CHAPTER XXXII.. Senses of Bees.

SENSES OF BEES.

In considering the phænomena of insect sensation, little advantage can be derived from analogy; the physiology of the senses of bees, and other insects, is therefore but imperfectly understood. Still they must have credit for the possession of senses, however differently modified from those of man. Some of their senses may open avenues to knowledge, with which he must ever remain unacquainted. Arts which he is obliged to attain by long labour and great diligence, they seem to derive from nature, through the medium no doubt of organs so exquisitely fine, as to elude not only his search, but even his conception.

Of all the senses of bees, none appears to be so acute, as that of +Smell+. It is this which, in all probability, enables them to distinguish, not only individuals of their own species, but one human being from another; and also to discover honey-dews and honey-bearing flowers, at a very considerable distance; (honey of all odorous substances, being the most attractive to them:) it may tend likewise to cause that neatness which they observe in themselves and in their habitations. An experiment, made by +Huber+, demonstrates that they possess the faculty of smell. He placed vessels of honey in boxes perforated with very small holes, to allow the odorous effluvia to escape, but not of sufficient size to permit a sight of the honey, when the bees came directly to the boxes. He also tried this experiment with the addition of small card valves, which the bees, after examining the boxes all round, contrived to raise up, that they might get at the honey. +Mr. Hunter+ states, that he has seen great commotion produced in a recent swarm in wet weather, when he supposes the bees to have been hungry, by placing honey on the floor of the hive. It was a glass-hive, which afforded him a good opportunity of observing their proceedings, and he says that all of them appeared to be upon the scent: even those that were weak and hardly able to crawl, threw out the proboscis as far as possible, to get at the honey, which he thinks must have arisen from their smelling and not from their seeing it.

This presumed nicety of their smell should induce a carefulness that no offensive odours be near an apiary. The notorious frequenting, by bees, of the depositories of urine and the dung of animals, might seem to render such carefulness futile: but upon this subject I have written in a former chapter, and have since had the pleasure of seeing my opinion confirmed by that of +Messrs. Kirby+ and +Spence+.--Bees appear to have an antipathy to particular individuals. Their aversion, in all probability, arises from the persons disliked having some peculiar odour about them, which though not unpleasant to man, may be so to bees. Whatever the odour, it seems to be transmitted by the breath: +Huber+ was of this opinion. Speaking of the impunity with which his assistant Francis Burnens performed his various operations upon bees, he observes that "the gentleness of his motions, and the habit of repressing his respiration, could alone preserve him from the wrath of such formidable insects."

The different reception which persons experience on approaching the domicile of bees is attributed by some apiarians to the different degrees of confidence manifested in the approach: they are of opinion, that if visitors could avoid the exhibition of all apprehension, they would not be attacked. My own experience has long convinced me of the erroneousness of this opinion: and a circumstance which occurred to +Monsieur de Hofer+, Conseilleur d'etat du +Grand Duc de Baden+, strengthens my dissent from it. He had for years been a proprietor and an admirer of bees, and almost rivalled Wildman in the power he possessed of approaching them with impunity: he would at any time search for the queen, and taking hold of her gently, place her upon his hand. But having been unfortunately attacked with a violent fever, and long confined by it; on his recovery he attempted to resume his favourite amusement among the bees, returning to them with all that confidence and pleasure which he had felt on former occasions; when to his great surprise and disappointment he discovered that he was no longer in possession of their favour; and that instead of being received by them as an old friend, he was treated as a trespasser: nor was he ever able, after this period, to perform any operation upon them, or to approach within their precincts, without exciting their anger. Here then it is pretty evident that some change had taken place in the Counsellor's secretions, in consequence of the fever, which though not noticeable by his friends, was offensive to the olfactory nerves of the bees. I had this anecdote from Monsieur de Hofer's son, with whom I passed a very agreeable evening in London at the house of my friend Joseph Hodgetts, Esq.

The extreme sensitiveness of smell in bees is evinced by their promptitude in resenting an injury inflicted on any of their community. In hiving, or performing any other operation upon them, great caution should therefore be observed, lest any of them be trodden upon or crushed to death. It may be thought that this promptitude to resent the injury I have here mentioned, may not proceed from the acuteness of their smell, but from an effect produced upon some other organ of sense. I infer that it proceeds from the former, on account of their being so quickly roused to anger from a state of tranquillity, by having a fresh envenomed sting and its appendages presented before the entrance of their dwelling. This experiment, of presenting fresh poison to the bees, was tried by +Huber+ in such a variety of ways, as to prove beyond all doubt that it was the penetrating odour of the poison only, and not the manner of presenting it, that affected them; for when the poison had coagulated, the same mode of presentation produced no sensible effect, it might be offered them with perfect impunity.

Butterflies and Moths are supposed to be directed by this sense to the discovery of their mates. If the female of the eggar moth (Phalæna quercus) be inclosed in a box, and placed in the neighbourhood of the males, they are attracted to the spot in such numbers as to show clearly that they are sensible of her presence. We have analogous instances of the existence of this faculty in other insects. The flesh-fly (Musca vomitoria) occasionally deposits its eggs on plants of the Stapelia genus, no doubt from their odour resembling that of putrefying flesh. This may be regarded by some as an evidence of mistaken instinct; but from what I have said in the chapter on Instinct, I think that my readers will consider this to be erroneous, and that it should rather be regarded as affording presumptive evidence of mistaken judgement. Instinct would direct the creature to deposit its eggs where the larvæ when hatched would be furnished with the means of subsistence, instead of thus exposing them to perish. At all events it affords tolerably good evidence of the existence of an organ of smell in the insect.

The sense of +Touch+ in bees, that is their active or exploring touch, seems to be very acute. To the nicety of this sense has been attributed their power of commencing and carrying on their works amid the darkness of the hives. The recognition of their queen evinces the existence of some such sense; for the experiments related at page 292, indicate that her presence is not ascertained either by the organs of sight, hearing, or smell.

The +Antennæ+ have generally been considered as their organs of touch; and indeed, in popular language, they are usually called Feelers or horns; they have likewise assigned to them the office of wiping and cleaning the eyes. The antennæ, however, are not regarded as feelers by our leading entomologists: at present their uses are not clearly defined. Some have regarded them as organs of smell; others as organs of hearing; a third party have conceived that they perform some function of which man has no definite idea,--supplying the insect with a sixth sense, an intermediate faculty, according to +Messrs. Kirby+ and +Spence+, between hearing and touch, rendering it sensible of the slightest movement of the circumambient air. +Dr. Evans+ designates the antennæ as their sight-supplying sense;

"The same keen horns, within the dark abode. Trace, for the sightless throng, a ready road, While all the mazy threads of touch convey, Shot inward to the mind, a semblant day."

+Evans.+

The antennæ, of which there are only a single pair, proceed from the anterior part of the head before the eyes.

The +Palpi+ are generally considered as the true feelers; which, as well from their texture as from the manner in which insects apply them to their food before they begin to eat it, seems probable: Cuvier and Lehmann were of this opinion. The palpi are attached to the under jaws and lips, and are four in number. In some respects they bear analogy to the antennæ; but the latter, being more articulated, have an extended power of motion. Some insects with small antennæ are observed to have very large palpi, which gives reason to suppose, that although their offices may be different, they are intended to assist each other.

The antennæ appear to be the more important organs of the two; as the palpi, when removed, have not been found to occasion much apparent inconvenience; whilst from the experiments of +Huber+ and others, it appears that the excision of the antenna deprives the insect of the perfect exercise of its functions. It seems immediately to lose its instincts. The amputation of one antenna produces no effect; but if both be cut off near the root, the bee no longer possesses the power of guiding itself; it cannot direct its tongue to receive food from its companions, nor take any share in the operations of the family; but exhibits perfect indifference, and keeps near the entrance, apparently for the sake of light; when that is withdrawn, it soon leaves the hive to return no more. "Their departure," says +Huber+, "must be ascribed to the loss of that sense, which is employed to guide them in the dark."

That bees possess a fine sense of +Taste+, may be readily conceived from the delicious food which they collect, and from their having a preference for those flowers that afford the best honey, whenever such flowers grow abundantly in the neighbourhood of the hives. Hence the superiority of the honey of Narbonne, Hymettus, and Pontus. +Huber+ regards Taste as the least perfect of the senses of bees, but the reasons he gives for this opinion are unsatisfactory. Indeed the tongue of the bee is an organ so considerably developed, as to afford very strong evidence of its power of discrimination in the selection of food. +Cuvier+ considers it to be one of the primary functions of its organization.

There is tolerably good presumptive evidence that bees have a quick sense of +Hearing+, from their being so sensibly affected by different sounds. The voice of the queen, for instance, has according to +Bonner+ and +Huber+ an almost magical effect upon them; and the practice of making some sort of noise at the time of hiving is founded upon this opinion. +Huber+ is of opinion that if bees do possess the sense of hearing it is differently modified from the same sense among beings of a higher order. The consequences which ensue upon the production of certain sounds either by themselves or others, show that the vibrations of the air make an impression upon some sense: +Huber+, for reasons which he does not well define, designates it as a sense analogous to hearing, a something acting in concert with and in aid of the antennæ.

+Linnæus+ and +Bonnet+ thought that insects do not possess the sense of hearing; but I think they were mistaken. I have just stated the effect produced by the voice of a queen-bee, under particular circumstances; and there are other evidences, equally strong, to show that insects possess this faculty. One grasshopper will chirp in response to another, and the female be attracted by the voice of the male. +Brunelli+ shut up a male in a box, and allowed the female her liberty: as soon as the male chirped she flew to him immediately. For further evidence of the existence of this faculty in insects, see page 262. (Organs of Sensation.)

The +Eye-Sight+ of bees, notwithstanding the wonderful mechanism of their eyes, seems less perfect than their other senses: on some occasions it scarcely serves them to distinguish the entrance of their hives, when they come home loaded with provision. +Wildman+ says that he has observed them go up and down, seeking the door of the hive, and be obliged after alighting to rise again in order to find it: he conceived that they see better when flying than when on foot. I believe, however, that this opinion of +Wildman+ will not, upon examination, be found quite correct. The mere act of flying does not enable them to see objects better; but when on the wing, they are at a greater distance from those objects, the eyes of these insects being so constructed as to enable them to see best at a moderate distance. As +Dr. Evans+ has justly remarked, therefore, "the poet's disdainful allusion to a

Fly whose feeble ray scarce spreads An inch around----

should here be exactly reversed." +Dr. Derham+ in his Physico-theology has observed, when speaking of the eye of the bee and other insects, that "the cornea and optic nerves, being always at one and the same distance, are fitted only to see distantial objects, but not such as are very nigh." This visual orb, this seemingly simple speck, though really complicated piece of mechanism, says +Derham+, "will be found upon examination to form a curious lattice-work of several thousand hexagonal lenses, each having a separate optic nerve ministering to it, and therefore to be considered as a distinct eye. +M. Leewenhoeck+, having properly prepared and placed an eye of this kind betwixt his microscope and a church steeple (299 feet high and 750 distant), saw plainly the steeple inverted, through every different lens, though each lens was not larger than a needle's point. Yet, doubtless the insect perceives but a single object, and that in an upright position. The hemispheric arrangement of these lenses enables the bee to see accurately in every direction, and without any interval of time or trouble."

"Not huge Behemoth, not the Whale's vast form. That spouts a torrent, and that breathes a storm. Transcends in organs apt this puny fly, Her fine-strung feelers, and her glanceful eye, Set with ten thousand lenses."

+Evans.+

The eyes of all insects are immoveable, and have neither iris nor pupil nor eyelids to cover them: but this apparent defect is amply made up to them in a variety of ways: in the case before us, by the complex structure of the organs. +Reaumur+ performed an experiment similar to that which I have just related of +Leewenhoeck+, and with a like result, +Hooke+ computed the lenses in the eye of a horse-fly to amount to nearly 7000. +Leewenhoeck+ found more than 12,000 in that of a dragon-fly; and 17,325 have been counted in the eye of a butterfly. The lenses are most numerous in the beetle, and so small as not to be easily discoverable under a pocket microscope, except the eye be turned white by long keeping.

The peculiar construction of the bee's eye, for seeing objects best at a moderate distance, will account for the circumstance noticed by +Wildman+, and also for the following observation of +Dr. Evans+. "We frequently observe bees flying straight homewards through the trackless air, as if in full view of the hive, then running their heads against it, and seeming to feel their way to the door with their antennæ, as if totally blind." +Sir C. S. Mackenzie+ remarked the imperfect vision of bees, and how very much puzzled they are to find the entrances to their hives, if the relative position of the entrances be altered, or the hives be removed two or three yards from the place where they have usually stood. In cases of removal, the bees do not during the first day fly to a distance, nor till they have visited and recognized neighbouring objects. +Mr. Rogers+, in his "Pleasures of Memory," has noticed this defective vision in the bee. Having spoken of her excursive flights to a distance, and referred to her bending her course homewards again, he observes,

"That eye so finely wrought. Beyond the search of sense, the soar of thought. Now vainly asks the scenes she left behind; Its orb so full, its vision so confined!"

And he concludes that it is by the aid of memory that she retraces her passage back to the hive, by recognizing the scents of the various flowers which she has passed or visited on her outward journey,--

"The varied scents that charm'd her as she flew."

But this idea, as Messrs. Kirby and Spence have observed, is more poetical than accurate, the bees being always accustomed to fly to their hives in right lines.

In consequence of this peculiarity of insect vision, many of those bees that return homewards after dusk in the evening, are obliged to lie abroad all night. The same peculiarity, added to the acuteness of their smell, has given birth to various contrivances for inducing bees of different hives to mingle peaceably together, as mentioned at page 154.

From the experiments of Swammerdam, Reaumur, Hooke and others, it seems that bees and other insects, particularly those of the hymenopterous order, possess organs of vision, besides those which are properly called their eyes. These organs, known by the name of +Stemmata+, are three smooth, glossy, hemispherical dots, placed in a triangular position upon the vertex or top of the head. The two reticular eyes of one of these insects having been covered with fluid pitch, (the stemmata being left open,) when placed under a glass, the insect ran up and down, but without striking against the sides of the glass. In a similar experiment upon a dragon-fly (Libellula), the insect flew away, but in its flight struck against walls and other objects. The stemmata in another insect being covered, and the reticular eyes left open, seemed to cause no impediment to its usual proceedings, it appeared to see as well as before. But when both the stemmata and the eyes were covered, the insect seemed to be totally deprived of sight, it walked slowly under the glass, and when allowed its liberty, would not venture to fly. These experiments being tried upon bees by Reaumur, they remained immoveable, appearing uncertain where to direct their flight: when their eyes only were covered, they flew perpendicularly upwards till they were out of sight, seeming to follow that direction which the aid of the stemmata afforded them. These stemmata may, from their situation, assist the insect in performing its various operations in the interior of the hive; may, as Reaumur has observed, answer to them the purpose of microscopes.

I cannot conclude this chapter on the Senses of Bees without noticing the theory of that eminent physiologist +Dr. Virey+. He has given it as his opinion, that there are seven senses, which he thus divides. Four physical, namely, Touch, Taste, Smell, and Love; three intellectual, namely. Hearing, Sight, and Thought. (N. Dict. d'Hist. Nat.) Whether Love and Thought should be added to my enumeration of the senses of bees I shall not now inquire: if they may be, this work will supply abundant evidence of both, if we comprehend the whole community of bees; for though physical love appears not to constitute any part of the pleasure of the working bee, (except from some accidental cause which has been already explained,) there is presumptive proof of its possessing thought or intellect: and although it may not be easy to adduce testimony in favour of the queen's or the drone's possessing thought, they both satisfactorily evince a susceptibility of physical love.