George John Romanes

BEES AND WASPS.

Arranging this chapter under the same general headings as the one on ants, we shall consider first—

Powers of Special Sense.

Bees and wasps have much greater powers of sight than ants. They not only perceive objects at a greater distance, but are also able to distinguish their colours. This was proved by Sir John Lubbock, who placed honey on slips of paper similarly formed, but of different colours; when a bee had repeatedly visited a slip of one colour (A), he transposed the slips during the absence of the bee; on its return the insect did not fly to slip B, although this now occupied the position which had been previously occupied by slip A, but again visited slip A, although this now occupied the position which had been previously occupied by slip B. Therefore, as these experiments were again and again repeated both on bees and wasps with uniform results, there can be no question that the insects by their first visits to slip A established an association between the colour of A and the honey upon it, such that, when they again returned and found B in the place of A, they were guided by their memory of the colour rather than by their memory of the position. It was thus shown that the insects could distinguish green, red, yellow, and blue. These experiments also brought out the further fact that both bees and wasps exhibit a marked preference for some colours over others. Thus, in a series of black, white, yellow, orange, green, blue, and red slips, two or three bees paid twenty-one visits to the orange and yellow, and only four to all the other slips. The slips were then moved, after which, out of thirty-two visits, twenty-two were to the orange and yellow. Another colour to which a similar preference is shown is blue.

As regards scent, Sir John found that on putting a few drops of eau de Cologne at the entrance of a beehive, 'immediately a number (about 15) came out to see what was the matter.' Other scents had a similar effect; but on repetition several times the bees became accustomed to the scent, and no longer came out.

As in ants, so in bees, Sir John's experiments failed to yield any evidence of a sense of hearing. But in this connection we must not forget the well-known fact, first observed by Huber, that the queen bee will answer by a certain sound the peculiar piping of a pupa queen; and again, by making a certain cry or humming noise, will strike consternation suddenly on all the bees in the hive—these remaining for a long time motionless as if stupefied.

Sense of Direction.

The following are Sir John Lubbock's observations upon this subject in the case of bees and wasps:—

Every one has heard of a 'bee-line.' It would be no less correct to speak of a wasp-line. On August 6 I marked a wasp, the nest of which was round the corner of the house, so that her direct way home was not out at the window by which she had entered, but in the opposite direction, across the room to a window which was closed. I watched her for some hours, during which time she constantly went to the wrong window, and lost much time in buzzing about at it. For ten consecutive days this wasp paid numerous visits, coming in at the open window, and always trying, though always unsuccessfully, to return to her nest in the 'wasp-line' of the closed window—buzzing about that window for hours at a time, though eventually on finding it closed she returned and went round through the open window by which she always entered.

This observation shows how strong must be the instinct in a wasp to take the shortest way home, and how much the insect depends upon its sense of direction in so doing. It also shows how long a time it requires to learn by individual experience the properties of a previously unknown substance such as glass. But to this latter point we shall presently have occasion to return.

Next we must adduce evidence to show that in way-finding the 'sense of direction' in bees appears to be largely supplemented by observation of particular objects.

Sir John Lubbock observes: 'I never found bees to return if brought any considerable distance at once. By taking them, however, some twenty yards each time they came to the honey, I at length trained them to come to my room;' that is to say, bees require to learn their way little by little before they can return to a store of honey which they may have been fortunate enough to find; their general sense of direction is not in itself a sufficient guide. This, at least, is the case where, as in the experiments in question, the bees are carried from the hive to the store of honey (here a distance of less than 200 yards): possibly if they had found the honey by themselves flying towards it, and so probably taking note of objects by the way, one journey might have proved sufficient to teach them the way. But, whether or not this would have been the case, the fact that when carried they required also to be taught the way piece by piece, is conclusive proof that their sense of direction alone is not sufficient to enable them to traverse a route of 200 yards a second time.

The same result is brought out by other experiments conducted on a different plan, though not apparently with this object. 'My room is square, with two windows on the south-west side, where the hive was placed, and one on the south-east.' Besides the ordinary entrance from outside, the hive had a small postern door opening into the room.

At 6.50 a bee came out through the little postern door. After she had fed, she evidently did not know her way home; so I put her back.

At 7.10 she came out again. I again fed her and put her back.

At 10.15 she came out a third time; and again I had to put her back.

At 10.55 she came out again, and still did not remember the door. Though I was satisfied that she really wished to return, and was not voluntarily remaining outside; still, to make the matter clear, I turned her out of a side window into the garden, when she at once returned to the hive.

At 11.15 she came out again; and again I had to show her the way back.

At 11.20 she came out again; and again I had to show her the way back (this makes five times); when, however,—

At 11.30 she came out again after feeding, she returned straight to the hive.

At 11.40 she came out, fed, and returned straight to the hive.

At 11.50 she came out, fed, and returned straight to the hive; she then stayed in for some time.

At 12.30 she came out again, but seemed to have forgotten the way back; after some time, however, she found the door and went in.

Again:—August 24 at 7.20 a bee came through the postern: I fed her; and though she was not frightened or disturbed, when she had finished her meal she flew to the window and had evidently lost her way; so at 8 o'clock I in pity put her back myself.

August 29.—A bee came out to the honey at 10.10; at 10.12 she flew to the window, and remained buzzing about till 11.12, when, being satisfied that she could not find her way, I put her in.

Nay, even those who seemed to know the postern, if taken near the other window, flew to it, and seemed to have lost themselves.

This cost me a great many bees. Those which got into my room by accident continually died on the floor near the window.

These observations show that even when a bee is not carried from the hive to the honey, but herself flies to it, her sense of direction is not alone sufficient to enable her to find the way back to the hive—or, rather, to the unaccustomed entrance to the hive from which she had come out. Probably if the side window had been open, the bee would have returned to the hive round the corner of the house, and through the entrance to which she was most accustomed. But as it was she had to learn, by five or six journeys, the way between the postern entrance and the food.

But the following observation on a wasp is in this connection the most conclusive.

A marked wasp visited honey exposed in the room before mentioned. 'The next morning she came—

At 7.25, and fed till 7.28, when she began flying about the room and even into the next; so I thought it well to put her out of the window, when she flew straight away to her nest. My room, as already mentioned, had windows on two sides; and the nest was in the direction of a closed window, so that the wasp had to go out of her way in going out through the open one.

At 7.45 she came back. I had moved the glass containing the honey about two yards; and though it stood conspicuously, the wasp seemed to have much difficulty in finding it. Again she flew to the window in the direction of her nest, and I had to put her out, which I did at 8.2.

At 8.15 she returned to the honey almost straight. 8.21, she flew again to the closed window, and apparently could not find her way; so at 8.35 I put her out again. It seems obvious from this that wasps have a sense of direction, and do not find their way merely by sight.

At 8.50 back to honey, and 8.54 again to wrong window; but finding it closed, she took two or three turns round the room, and then flew out through the open window.

At 9.24 back to the honey; and 9.27 away, first, however, paying a visit to the wrong window, but without alighting.

At 9.36 back to the honey, and 9.39 away, but, as before, going first to wrong window.

			She was	away therefore	9	minutes.
9.50	back to the honey	9.53	away,	this time straight.	11	"
10	"	10. 7	"	"	11	"
10.19	"	10.22	"	"	12	"
10.35	"	10.39	"	"	13	"
10.47	"	10.50	"	"	9	"
11. 4	"	11. 7	"	"	14	"
11.21	"	11.24	"	"	14	"
11.34	"	11.37	"	"	10	"
11.49	"	11.52	"	"	1	"
12. 3	"	12. 5	"	"	11	"
12.13	"	12.15½	"	"	8	"
12.25	"	12.28	"	"	10	"
12.39	"	12.43	"	"	11	"
12.54	"	12.57	"	"	11	"
1.15	"	1.19	"	"	18	"
1.27	"	1.30	"	"	8	minutes,'
&c., &c., the way being now clearly well learnt.

But that the sense of direction is of much service to bees in finding the locality of their hives seems to be indicated by the following observation thus narrated, on the authority of the authors themselves, by Messrs. Kirby and Spence:—

In vain, during my stay at St. Nicholas, I sallied out at every outlet to try to gain some idea of the extent and form of the town. Trees, trees, trees, still met me, and intercepted the view in every direction; and I defy any inhabitant bee of this rural metropolis, after once quitting its hive, ever to gain a glimpse of it again until nearly perpendicularly over it. The bees, therefore, .... must be led to their abodes by instinct, &c.

The observation, however, is not so conclusive as its authors suppose; for there is nothing to show that the bees did not take note of particular objects on their accustomed routes, and so learn these routes by stages. It would be worth while in this connection to try the effect of hooding the eyes of a bee, or, if this were deemed too disturbing an experiment, removing the hive bodily to a distance from its accustomed site, and observing whether the bees start away boldly as before for long flights, or learn their new routes by stages.

In this connection I may quote the following.

Mr. John Topham, of Marlborough House, Torquay, writing to 'Nature,'[46] says:—

On October 29, 1873, I removed a hive of bees in my garden, after it was quite dark, for a distance of 12 yards from the place in which it had stood for several months; and between its original situation and the new one there was a bushy evergreen tree, so that all sight of its former place was obstructed to a person looking from the new situation of the hive.

Notwithstanding this change, the bees every day flew to the locality where they formerly lived, and continued flying around the site of what had been their home until, as night came on, they many of them sank upon the grass exhausted and chilled by the cold. Numbers, however, returned alive to their new position, after having looked in vain for their hive in its old place. At night I picked the exhausted bees up, and having restored warmth to them (by leaving them for a time on my coat-sleeve), I returned them to their companions.

Here was an illustration that the faculty of memory was superior to that of observation; but that was not all. Nearly every bee which I picked up during the 23 days through which this effort of memory lasted was an old one, as was easily deduced from observing the worn edges of the wings; showing that whilst the young insects were quick in receiving new impressions and in correcting errors, the nervous system of the old bees continued acting in the direction which early habit had effected. So true it is that 'one touch of nature makes the whole world kin.'

A closely similar observation has been told me by a friend, Mr. George Turner. He found that when he removed a beehive only a yard or two from its accustomed site, the bees, on returning home, flew in swarms around the latter, and for a long time were unable to find the hive. And several other similar cases might be adduced. Lastly, Thompson says:—

It is highly remarkable that they [bees] know their hive more from its locality than from its appearance, for if it be removed during their absence and a similar one be substituted, they enter the strange one. If the position of a hive be changed, the bees for the first day take no distant flight till they have thoroughly scrutinised every object in its neighbourhood.[47]

On the other hand, the writer of the article on 'Bees' in the 'EncyclopÆdia Britannica' says that in certain parts of France it is the habit of bee-keepers to place a number of hives upon a boat, which, in charge of a man, floats slowly down a river. The bees are thus continuously changing their pasture-ground, and yet do not lose their locomotive hives.

It may be here worth while to add, parenthetically, as the only authentic observation with which I am acquainted concerning the distance that bees are accustomed to forage, the following statement of Prof. Hugh Blackburn. Writing from Glasgow University to 'Nature,'[48] he says that bees are found in a certain peach-house every spring at the time of blossom, although, so far as he can ascertain, the beehives nearest to the peach-house in question are his own, and these are at a distance of ten miles.

On the whole, then, and in the absence of further experiments, we must conclude it to be probable that the sense of direction with which hymenopterous insects are, as shown by some of Sir John Lubbock's experiments, unquestionably endowed, is of no small use to them in finding their way from home to food and vice versÂ; although it appears certain, from other of his experiments, that this sense of direction is not in all cases a sufficient guide, and therefore requires to be supplemented by the definite observation of landmarks.

But the most conclusive evidence on this latter point is afforded by a highly interesting observation of Mr. Bates on the sand-wasps at Santurem, which may here be suitably introduced, as the insects are not distantly allied. He describes these animals as always taking a few turns in the air round the hole they had made in the sand before leaving to seek for flies in the forest, apparently in order to mark well the position of the burrow, so that on their return they might find it without difficulty. This observation has been since confirmed in a striking manner by Mr. Belt, who found that the sand-wasp takes the most precise bearings of an object the position of which she desires to remember. This observation is so interesting that it deserves to be rendered in extenso:—

A specimen of Polistes carnifex (i.e. the sand-wasp noticed by Mr. Bates) was hunting about for caterpillars in my garden. I found one about an inch long, and held it out towards it on the point of a stick. It seized it immediately, and commenced biting it from head to tail, soon reducing the soft body to a mass of pulp. It rolled up about one-half of it into a ball, and prepared to carry it off. Being at the time amidst a thick mass of a fine-leaved climbing plant, it proceeded, before flying away, to take note of the place where it was leaving the other half. To do this, it hovered in front of it for a few seconds, then took small circles in front of it, then larger ones round the whole plant. I thought it had gone, but it returned again, and had another look at the opening in the dense foliage down which the other half of the caterpillar lay. It then flew away, but must have left its burden for distribution with its comrades at the nest, for it returned in less than two minutes, and making one circle around the bush, descended to the opening, alighted on a leaf, and ran inside. The green remnant of the caterpillar was lying on another leaf inside, but not connected with the one on which the wasp alighted, so that in running in it missed it, and soon got hopelessly lost in the thick foliage. Coming out again, it took another circle, and pounced down on the same spot again, as soon as it came opposite to it. Three small seed-pods, which here grew close together, formed the marks that I had myself taken to note the place, and these the wasp seemed also to have taken as its guide, for it flew directly down to them, and ran inside; but the small leaf on which the fragment of caterpillar lay not being directly connected with any on the outside, it again missed it, and again got far away from the object of its search. It then flew out again, and the same process was repeated again and again. Always when in circling round it came in sight of the seed-pods down it pounced, alighted near them, and recommenced its quest on foot. I was surprised at its perseverance, and thought it would have given up the search; but not so, it returned at least half-a-dozen times, and seemed to get angry, hurrying about with buzzing wings. At last it stumbled across its prey, seized it eagerly, and as there was nothing more to come back for, flew straight off to its nest, without taking any further note of the locality. Such an action is not the result of blind instinct, but of a thinking mind; and it is wonderful to see an insect so differently constructed using a mental process similar to that of man.

Memory.

We may here first allude to an observation of Sir John Lubbock already quoted in another connexion (see p. 147). It is here evident that the wasp, after finding the store of honey in the room, and after finding the window closed in the 'wasp-line' direction to its nest, required three repeated lessons from Sir John before she learnt that the window on the other side of the room, and away from the direction of her nest, afforded no obstacle to her exit. Having learnt this, the fourth time she came she again flew to the closed window as before, and then, as if but dimly remembering that there was another opening somewhere that offered no such mysterious resistance to her passage, 'she took two or three turns round the room, and then flew out through the open window.' Having now taken the bearings of all the room upon her own wings, and having again found the difference between the two windows in respect of resistance, although in all other respects so much alike, the next time she came she made in the first instance as it were an experimental flight towards the closed window, but clearly had the alternative of going to the open one in her memory; for on finding the window closed as before, she did not alight, but flew straight from the closed to the open window. The same thing happened once again, but now, with the distinction between the two windows thus fully learnt, and with it the perception that in this case 'the shortest cut was the longest way round,' she never again flew to the closed window; in the forty successive visits which she paid through the remainder of that day, and the hundred visits or so which she made during the two following days, she seems to have uniformly flown to the open window.

As evidence of forgetfulness, it will be enough to refer to the case of another wasp which, under precisely similar circumstances to those just detailed, learnt her way out of the open window one day, having made fifty passages through it in five hours. Yet Sir John remarks,—

It struck me as curious that on the following day this wasp seemed by no means so sure of her way, but over and over again went to the closed window.

It is further of interest to note, as showing the similarity of the memory displayed by these insects with that of the higher animals, that there are considerable individual differences to be found in the degree of its manifestation.

In this respect they certainly differ considerably. Some of the bees which came out of the little postern door (already described) were able to find their way back after it had been shown to them a few times. Others were much more stupid; thus one bee came out on the 9th, 10th, 11th, 12th, 14th, 15th, 16th, 17th, 18th, and 19th, and came to the honey; but though I repeatedly put her back through the postern, she was never able to find her way for herself.

I often found that if bees which were brought to honey did not return at once, still they would do so a day or two afterwards. For instance, on July 11, 1874, a hot thundery day, and when the bees were much out of humour, I brought twelve bees to some honey; only one came back, and that one only twice; but on the following day several of them returned.

This latter observation is important, as proving that bees can remember for at least a whole day the locality where they have found honey only once before, and that they so far think about their past experiences as to return to that locality when foraging.

As the association of ideas by contiguity is the principle which forms the basis of all psychology, it is desirable to consider still more attentively this the earliest manifestation that we have of it in the memory of the Hymenoptera. That it is not exercised with exclusive reference to locality is proved by the following observation of Sir John Lubbock:—

I kept a specimen of Polistes Gallica for no less than nine months.[49] .... I had no difficulty in inducing her to feed on my hand; but at first she was shy and nervous. She kept her sting in constant readiness..... Gradually she became quite used to me, and when I took her on my hand apparently expected to be fed. She even allowed me to stroke her without any appearance of fear, and for some months I never saw her sting.

One other observation which goes to prove that other things besides locality are noted and remembered by bees may here be quoted. Sir John placed a bee in a bell jar, the closed end of which he held towards a window. The bee buzzed about at that end trying to make for the open air. He then showed her the way out of the open end of the jar, and after having thus learnt it, she was able to find the way out herself. This seems to show that the bee, like the wasp on the closed window-pane, was able to appreciate and to remember the difference between the quality of glass as resisting and air as permeable, although to her sense of vision the difference must have been very slight. In other words, the bee must have remembered that by first flying away from the window, round the edge of the jar, and then towards the window, she could surmount the transparent obstacle; and this implies a somewhat different act of memory from that of associating a particular object—such as honey—with a particular locality. It is noteworthy that a fly under similar circumstances did not require to be taught to find its way out of the jar, but spontaneously found its own way out. This, however, may be explained by the fact that flies do not always direct their flight towards windows, and therefore the escape of this one was probably not due to any act of intelligence.

While upon the subject of memory in the Hymenoptera, it is indispensable that we should again refer to the observation of Messrs. Belt and Bates already alluded to on pages 150-51. For it is from that observation rendered evident that these sand-wasps took definite pains, as it were, to teach themselves the localities to which they desired to return. Mr. Bates further observed that after thus taking a careful mental note of the place, they would return to it without a moment's hesitation after an absence of an hour. The observation of Mr. Belt, already quoted in extenso, proves that these mental notes may be taken with the utmost minuteness, so that even in the most intricate places the insect, on its return, is perfectly confident that it has not made a mistake.

With regard to the duration of memory, Stickney relates a case in which some bees took possession of a hollow place beneath a roof, and having been then removed into a hive, continued for several years to return and occupy the same hole with their successive swarms.[50]

Similarly Huber relates an observation of his own showing the duration of memory in bees. One autumn he put some honey in a window, which the bees visited in large numbers. During the winter the honey was taken away and the shutters shut. When they were again opened in the spring the bees returned, although there was no honey in the window.

These two cases amply prove that the memory of bees is comparable with that of ants, which, as we have seen from analogous facts, also extends at least over a period of many months.

Emotions.

Sir John Lubbock's experiments on this head go to show that the social sympathies of bees are even less developed than he found them to be in certain species of ants. Thus he says:—

I have already mentioned with reference to the attachment which bees have been said to show for one another, that though I have repeatedly seen them lick a bee which had smeared herself in honey, I never observed them show the slightest attention to any of their comrades who had been drowned in water. Far, indeed, from having been able to discover any evidence of affection among them, they appear to be thoroughly callous and utterly indifferent to one another. As already mentioned, it was necessary for me occasionally to kill a bee; but I never found that the others took the slightest notice. Thus on the 11th of October I crushed a bee close to one which was feeding—in fact, so close that their wings touched; yet the survivor took no notice whatever of the death of her sister, but went on feeding with every appearance of composure and enjoyment, just as if nothing had happened. When the pressure was removed, she remained by the side of the corpse without the slightest appearance of apprehension, sorrow, or recognition. It was, of course, impossible for her to understand my reason for killing her companion; yet neither did she feel the slightest emotion at her sister's death, nor did she show any alarm lest the same fate should befall her also. In a second case exactly the same occurred. Again, I have several times, while a bee has been feeding, held a second bee by the leg close to her; the prisoner, of course, struggled to escape, and buzzed as loudly as she could; yet the selfish eater took no notice whatever. So far, therefore, from being at all affectionate, I doubt whether bees are in the least fond of one another.

RÉaumur, however ('Insects,' vol. v., p. 265), narrates a case in which a hive-bee was partly drowned and so rendered insensible; the others in the hive carefully licked and otherwise tended her till she recovered. This seems to show that bees, like ants, are more apt to have their sympathies aroused by the sight of ailing or injured companions than by that of healthy companions in distress; but Sir John Lubbock's observations above quoted go to prove that even in this case display of sympathy is certainly not the rule.

Powers of Communication.

Huber says that when one wasp finds a store of honey 'it returns to its nest, and brings off in a short time a hundred other wasps;' and this statement is confirmed by Dujardin, who witnessed a somewhat similar performance in the case of bees—the individual which first found a concealed store informing other individuals of the fact, and so on till numberless individuals had found it.

Although the systematic experiments of Sir John Lubbock have not tended to confirm these observations with regard to bees and wasps, we must not too readily allow his negative results to discredit these positive observations—more especially as we have seen that his later experiments have fully confirmed the opinion of these previous authors with respect to ants. His experiments on bees and wasps consisted in exposing honey in a hidden situation, marking a bee or wasp that came to it, and observing whether it afterwards brought any companions to share the booty. He found that although the same insect would return over and over again, strangers came so rarely that their visits could only be attributed to accidental and independent discovery. Only if the honey were in an exposed situation, where the insects could see one another feeding, would one follow the other to the food.

But we have the more reason not to accept unreservedly the conclusion to which these experiments in themselves might lead, because the very able observer F. MÜller states an observation of his own which must be considered as alone sufficient to prove that bees are able to communicate information to one another:—

Again, Mr. Josiah Emery, writing to 'Nature,'[52] with reference to Sir John Lubbock's experiments, says that the faculty of communication which bees possess is so well and generally known to the 'bee-hunters' of America, that the recognised method of finding a bees' nest is to act upon the faculty in question:—

According to De FraviÈre, bees have a number of different notes or tones which they emit from the stigmata of the thorax and abdomen, and by which they communicate information. He says:—

This account, which is quoted from BÜchner, no doubt bears indications of imaginative colouring; but if the observation as to the emission of sounds is correct—and, as we shall see, this point is well confirmed by other observers—it is most likely concerned in communicating by tone a general idea of good or harm: probably in the former case it acts as a sign, 'follow me;' and in the latter as a signal of danger. BÜchner further says that, according to Landois, if a saucer of honey is placed before a hive, a few bees come out, which emit a cry of tut, tut, tut. This note is rather shrill, and resembles the cry of an attacked bee. Hereupon a large number of bees come out of the hive to collect the offered honey.

Again,—

Lastly, under the present heading I shall quote one other observation, for which I am also indebted to BÜchner's very admirable collection of facts relating to the psychology of Hymenoptera:—

General Habits.

The active life of bees is divided between collecting food and rearing young. We shall therefore consider these two functions separately.

The food collected consists of two kinds, honey (which, although stored in the 'crop' for the purpose of carriage from the flowers to the cells, appears to be but the condensed nectar of flowers) and so-called 'bee-bread.' This consists of the pollen of flowers, which is worked into a kind of paste by the bees and stored in their cells till it is required to serve as food for their larvÆ. It is then partly digested by the nurses with honey, so that a sort of chyle is formed. It is observable that in each flight the 'carrier bees' collect only one kind of pollen, so that it is possible for the 'house bees' (which, by the way, are the younger bees left at home to discharge domestic duties with only a small proportion of older ones, left probably to direct the more inexperienced young) to sort it for storage in different cells. In the result there are several different kinds of bee-bread, some being more stimulating or nutritious than others. The most nutritious has the effect, when given to any female larva, of developing that larva into a queen or fertile female. This fact is well known to the bees, who only feed a small number of larvÆ in this manner, and the larvÆ which they select so to feed they place in larger or 'royal' cells, with an obvious foreknowledge of the increased dimensions to which the animal will grow under the influence of this food. Only one queen is required for a single hive; but the bees always raise several, so that if any mishap should occur to one, other larvÆ may be ready to fall back upon.

Besides honey and bee-bread two other substances are found in beehives. These are propolis and beeswax. The former is a kind of sticky resin collected for the most part from coniferous trees. This is used as mortar in building, &c. It adheres so strongly to the legs of the bee which has gathered it, that it can only be detached by the help of comrades. For this purpose the loaded bee presents her legs to her fellow-workers, who clean it off with their jaws, and while it is still ductile, apply it round the inside of the hive. According to Huber, who made this observation, the propolis is applied also to the insides of the cells. The workers first planed the surfaces with their mandibles, and one of them then pulled out a thread of propolis from the heap deposited by the carrier bees, severed it by a sudden throwing back of the head, and returned with it to the cell which it had previously been planing. It then laid the thread between the two walls which it had planed; but, proving too long, a portion of the thread was bitten off. The properly measured portion was then forced into the angle of the cell by the fore-feet and mandibles. The thread, now converted into a narrow ribbon, was next found to be too broad. It was therefore gnawed down to the proper width. Other bees then completed the work which this one had begun, till all the walls of the cells were framed with bands of propolis. The object of the propolis here seems to be that of giving strength to the cells.

The wax is a secretion which proceeds from between the segments of the abdomen. Having ingested a large meal of honey, the bees hang in a thick cluster from the top of their hive in order to secrete the wax. When it begins to exude, the bees, assisted by their companions, rub it off into heaps, and when a sufficient quantity of the material has been thus collected, the work begins of building the cells. As the cells are used both for storing food and rearing young, I shall consider them later on. Now we have to pass to the labours incidental to propagation.

All the eggs are laid by one queen, who requires during this season a large amount of nourishment, so much, indeed, that ten or twelve working bees (i.e. sterile females) are set apart as her feeders. Leaving the 'royal cell,' she walks over the nursery-combs attended by a retinue of workers, and drops a single egg into each open cell. It is a highly remarkable fact that the queen is able to control the sex of the eggs which she lays, and only deposits drone or male eggs in the drone cells, and worker or female eggs in the worker cells—the cells prepared for the reception of drone larvÆ being larger than those required for the worker larvÆ. Young queens lay more worker eggs than old queens, and when a queen, from increasing age or any other cause, lays too large a proportion of drone eggs, she is expelled from the community or put to death. It is remarkable, also, under these circumstances, that the queen herself seems to know that she has become useless, for she loses her propensity to attack other queens, and so does not run the risk of making the hive virtually queenless. There is now no doubt at all that the determining cause of an egg turning out male or female is that which Dzierzon has shown, namely, the absence or presence of fertilisation—unfertilised eggs always developing into males, and fertilised ones into females. The manner, therefore, in which a queen controls the sex of her eggs must depend on some power that she has of controlling their fertilisation.

The eggs hatch out into larvÆ, which require constant attention from the workers, who feed them with the chyle or bee-bread already mentioned. In three weeks from the time that the egg is deposited, the white worm-like larva has passed through its last metamorphosis. When it has emancipated itself its nurses assemble round it to wash and caress it, as well as to supply it with food. They then clean out the cell which it has left.

When so large a number of the larvÆ hatch out as to overcrowd the hive, it is the function of the queen to lead forth a swarm. Meanwhile several larval queens have been in course of development, and matters are so arranged by the foresight of the bees, that one or more young queens are ready to emerge at a time when otherwise the hive would be left queenless. But the young queen or queens, although perfectly formed, must not escape from their royal prison-houses until the swarm has fairly taken place; the worker bees will even strengthen the coverings of these prison-houses if, owing to bad weather or other causes, swarming is delayed. The prisoner queens, which are fed through a small hole in the roof of their cells, now continually give vent to a plaintive cry, called by the bee-keepers 'piping,' and this is answered by the mother queen. The tones of the piping vary. The reason why the young queens are kept such close prisoners till after the departure of the mother queen with her swarm, is simply that the mother queen would destroy all the younger ones, could she get the chance, by stinging them. The workers, therefore, never allow the old queen to approach the prisons of the younger ones. They establish a guard all round these prisons or royal cells, and beat off the old queen whenever she endeavours to approach. But if the swarming season is over, or anything should prevent a further swarm from being sent out, the worker bees offer no further resistance to the jealousy of the mother queen, but allow her in cold blood to sting to death all the young queens in their nursery prisons. As soon as the old queen leaves with a swarm, the young queens are liberated in succession, but at intervals of a few days; for if they were all liberated at once they would fall upon and destroy one another. Each young queen as it is liberated goes off with another swarm, and those which remain unliberated are as carefully guarded from the liberated sister queen as they were previously guarded from the mother queen. When the season is too late for swarming the remaining young queens are liberated simultaneously, and are then allowed to fight to the death, the survivor being received as sovereign.

Similarly, when a strange queen is put into a hive already provided with a queen—

All these facts display a wonderful amount of apparently sagacious purpose on the part of the workers, although they may not seem to reflect much credit on the intelligence of the queens. But in this connection we must remember the observation of F. Huber, who saw two queens, which were the only ones left in the hive, engaged in mortal combat; and when an opportunity arose for each to sting the other simultaneously, they simultaneously released each other's grasp, as if in horror of a situation that might have ended in leaving the hive queenless. This, then, is the calamity to avert which all the instincts both of workers and queens are directed. And that these instincts are controlled by intelligence is suggested, if not proved, by the adaptations which they show to special circumstances. Thus, for instance, F. Huber smoked a hive so that the queen and older bees effected their escape, and took up their quarters a short distance away. The bees which remained behind set about constructing three royal cells for the purpose of rearing a new queen. Huber now carried back the old queen and ensconced her in the hive. Immediately the bees set about carrying away all the food from the royal cells, in order to prevent the larvÆ contained therein from developing into queens. Again, if a strange queen is presented to a hive already provided with one, the workers do not wait for their own queen to destroy the pretender, but themselves sting or smother her to death. When, on the other hand, a queen is presented to a hive which is without one, the bees adopt her, although it is often necessary for the bee-master to protect her for a day or two in a trellis cage, until her subjects have become acquainted with her. When a hive is queenless, the bees stop all work, become restless, and make a dull complaining noise. This, however, is only the case if there is likewise a total absence of royal pupÆ, and of ordinary pupÆ under three days of age—i.e. the age during which it is possible to rear an ordinary larva into a queen.

As soon as the queen has been fertilised, and the services of the drones therefore no longer required, the worker bees fall upon their unfortunate and defenceless brothers to kill them, either by direct stinging or by throwing them out of the hive to perish in the cold. The drones' cells are then torn down, and any remaining drone eggs or pupÆ destroyed. Generally all the drones—which may number more than a thousand—are slaughtered in the course of a single day. Evidently the object of this massacre is that of getting rid of useless mouths; but there is a more difficult question as to why these useless mouths ever came into existence. It has been suggested that the enormous disproportion between the present number of males and the single fertile female refers to a time before the social instincts became so complex or consolidated, and when, therefore, bees lived in lesser communities. Probably this is the explanation, although I think we might still have expected that before this period in their evolution had arrived bees might have developed a compensating instinct, either not to allow the queen to lay so many drone eggs, or else to massacre the drones while still in the larval state. But here we must remember that among the wasps the males do work (chiefly domestic work, for which they are fed by their foraging sisters); so it is possible that in the hive-bee the drones were originally useful members of the community, and that they have lost their primitively useful instincts. But whatever the explanation, it is very curious that here, among the animals which are justly regarded as exhibiting the highest perfection of instinct, we meet with perhaps the most flagrant instance in the animal kingdom of instinct unperfected. It is the more remarkable that the drone-killing instinct should not have been better developed in the direction of killing the drones at the most profitable time—namely, in their larval or oval state—from the fact that in many respects it seems to have been advanced to a high degree of discriminative refinement. Thus, to quote BÜchner,—

But the philosophy of drone-killing is, I think, even more difficult in the case of the wasps than in that of the bees. For, unlike the bees, whose communities live from year to year, the wasps all perish at the end of autumn, with the exception of a very few fertilised females. As this season of universal calamity approaches, the workers destroy all the larval grubs—a proceeding which, in the opinion of some writers, strikingly exemplifies the beneficence of the Deity! Now, it does not appear to me easy to understand how the presence of such an instinct in this case is to be explained. For, on the one hand, the individual females which are destined to live through the winter cannot be conspicuously benefited by this slaughter of grubs; and, on the other hand, the rest of the community is so soon about to perish, that one fails to see of what advantage it can be to it to get rid of the grubs. If the whole human race, with the exception of a few women, were to perish periodically once in a thousand years, the race would profit nothing by destroying, a few months before the end of each millennium, all sick persons, lunatics, and other 'useless mouths.' I have not seen this difficulty with regard to the massacring instinct in wasps mentioned before, and I only mention it now in order to draw attention to the fact that there seems to be a more puzzling problem presented here than in the case of the analogous instinct as exhibited by bees. The only solution which has suggested itself to my mind is the possibility that in earlier times, or in other climates, wasps may have resembled bees in living through the winter, and that the grub-slaying instinct is in them a survival of one which was then, as in the case of the bees now, a clearly beneficial instinct.

For some days before swarming begins, there is a great excitement and buzzing in the hive, the temperature of which rises from 92° to 104°. Scouts having been previously sent out to explore for suitable quarters wherein to plant the new colony, these now act as guides. The swarm leaves the hive with their queen. The bees which remain behind busy themselves in rearing out the pupÆ, which soon arriving at maturity, also quit the hive in successive swarms. According to BÜchner, 'secondary swarms with young queens send out no scouts, but fly at random through the air. They clearly lack the experience and prudence of the older bees.' And, regarding the behaviour of the scouts sent out by primary swarms, this author says:—

Wars.—As with ants, so with bees, the great cause of war is plunder; and facts now well substantiated by numberless observers concerning 'robber-bees' indicate a large measure of intelligence. These aim at lessening their labour in collecting honey by plundering the store of other hives. The robberies may be conducted singly or in concert. When the thieving propensity is developed only in individual cases, the thieves cannot rely on force in plundering a foreign state, and so resort to cautious stealth. 'They show by their whole behaviour—creeping into the hive with careful vigilance—that they are perfectly conscious of their bad conduct; whereas the workers belonging to the hive fly in quickly and openly, and in full consciousness of their right.' If such solitary burglars are successful in obtaining plunder, their bad example leads other members of their own community to imitate them; thus it is that the whole bee-nation may develop marauding habits, and when they do this they act in concert to rob by force. In this case an army of bees precipitates itself upon the foreign hive, a battle ensues, and if successful in overcoming resistance, the invaders first of all search out the queen-bee and put her to death, whereby they disorganise their enemies and plunder the hive with ease. It is observed that when this policy is once successful, the spirit of aggrandisement is encouraged, so that the robber-bees 'find more pleasure in robbery than in their own work, and become at last formidable robber-states.' When an invaded hive is fairly overcome by the invaders killing the queen, the owners of the hive, finding that all is lost, not only abandon further resistance, but very often reverse their policy and join the ranks of their conquerors. They assist in the tearing down of their cells, and in the conveyance of the honey to the hive of their invaders. 'When the assailed hive is emptied, the next ones are attacked, and if no effective resistance is offered, are robbed in similar fashion, so that in this way a whole bee-stand may be gradually destroyed.' Siebold observed the same facts in the case of wasps (Polistes gallica). If, however, the battle turns in favour of the defenders, they pursue the flying legions of their enemies to a distance from their home. It sometimes happens that the plundered hive offers no resistance at all, owing to the robbers having visited the same flowers as the robbed, and so probably (having much the same smell) not being recognised as belonging to a different community. The thieves, when they find such to be the case, may become so bold as to stop the bees that are returning to the hive with their loads, of which they deprive them at the entrance of the hive. This is done by a process which one observer, Weygandt,[56] calls 'milking,' and it seems that the milking bee attains the double advantage of securing the honey from the milked one and disarming suspicion of the other bees by contracting its smell and entering the hive loaded, into which it is admitted without opposition to continue its plunder.

Sometimes robber-bees attack their victims in the fields at a distance from the hives. This sort of highway robbery is generally conducted by a gang of four or five robber-bees which set upon a single honest bee, 'hold him by the legs, and pinch him until he unfolds his tongue, which is sucked in succession by his assailants, who then suffer him to depart in peace.'

It is strange that hive-bees of dishonest temperaments seem able to coax or wheedle humble-bees into the voluntary yielding of honey. 'Humble-bees have been known to permit hive-bees to take the whole honey that they have collected, and to go on gathering more, and handing it over, for three weeks, although they refuse to part with it, or seek refuge in flight, when wasps make similar overtures.'[57]

Besides theft and plunder, there are other causes of warfare among bees, which, however, are only apparent in their effects. Thus, for some undiscernible reason, duels are not infrequent, which generally end in the death of one or both combatants. At other times, equally without apparent reason, civil war breaks out in a hive, which is sometimes attended with much slaughter.

Architecture.—Coming now to the construction of the cells and combs, there is no doubt that here we meet with the most astonishing products of instinct that are presented in the animal kingdom. A great deal has been written on the practical exhibition of high mathematical principles which bees display in constructing their combs in the form that secures the utmost capacity for storage of honey with the smallest expenditure of building material. The shortest and clearest statement of the subject that I have met with is the following, which has been given by Dr. Reid:—

Marvellous as these facts undoubtedly are, they may now be regarded as 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,—

This statement having fully borne out his theory, Mr. Darwin continues:—

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.