Part 13

By chemical analysis, however, it appears that the wax of the rings is a more simple substance than that which composes the cells; for the latter is soluble in ether, and in spirit of turpentine, while the former is insoluble in ether, and but partially soluble in spirit of turpentine. It should seem to follow, that if the substance found lying under the rings be really the elements of wax, it undergoes some subsequent preparation after it is detached; and that the bees, in short, are capable of impregnating it with matter, imparting to it whiteness and ductility, whereas in its unprepared state it is only fusible.

Propolis.

Wax is not the only material employed by bees in their architecture. Beside this, they make use of a brown, odoriferous, resinous substance, called propolis, more tenacious and extensible than wax, and well adapted for cementing and varnishing. It was strongly suspected by Réaumur that the bees collected the propolis from those trees which are known to produce a similar gummy resin, such as the poplar, the birch, and the willow; but he was thrown into doubt by not being able to detect the bees in the act of procuring it, and by observing them to collect it where none of those trees, nor any other of the same description, grew. His bees also refused to make use of bitumen, and other resinous substances, with which he supplied them, though Mr. Knight, as we shall afterwards see, was more successful.

Long before the time of Réaumur, however, Mouffet, in his Insectarum Theatrum, quotes Cordus for the opinion that propolis is collected from the buds of trees, such as the poplar and birch; and Reim says it is collected from the pine and fir. Huber at length set the question at rest; and his experiments and observations are so interesting, that we shall give them in his own words:--

"For many years," says he, "I had fruitlessly endeavoured to find them on trees producing an analogous substance, though multitudes had been seen returning laden with it.

"In July, some branches of the wild poplar, which had been cut since spring, with very large buds, full of a reddish, viscous, odoriferous matter, were brought to me, and I planted them in vessels before hives, in the way of the bees going out to forage, so that they could not be insensible of their presence. Within a quarter of an hour, they were visited by a bee, which separating the sheath of a bud with its teeth, drew out threads of the viscous substance, and lodged a pellet of it in one of the baskets of its limbs; from another bud it collected another pellet for the opposite limb, and departed to the hive. A second bee took the place of the former in a few minutes, following the same procedure. Young shoots of poplar, recently cut, did not seem to attract these insects, as their viscous matter had less consistence than the former.

"Different experiments proved the identity of this substance with the propolis; and now, having only to discover how the bees applied it to use, we peopled a hive, so prepared as to fulfil our views. The bees, building upwards, soon reached the glass above; but, unable to quit their habitation, on account of rain, they were three weeks without bringing home propolis. Their combs remained perfectly white until the beginning of July, when the state of the atmosphere became more favourable for our observations. Serene, warm weather engaged them to forage, and they returned from the fields laden with a resinous gum, resembling a transparent jelly, and having the colour and lustre of the garnet. It was easily distinguished from the farinaceous pellets then collected by other bees. The workers bearing the propolis ran over the clusters, suspended from the roof of the hive, and rested on the rods supporting the combs, or sometimes stopped on the sides of their dwelling, in expectation of their companions coming to disencumber them of their burthen. We actually saw two or three arrive, and carry the propolis from off the limbs of each with their teeth. The upper part of the hive exhibited the most animated spectacle; thither a multitude of bees resorted from all quarters, to engage in the predominant occupation of the collection, distribution, and application of the propolis. Some conveyed that of which they had unloaded the purveyors in their teeth, and deposited it in heaps; others hastened, before its hardening, to spread it out like a varnish, or formed it into strings, proportioned to the interstices of the sides of the hives to be filled up. Nothing could be more diversified than the operations carried on.

"The bees, apparently charged with applying the propolis within the cells, were easily distinguished from the multitude of workers, by the direction of their heads towards the horizontal pane forming the roof of the hive, and on reaching it, they deposited their burthen nearly in the middle of intervals separating the combs: then they conveyed the propolis to the real place of its destination. They suspended themselves by the claws of the hind legs to points of support, afforded by the viscosity of the propolis on the glass; and, as it were, swinging themselves backwards and forwards, brought the heap of this substance nearer to the cells at each impulse. Here the bees employed their fore feet, which remained free, to sweep what the teeth had detached, and to unite the fragments scattered over the glass, which recovered all its transparency when the whole propolis was brought to the vicinity of the cells.

"After some of the bees had smoothed down and cleaned out the glazed cells, feeling the way with their antennæ, one desisted, and having approached a heap of propolis, drew out a thread with its teeth. This being broken off, it was taken in the claws of the fore feet, and the bee, re-entering the cell, immediately placed it in the angle of two portions that had been smoothed, in which operation the fore feet and teeth were used alternately; but probably proving too clumsy, the thread was reduced and polished; and we admired the accuracy with which it was adjusted when the work was completed. The insect did not stop here: returning to the cell, it prepared other parts of it to receive a second thread, for which we did not doubt that the heap would be resorted to. Contrary to our expectation, however, it availed itself of the portion of the thread cut off on the former occasion, arranged it in the appointed place, and gave it all the solidity and finish of which it was susceptible. Other bees completed the work which the first had begun: and the sides of the cells were speedily secured with threads of propolis, while some were also put on the orifices; but we could not seize the moment when they were varnished, though it may be easily conceived how it is done."

This is not the only use to which bees apply the propolis. They are extremely solicitous to remove such insects or foreign bodies as happen to get admission into the hive. When so light as not to exceed their powers, they first kill the insect with their stings, and then drag it out with their teeth. But it sometimes happens, as was first observed by Maraldi, and since by Réaumur and others, that an ill-fated slug creeps into the hive: this is no sooner perceived than it is attacked on all sides, and stung to death. But how are the bees to carry out so heavy a burthen? Such a labour would be in vain. To prevent the noxious smell which would arise from its putrefaction, they immediately embalm it, by covering every part of its body with propolis, through which no effluvia can escape. When a snail with a shell gets entrance, to dispose of it gives much less trouble and expense to the bees. As soon as it receives the first wound from a sting, it naturally retires within its shell. In this case, the bees, instead of pasting it all over with propolis, content themselves with gluing all round the margin of the shell, which is sufficient to render the animal for ever immovably fixed.

Mr. Knight, the learned and ingenious President of the Horticultural Society, discovered by accident an artificial substance, more attractive than any of the resins experimentally tried by Réaumur. Having caused the decorticated part of a tree to be covered with a cement composed of bees'-wax and turpentine, he observed that this was frequented by hive-bees, who, finding it to be a very good propolis ready made, detached it from the tree with their mandibles, and then, as usual, passed it from the first leg to the second, and so on. When one bee had thus collected its load, another often came behind and despoiled it of all it had collected; a second and a third load were frequently lost in the same manner; and yet the patient insect pursued its operations without manifesting any signs of anger. Probably the latter circumstance, at which Mr. Knight seems to have been surprised, was nothing more than an instance of the division of labour so strikingly exemplified in every part of the economy of bees.

It may not be out of place here to describe the apparatus with which the worker-bees are provided for the purpose of carrying the propolis as well as the pollen of flowers to the hive, and which has just been alluded to in the observations of Mr. Knight. The shin or middle portion of the hind pair of legs is actually formed into a triangular basket, admirably adapted to this design. The bottom of this basket is composed of a smooth, shining, horn-like substance, hollowed out in the substance of the limb, and surrounded with a margin of strong and thickly-set bristles. Whatever materials, therefore, may be placed by the bee in the interior of this basket, are secured from falling out by the bristles around it, whose elasticity will even allow the load to be heaped beyond their points without letting it fall.

In the case of propolis, when the bee is loading her singular basket, she first kneads the piece she has detached with her mandibles, till it becomes somewhat dry and less adhesive, as otherwise it would stick to her limbs. This preliminary process sometimes occupies nearly half an hour. She then passes it backwards by means of her feet to the cavity of her basket, giving it two or three pats to make it adhere; and when she adds a second portion to the first, she often finds it necessary to pat it still harder. When she has procured as much as the basket will conveniently hold, she flies off with it to the hive.

The Building of the Cells.

The notion commonly entertained respecting glass hives is altogether erroneous. Those who are unacquainted with bees, imagine that, by means of a glass hive, all their proceedings may be easily watched and recorded; but it is to be remembered that bees are exceedingly averse to the intrusion of light, and their first operation in such cases is to close up every chink by which light can enter to disturb them, either by clustering together, or by a plaster composed of propolis. It consequently requires considerable management and ingenuity, even with the aid of a glass hive, to see them actually at work. M. Huber employed a hive with leaves, which opened in the manner of a book; and for some purposes he used a glass box, inserted in the body of the hive, but easily brought into view by means of screws.

But no invention hitherto contrived is sufficient to obviate every difficulty. The bees are so eager to afford mutual assistance, and for this purpose so many of them crowd together in rapid succession, that the operations of individuals can seldom be traced. Though this crowding, however, appears to an observer to be not a little confused, it is all regulated with admirable order, as has been ascertained by Réaumur and other distinguished naturalists.

When bees begin to build the hive, they divide themselves into bands, one of which produces materials for the structure; another works upon these, and forms them into a rough sketch of the dimensions and partitions of the cells. All this is completed by the second band, who examine and adjust the angles, remove the superfluous wax, and give the work its necessary perfection; and a third band brings provisions to the labourers, who cannot leave their work. But no distribution of food is made to those whose charge, in collecting propolis and pollen, calls them to the field, because it is supposed they will hardly forget themselves; neither is any allowance made to those who begin the architecture of the cells. Their province is very troublesome, because they are obliged to level and extend, as well as cut and adjust the wax to the dimensions required; but then they soon obtain a dismission from this labour, and retire to the fields to regale themselves with food, and wear off their fatigue with a more agreeable employment. Those who succeed them, draw their mouth, their feet, and the extremity of their body, several times over all the work, and never desist till the whole is polished and completed; and as they frequently need refreshments, and yet are not permitted to retire, there are waiters always attending, who serve them with provisions when they require them. The labourer who has an appetite, bends down his trunk before the caterer to intimate that he has an inclination to eat, upon which the other opens his bag of honey, and pours out a few drops: these may be distinctly seen rolling through the hole of his trunk, which insensibly swells in every part the liquor flows through. When this little repast is over, the labourer returns to his work, and his body and feet repeat the same motions as before.

Before they can commence building, however, when a colony or swarm migrates from the original hive to a new situation, it is necessary first to collect propolis, with which every chink and cranny in the place where they mean to build may be carefully stopped up; and secondly, that a quantity of wax be secreted by the wax-workers to form the requisite cells. The secretion of wax, it would appear, goes on best when the bees are in a state of repose; and the wax-workers, accordingly, suspend themselves in the interior in an extended cluster, like the curtain which is composed of a series of intertwined festoons or garlands, crossing each other in all directions--the uppermost bee maintaining its position by laying hold of the roof with its fore legs, and the succeeding one by laying hold of the hind legs of the first.

"A person," says Réaumur, "must have been born devoid of curiosity not to take interest in the investigation of such wonderful proceedings." Yet Réaumur himself seems not to have understood that the bees suspended themselves in this manner to secrete wax, but merely, as he imagined, to recruit themselves by rest for renewing their labours. The bees composing the festooned curtain are individually motionless; but this curtain is, notwithstanding, kept moving by the proceedings in the interior; for the nurse-bees never form any portion of it, and continue their activity--a distinction with which Réaumur was unacquainted.

Although there are many thousand labourers in a hive, they do not commence foundations for combs in several places at once, but wait till an individual bee has selected a site, and laid the foundation of a comb, which serves as a directing mark for all that are to follow. Were we not expressly told by so accurate an observer as Huber, we might hesitate to believe that bees, though united in what appears to be an harmonious monarchy, are strangers to subordination, and subject to no discipline. Hence it is, that though many bees work on the same comb, they do not appear to be guided by any simultaneous impulse. The stimulus which moves them is successive. An individual bee commences each operation, and several others successively apply themselves to accomplish the same purpose. Each bee appears, therefore, to act individually, either as directed by the bees preceding it, or by the state of advancement in which it finds the work it has to proceed with. If there be anything like unanimous consent, it is the inaction of several thousand workers while a single individual proceeds to determine and lay down the foundation of the first comb. Réaumur regrets that, though he could by snatches detect a bee at work in founding cells or perfecting their structure, his observations were generally interrupted by the crowding of other bees between him and the little builder. He was therefore compelled rather to infer the different steps of their procedure from an examination of the cells when completed, than from actual observation. The ingenuity of Huber, even under all the disadvantages of blindness, succeeded in tracing the minutest operations of the workers from the first waxen plate of the foundation. We think the narrative of the discoverer's experiments, as given by himself, will be more interesting than any abstract of it which we could furnish:--

"Having taken a large bell-shaped glass receiver, we glued thin wooden slips to the arch at certain intervals, because the glass itself was too smooth to admit of the bees supporting themselves on it. A swarm, consisting of some thousand workers, several hundred males, and a fertile queen, was introduced, and they soon ascended to the top. Those first gaining the slips fixed themselves there by the fore-feet; others, scrambling up the sides, joined them, by holding their legs with their own, and they thus formed a kind of chain, fastened by the two ends to the upper parts of the receiver, and served as ladders or a bridge to the workers enlarging their number. The latter were united in a cluster, hanging like an inverted pyramid from the top to the bottom of the hive.

"The country then affording little honey, we provided the bees with syrup of sugar, in order to hasten their labour. They crowded to the edge of a vessel containing it; and, having satisfied themselves, returned to the group. We were now struck with the absolute repose of this hive, contrasted with the usual agitation of bees. Meanwhile, the nurse-bees alone went to forage in the country; they returned with pollen, kept guard at the entrance of the hive, cleansed it, and stopped up its edges with propolis. The wax-workers remained motionless about fifteen hours: the curtain of bees, consisting always of the same individuals, assured us that none replaced them. Some hours later, we remarked that almost all these individuals had wax scales under the rings; and next day this phenomenon was still more general. The bees forming the external layer of the cluster, having now somewhat altered their position, enabled us to see their bellies distinctly. By the projection of the wax scales, the rings seemed edged with white. The curtain of bees became rent in several places, and some commotion began to be observed in the hive.

"Convinced that the combs would originate in the centre of the swarm, our whole attention was then directed towards the roof of the glass. A worker at this time detached itself from one of the central festoons of the cluster, separated itself from the crowd, and, with its head, drove away the bees at the beginning of the row in the middle of the arch, turning round to form a space an inch or more in diameter, in which it might move freely. It then fixed itself in the centre of the space thus cleared.

"The worker now employing the pincers at the joint of one of the third pair of its limbs, seized a scale of wax projecting from a ring, and brought it forward to its mouth with the claws of its fore-legs, where it appeared in a vertical position. We remarked that, with its claws, it turned the wax in every necessary direction; that the edge of the scale was immediately broken down, and the fragments having been accumulated in the hollow of the mandibles, issued forth like a very narrow ribbon, impregnated with a frothy liquid by the tongue. The tongue itself assumed the most varied shapes, and executed the most complicated operations,--being sometimes flattened like a trowel, and at other times pointed like a pencil; and, after imbuing the whole substance of the ribbon, pushed it forward again into the mandibles, whence it was drawn out a second time, but in an opposite direction.

"At length the bee applied these particles of wax to the vault of the hive, where the saliva impregnating them promoted their adhesion, and also communicated a whiteness and opacity which were wanting when the scales were detached from the rings. Doubtless this process was to give the wax that ductility and tenacity belonging to its perfect state. The bee then separated those portions not yet applied to use with its mandibles, and with the same organs afterwards arranged them at pleasure. The founder bee, a name appropriated to this worker, repeated the same operation, until all the fragments, worked up and impregnated with the fluid, were attached to the vault, when it repeated the preceding operations on the part of the scale yet kept apart, and again united to the rest what was obtained from it. A second and third scale were similarly treated by the same bee; yet the work was only sketched; for the worker did nothing but accumulate the particles of wax together. Meanwhile the founder, quitting its position, disappeared amidst its companions. Another, with wax under the rings, succeeded it, which suspending itself to the same spot, withdrew a scale by the pincers of the hind legs, and passing it through its mandibles, prosecuted the work; and taking care to make its deposit in a line with the former, it united their extremities. A third worker, detaching itself from the interior of the cluster, now came and reduced some of the scales to paste, and put them near the materials accumulated by its companions, but not in a straight line. Another bee, apparently sensible of the defect, removed the misplaced wax before our eyes, and carrying it to the former heap, deposited it there, exactly in the order and direction pointed out.

"From all these operations was produced a block of a rugged surface, hanging down from the arch, without any perceptible angle, or any traces of cells. It was a simple wall, or ridge, running in a straight line, and without the least inflection, two-thirds of an inch in length, above two-thirds of a cell, or two lines, high, and declining towards the extremities. We have seen other foundation walls from an inch to an inch and a half long, the form being always the same; but none ever of greater height.

"The vacuity in the centre of the cluster had permitted us to discover the first manoeuvres of the bees, and the art with which they laid the foundations of their edifices. However, it was filled up too soon for our satisfaction; for workers collecting on both faces of the wall obstructed our view of their further operations."

CHAPTER VI.