The nests of many of these little bees are rich in honey, and they have a host of enemies from man and monkeys downwards; and as they do not defend themselves by stinging, it might be supposed they would have but a poor time of it. From the accounts that have been published we may, however, gather that they are rich in devices for the protection of their nests, and for the exclusion of intruders. Bates has given some particulars as to Melipona interrupta (fasciculata); it is about one-third shorter than the hive-bee, and its colonies are composed of an immense number of individuals. The workers are usually occupied in gathering pollen; but they also collect clay in a similar manner, and convey it to the nest, where it is used for building a wall to complete the fortification of the nest, which is placed either in a suitable bank, or in a trunk of a tree; in either situation it is completely built in with clay. A nest which Bates saw opened contained about two quarts of pleasantly-tasted liquid honey. Forty-five species of these little bees were found in different parts of the Amazons Valley, the largest kind being half an inch in length, the smallest very minute, not more than one-twelfth of an inch. These little creatures are thus masons as well as workers in wax and resin, and they are also gatherers of nectar, pollen, and resin.
According to Gosse, one of these bees is well known in Jamaica, where they are called "Angelitos," in consequence of their not stinging people. He observed a nest of this bee in a tree, and found it to be much infested by black ants anxious to obtain entrance to it; three bees, however, stood sentinel in the entrance, so as to completely block it and keep out intruders, but the middle bee moved on one side out of the way directly one of its fellows wished to come in or out of the nest. The honey accumulated by this species is kept in clusters of cups about the size of a pigeon's egg, at the bottom of the hive and away from the brood-cells. The queen or mother-bee is lighter in colour than the others, and has the hind body twice the length of theirs.
Hockings[[36]] has given us some details as to the natural history of two of these bees that inhabit Australia, where they are called "Karbi" and "Kootchar," the first being, it is supposed, Trigona carbonaria, Smith: it is usually about three-sixteenths of an inch in length, the queen, when fully developed, being nearly twice that length. The comb is built in a most peculiar form, being, it is said, in the shape of a spiral staircase, and tapering towards the ends: honey-pots and pollen are constructed for the storage of food. The comb is encased in wax, and outside it a labyrinth of waxen passages is formed. The entrance to the colony is guarded by a line of bees who inspect every one that arrives, and it is surprising to see how soon a stranger is discovered and pounced upon before it has time even to alight; the intruder, when caught, is held by several bees, who put it on the rack by holding and stretching out its limbs to their full extent, retaining it in this position for as long as an hour, by which time the unfortunate prisoner is usually dead. These bees, as well as many other allied species, fight desperately with their mandibles, and are apparently of a very fierce disposition. The other species, called "Kootchar," is said to produce a very large number of drones, and the habits and dispositions of the bees differ considerably from those of the "Karbi": the entrance to their hive is guarded by a pipe of propolis (a sort of resinous wax) about an inch in length, having an exceedingly sticky outer edge, and it is by this pipe alone that access to the interior can be gained. At night the entrance is closed by numerous minute globules of semi-fluid gum placed against it, thus forming a thin wall full of air-holes. The colonies of "Kootchar" can be united by taking away a queen and then packing her brood-nest, bees and all, against that of the colony it is to be joined to. This cannot be done with the "Karbi." The account given by Mr. Hockings contains a great many other interesting details, and there can be no doubt that a full account of the natural history of these Insects would be very instructive.
Fritz Müller has recorded a singular case bearing on the instinct of these social Insects: he says that a nest of a small Trigona was built in a hollow tree, and that as a consequence of the irregularity of the hole the bees were obliged to give a very irregular shape to their combs of honey. These bees were captured and put in a spacious box (presumably together with the irregular comb, but this he unfortunately does not mention): after a year, "when perhaps not a single bee survived of those which had come from the canella tree," they still continued to build irregular combs, though quite regular combs were built by several other communities of the same species that he had kept. These bees, he also tells us, do not use pure wax for the construction of their combs, but mix it with resin or gum that gives it a peculiar odour and appearance. He captured two communities of a common Melipona, one of which had the combs made of dark reddish brown, the other of pale yellowish brown, wax, and in captivity in a distant locality each of the two communities continued to form its comb in the same way, thus showing the continuity that prevails in these cases as long as circumstances permit. Müller thinks this due to imitation, but it seems at least as probable that it is due to perception of the properties of the nest. The nest has a certain colour that the worker-bee matches.
Several species of the Melipona and Trigona were imported from Brazil to France, and kept there for some time in captivity by M. Drory. Girard has published[[37]] some details as to these colonies, and is of opinion that some of them indicate an intelligence or instinct superior to that of the honey-bee. The queen-bee of M. scutellaris seems to display more intelligence than the corresponding sex of A. mellifica. The mode of feeding the larvae apparently differs from that of A. mellifica, a provision of pollen being first placed in the cell, then some honey; when sufficient food for the whole consumption of a larva is accumulated the queen deposits an egg in the cell, which is at once completely closed by the worker. The interior of the abode of these bees is quite dark, only a very small orifice being left, and in this a sentinel is constantly on the alert. The same writer states that Trigona crassipes has the very peculiar habit of always locating its brood-comb in the nest of a species of Termes.
The honey-bee, Apis mellifica (Fig. 6), is considered the highest form attained by the Anthophilous division of the Hymenoptera. The differentiation of the three forms, male, female, and worker, is here carried to a greater degree of perfection than in the other bees. The drones are the males; the individuals we see gathering honey are always workers, neither the male nor the female in this species taking any part in procuring food for themselves or for the colony. In addition to this the colonies formed may be described as permanent: they do not come to an end at the close of one season, and provision is made for the formation of a new colony while the old one still persists, by means of a peculiar process called swarming. The life-history of Apis mellifica and its anatomy and physiology have been discussed in a whole library of works, and we need only notice the chief features. When a swarm of bees leaves a hive it consists of the queen-bee or female, and a number of workers, these latter being, in fact, the surplus population that has been produced in the hive. The swarm is not a nuptial flight, as is often supposed, but an act of emigration. When this swarm has been housed, the bees commence operations in their new quarters, by secreting wax; they are enabled to do this by having consumed much saccharine food; the wax is produced by means of glands in the hind-body over the inner faces of the ventral plates of the abdominal rings, and it makes its appearance there, after passing from the interior of the body through some peculiar membranes on the ventral segments, in the form of thin projecting plates. These the bee takes off with an apparatus on the hind pair of legs and applies, after working up with the mandibles, to form the cells in which young ones are to be reared and food stored. A large number of bees working in common thus produce the regular and beautiful structure known as the comb; the queen afterwards lays an egg in each cell, and as these soon hatch, great labour is thrown on the workers, which have then to feed the young; this they do by eating honey and pollen, which, being formed into a sort of pap by a portion of their digestive organs, is then regurgitated and given to the young, a quantity of it being placed in the cell, so that the larva is bathed by it, and possibly may absorb the food by the skin as well as the mouth. When the colony is in good progress and young bees emerge, these act as nurses, the older ones cease to prepare food and act as foragers, bringing in honey and pollen which are each stored in separate cells. The larva in the cell increases its size and sheds a very delicate skin several times; when the larva has reached its full size no more food is supplied, but the worker-bees seal up the cell by means of a cover formed of pollen and wax, in such a manner as to be pervious to air: sealed up in the cell the larva spins a cocoon for itself, remains therein for a little time as a larva, then changes to a pupa, and thereafter bites its way out through the cover of the cell, and appears for the first time as a new being in the form of a worker-bee; the whole process of development from the egg-state to the perfect condition of the worker-bee occupies about three weeks.
When the denizens of a hive are about to produce another queen, one or more royal cells are formed; these are much larger than the ordinary worker-cells, and of a quite different form. In this cell is placed an egg, not differing in any respect from the egg that, if placed in an ordinary cell, produces a worker; when the egg has produced a larva this is tended with great care and fed throughout its life with royal jelly. This food appears to be the same as that supplied to an ordinary worker-larva when it is first hatched; but there is this difference, that whereas the worker-larva is weaned, and supplied, after the first period of its existence, with food consisting largely of honey, pollen and water, the queen-larva is supplied with the pap or royal jelly until it is full grown. Some difference of opinion exists as to this royal jelly, some thinking that it is a different substance from what the workers are fed with; and it is by no means improbable that there may be some difference in the secretion of the glands that furnish a part of the material composing the pap. The queen is produced more rapidly than workers are, about sixteen days being occupied in the process of her development. Only one queen is allowed in a hive at a time; so that when several queen-cells are formed, and queen-larvae nurtured in them, the first one that is developed into a perfect queen goes round and stings the royal nymphs to death while they are still in their cells. The production of drones is supposed to depend chiefly on the nature of the egg laid by the queen; it being considered that an unfertilised egg is deposited for this purpose. There is still some doubt on this point, however. Though there is no doubt that drones are produced in great numbers from unfertilised eggs, yet there is not evidence that they cannot also be produced from fertilised eggs.[[38]] The drone-cells are somewhat larger than the ordinary worker-cells, but this is probably not of much import, and it is said that the larvae intended to produce drones receive a greater proportion of pap than worker-larvae do: about twenty-four days are required to produce a drone from the egg.
From this sketch it will be seen that the production of the worker (or third sex, as it is improperly called, the workers being really females atrophied in some points and specially developed in others) is dependent on the social life, in so far at any rate as the special feeding is concerned. There is good reason for supposing that A. mellifica has been kept in a state of domestication or captivity for an enormous period of time; and this condition has probably led to an increase of its natural peculiarities, or perhaps we should say to a change in them to suit a life of confinement. This is certainly the case in regard to swarming, for this process takes place with comparative irregularity in Apis mellifica in a wild condition. The killing of superfluous queens is also probably a phenomenon of captivity, for it varies even now in accordance with the numbers of the colony. It is interesting to notice that in confinement when a swarm goes from the hive it is the old queen that accompanies it, and this swarm as a rule settles down near the old hive, so that the queen-bee being already fertilised, the new swarm and its subsequent increase are nothing but a division of the old hive, the total products of the two having but a single father and mother. When a second swarm goes off from a hive it is accompanied by a young queen, who frequently, perhaps, in the majority of cases, is unfertilised; this swarm is apt to fly for long distances, so that the probability of cross-fertilisation is greatly increased, as the fertilisation of the young new queen is effected during a solitary flight she makes after the colony has settled down. But in a state of nature the colonies do not send off swarms every year or once a year, but increase to an enormous extent, going for years without swarming, and then when their home is really filled up send off, it may be presumed, a number of swarms in one year. Thus the phenomena of bee-life in a wild condition differ considerably from those we see in artificial confinement. And this difference is probably greatly accentuated by the action of parasites, the proportions of which to their guests are in a state of nature liable to become very great; as we have seen to be the case in Bombus.
Under these circumstances it is not a matter for surprise when we find that the honey-bee has formed distinct races analogous to those that exist in the case of the domesticated vertebrate animals. The knowledge of these races is, however, at present very little advanced, and is complicated by the fact that only imperfect information exists as to the true species of the genus Apis. There is a bee very like our common honey-bee found in southern Europe called A. ligustica; this is certainly a variety of A. mellifica, and the same remark applies to a bee found in Egypt, and called A. fasciata. This gives the honey-bee a very wide distribution, extending possibly over the whole of the palaearctic region: besides this, the species has been introduced into various other parts of the world.
According to Karsch the honey-bee shows in Germany several varieties, all of which belong to the northern form, which may be spoken of as the A. domestica of Ray; the A. ligustica and A. fasciata form as we have said distinct races, and it is a remarkable fact that these races remain distinct even when imported into other climates; though for how long a period of time this remains true there is very little evidence to show. The northern form, A. domestica, is now found in very widely separated parts of the world, in some of which it is wild; Smith mentions it as occurring in the West India islands, throughout the North American continent as far south as Mexico, even in Central and Southern Africa, and in Australia and New Zealand. The var. ligustica has been found also at the Cape of Good Hope. The other species known of the genus Apis all belong to the Old World, so that there is very little doubt that A. mellifica is also a true native of the eastern hemisphere, and its original home may possibly have been not far from the shores of the eastern portion of the Mediterranean sea. Seven or eight other species of Apis are known, all but one of which occur in Asia, extending as far as Timor and Celebes. The exceptional one, A. adansonii, occurs in tropical Africa and in Madagascar. Gerstaecker thought these species might be reduced to four, but Smith's statement that the males and even the workers show good distinctive characters seems to be correct. Very little is known as to the honey-bees of China and Japan.