Messrs. Huber and Son ascertained that the office of collecting honey, for the elaboration of wax, is filled by a particular description of bees or labourers, to which they have given the name of wax-workers. These bees are susceptible of an increase in size, as is evident from the state of their stomachs, when quite full of honey. Dissection has shown that their stomachs are more capacious than those of the bees that are differently occupied. Bees not possessed of this expanding stomach, gather no more honey than is necessary to supply the immediate wants of themselves and their companions, with whom they readily share it: these are called nursing-bees, their principal duty being to attend the eggs and larvæ. The task of storing the hive with provisions devolves upon the wax-workers, who, when not occupied in the construction of comb, disgorge their honey into those cells which are intended for its reception. By marking the bees, it was found that they never encroached upon each other’s employment: this strict adjustment of duty is the more remarkable, since the power of producing wax is common both to the nursing- and wax-working bees, a small quantity of wax being really found in the receptacles of the nursing-bees.

In the foregoing experiments for ascertaining the sources of wax, the bees had borne their confinement without evincing the least impatience; but on another occasion, when shut up with a brood of eggs and larvæ, and without pollen, though honey was copiously supplied, they manifested uneasiness and rage at their imprisonment. Fearing the consequence of this state of tumult being prolonged, Huber allowed them to escape in the evening, when too late to collect provisions; the bees soon returned home. At the end of five days, during which this experiment was tried, the hive was examined:—the larvæ had perished, and the jelly that surrounded them on their introduction into the hive had disappeared. The same bees were then supplied with a fresh brood, together with some comb containing pollen: very different indeed was their behaviour with this outfit; they eagerly seized the pollen and conveyed it to the young; order and prosperity were re-established in the colony; the larvæ underwent the usual transformations; royal cells were completed and closed with wax, and the bees showed no desire to quit their habitation. These experiments afford indisputable evidence of the origin of wax and the destination of pollen.

Though the wax of honey and brood-comb be an original secretion from the body of the bee, wax is also considered by some as a vegetable substance existing abundantly in nature. According to Proust, it forms the silvery down on the leaves, flowers and fruit of many plants, and resides likewise in the feculæ of others. Dr. Darwin, in his Phytologia, supposes that wax is secreted to glaze over the fecundating dust of the anthers, and prevent its premature explosion from excessive moisture: to an unseasonable dispersion of anther-dust he ascribes the failure of orchard and corn crops in summers of extreme humidity. The wax-tree of Louisiana[AC] (Myrica cerifera) contains immense quantities of wax. In this respect there appears an identity betwixt animal and vegetable secretion, which may be viewed as indicative of simplicity in the structure of the bee: a still simpler organization exists in the aphis, which extracts the saccharine juices from the leaves and bark of trees, and expels them again nearly unchanged[AD].

CHAPTER XXXVI.

POLLEN.

Pollen and Farina, in the language of Botanists, are terms applied to the powdery particles discharged by the anthers of flowers in warm dry weather, and which hang about the stamina. The colour, as well as the structure of pollen, varies in different plants. Its use, in fecundating the germens of flowers, is well known: the services of bees, towards that end, will be noticed in a separate chapter. The sixth volume of the Linnæan Transactions contains an interesting paper upon this substance, from the pen of Mr. Luke Howard.

Pollen has a capsular structure, varying its shape in different flowers, insomuch as to be a popular object for the microscope. Each grain consists commonly of a membranous bag, which, when it has come to maturity, bursts on the application of moisture: this bursting is naturally effected by the honey-like exudation of the stigma; but if extraneous moisture accomplish it prematurely, the pollen is rendered useless for the purpose of fructification. Whenever moistened, the bag explodes with great force, and discharges a subtle vapour or essence, which, when released by the peculiar moisture of the stigma, performs effectually its final purpose.

This substance was once erroneously supposed to be the prime constituent of wax; but the experiments of Hunter and Huber have proved that wax is a secretion from the bodies of wax-working bees[AE], and that the principal purpose of pollen is to nourish the embryo-bees; (it has been called the ambrosia of the hive). Huber was the first who suggested this idea, and it well accords with what we observe among other parts of the animal kingdom;—birds, for instance, feed their young with different food from what they take themselves. Mr. Hunter examined the stomachs of the maggot-bees, and found farina in all, but not a particle of honey in any of them. Huber considers the pollen as undergoing a peculiar elaboration in the stomachs of the nursing-bees, to be fitted for the nutriment of the larvæ.

“In spring,” says Dr. Evans, “which may be called the bee’s first carrying season, scarcely one of the labourers is seen returning to the hive, without a little ball or pellet of farina, on each of its hinder legs. These balls are invariably of the same colour as the anther-dust of the flowers then in bloom, the different tints of yellow, as pale, greenish or deep orange, being most prevalent.” The bees may frequently be observed to roll their bodies on the flower, and then, brushing off the pollen which adheres to them, with their feet, form it into two masses, which they dispose of in the usual way. In very dry weather, when probably the particles of pollen cannot be made to cohere, I have often seen them return home so completely enveloped by it, as to give them the appearance of a different species of bee. The anther-dust, thus collected, is conveyed to the interior of the hive, and there brushed off by the collector or her companions. Reaumur and others have observed, that bees prefer the morning for collecting this substance, most probably that the dew may assist them in the moulding of their little balls. “I have seen them abroad,” says Reaumur, “gathering farina before it was light;” they continue thus occupied till about ten o’clock.

This is their practice during the warmer months; but in April and May, and at the settlement of a recent swarm, they carry pollen throughout the day; but even in these instances, the collection is made in places most likely to furnish the requisite moisture for moulding the pellets, namely, in shady and sometimes in very distant places.

When a bee has completed her loading, she returns to the hive, part of her cargo is instantly devoured by the nursing-bees, to be regurgitated for the use of the larvæ, and another part is stored in cells for future exigencies, in the following manner. The bee, while seeking a fit cell for her freight, makes a noise with her wings, as if to summon her fellow-citizens round her; she then fixes her two middle and her two hind legs upon the edge of the cell which she has selected, and curving her body, seizes the farina with her fore legs, and makes it drop into the cell: thus freed from her burthen, she hurries off to collect again. Another bee immediately packs the pollen, and kneads and works it down into the bottom of the cell, probably mixing a little honey with it, judging from the moist state in which she leaves it; an air-tight coating of varnish finishes this storing of pollen.

From the uniform colour of each collection, it is reasonable to suppose that the bee never visits more than one species of flower on the same journey; this was the opinion of Aristotle, and the generality of modern observers have confirmed it. Reaumur, however, supposed that the bee ranged from flowers of one species to those of another indiscriminately. Mr. Arthur Dobbs, in the Philosophical Transactions for 1752, states that he has repeatedly followed bees when collecting pollen; and that whatever flowers they first alighted upon decided their choice for that excursion, all other species being passed over unregarded: Butler had previously asserted the same thing. Here we see the operation of a discriminating instinct, which in the first place leads the insect to make an aggregation of homogeneous particles, which of course form the closest cohesion; and in the next place prevents the multiplication of hybrid plants. This remark was made by Sprengel, who has confirmed the observations of Dobbs, Butler, and others. The bees, which Reaumur observed to visit flowers of different species, might have been in quest of honey as well as of pollen.

CHAPTER XXXVII.

PROPOLIS.

Besides the honey and pollen which are gathered by bees, they collect a resinous substance, that is very tenacious, semitransparent, and which gives out a balsamic odour, somewhat resembling that of storax. In the mass, it is of a reddish brown colour; when broken, its colour approaches that of wax. Dissolved in spirit of wine or oil of turpentine, it imparts, as varnish, a golden colour to silver, tin, and other white polished metals. Being supposed to possess medicinal virtue, it was formerly kept in the shop of the apothecary. According to Vauquelin, propolis consists of one part of wax and four of pure resin; in which respect, and in its yielding the same acid, (the benzoic,) it resembles balsam Peru. It also contains some aromatic principles.

With propolis, bees attach the combs to the roof and sides of their dwelling, stop crevices, fasten the hives or boxes to the floors and roofs, strengthen the weak places of their domicile, and varnish the cell-work of their combs. The chapter on Instincts details the modes in which bees employ it for their protection against intruders into their hives. From its being used for the firm attachment of combs to the roofs of hives, it must be the first matter collected by a recent swarm. The term Propolis is derived from the Greek, and signifies ‘before the city,’ bees having been observed to make use of it, in strengthening the outworks of their city.

Reaumur was unable to discover its vegetable source. It is generally supposed to be gathered from the resinous exudations of the poplar, alder, birch, and willow; according to Riem, from pines and other trees of the fir tribe; though some authors have alleged that bees can produce it where no such trees are near them, and that turpentine and other resins have been disregarded when laid before them. A recent experiment of Huber has solved this question: he planted in spring some branches of the wild poplar, before the leaves were developed, and placed them in pots near his apiary: the bees alighting on them separated the folds of the largest buds with their forceps, extracted the varnish in threads, and loaded with it, first one thigh and then the other; for they convey it like pollen, transferring it by the first pair of legs to the second, by which it is lodged in the hollow of the third. Huber examined the chemical properties of this varnish, and identified it with the propolis which fastens the combs to the hives.

With respect to the absence of fir-trees, &c. in the neighbourhood of the hives, it is to be recollected, in the first place, that bees will fly about three miles (some say five,) for what they may want: Huber thinks that the radius of the circle they traverse does not exceed half a league, yet says that the question is undecided. In the second place, that a balsamic and tenacious secretion is found upon the buds of several plants and trees, which are often crowded with these insects; such for instance as the tacamahac, horse-chesnut, and hollyhock. Dr. Evans says that he has been an eye-witness of their collecting the balsamic varnish which coats the young blossom buds of the hollyhock, and has seen them rest at least ten minutes on the same bud, moulding the balsam with their fore-feet and transferring it to the hinder legs, as above stated. When finally moulded, the pellets of propolis are of a lenticular form.

As to the bees refusing resinous substances, when presented to them, as substitutes for propolis, Mr. Knight has assured us, in the Philosophical Transactions, that this is not the fact; as he had seen them carry off a composition of wax and turpentine, which had been laid over the decorticated parts of his trees.

The bees blend this substance with wax in different proportions, as occasion may require. Among the ancients, it bore different names, according to the quantity of wax it contained. Virgil made this distinction, though Mr. Martin conceives that his narcissi lachrymæ, cera [cum quâ]—“spiramenta tenuia linunt,”—and gluten, all mean the same thing: this is probably a mistake. It seems much more likely that Virgil should mean metys, pissoceron and propolis, the three names by which Pliny says that the varieties of propolis were distinguished in his time.

I have before alluded to the fortification of the weak places of hives with propolis. M. Reaumur, whose hives consisted of wooden frames and panes of glass, wishing to put this talent of the bees to the test, carelessly fastened the glass of a hive with paper and paste, before putting in a swarm; the bees soon discovered the weakness of his paste-work, and indignantly gnawing to pieces this feeble fence, secured the glass with their own cement.

I have already observed, that the sage bee chooses the morning for collecting pollen, on account of the dew’s enabling her to compress it better; but, as moisture would render propolis less coherent, she gathers this substance when the day is somewhat advanced, and when the warmth of the sun has imparted to it softness and pliancy. These qualities are however soon lost, after it has been detached from the secreting surfaces, and exposed to the oxygenizing power of the air. So rapid is this hardening process, that the bees which store it, oftentimes find some difficulty in tearing it with their jaws from the thighs of its collectors.

CHAPTER XXXVIII.

IMPORTANCE OF BEES TO THE FRUCTIFICATION OF FLOWERS.

Honey is regarded by modern naturalists as of no other use to plants but to allure insects, which, by visiting the nectaries of their flowers to procure it, become instrumental to their fertilization, either by scattering the dust of the stamens upon the stigmata of the same flower, or by carrying it from those which produce only male blossoms to those that bear female ones, and thereby rendering the latter fertile.

No class of insects renders so much service in this way as bees; they have however been accused of injuring vegetables, in three ways: 1st, by purloining for their combs the wax which defends the prolific dust of the anthers from rain; 2ndly, by carrying off the dust itself, as food for their young larvæ; and 3dly, by devouring the honey of the nectaries, intended to nourish the vegetable organs of fructification[AF].

In defence of his insect protegées, Dr. Evans has observed:

“First, That the proportion of wax collected from the anthers is probably very trifling, it being so readily and abundantly obtainable from honey.

“Secondly, That for any depredations committed on the farina, they amply compensate, by their inadvertent yet providential conveyance of it, on their limbs and corslets, to the female organs of monoecious or dioecious plants; whose impregnation must otherwise have depended on the uncertain winds. This is exemplified in the practice of our gardeners, who in early spring, before they dare expose their hotbeds to the open air, and consequently to the access of insects, insure the fertility of the cucumbers and melons, by shaking a male blossom over each female flower. For the same purpose, and with the same success, a gentleman in Shropshire substitutes a male blossom, in place of the female one, at the top of his embryo cucumber, which instantly adheres, and falls off in due time. To the same kind intrusion of insects we owe the numberless new sorts of esculents and endless varieties of flowers in the parterre:

“Thirdly, That in a great many instances, the honey-cups are completely beyond the reach of the fructifying organs, and cannot possibly be subservient to their use. Hence Sir J. E. Smith believes the honey to be intended, by its scent, to allure these venial panders to the flowers, and thereby shows how highly he estimates their value to vegetation. See his Introduction to Botany. In the same work, the author observes that Sprengel has ingeniously demonstrated, in some hundreds of instances, how the corolla serves as an attraction to insects, indicating by various marks, sometimes perhaps by its scent, where they may find honey, and accommodating them with a convenient resting-place or shelter while they extract it. This elegant and ingenious theory receives confirmation from almost every flower we examine. Proud man is disposed to think that

because he has not deigned to explore it; but we find that even the beauties of the most sequestered wilderness are not made in vain. They have myriads of admirers, attracted by their charms, and rewarded by their treasures, which would be as useless as the gold of a miser, to the plant itself, were they not the means of bringing insects about it.”

Thus the bee, by settling upon and collecting honey from a thousand different flowers, is thereby assisting the great purpose of vegetable reproduction, at the same time that the loads she carries home enable her to construct receptacles for the reproduction of her own race.

“For the due fertilization of the common Barberry, it is necessary that its irritable stamens should be brought into contact with the pistil, by the application of some stimulus to the base of the filament; but this would never take place were not insects attracted, by the melliferous glands of the flower, to insinuate themselves amongst the filaments, and thus, while seeking their own food, unknowingly to fulfil the intentions of Nature in another department.” In some cases the agency of the hive-bee is inadequate to produce the required end; in these the humble-bee is the operator: these alone, as Sprengel has observed, are strong enough for instance, to force their way beneath the style-flag of the Iris Xiphium, which in consequence is often barren. Other insects besides bees are instrumental in producing the same ends; indeed they are necessary instruments: and hence according to the same naturalist, in some places, where the particular insect required is not to be met with, no fruit is formed upon the plant which is usually visited by it, where it is indigenous; for he supposes that some plants have particular insects appropriated to them. The American Aristolochia Sipho, though it flowers plentifully, never forms fruit in our gardens, probably for the reason just assigned. The Date Palm affords a striking instance of the necessity of extraneous intervention to perfect fructification; male and female flowers are borne on separate trees, and unless the two sorts be in the neighbourhood of each other, the fruit has no kernel and is not proper for food. There was a tree of this kind, bearing female flowers, at Berlin, for the fructification of which, a branch, with male flowers upon it, was once sent by post from Leipsic, (20 German miles,) and being suspended over some of the pistils, the tree afterwards yielded fruit and seed in abundance. Professor Willdenow has stated a very curious circumstance, concerning the Aristolochia Clematitis. He observes that the stamens and pistils of the flower are inclosed in its globular base, the anthers being under the stigma, which thereby requires the intervention of an insect, to convey the pollen to it. The Tipula pennicornis accomplishes this object; it enters the flower by its tubular part, which is thickly lined with inflected hairs, so as readily to admit the fly, but totally to prevent its release, till by the fading of the corolla the hairs have fallen flat against its sides. Hence the insect in struggling to effect its escape, brushes off the pollen and applies it to the stigma, thereby accomplishing the fertilization of the flower.

INDEX.