an observation
communicated to me by a correspondent, Sir J. Clarke Jervoise. Speaking
of a humble-bee, he says: 'I watched him into the flower of a foxglove,
and, when out of sight, I closed the lips of the flower with my finger
and thumb. He did not hesitate a moment, but cut his way out at the
further end as if he had been served the same trick before. I never did
it.'
Bees are highly particular in the matter of keeping their hives pure,
and their sanitary arrangements often exhibit intelligence of a high
order.
The following is quoted from Büchner (_loc. cit._, p. 248):--
Impure air within the hive is that which the bees must
above all things fear and avoid, for with the pressure
together of so many individuals in a comparatively
small space, it would not only be directly harmful to
individual bees, but would produce among them
dangerous diseases. They therefore also never void
their excrements within, but always outside the hive.
While this is very easy to do in summer, it is, on the
contrary, very difficult in the winter, when the bees
sit close together and generally motionless in the
upper part of the hive, and when, from impure air and
foul evaporations, as well as from bad and
insufficient food, dysentery-like diseases break out
among them, and often carry off the whole community in
a brief space of time. In such cases they utilise the
first fine day to relieve themselves, and in the
spring they take a long general cleansing flight. But
they also know how to take advantage of special
circumstances so as to perform the process of
purification in the way least harmful to the hive.
Herr Heinrich Lehr, of Darmstadt, a bee-keeping friend
of the author, has sent the following
communication:--During an epidemic of dysentery in
winter, from which most of his hives suffered (as the
bees were no longer able to retain their excrements),
one hive suffered less than the others. Exact
investigation showed that this hive was soiled all
over at the back with the excrement of the bees, and
that the inmates had here made a kind of drain. On
this spot a little opening had been made by the
falling off of the covering clay, which led directly
to the upper part of the hive, where the bees were
accustomed to sit together during the winter. This
excellent opportunity, whereby they could reach in the
shortest way an otherwise difficult object, and one
rendered complicated by circumstances, did not escape
them.
It sometimes happens that mice, slugs, &c., enter a beehive. They are
then killed and covered with a coating of propolis. Réaumur says[70] that
he once saw a snail enter a hive in this way. The hard shell was an
effective protection against the stings of the bees, so the insects
smeared round the edges of the shell with wax and resin, fastening down
the animal to the wall of the hive, so that it died of starvation or
want of air. If the encasing of an animal (such as a mouse) with
propolis is not sufficient to prevent its putrefaction, the bees gnaw
away all the putrescible parts of the carcass and carry them out of the
hive, leaving only the skeleton behind. The dead bodies of their
companions are also carried out of the hive and deposited at a distance.
There is no question about this fact (which it will be remembered is
analogous to that already mentioned in the case of ants); according to
Büchner, however, bees not only remove their dead, but also,
occasionally at least, bury them. But as he gives very inadequate
evidence in support of this assertion, we may safely set it aside as
insufficiently proven.
Büchner, however, gives an admirable summary, and makes some judicious
remarks on the well-known and highly remarkable habit which bees
practise for the obvious purpose of ventilating their hives. As this
account gives all the facts in a brief compass, I cannot do better than
quote it:--
Very interesting, and closely connected with this
characteristic of cleanliness, is the conduct of the
so-called ventilating-bees, which have to take care
that in summer or hot weather the air necessary for
respiration of the bees in the interior of the hive is
renewed, and the too high temperature cooled down. The
latter precaution is necessary, not only on account of
the bees working within the hive, to whom, as already
said, a temperature risen beyond a certain point would
be intolerable, but also to guard against the melting
or softening of the wax. The bees charged with the
care of the ventilation divide themselves into rows
and stages in regular order through all parts of the
hive, and by swift fanning of their wings send little
currents of air in such fashion that a powerful stream
or change of air passes through all parts of the hive.
Other bees stand at the mouth of the hive, which fan
in the same way and considerably accelerate the wind
from within. The current of air thus caused is so
strong that little bits of paper hung in front of the
mouth are rapidly moved, and that, according to F.
Huber, a lighted match is extinguished. The wind can
be distinctly felt if the hand be held in front.
The motion of the wings of the ventilating bees is so
rapid that it is scarcely perceptible, and Huber saw
some bees working their wings in this way for
five-and-twenty minutes. When they are tired they are
relieved by others. According to Jesse, the bees in
very hot weather, in spite of all their efforts, are
unable to sufficiently lower the temperature, and
prevent the melting of some of the wax; they then get
into a condition of great excitement, and it is
dangerous to approach them. In such a case they also
try to mend matters by a number leaving the hive and
settling in large masses on its surface, so as to
protect it as much as possible from the scorching rays
of the sun.
Although the described plan of ventilation is
remarkable enough in itself, it is yet more remarkable
in that it is clearly only the result of bee-keeping,
and is evoked by this misfortune. For there could be
no need of such ventilation for bees in a state of
nature, whose dwellings in hollow trees and clefts of
rocks leave nothing to be desired as to roominess and
airiness, while in the narrow artificial hive this
need at once comes out strongly. In fact, the fanning
of the bees almost entirely ceased when Huber brought
them into large hives five feet high, in which there
was plenty of air. It follows, therefore, that the
fanning and ventilating can have absolutely nothing to
do with an inborn tendency or instinct, but have been
gradually evoked by necessity, thought, and
experience.
As the following observation on the cautious sagacity of wasps is, so
far as I am aware, new, and as it certainly does not admit of
mal-observation, I introduce it on the authority of a correspondent, the
Rev. Mr. J. W. Mossman, who writes from Tarrington Rectory, Wragby. He
found an apple in his orchard which had fallen from a tree in apparently
good condition; but on taking it up observed that it was little more
than a shell filled with wasps. Giving the apple a shake, he saw a wasp
slowly emerging from a single small aperture in the rind:--
This aperture was sufficient, and only just
sufficient, to admit of the ingress or egress of a
single wasp. The circumstance which struck me as very
remarkable was this--that the wasp did not make its
way through the aperture with its head first, as I
should have expected, but with its tail, darting out
its sting to its utmost extent, and brandishing it
furiously. In this manner it came out of the apple
backwards. Then, finding itself in the open air upon
the outer surface of the apple, it turned round, and
without any attempt to molest me, flew off in the
usual way. The moment this first wasp had emerged, the
sting and tail of another was seen protruding. This,
too, I watched with much interest, and exactly the
same process was repeated as in the case of the first.
I held the apple in my hand until some ten or a dozen
wasps had made their exit in the same identical manner
in each individual case. I then threw down the apple,
inside of which, however, there were still apparently
a good many wasps.
It seemed to me at the time, and I have always felt
since, that the wasps coming out of the apple
backwards, brandishing their stings as a defensive
weapon against possible enemies, whom of course they
were not able to see, was an evidence of what would be
called thought and reflection in the case of human
beings. It seems to me that these wasps must have
reflected that if they came out of the narrow aperture
in the apple, which was their only possible means of
ready egress, in the usual manner, head first, they
might be taken at a disadvantage by a possible enemy,
and destroyed in detail. They, therefore, with great
prudence and foresight, came out of the apple
backwards, protecting themselves by means of their
chief offensive and defensive weapons, their stings,
which, according to their normal method of locomotion,
would have been useless to them as long as they were
making their exit.
With regard to the tactics displayed by hunting wasps I may quote the
following cases:--
Mr. Seth Green, writing to the _New York World_ of May
14, says that one morning when he was watching a
spider's nest, a wasp alighted within an inch or two
of the nest, on the side opposite the opening.
Creeping noiselessly around towards the entrance of
the nest the wasp stopped a little short of it, and
for a moment remained perfectly quiet; then reaching
out one of his antennæ he wriggled it before the
opening and withdrew it. This overture had the desired
effect, for the boss of the nest, as large a spider as
one ordinarily sees, came out to see what was wrong
and to set it to rights. No sooner had the spider
emerged to that point at which he was at the worst
disadvantage than the wasp, with a quick movement,
thrust his sting into the body of his foe, killing him
easily and almost instantly. The experiment was
repeated on the part of the wasp, and when there was
no response from the inside he became satisfied,
probably, that he held the fort. At all events, he
proceeded to enter the nest and slaughter the young
spiders, which were afterwards lugged off one at a
time.
Mr. Henry Cecil writes as follows (_Nature_, vol. xviii., p. 311):--
I was sitting one summer's afternoon at an open window
(my bedroom) looking into a garden, when I was
surprised to observe a large and rare species of
spider run across the window-sill in a crouching
attitude. It struck me the spider was evidently
alarmed, or it would not have so fearlessly approached
me. It hastened to conceal itself under the projecting
ledge of the window-sill inside the room, and had
hardly done so when a very fine large hunting wasp
buzzed in at the open window and flew about the room,
evidently in search of something. Finding nothing, the
wasp returned to the open window and settled on the
window-sill, running backwards and forwards as a dog
does when looking or searching for a lost scent. It
soon alighted on the track of the poor spider, and in
a moment it discovered its hiding-place, darted down
on it, and no doubt inflicted a wound with its sting.
The spider rushed off again, and this time took refuge
under the bed, trying to conceal itself under the
framework or planks which supported the mattress. The
same scene occurred here; the wasp now appeared to
follow the spider by sight, but ran backwards and
forwards in large circles like a hound. The moment the
trail of the spider was found the wasp followed all
the turns it had made till it came on it again. The
poor spider was chased from hiding-place to
hiding-place, out of the bedroom, across a passage,
and into the middle of another large room, where it
finally succumbed to the repeated stings inflicted by
the wasp. Rolling itself up into a ball the wasp then
took possession of its prey, and after ascertaining it
could make no resistance, tucked it up under its _very
long hind legs_, just as a hawk or eagle carries off
its quarry, when I interposed and secured both for my
collection.
Mr. Belt, in his work already frequently quoted, gives the following
account of a struggle which not unfrequently occurs between wasps and
ants for the sweet secretion of 'frog-hoppers:'--
Similarly as, on the savannahs, I had observed a wasp
attending the honey-glands of the bull's-horn acacia
along with the ants; so at Santo Domingo another wasp,
belonging to quite a different genus (_Nectarina_),
attended some of the clusters of frog-hoppers, and for
the possession of others a constant skirmishing was
going on. The wasp stroked the young hoppers, and
sipped up the honey when it was exuded, just like the
ants. When an ant came up to a cluster of
leaf-hoppers attended by a wasp, the latter would not
attempt to grapple with its rival on the leaf, but
would fly off and hover over the ant; then when its
little foe was well exposed, it would dart at it and
strike it to the ground. The action was so quick that
I could not determine whether it struck with its
fore-feet or its jaws; but I think it was with the
feet. I often saw a wasp trying to clear a leaf from
ants that were already in full possession of a cluster
of leaf-hoppers. It would sometimes have to strike
three or four times at an ant before it made it quit
its hold and fall. At other times one ant after the
other would be struck off with great celerity and
ease, and I fancied that some wasps were much cleverer
than others. In those cases where it succeeded in
clearing the leaf, it was never left long in peace;
for fresh relays of ants were continually arriving,
and generally tired the wasp out. It would never wait
for an ant to get near it, doubtless knowing well that
if its little rival once fastened on its leg, it would
be a difficult matter to get rid of it again. If a
wasp first obtained possession, it was able to keep
it; for the first ants that came up were only
pioneers, and by knocking these off, it prevented them
from returning and scenting the trail to communicate
the intelligence to others.
Dr. Erasmus Darwin records an observation ('Zoonomia,' i., p. 183)
which, from having since been so widely quoted, deserves to be called
classical. He saw a wasp upon the ground endeavouring to remove a large
fly which was too heavy for it to carry off. The wasp cut off the head
and abdomen, and flew away with the thorax alone. The wind, however,
catching the wings of this portion made it still too unwieldy for the
wasp to guide. It therefore again alighted, and nipped off first one
wing and then the other, when it was able to fly off with its booty
without further difficulty.
This observation has since been amply confirmed. I shall quote some of
the confirmatory cases.
Mr. R. S. Newall, F.R.S., in _Nature_, vol. xxi., p. 494, says:--
Many years ago I was examining an apple tree, when a
wasp alighted on a leaf which formed a caterpillar's
nest neatly rolled up. The wasp examined both ends,
and finding them closed, it soon clipped a hole in the
leaf at one end of the nest about one-eighth of an
inch in diameter. It then went to the other end and
made a noise which frightened the caterpillar, which
came rushing out of the hole. It was immediately
seized by the wasp, who finding it too large to carry
off at once, cut it in two and went off with his game.
I waited a little and saw the wasp come back for the
other half, with which it also flew away.
Again, Büchner (_loc. cit._, p. 297) gives the following account in the
words of his informant, Herr H. Löwenfels, who himself witnessed the
incident:--
I here found a robber-wasp busied in lifting from the
ground a large fly which it had apparently killed. It
succeeded indeed in its attempt, but had scarcely
raised its prey a few inches above the ground when the
wind caught the wings of the dead fly, and they began
to act like a sail. The wasp was clearly unable to
resist this action, and was blown a little distance in
the direction of the wind, whereupon it let itself
fall to the ground with its prize. It now made no more
attempts to fly, but with eager industry pulled off
with its teeth the fly's wings which hindered it in
its object. When this was quite done it seized the
fly, which was heavier than itself, and flew off with
it untroubled on its journey through the air at a
height of about five feet.
Büchner also records the two following remarkable observations, which
from being so similar corroborate one another. The first is received
from Herr Albert Schlüter, who writing from Texas says that he there saw
a cicada pursued by a large hornet, which threw itself upon its prey and
seemed to sting it to death:--
The murderer walked over its prey, which was
considerably larger than itself, grasped its body with
its feet, spread out its wings, and tried to fly away
with it. Its strength was not sufficient, and after
many efforts it gave up the attempt. Half a minute
went by; sitting astride on the corpse and
motionless--only the wings occasionally jerking--it
seems to reflect, and indeed not in vain. A mulberry
tree stood close by, really only a trunk--for the top
had been broken off, clearly by the last flood--of
about ten or twelve feet high. The hornet saw this
trunk, dragged its prey toilsomely to the foot of it,
and then up to the top. Arrived thereat, it rested for
a moment, grasped its victim firmly, and flew off with
it to the prairies. That which it was unable to raise
off the ground it could now carry easily once high in
the air.
The other instance is as follows:--
Th. Meenan ('Proc. of the Acad. of Nat.,'
Philadelphia, Jan. 22, 1878) observed a very similar
case with _Vespa maculata_. He saw one of these wasps
try in vain to raise from the ground a grasshopper it
had killed. When all its efforts proved to be in vain,
it pulled its prey to a maple tree, about thirty feet
off, mounted it with its prize, and flew away from it.
'This,' adds the writer, 'was more than instinct. It
was reflection and judgment, and the judgment was
proved to be correct.'
Depriving bees of their antennæ has the effect of producing an even more
marked bewilderment than results from this operation in the case of
ants. A queen thus mutilated by Huber ran about in confusion, dropping
her eggs at random, and appeared unable to take with precision the food
that was offered her. She showed no resentment to a similarly mutilated
stranger queen that was introduced: the workers also heeded not the
mutilated stranger; but when an unmutilated stranger was introduced they
fell upon her. When the mutilated queen was allowed to escape, none of
the workers followed.
FOOTNOTES:
[46] Vol. ix. p. 484.
[47] _Passions of Animals_, p. 53.
[48] Vol. xii. p. 68.
[49] 'Three months' in the Journal of the Linnæan Society, but Sir John
Lubbock informs me that this is a misprint.
[50] See Kirby and Spence, vol. ii. p. 591.
[51] Letter to Mr. Darwin, published in _Nature_, vol. x., p. 102.
[52] Vol. xii., pp. 25-6.
[53] _Loc. cit._
[54] Art. 'Bees,' _Encycl. Brit._
[55] Dr. Kemp, _Indications of Instinct_.
[56] _The Bee_, 1877, No. 1.
[57] Dr. Lindley Kemp, _Indications of Instinct_.
[58] Handcock on Instinct, p. 18.
[59] _Introd. Ent._, ii, p. 465.
[60] _Origin of Species_, 'Cell-making Instinct.'
[61] _Origin of Species_, p. 225.
[62] _Mind in Animals_, pp. 252-3.
[63] For a complete account of these habits see Bingley, _Animal
Biography_, vol. iii., pp. 272-5.
[64] _Mém. sur les Insectes_, tom. vi., p. 39.
[65] Vol. i., pp. 22-3 (3rd ed.).
[66] Vol. xvii., p. 373.
[67] See Brehm, _Thierleben_, ix., p. 252.
[68] An exactly similar case is recorded by Stodmann in his _Travels in
Surinam_, ii., p. 286.
[69] _Nature_, ix., p. 189.
[70] See _Kirby and Spence_, vol. ii., p. 229.