Fertile Workers.
It has already been remarked, that the workers are proved by dissection to be females, all of which, under ordinary circumstances, are barren. Occasionally, some of them appear to be more fully developed than common, so as to be capable of laying eggs: these eggs, like those of Queens whose impregnation has been retarded, always produce drones! Sometimes, when a colony has lost its Queen, these drone-laying workers are exalted to her place, and treated with equal respect and affection, by the bees. Huber ascertained that these fertile workers were generally reared in the neighborhood of the young Queens, and he thought that they received some particles of the peculiar food or jelly on which the Queens are reared. (See Royal Jelly.) He did not pretend to account for the effect of retarded impregnation; and made no experiments to determine the facts, as to the fecundation of these fertile workers.
Since the publication of Huber's work, nearly 50 years ago, no light has been shed upon the mysteries of drone-laying Queens and workers, until quite recently. Dzierzon appears to have been the first to ascertain the truth on this subject; and his discovery must certainly be ranked as unfolding one of the most astonishing facts in all the range of animated nature. This fact seems, at first view, so absolutely incredible, that I should not dare to mention it, if it were not supported by the most indubitable evidence, and if I had not, (as I have already observed,) determined to state all important and well ascertained facts, without seeking, by any concealments, to pander to the prejudices of conceited, and often, very ignorant Bee-Keepers.
Dzierzon advances the opinion that impregnation is not needed in order that the eggs of the Queen may produce drones; but, that all impregnated eggs produce females, either workers or Queens; and all unimpregnated ones, males or drones! He states that he found drone-laying Queens in several of his hives, whose wings were so imperfect that they could not fly, and that on examination, they proved to be unfecundated. Hence he concluded that the eggs of the Queen Bee or fertile worker, had from the previous impregnation of the egg which produced them, sufficient vitality to produce the drone, which is a less highly organized insect, and one inferior to the Queen or workers. It had long been known, that the Queen deposits drone eggs in the large or drone cells, and worker eggs in the small or worker cells, and that she makes no mistakes. Dzierzon inferred, therefore, that there was some way in which she was able to decide as to the sex of the egg before it was laid, and that she must have a control over the mouth of the seminal sac, so as to be able to extrude her eggs, allowing them to receive or not, just as she pleased, a portion of its fertilizing contents. In this way he thought she determined the sex, according to the size of the cells in which she laid them. Mr. Samuel Wagner of York, Pa., has recently communicated to me a very original and exceedingly ingenious theory of his own, which he thinks will account for all the facts without admitting that the Queen Bee has any special knowledge or will on the subject. He supposes that when she deposits her eggs in the worker cells, her body is slightly compressed by the size of the cells, and that the eggs, as they pass the spermatheca, receive in this manner, its vivifying influence. On the contrary, when she is egg-laying in drone cells, this compression cannot take place, the mouth of the spermatheca is kept closed, and the eggs are, necessarily, unfecundated. This theory may prove to be true, but at present, it is encumbered with some difficulties and requires further investigation, before it can be considered as fully established.
Leaving then the question whether the Queen exercises any volition in this matter, for the present undecided, I shall state some facts which occurred in the summer of 1852, in my own Apiary, and shall then endeavor to relieve, as far as possible, this intricate subject from some of the difficulties which embarrass it.
In the Autumn of 1852, my assistant found, in one of my hives, a young Queen, the whole of whose progeny was drones. The colony had been formed by removing part of the combs containing bees, brood and eggs from another hive. It had only a few combs, and but a small number of bees. They raised a new Queen in the manner which will hereafter be particularly described. This Queen had laid a number of eggs in one of the combs, and the young bees from some of them were already emerging from the cells. I perceived, at the first glance, that they were drones. As there were none but worker cells in the hive, they were reared in them, and not having space for full development, they were dwarfed in size, although the bees, in order to give them more room, had pieced out the cells so as to make them larger than usual! Size excepted, they appeared as perfect as any other drones.
I was not only struck with the singularity of finding drones reared in worker cells, but with the equally singular fact that a young Queen, who at first lays only the eggs of workers, should be laying drone eggs at all; and at once conjectured that this was a case of a drone-laying, unimpregnated Queen, as sufficient time had not elapsed for her impregnation to be unnaturally retarded. I saw the great importance of taking all necessary precautions to determine this point. The Queen was removed from the hive, and carefully examined. Her wings, although they appeared to be perfect, were so paralized that she could not fly. It seemed probable, therefore, that she had never been able to leave the hive for impregnation.
To settle the question beyond the possibility of doubt, I submitted this Queen to Dr. Joseph Leidy for microscopic examination. The following is an extract from his report: "The ovaries were filled with eggs; the poison sac was full of fluid, and I took the whole of it into my mouth; the poison produced a strong metallic taste, lasting for a considerable time, and at first, it was pungent to the tip of the tongue. The spermatheca was distended with a perfectly colorless, transparent, viscid liquid, without a trace of spermatozoa."
This examination seems perfectly to sustain the theory of Dzierzon, and to demonstrate that Queens do not need to be impregnated, in order to lay the eggs of males.
I must confess that very considerable doubts rested on my mind, as to the accuracy of Dzierzon's statements on this subject, and chiefly because of his having hazarded the unfortunate conjecture that the place of the poison bag in the worker, is occupied in the Queen, by the spermatheca. Now this is so completely contrary to fact, that it was a very natural inference that this acute and thoroughly honest observer, made no microscopic dissections of the insects which he examined. I consider myself peculiarly fortunate in having enjoyed the benefit of the labors of a Naturalist, so celebrated as Dr. Leidy, for microscopic dissections. The exceeding minuteness of some of the insects which he has completely figured and described, almost passes belief.
On examining this same colony a few days later, I obtained the most satisfactory evidence that these drone eggs were laid by the Queen which had been removed. No fresh eggs had been deposited in the cells, and the bees, on missing her, had commenced the construction of royal cells, to rear if possible, another Queen, a thing which they would not have done, if a fertile worker had been present, by which the drone eggs had been laid.
Another very interesting fact proves that all the eggs laid by this Queen, were drone eggs. Two of the royal cells were, in a short time, discontinued, and were found to be empty, while a third contained a worm, which was sealed over the usual way, to undergo its changes from a worm to a perfect Queen.
I was completely at a loss to account for this, as the bees having an unimpregnated drone-laying Queen, ought not to have had a single female egg from which they could rear a Queen.
At first I imagined that they might have stolen it from another hive, but when I opened this cell, it contained, instead of a queen, a dead drone!
I then remembered that Huber has described the same mistake on the part of some of his bees. At the base of this cell, was an extraordinary quantity of the peculiar jelly or paste, which is fed to the young that are to be transformed into queens. The poor bees in their desperation, appear to have dosed the unfortunate drone to death: as though they expected by such liberal feeding, to produce some hopeful change in his sexual organization!
It appears to me that these facts constitute all the links in a perfect chain, and demonstrate beyond the possibility of doubt, that unfecundated queens are not only capable of laying eggs, (this would be no more remarkable than the same occurrence in a hen,) but that these eggs are possessed of sufficient vitality to produce drones. Aristotle, who flourished before the Christian era, had noticed that there was no difference in appearance, between the eggs producing drones and those producing workers; and he states that drones only are produced in hives which have no queen; of course the eggs producing them, were laid by fertile workers. Having now the aid of powerful microscopes, we are still unable to detect the slightest difference in size or appearance in the eggs, and this is precisely what we should expect if the same egg will produce either a worker or a drone, according as it is or is not impregnated. The theory which I propose, will, I think, perfectly harmonize with all the observed facts on this subject.
I believe that after fecundation has been delayed for about three weeks, the mouth of the spermatheca becomes permanently closed, so that impregnation can no longer be effected; just as the parts of a flower, after a certain time, wither and shut up, and the plant is incapable of fructification. The fertile drone-laying workers, are in my opinion, physically incapable of being impregnated. However strange it may appear, or even improbable, that an unimpregnated egg can give birth to a living being, or that the sex can be dependent on impregnation, we are not at liberty to reject facts, because we cannot comprehend the reasons of them. He who allows himself to be guilty of such folly, if he seeks to maintain his consistency, will be plunged, sooner or later, into the dreary gulf of atheism. Common sense, philosophy and religion alike teach us to receive all undoubted facts in the natural and the spiritual world, with becoming reverence; assured that however mysterious to us, they are all most beautifully harmonious and consistent in the sight of Him whose "understanding is infinite."
There is something analogous to these wonders in the bee, in what takes place in the aphides or green lice which infest our rose bushes and other plants. We have the most undoubted evidence that a fecundated female gives birth to other females, and they in turn to others still, all of which, without impregnation, are able to bring forth young, until at length, after a number of generations, perfect males and females are produced, and the series starts anew!
The unequaled facilities, furnished by my hives, have seemed to render it peculiarly incumbent on me, to do all in my power to clear up the difficulties in this intricate and yet highly important branch of Apiarian knowledge. All the leading facts in the breeding of bees ought to be as well known to the bee keeper, as the same class of facts in the rearing of his domestic animals. A few crude and hasty notions, but half understood and half digested, will answer only for the old fashioned bee keeper, who deals in the brimstone matches. He who expects to conduct bee keeping on a safe and profitable system, must learn that on this, as on all other subjects, "knowledge is power."
The extraordinary fertility of the queen bee has already been noticed. The process of laying has been well described by the Rev. W. Dunbar, a Scotch Apiarian.
"When the queen is about to lay, she puts her head into a cell, and remains in that position for a second or two, to ascertain its fitness for the deposit which she is about to make. She then withdraws her head, and curving her body downwards,[2] inserts the lower part of it into the cell: in a few seconds she turns half round upon herself and withdraws, leaving an egg behind her. When she lays a considerable number, she does it equally on each side of the comb, those on the one side being as exactly opposite to those on the other as the relative position of the cells will admit. The effect of this is to produce the utmost possible concentration and economy of heat for developing the various changes of the brood!"
Here as at every step in the economy of the bee our minds are filled with admiration as we witness the perfect adaptation of means to ends. Who can blame the warmest enthusiasm of the Apiarian in view of a sagacity which seems scarcely inferior to that of man.
"The eggs of bees," I quote from the admirable treatise of Bevan, "are of a lengthened oval shape, with a slight curvature, and of a bluish white color: being besmeared at the time of laying, with a glutinous substance,[3] they adhere to the bases of the cells, and remain unchanged in figure or situation for three or four days; they are then hatched, the bottom of each cell presenting to view a small white worm. On its growing so as to touch the opposite angle of the cell, it coils itself up, to use the language of Swammerdam, like a dog when going to sleep; and floats in a whitish transparent fluid, which is deposited in the cells by the nursing-bees, and by which it is probably nourished; it becomes gradually enlarged in its dimensions, till the two extremities touch one another and form a ring. In this state it is called a larva or worm. So nicely do the bees calculate the quantity of food which will be required, that none remains in the cell when it is transformed to a nymph. It is the opinion of many eminent naturalists that farina does not constitute the sole food of the larva, but that it consists of a mixture of farina, honey and water, partly digested in the stomachs of the nursing-bees."
"The larva having derived its support, in the manner above described, for four, five or six days, according to the season," (the development being retarded in cool weather, and badly protected hives,) "continues to increase during that period, till it occupies the whole breadth and nearly the length of the cell. The nursing bees now seal over the cell, with a light brown cover, externally more or less convex, (the cap of a drone cell is more convex than that of a worker,) and thus differing from that of a honey cell which is paler and somewhat concave." The cap of the brood cell appears to be made of a mixture of bee-bread and wax; it is not air tight as it would be if made of wax alone; but when examined with a microscope it appears to be reticulated, or full of fine holes through which the enclosed insect can have air for all necessary purposes. From its texture and shape it is easily thrust off by the bee when mature, whereas, if it consisted wholly of wax, the young bee would either perish for lack of air, or be unable to force its way into the world! Both the material and shape of the lids which seal up the honey cells are different, because an entirely different object was aimed at; they are of pure wax to make them air tight and thus to prevent the honey from souring or candying in the cells! They are concave or hollowed inwards to give them greater strength to resist the pressure of their contents!
To return to Bevan. "The larva is no sooner perfectly inclosed than it begins to line the cell by spinning round itself, after the manner of the silk worm, a whitish silky film or cocoon, by which it is encased, as it were, in a pod. When it has undergone this change, it has usually borne the name of nymph or pupa. The insect has now attained its full growth, and the large amount of nutriment which it has taken serves as a store for developing the perfect insect."
"The working bee nymph spins its cocoon in thirty-six hours. After passing about three days in this state of preparation for a new existence, it gradually undergoes so great a change as not to wear a vestige of its previous form, but becomes armed with a firmer mail, and with scales of a dark brown hue. On its belly six rings become distinguishable, which by slipping one over another enables the bee to shorten its body whenever it has occasion to do so.
"When it has reached the twenty-first day of its existence, counting from the moment the egg is laid, it comes forth a perfect winged insect. The cocoon is left behind, and forms a closely attached and exact lining to the cell in which it was spun; by this means the breeding cells become smaller and their partitions stronger, the oftener they change their tenants; and may become so much diminished in size as not to admit of the perfect development of full sized bees."
"Such are the respective stages of the working bee: those of the royal bee are as follows: she passes three days in the egg and is five a worm; the workers then close her cell, and she immediately begins spinning her cocoon, which occupies her twenty four hours. On the tenth and eleventh days and a part of the twelfth, as if exhausted by her labor, she remains in complete repose. Then she passes four days and a part of the fifth as a nymph. It is on the sixteenth day therefore that the perfect state of queen is attained."
"The drone passes three days in the egg, six and a half as a worm, and changes into a perfect insect on the twenty-fourth or twenty-fifth day after the egg is laid."
"The development of each species likewise proceeds more slowly when the colonies are weak or the air cool, and when the weather is very cold it is entirely suspended. Dr. Hunter has observed that the eggs, worms and nymphs all require a heat above 70° of Fahrenheit for their evolution."
In the chapter on protection against extremes of heat and cold, I have dwelt, at some length, upon the importance of constructing the hives in such a manner as to enable the bees to preserve, as far as possible, a uniform temperature in their tenement. In thin hives exposed to the sun, the heat is sometimes so great as to destroy the eggs and the larvæ, even when the combs escape from being melted; and the cold is often so severe as to check the development of the brood, and sometimes to kill it outright.
In such hives, when the temperature out of doors falls suddenly and severely, the bees at once feel the unfavorable change; they are obliged in self defence to huddle together to keep warm, and thus large portions of the brood comb are often abandoned, and the brood either destroyed at once by the cold, or so enfeebled that they never recover from the shock. Let every bee keeper, in all his operations, remember that brood comb must never be exposed to a low temperature so as to become chilled: the disastrous effects are almost as certain, as when the eggs of a setting hen are left, for too long a time, by the careless mother. The brood combs are never safe when taken for any considerable time from the bees, unless the temperature is fully up to summer heat.
"[4]The young bees break their envelope with their teeth, and assisted, as soon as they come forth, by the older ones, proceed to cleanse themselves from the moisture and exuviæ with which they were surrounded. Both drones and workers on emerging from the cell are, at first grey, soft and comparatively helpless so that some time elapses before they take wing.
"With respect to the cocoons spun by the different larvæ, both workers and drones spin complete cocoons, or inclose themselves on every side; royal larvæ construct only imperfect cocoons, open behind, and enveloping only the head, thorax, and first ring of the abdomen; and Huber concludes, without any hesitation, that the final cause of their forming only incomplete cocoons is, that they may thus be exposed to the mortal sting of the first hatched queen, whose instinct leads her instantly to seek the destruction of those who would soon become her rivals.
"If the royal larvæ spun complete cocoons, the stings of the queens seeking to destroy their rivals might be so entangled in their meshes that they could not be disengaged. 'Such,' says Huber, 'is the instinctive enmity of young queens to each other, that I have seen one of them, immediately on its emergence from the cell, rush to those of its sisters, and tear to pieces even the imperfect larvæ. Hitherto philosophers have claimed our admiration of nature for her care in preserving and multiplying the species. But from these facts we must now admire her precautions in exposing certain individuals to a mortal hazard.'"
The cocoon of the royal larva is very much stronger and coarser than that spun by the drone or worker, its texture considerably resembling that of the silk worm's. The young queen does not come forth from her cell until she is quite mature; and as its great size gives her abundant room to exercise her wings she is capable of flying as soon as she quits it. While still in her cell she makes the fluttering and piping noises with which every observant bee keeper is so well acquainted.
Some Apiarians have supposed that the queen bee has the power to regulate the development of eggs in her ovaries, so that few or many are produced, according to the necessities of the colony. This is evidently a mistake. Her eggs, like those of the domestic hen, are formed without any volition of her own, and when fully developed, must be extruded. If the weather is unfavorable, or if the colony is too feeble to maintain sufficient heat, a smaller number of eggs are developed in her ovaries, just as unfavorable circumstances diminish the number of eggs laid by the hen; if the weather is very cold, egg-laying usually ceases altogether. In the latitude of Philadelphia, I opened one of my hives on the 5th day of February, and found an abundance of eggs and brood, although the winter had been an unusually cold one, and the temperature of the preceding month very low. The fall of 1852 was a warm one, and eggs and brood were found in a hive which I examined on the 21st of October. Powerful stocks in well protected hives contain some brood, at least ten months in the year; in warm countries, bees probably breed, every month in the year.
It is highly interesting to see in what way the supernumerary eggs of the queen are disposed of. When the number of workers is too small to take charge of all her eggs, or when there is a deficiency of bee bread to nourish the young, (See chapter on [Pollen],) or when, for any reason, she judges it not best to deposit them in cells, she stands upon a comb, and simply extrudes them from her oviduct, and the workers devour them as fast as they are laid! This I have repeatedly witnessed in my observing hives, and admired the sagacity of the queen in economizing her necessary work after this fashion, instead of laboriously depositing the eggs in cells where they are not wanted. What a difference between her wise management and the stupidity of a hen obstinately persisting to set upon addled eggs, or pieces of chalk, and often upon nothing at all.
The workers eat up also all the eggs which are dropped, or deposited out of place by the queen; in this way, nothing goes to waste, and even a tiny egg is turned to some account. Was there ever a better comment upon the maxim? "Take care of the pence, and the pounds will take care of themselves."
Do the workers who appear to be so fond of a tit-bit in the shape of a new laid egg, ever experience a struggle between their appetites and the claims of duty, and does it cost them some self denial to refrain from making a breakfast on a fresh laid egg? It is really very difficult for one who has carefully watched the habits of bees, to speak of his little favorites in any other way than as though they possessed an intelligence almost, if not quite, akin to reason.
It is well known to every breeder of poultry, that the fertility of a hen decreases with age, until at length, she becomes entirely barren; it is equally certain that the fertility of the queen bee ordinarily diminishes after she has entered upon her third year. She sometimes ceases to lay Worker eggs, a considerable time before she dies of old age; the contents of the spermatheca are exhausted; the eggs can no longer be impregnated and must therefore produce drones.
The queen bee usually dies of old age, some time in her fourth year, although instances are on record of some having survived a year longer. It is highly important to the bee keeper who would receive the largest returns from his bees, to be able, as in my hives, to catch the queen and remove her, when she has passed the period of her greatest fertility. In the sequel, full directions will be given, as to the proper time and mode of effecting it.
Before proceeding farther in the natural history of the queen bee, I shall describe more particularly, the other inmates of the hive.