CHAPTER IIGENERAL HISTORY OF BEES.

THE EGG.â€”THE LARVA.â€”THE PUPA.â€”THE IMAGO.

Althoughthe preceding pages have been written upon the assumption that the reader knows what a bee is, now that we are gradually approaching the more special and technical portion of the subject it will be desirable to conform a little to the ordinary usages of scientific treatment.

The bees constitute a family of the orderHymenoptera, viz. insects ordinarily, but in the case of bees always, with four transparent wings, which are variously but partially traversed longitudinally and transversely with threads, called nervures, supposed to be tubular, the relative position of which, together with the areas they enclose, called cells, help to give characters to the genera.

Most of theHymenopterafurther possess some kind of an ovipositor,â€”of course restricted to the females,â€”varying considerably in the different families. This is sometimes external, but is often seated within the apex of the abdomen, whence it can be protruded for the purpose of depositing the egg in its right nidus. In our insect this organ is converted into a weapon of defenceand offence, and forms a sting, supplied by glands with a very virulent poison, which the bee can inject into the wound it inflicts. It is not certain that this organ is used by the bee as an ovipositor, although it is evident it is its analogue. This brief description of the essential peculiarities of the family will, for the present, suffice. In the notice of the imago, I shall enlarge upon the general structure, and then particularize those portions of it which may facilitate further progress.

The Egg.â€”Although the egg of the parent is the source of the origin of the bee, we cannot abruptly commence from this point, for the preliminary labours of the mother are indispensable to the evolution of its offspring. This egg has to be placed in a suitable depository, together with the requisite food for the sustenance of the vermicule that will be disclosed from it.

Instinct instructs the parent where and how to form the nidus for its egg. These depositories differ considerably in the several genera, but, as a general rule, they are tubes burrowed by the mother either in earth, sand, decaying or soft wood, branches of plants having a pith, the halm of grain, cavities already existing in many substances, and even within the shells of dead snails. These perforations are sometimes simple, and sometimes they have divergent and ramifying channels. Sometimes they are carefully lined with a silky membrane secreted by the insect, and sometimes they are hung with a tapestry of pieces of leaves, cut methodically from plants, but some leave their walls entirely bare. All these particulars I shall have ample opportunity to note in the special descriptions of the genera. I merely indicate them to show how various are the receptacles for the offspring of our bees.

Fig. 1. The Egg.

Before the egg is placed within its nidus, this is supplied with the requisite quantity of food needful for the support of the young to the full period of its maturity. The receptacle is then closed, and the same process is repeated again and again until the parent has laid her whole store of eggs. In other cases one tube, or its ramification, contains but one egg. These eggs are usually oblong, slightly curved, and tapering at one extremity; they vary in size according to the species, but are never, however, above a line in length, and sometimes they are very minute. When the stock of the mother bee is exhausted she leaves them to the careful nursing of nature, and the young is speedily evolved. She then wanders forth; time has brought senility; her occupation has gone; and she passes away; but her progeny survive to perpetuate the continual chain of existence.

The Larva.â€”The temperature of the perforated tube wherein the egg is deposited must necessarily be higher and more equal than that of the external atmosphere, being secluded from its vicissitudes. The egg is soon hatched, and the larva emerges from its shell to feed ravenously upon the sustenance stored up for its supply. This consists of an admixture of pollen and honey formed into a paste, the quantities varying according to the size of the species. By some species it is formed into little balls; by others, it is heaped irregularly at the bottom of the cell. In the case ofAndrenathe quantity stored is of about the size of a pea. That it must be exceeding nutritious may be inferred from its very nature, consisting, as it does, of the virile, energetic, and fertilizing powder of plants,â€”the concentration of their living principle. It is strictly analogous to thefecundating property of the semen in animals, and, like them, produces spermatozoa, a fact corroborated by the researches of Robert Brown, Mirbel, and other distinguished vegetable physiologists.[1]

1.Might not, by parity of inference, the milt of fishes, such as the herring, mackerel, etc., be a useful food in cases of consumption, both from the iodine necessarily existing in it, and also from its doubtless nutritive nature?

We are told that the cells ofHylÃ¦us, orProsopis, and ofCeratinaare supplied with a semifluid honey. It is very doubtful ifHylÃ¦uscollects its own store, but thatCeratinadoes, I have the authority of an exact observer (Mr. Thwaites) to verify it, for he has caught this insect with pollen on its posterior legs, which the long hair covering the tibia is intended for. What may be the nature of this semifluid honey? It is questionable if the larva could be nurtured upon honey alone without the admixture of pollen, thus contradicting analogies presumable from ample verification in natureâ€™s processes. How, too, does it become semifluid? It is the property of honey, at a certain temperature, to be very fluid, and this is doubtless the temperature that prevails within the receptacle of the larva during the time of the operations of the bees.

Its semifluid consistency could then apparently be produced only by some more solid admixture, which, if not of pollen, of what can it be? This, even in small quantities, might, upon the bursting of its vesicles, have the power of thickening the fluent honey to the necessary consistency.

But a bee without polliniferous organs cannot collect pollen, and the instance of the hive bee, which collects honey in superabundance, feeding its larva with the bee-bread,must inevitably lead to the conclusion that the larvÃ¦ of bees require more than honey for their sustenance. Nature is not usually wantonly wasteful of its resources, and if honey sufficed for the nurture of the grub, so much pollen would not be abstracted from its legitimate purpose, nor would bees have this double trouble given to them. By the admixture of pollen the honey has energetic power infused into it by the spermatozoa which that contains. But it must necessarily be collected, for I never observed, nor have I seen recorded, any instance of the pollen being eaten on the flower and regurgitated into the cell in combination with the imbibed honey.

Pollen is eaten by the domestic bee and humble-bee to form wax for the structure of their cells, but the solitary bees do not themselves consume it.

Fig. 2.â€”a, the Larva, when growing;b, when preparing to change;c, the head, viewed in front.

The larva, when excluded from the egg, is a fleshy grub, slightly curved, and a little pointed at each extremity. Its body is transversely constricted, the constrictions corresponding with its fifteen segments, each of which, excepting the head and four terminal ones, is supplied with a spiracle placed at the sides, whereby it breathes; and it has no feet. These segments have on each side a series of small tubercles, which facilitate the restricted motions of the grub, confined to the boundariesof its cell. Its small head, which is smooth above, has a little projecting horn on each side representing the future antennÃ¦. The small lateral jaws articulate beneath a narrow labrum or lip, which folds down over them. To prove that the food provided requires still further comminution, these jaws are incessantly masticating it. The form of these jaws approximates to that of the insect which it will produce, being toothed and broad at the apex in the artisan and wood-boring bees, and simple in those which burrow in softer substances. On each side beneath these jaws there is an appendage, rather plump, having a setiform process at its extremity, and beneath these, in the centre, we observe a fleshy protuberance which, at its tip, has a smaller perforated process that emits the viscid liquid with which the grub spins its cocoon, and which immediately hardens to the consistency of silk.

Fig. 3.â€”a, the pupa, seen beneath;b, seenabove;c, seen laterally.

Having constructed its cocoon, where the species does so,â€”for it is not incidental to all the genera,â€”and shrunk to its most compact dimensions, the larva becomes transformed into

The Pupa.â€”This is semi-transparent at first, and there may be seen through the thin pellicle, which invariably clothes every portion separately of the body, the ripening bee, which lies, like a mummy, with its wings and legs folded lengthwise along its breast. The parts gradually assume consistency, and the natural colours andclothing of the perfect insect display themselves through its pellucid envelope. When arrived at perfect maturity, and ready to commence the part it has to perform in the economy of nature, it bursts its cerements, making its way through the dorsal covering of its silken skin, and, leaving the exuviÃ¦ behind, it crawls forth from its dormitory, when, becoming invigorated by the bracing air and the genial sunshine, it stretches its legs and expands its wings, and flies forth jubilant, rejoicing in its awakened faculties.

The Imago.â€”The bee having attained its majority, loses no time in quitting the confined abode wherein it has been hitherto secluded. It comes forth prepared to undertake the cares, and meet the vicissitudes of existence. The new life that now opens to it is one apparently teeming exuberantly with every delight. It dwells in sunshine and amidst flowers; it revels in their sweets, attracted by their beautiful colours and their delightful odours; and the consummation of its bliss is to find a congenial partner. With him it enjoys a brief connubial transport, but which is speedily succeeded by life-long labour, for the cares of maternity immediately supervene.

I believe the wild bees are not polyandrous, and therefore many males, if there be any preponderating discrepancy in favour of that sex, must die celibate. But the fact of finding the males associated together in great numbers upon the same flowers or hedges, is certainly not conclusive of this being the case. To provide a fitting receptacle, furnished with suitable provision, for its future progeny, occupies all the subsequent solicitude of the female.

As frequent reference will hereafter be made topeculiarities of structure, it will be desirable to take a rapid survey of the external anatomy of the bee, for it will enable me to introduce in due order the requisite technicalities with their local explanations. This course will be found most subservient to preciseness and accuracy, and when mastered, which will be found to be a very simple affair, it will greatly facilitate exact comprehension. No circumlocution can convey what a few technicalities, thoroughly understood, will immediately explain, and no special scientific work can be read with any profit until they are acquired.

Diagrams are introduced to aid the imagination in its conception of what is meant to be conveyed.

This necessary detail I shall endeavour to make as entertaining as I possibly can, by introducing, with the description of the organ, the uses it serves in the economy of the insect. I hope thus to add an interest to it which a merely dry technical and scientific definition would not possess.

Structure is always expressive of the habits of the bees, and is as sure a line of separation, or means of combination, as instinct could be were it tangible. Hence the conclusion always follows with a certainty that such-and-such a form is identical with such-and-such habits, and that, in the broad and most distinguishing features of its economy, the genus is essentially the same in every climate. Climate does not act upon these lower forms of animal life, with the modifying influences it exercises upon the mammalia and man. AMegachileis as essentially aMegachilein all its characteristics in Arctic America, the Brazils, tropical Africa, Northern China, and Van Diemenâ€™s Land, as in these islands, andApisis, wherever it occurs, as truly anApis. Thereforethe habits, in whatever country the genus may be found, can thus be as surely affirmed of all its species, from the knowledge we have of those at home, as if observation had industriously tracked them. Therefore, the technicalities of structure once learnt, they become permanently and widely useful.

The body of the bee consists of a head, thorax, and abdomen, which, although to the casual observer, seemingly not separated from each other, are, upon closer inspection, more or less distinctly disconnected. The three parts are merely united by a very short and slight tubular cylinder. This is sometimes so much reduced as to be only a perforation of the parts combined by a ligament, and through which aperture a requisite channel is formed for the passage of the ganglion or nervous chord, which extends from one portion of the body to the other, giving off laterally, in its progress from the sensorium in the head onwards, the filaments required by the organs of sensation and motion, as well as all which control the other functions of the body of the insect.

Fig. 4.â€”Body of the bee.a, head and antennÃ¦;b, vertex and ocelli;c, genÃ¦, or cheeks;d, prothorax;e, mesothorax;f, squamulÃ¦;g, insertion of the wings;h, scutellum;i, post-scutellum;k, metathorax;l, abdomen.

These apertures form also the necessary medium of connection between the several viscera, whereby the food and other sustaining juices are conveyed from the mouth through the Å“sophagus to the various parts of the body.

As this work will impinge but very incidentally upon the internal organization of the bee, it is unnecessary to be more explanatory. All that I shall have to noticehere are those portions of the external structure which have any special bearing upon the economy and habits, or upon the generic and specific determination of the insects, and to which therefore I shall specially limit myself.

Fig. 5.â€”Front of the head of the bee.a, vertex;b, face;c, ocelli or stemmata;d, compound eyes;e, clypeus;f, mandibles;g, labrum;h, lingual apparatus folding for repose.

Theheadis the most important segment of the insectâ€™s body, if we may elevate to such distinction any portion, when all conduce to the same end, and either would be imperfect without the other, yet we may perhaps thus distinguish it from the rest as it exclusively contains that higher class of organs, those of sense, which are most essential to the functions of the creature. The head consists of thevertex, or crown; thegenÃ¦, or cheeks; the face; theclypeus, or nose; the compound eyes; thestemmata, or simple eyes; theantennÃ¦, or feelers, and thetrophi, or organs of the mouth collectively.

Thethorax, the second segment, carries all the organs of locomotion. It consists of theprothoraxor collar, which carries beneath the anterior pair of legs; themesothorax, or central division, with which articulate laterally above the four wings, the anterior of which have their base protected by thesquamulÃ¦, or epaulettes, or wing-scales, and beneath it carries the intermediate pair of legs; themetathorax, or hinder portion, which has in the centre above, behind thescutellum, thepost-scutellum, and at the extremity of this division just above the articulation of the posterior legs is attached the last segment of the insect,â€”theAbdomen.

Thevertex, or crown of the head, is that portionwhich lies between the upper extremities of the compound eyes. Upon the vertex are placed thestemmata, orocelli(the simple eyes), in a curve or triangle; they are three in number, and are small, hyaline, circular protuberances, each containing within it a lens; sometimes they occur very far forward upon the face, especially when the compound lateral eyes meet above, as in the male domestic bee or drone. The uses of these simple eyes, from the experiments which have been made, seem to be for long and distant vision. To test their function, RÃ©aumur covered them with a very adhesive varnish, which the bee could not remove, and he then let it escape. He found upon several repeated trials, that the insect always flew perpendicularly upwards, and was lost. Although this was anything but conclusive as to the uses of these eyes, it would seem that by losing the vision of this organ, the insect lost with it all sense of distance.

Thecompound eyes, seated on each side of the head, extend from the vertex generally to the articulation of the mandibles or jaws, their longitudinal axis being perpendicular to the station of the insect. They vary in external shape and convexity in the several species and genera, although not greatly, and consist of a congeries of minute, hexagonal, crystalline facets, each slightly convex externally, and their interstices are sometimes clothed with a short and delicate pubescence. Each separate hexagon has its own apparatus of lens and filament of optic nerve, each having its own distinct vision, but all converge to convey one object to the sensorium. The function of the compound eyes is concluded to be the microscopic sight of near objects.

Theface, which sometimes has a longitudinalcarina,or prominent ridge, down its centre, lies between these eyes, descending from the vertex to the base of the clypeus, or nose, but which is without the function of that organ. This clypeus is sometimes protuberant, and from shape or armature, characteristic. This part, however, is not always distinctly apparent, although a line or suture usually separates it above, from the face. At its lower extremity thelabrum, or upper lip, articulates, over which it is sometimes produced; and it extends at each lateral apex to the base of the insertion of the mandibles. ThegenÃ¦, or cheeks, descend from the vertex laterally, behind the compound eyes, to the cavity of the head which contains the lingual apparatus, when folded in repose. These cheeks, at their lower extremity, sometimes embrace the articulation of the mandibles.

Fig. 6.â€”1, Clavate antennÃ¦;2, filiform ditto;a, scape;b, flagellum.

TheantennÃ¦, or feelers, are two filamentary organs articulating on each side of the face and above the clypeus. They comprise thescape(a), or basal joint, and (b) theflagellumor terminal apparatus; the latter consists of closely attached conterminal joints, and usually forms an elbow with the scape; collectively these joints number twelve in the female and thirteen in the male. They are all of various relative lengths, which sometimes aid specific determination. The scape, however, is usually much longer than any of the rest, and in some males has a very robust and even angulated shape. A description of the antennÃ¦ always enters into the generic character; they usually differ very materially both in length and form in the sexes. They are often filiform (2), but more generally subclavate (1), and sometimes distinctly so, and where they have the latter structure it is found in bothsexes. They constantly differ in the species of a long genus (Andrena,Normada,Halictus). In the male of the genusEucera, they have a remarkable extension, being as long as the body, whereas folded back they are rarely so long, or not longer than the thorax in other males, speaking in reference only to our native kinds. In the females they are not often longer than the head. It is in the males of the genusHalictusthat they take the greatest extension. In the male of the genusEucera, we also find the remarkable peculiarity of the integument of some of the joints being distinctly of an hexagonal structure,â€”a peculiarity often observable in natural structures. In this case it may refer to the sensiferous function of the organ, and to which I shall have occasion to revert when I speak of the senses of our insects. We sometimes find the joints of the antennÃ¦ moniliform, something like a string of beads, or with each separate joint forming a curve, or with their terminal one, as inMegachile, greatly compressed.

The relative lengths of the joints often yield conclusive separative specific characters, and which may be very advantageously made available, especially where other distinctive differences are obscure, and in cases where the practised eye observes a distinction of habit, evidently specific, although it is difficult to seize tangible characteristics.

Thetrophiare the organs of the mouth of the bee collectively. When complete in all the parts, as exemplified in the genusAnthoptera, they consist of thelabrum, or upper lip; theepipharynx, or valve, falling over and closing the aperture of the gullet; thepharynx, or gullet, which forms the true mouth and entrance to the Å“sophagus; thehypopharynxwhich lies immediately belowthe gullet and assists deglutition; thelabium, or lower lip, and the true tongue. These parts are all single; the parts in pairs are themandibles, themaxillÃ¦, themaxillary palpi, thelabial palpi, and theparaglossÃ¦.

Fig. 7.â€”Trophi and their unfolding.a, labrum;b, epipharynx;c, pharynx;d, hypopharynx;e, mandible;f, maxillÃ¦;g, maxillary palpi;h, mandible;i, cardium;k, labium;l, labial palpi;m, paraglossÃ¦;n, tongue.

Thelabrum, or upper lip, is attached by joint to the apex of theclypeus; it has a vertical motion, and falls over the organs beneath it, in repose, when it is itself covered by the mandibles. It is usually transverse in form, but is sometimes perpendicular, especially in the artisan bees. It takes many forms, sometimes semilunar or linear, emarginate or entire, convex, concave, or flat, and is occasionally armed with one or two processes, like minute teeth projecting from its surface, but of what use these may be we do not know. In the female ofHalictus, it has a slightly longitudinal appendage in the centre. It is usually horny, but is sometimes coriaceous or leathery. This labrum often yields good specific characters.

Thepharynx, or gullet, is a cavity immediately beneath theepipharynx, which articulates directly under the base of the labrum, and which closes the pharynx from above, and immediately beneath this cavity is another small appendage, almost triangular, which receives the food or honey from the canal conveying itfrom the tongue, or directly from the mandibles, when it is masticated, and helps it forward to the pharynx to be swallowed. Theepipharynxcloses this orifice from above, thelabrumthen laps over it and the articulation of the lingual apparatus, both which are further protected in repose by the mandibles closing over the labrum. This triple protection shows the importance nature attaches to these organs. The more direct portions of the lingual apparatus are thelabium, or lower lip, which forms the main stem of the rest, and articulates beneath the hypopharynx, and is beneath of a horny texture; it forms a knee or articulating bend at about half its length, and has a second flexure at its apex, where the true tongue is inserted. Thislabiumis extensible and retractile at the will of the insect, and lies inserted within the under cavity of the head when in complete repose, and the insect can withdraw or extend a portion or the whole at its pleasure. Attached on each side, at its first bend or elbow, lie themaxillÃ¦, which, for want of a better term, are called the lower jaws, and perhaps properly so from the function they perform; for at the point of their downward flexure, which occurs at the apex of the labium, and where the true tongue commences, they each extend forward in a broad, longitudinal membrane, partly coriaceous throughout its whole length, and these, folded together and beneath, form the under sheath of the whole of the rest of the lingual apparatus in repose, and often lap over its immediate base when even it is extended. Externally continuous, the line of thesemaxillÃ¦is broken at the point of flexure at the apex of thelabium, by a deep sinus or curve, and within this is inserted the first joint of the maxillary palpi. The portion of the maxillÃ¦extending forwards, hence takes several forms, usually tapering to an acute point, but sometimes rounded or hastate, according to the structure of the tongue, to which they form a protection.

Themaxillary palpiare small, longitudinal joints, never exceeding six in number, and generally in the normal or true bees not so numerous. They vary in relative length to the organ to which they are attached, and usually progressively decrease in length and size from the basal ones to the apical, but each joint, excepting the terminal one, is generally more robust at its apex than at its own special base. The function of these maxillary palpi is unknown. They are always present in full number in theAndrenidÃ¦, and in some few genera of the true bees, but they vary from their normal number of six to five, four, three, two, and one in the latter; and it is curious that they are most deficient in those bees having the most complicated economy, as in the artisan bees and the cenobite bees; they thus evidently show that it is not a very paramount function that they perform. On each side, at the apical summit of thelabium, are inserted thelabial palpi. These are invariably four in number, but vary considerably in length and substance. In theAndrenidÃ¦they have always the form of subclavate, robust joints, and are usually as long as the tongue, but not always; they are only half the length of that organ in the subsection of the acute-tonguedAndrenidÃ¦. In the normal bees, even in the genusPanurgus, which is the most closely allied to theAndrenidÃ¦, the labial palpi immediately take excessive development, especially in their two basal joints, and the structure of these two joints, excepting in this genus and inNomada, partakes of a flattened formand membranous substance. All these four joints are either conterminal, or the two apical ones, or one of them is articulated laterally, towards the apex of the preceding joint. These two are always very short joints, and are comparatively robust.

Thelabial palpiare, in the majority of cases, about half or two-thirds the length of the tongue, but inApathusandApisthey are of its full length. At the immediate base of the tongue, and attached to it laterally, rather than to the apex of thelabium, are theparaglossÃ¦, or lingual appendages, which are membranous and acute, except in theAndrenidÃ¦, where, in some, their apex is lacerated and fringed with short hairs. These organs are always present in theAndrenidÃ¦and generally in theApidÃ¦, where they usually obtain extensive relative development; but in the artisan bees they are all but obsolete, and inCeratina,CÃ¦lioxys,Apathus, andApis, they are not even apparent. Their use also has hitherto eluded discovery, but that they are not essential to the honey-gathering instinct of the bee is especially proved by the latter instance.

The true tongue is attached to the centre of the apex of the labium, having the paraglossÃ¦, when extant, and the labial palpi at its sides. In theAndrenidÃ¦it is a flat short organ of varying form, either lobated, emarginate, acute, or lanceolate; but in theApidÃ¦, withPanurgusit immediately becomes very much elongated, and with this genus the apparatus whereby the tongue folds beneath obtains its immediate development; but this development exhibits itself most fully in the genusAnthophora. The tongue is usually linear, tapering slightly to its extremity, and terminating in some genera with a small knob. It is clothed throughout with a very delicatepubescence, which enables the bee to gather up the nectar it laps. That it should be called the lip seems an absurdity, for it exercises all the functions of a tongue, and it would seem almost that the fine hairs, with which it is covered, are the papillÃ¦ of taste. Its structure in some genera seems to be a spiral thread twining closely round and round, but in others it appears throughout identical.

Fig. 8.â€”Extremes of structure of tongues:1, in subnormal bees (Colletes);2, in normal bees (Anthophora).a, tongue;b, paraglossÃ¦;c, labial palpi;d, maxillÃ¦;e, maxillary palpi;f, labium.

This tongue was formerly thought to be tubular, and that the bee sucked the honey through an aperture at its apex. The knowledge of the flat form of the tongues of other bees should have dissipated the illusion, for we could have been perfectly sure of the analogical structure and function of an organ in creatures so nearly alike. RÃ©aumurâ€™s patient observations have totally dissipated the mistake, and through him we exactly know how the bee conveys the honey into its stomachAs it exhibits an agreeable instance of the persevering industry and unblenching patience with which he made his researches, I will give a summary of what he says, for his bulky volumes, although teeming with delightful instruction, pleasantly narrated, will necessarily not be in every entomologistâ€™s hand, and where not, not even always readily accessible. His observations were made upon the honey-bee, but we may attribute the same mode of collecting to all the rest. He says:â€”When this tongue is not lapping the nectar of flowers but in a state of perfect repose it is flattened. It is then at least three times broader than thick, but its edges are rounded. It gradually narrows from its base to its extremity. It terminates in a slight inflation, almost cylindrical, at the end of which there is a little knob, which appears perforated in the centre. From the circumference of this knob tolerably long hairs radiate, and the upper side of the tongue is also entirely covered with hairs. The basal and widest portion above seems striated transversely with minute lines closely approaching each other.

The upper side of the anterior portion of the tongue seems of a cartilaginous substance, but the under side of the same part appears cartilaginous only over a portion of its width. The centre is throughout its whole course more transparent than the rest, and seems membranous and folded. It is only necessary to press the posterior portion of this trunk, whilst holding its anterior part closely to a light, towards which its upper surface must be turned, and then upon examining its inner surface with a lens of high power, a drop of liquid may be soon observed at its foremost portion. By continuing to press it this drop is urged forward, and as it passes everyportion swells considerably, and the two edges separate more widely from each other. The under side of the tongue, which was before flat, rises and swells considerably, and all that thus rises up is evidently membranous. It looks like a long vessel of the most transparent material. But whilst this great increase of bulk is made upon the lower surface, the upper surface swells only a little, which seems to prove that its immediate envelope is not capable of much distension.

If a bee be observed whilst sipping any sweet liquor, the anterior portion of its trunk will be sometimes seen more swollen than when in action, and alternations will be observed in it of varying expansion.

The posterior portion of the trunk is a great deal larger than the anterior, and it is only in repose that the former nearly equals the latter in length. This posterior portion (this is the portion treated above as thelabium, or under lip) is joined to the anterior by a very short ligature, wholly fleshy, and very flexible, which permits the folding of the trunk, and then its under side is quite scaly, very shiny, and rounded (the maxillÃ¦). This portion is apparently more substantial than the rest. Its diameter gradually increases as it recedes from about the middle to about two-thirds of its length; there it is a little constricted, and the first of the two pieces of which it is composed there terminates. The first piece is rounded, for the purpose, it would appear, of fitting itself upon another, which serves as its base and pivot. This base is conical and of a scaly texture, and terminates in rather an acute point. It is this point which is articulated at the junction of the two small elongate portions of which we spoke at the commencement, and which carry the trunk forward.

In repose, the posterior part of the trunk lies along the lower part of the mouth, and the anterior part is folded back upon it, when it is covered by the maxillÃ¦, which then seem to form a portion of it. It has further another interior envelope; these are the two first joints of the labial palpi (in theApidÃ¦), which are entirely membranous, and these in repose cling closely to the tongue laterally.

The bee would certainly not collect its honey differently from a flower than it would from a glass wherein it might be placed to observe the process; and here it never appeared to obtain the honey by suction. The bee was never observed to place the end of its tongue in the drop of syrup, as it would necessarily do if it were requisite to imbibe it through what seems the small aperture at the extremity of the knob, at the end of the tongue, previously described. As soon as the bee finds itself near the spot spread with honey or syrup, it extends its tongue a line or so beyond the end of the palpi, which continue to envelope it throughout the rest of its length. If the honey be spread over the glass, the anterior portion of the tongue, which is exposed, is turned round that its superior surface may be applied to the glass. There this portion does precisely what the tongue of any animal would do in lapping a liquid. This tongue repeatedly rubs the glass, and, moving about with astonishing rapidity, it makes hundreds of different inflexions.

If the drop of syrup presented to the bee be thicker, or if it meet with a drop of honey, it then thrusts the anterior portion of its tongue into the liquid, but apparently only to use it as a dog might do its tongue in lapping milk or water. Even in the drop of honey the bee bends theend of its tongue about, and lengthens and shortens it successively, and, indeed, withdraws it from moment to moment. We then observe it not merely lengthen and shorten this end, but it is also seen to curve it about, causing from time to time the superior surface to become concave,â€”to give, as it were, to the liquid with which it is loaded a downward inclination towards the head. In fact, this portion of the trunk appears to act as a tongue, and not as a pump. Indeed its extremity, where the aperture for receiving the liquid is assumed to be, is repeatedly above the surface of the liquid which the insect is lapping.

By these continuous motions this anterior extremity of the tongue charges itself with the nectareous fluid, and conveys it to the mouth. It is along the upper surface of this pilose tongue that the liquid passes. The bee strives especially to load and cover it with honey. In shortening the tongue to the extent, sometimes, of withdrawing it entirely beneath its sheaths, it conveys and deposits the liquid with which it is charged within a sort of channel, formed by the upper surface of the tongue and the sheaths which fold over it. Thus, these sheaths are, perhaps, less for the purpose of covering the tongue than to form and cover the channel by which the liquid is conveyed to the mouth. I have previously remarked that the trunk can swell and contract; these swellings and constrictions are observed to succeed each other, and may be for the purpose of urging the liquid, already in transit beneath the sheaths, forward towards the true mouth. Further, I moved the sheaths aside from their position above the tongue of a bee which I held in my fingers, and I succeeded, by means of the point of a pin, in placing an extremely small drop ofhoney upon the tongue of this bee at a spot where it could be covered by the extremities of the external sheath. I then let these sheaths loose. Sometimes they spontaneously resumed their previous position, and sometimes I assisted them to resume it. The drop of honey which they then covered has in no instance returned to the extremity of the tongue; it has always passed towards the mouth, and doubtless entered that orifice itself. It is therefore very certain that the bee imbibes its honey by lapping, and that it never passes through the aperture which has been supposed to have been seen at the extreme apex of the tongue. Did this aperture really exist, it would be of extreme minuteness, and it did not appear to me possible that a large drop of honey, which I have seen imbibed in a very few instants, could in so short a time have passed by so minute an opening. A further confirmation of the non-existence of this orifice has been given me when, by pressing a tongue towards its origin to compel it to swell, I have detected the liquid which gave it its extension, but all my pressing would never make the liquid pass through the extremity, although the pressure has sometimes made it almost rend the membranes, to give it an opening to escape by. Having thus passed through the Å“sophagus into the stomach, it is then regurgitated into its requisite repository upon arriving at home.

AndrenidÃ¦

ApidÃ¦.Fig. 9.â€”Mode of folding the tongue in repose.1. In abnormal bee.2. In normal bee.a, point of articulation beneath the hypopharynx:b, apex of the tongue.

The entire proboscis, with all its appendages attached, has in theApidÃ¦three distinct hinges or articulations, including that which attaches it by its extreme base tothe under surface of the mouth and lower portion of the head, the cavity of which, when folded, it fills, and even then the apex of the tongue protrudes in some genera beyond the sheathing maxillÃ¦. In theAndrenidÃ¦it has but two articulations, and the maxillÃ¦ always cover them entirely in repose. The first articulation, forming the fulcrum of the whole, is always elbowed in theApidÃ¦, and consequently not capable, like the rest of the joints, of full linear extension. The attached diagram will give a clearer conception of the mode of folding:ais the labium, andbthe tongue.

As we have no complete description of the mode by which the tongue of the bee is worked, and how it gathers up its honey, I thought it desirable to be fuller upon the subject than was originally my intention.

Fig. 10.â€”Mandibles: 1, of leaf-cutter bee (Megachile);2, of burrower (Andrena);3, of parasite (Nomada).

The last portion of thetrophi, also double, are the mandibles; they articulate on each side with the cheeks; they act laterally, and are variously formed, according to the economy of the insect. In the females they are usually more or less toothed, and are especially broad, curved, and toothed in the artisan bees. InApisandBombusthey are subdentate. In males they are frequently simply acute, but in some species, especially inAndrena, they have a long spine at the base, which points downwards when they are closed. To this sex they appear to be of no use beyond aiding them to stay the wayward caprice or flight of their mistresses; and, although they have an analogical structure in the males of those genera wherein they are much dilated and toothed, yet they donot seem to be at all used by that sex for any purpose but sexual. In the females they are used for the construction of their burrows and nests, and for the purpose of nipping the narrow spurs and tubes of flowers to get at the nectar; and they often nip, whilst seeking pollen, the anthers of the flowers which have not yet burst their receptacles of pollen.

These insects must necessarily nicely appreciate the quantity of pollen requisite to the full development of the young insect, and, although we often observe a remarkable difference of size in the individuals of a species, this may rather arise from some defect in the quality of the nutritive purveyance than in its quantity, for instinct would as efficiently provide for this purpose as it unquestionably guides to the collection and storing of the nutritive supplies.

Having thus completed the description of the head and of all its attachments, I proceed toâ€”

TheThorax, which is divided by sutures into three parts already mentioned above, viz. theprothorax, themesothorax, and themetathorax.

The collar, or upper part of the prothorax, is often very distinct, and even angulated laterally in front, and frequently presents, both in colouring and form, a specific character. At its under portion on each side the anterior legs are articulated.

Fig. 11.â€”Anterior leg.a, coxa;b, trochanter;c, femur, or thigh;d, tibia, or shank;e, spur and velum;f, planta and strigilis;g, digitus;h, claw;i, pulvillus, or cushion.

All the legs comprise thecoxa, or hip-joint; thetrochanter, which is a small joint forming the connection between this and the next joint thefemur, or thigh; thetibia, or shank; and thetarsus, or foot. The latter consists of five joints, declining in length from the first, which is generally as long as all the rest united together; the first, in the anterior pair, being called thepalmÃ¦,or palms; and in the four posteriorplantÃ¦, or soles; the other joints are called thedigiti, or fingers, or tarsus collectively; at the extremity of the terminal one are the two claws, which are sometimes simple hooks, but usually have a smaller hooklet within; they have both lateral and perpendicular motion, and between their insertion is affixed thepulvillus, or cushion. ThecoxÃ¦in their occasional processes exhibit very useful specific characters, as do the markings and form of the remaining joints of the leg and foot, which in several genera furnish generic peculiarities. The four anterior tarsi have each a moveable spine, or spur, at their apex within, which can be expanded to the angle at which the insect wishes to place the limb, and to which it forms a collateral support; the posterior tibiÃ¦ have two each of these spurs, excepting in the genusApis, which has none to this leg. Attached to this spur on the anterior tibiÃ¦ of all the bees, there is, within, a smallvelum, or sail, as it has been called; this is a small angular appendage affixed within the spur by its base. At the base of the palmÃ¦ of the same legs, and opposite the play of this velum, there is a deepsinus, or curved incision, thestrigilis, called thus or the curry-comb, from the pecten, or comb of short stiff hair which fringes its edge. Upon this aperture thevelumcan act at the will of the insect, and combined they form a circular orifice. The object of this apparatus is to keep the antennÃ¦ clean, for the insect, when it wishes to cleanse one or the other of them, lays it within this sinus of the palma, and then, pressing thevelum of the spur upon it, removes, by the combined action of the comb and the velum, all excrescences or soilure from it, and this process it repeats until satisfied with the cleanliness of the organ: and this it may be frequently seen doing. This arrangement proves how essential to the well-being of the insect is the condition of its antennÃ¦, the sinus, or strigilis, or curry-comb, as it may be called, being always adapted in size to the thickness of the antennÃ¦, for insects being always both right- and left-handed, they therefore use the limb on each side to brush the antenna of that side. The palmÃ¦ and other joints of the tarsus of the fore legs are greatly dilated in many males, or fringed externally with stiff setÃ¦, which give it as efficient a dilatation as if it were the expansion of its corneous substance. The anterior tarsi of the females are likewise fringed with hair, to enable them to sweep off and collect the pollen, and to assist also in the construction and furnishing of their burrows. The intermediate tarsi are as well often very much extended in the males, being considerably longer than those of the other legs. The use of the claws at the apex of the tarsi is evidently to enable the insect to cling to surfaces.

The manner in which the bee conveys either the pollen, or other material it purposes carrying home, to the posterior legs, or venter, which is to bear it, is very curious. The rapidity of the motions of its legs is then very great; so great, indeed, as to make it very difficult to follow them; but it seems first to collect its material gradually with its mandibles, from which the anterior tarsi gather it, and that on each side passes successively the grains of which it consists to the intermediate legs by multiplicated scrapings and twistings of the limbs; this then passes it on by similar manÅ“uvres, and depositsit, according to the nature of the bee, upon the posteriortibiÃ¦andplantÃ¦, or upon theventer. The evidence of this process is speedily manifested by the posterior legs gradually exhibiting an increasing pellet of pollen. Thus, for this purpose, all the legs of the bees are more or less covered with hair. It is the mandibles which are chiefly used in their boring or excavating operations, applying their hands, or anterior tarsi, only to clear their way; but by the constructive or artisan bees they are used both in their building and mining operations, and are worked like trowels to collect moist clay, and to apply it to the masonry of their habitations.

Themesothorax, or central division of the thorax, has inserted on each side near the centre the four wings, the anterior pair articulating beneath thesquamulÃ¦, or wing-scales, which cover their base like an epaulette, and this wing scale often yields a specific character. In repose the four wings lie, horizontally, along the body, over the abdomen, the superior above, the inferior beneath. The wings themselves are transparent membranes, intersected by threads darker than their own substance, called their nervures, which are supposed to be tubular. These nervures and the spaces they enclose, called cells, are used in the superior wing only, and only occasionally, as subsidiary generic characters, and their terminology it will be desirable to describe, as use will be made subsequently of it. At the same time, to facilitate the comprehension of the terms, an illustrative diagram is appended; but those parts only will be described which have positive generic application. I may, however, first observe that upon the expansion of the wings in flight, the insect has the voluntary powerof making the inferior cling to the superior wing by a series of hooklets with which its anterior edge is furnished at about half the length of that wing, which gives to the thus consolidated combination of the two a greater force in beating the air to accelerate its progress. That the insect has a control over the operation of these hooklets is very evident, for, upon settling, it usually unlocks them, and the anterior are often seen separated and raised perpendicularly over the insect; but that this can be mechanically effected also is shown sometimes in pinning a bee for setting, when by a lucky accident the pin catches the muscles which act upon the wings, and they become distended, as in flight, closely linked together. Both the diagram and the description of this superior wing I borrow from an elaborate paper of my own in the first volume of the â€˜Transactions of the Entomological Society of London,â€™ wherein I gave a tabulated view, in chronological order, of the nomenclature introduced by successive entomologists in the use they made of the anterior wing of theHymenopterafor generic subdivision, and which I subsequently applied to my own work upon the â€˜Fossorial Hymenoptera of Great Britain.â€™

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