Part 12

Very soon the outline of the comb may be seen. In form it is still lenticular, for the little prismatic tubes of which it is composed are unequally prolonged, and they diminish as they get away from the centre towards the extremities. At this moment it might be compared, both in form and in thickness, to a human tongue hanging down from two of the sides of the hexagonal cells which are placed back to back.

As soon as the first cells are constructed, the workers add a roof to the second and so on to the third and to the fourth. These sets of cells are divided by irregular intervals, and they are calculated in such a manner that when they are made to receive their full complement, the bees always have room enough to move about between the parallel walls of the honeycombs.

It follows then that in making their original plan the different thicknesses of every honeycomb must be fixed upon, and at the same time the alley-ways which separate each must be different in turn, and this width must be twice the height of a bee since they have to pass each other between the upright combs.

But even the bees are not infallible, and they do not always work with exact mechanical certainty. When they find themselves in a difficult place they sometimes make very great blunders. One often finds that they leave too much, and often too little, space between the honeycombs, and they remedy these faults as well as they can--sometimes in finishing the comb which is too near another in an oblique line, or sometimes when they have left too much space they interpose a smaller comb between it.

Reamur, on this subject, says:--"Since bees sometimes make mistakes and rectify them, this must be a proof that they possess the power of reason."

[Illustration: QUEEN BEE.]

It is known that bees make four different kinds of cells. There are first the "royal cells" which are exceptional and are of acorn shape. Then there are the large cells in which the male bees are reared, and in which provisions are stored when the flowers furnish forth of their abundance. Then there are the little cells which may be called the "cradles of the working bees," which are also employed as ordinary store-rooms. These generally occupy about eight-tenth's of the total surface of the combs in a hive; and finally there are a certain number of what may be called transition cells. Although these latter are inevitably irregular, the dimensions of the second or third type are so well calculated that when the decimal system was first established, and people were seeking an incontestable standard of measurement, it was the cell of the bee which was proposed first of all by Reamur. Each one of these cells is an hexagonal tube placed upon a pyramid form, and each honeycomb is formed of two strata of these tubes, base to base, in such a way that the three lozenges which make the pyramid-like base of one cell form at the same time the pyramid-like bases of the three cells on the other side.

[Illustration: WORKER.] [Illustration: DRONE.]

In these prismatic tubes the honey is stored away--and so that the honey shall not trickle out as it would be likely to do if they were built strictly horizontal--they are tilted up at the outer edge of an angle of four or five degrees.

"Besides the saving in wax," says Reamur, speaking of this marvellous building, "which is effected by this arrangement of the cells,--besides the fact that by this plan the comb may be filled without a single gap, there are other advantages in the way of the solidity thus given.... Every possible advantage in the way of the solidity of each cell is brought about by the manner of its construction, and by its place with reference to the rest of the cells in the comb."

"Students of geometry know," says Dr. Reid, "that there are only three shapes that can be employed to divide a surface into, uniform spaces, that shall be regular in shape, and without interstices.

[Illustration: SECTION OF CELLS CONSTRUCTED BY BEES.]

"They are the equilateral triangle, the square, and the regular hexagon, which latter, in the matter of cell construction, is superior to the two first both from the point of view of strength and utility, and it is just this form that the bees have adopted, precisely as though its advantages were familiar to them.

"Furthermore, the bottoms of the cells form three planes meeting at one point, and it has been demonstrated that both in economy of labor and material this system of construction is the best--again, the angle of the inclination of the planes affects this question of economy: this problem has been solved by the bees and confirmed by Maclaurin by abstruse mathematical calculations published in the "Transactions of the Royal Society of London.""

Of course I do not suppose for a moment that the bees themselves have made these calculations, but on the other hand I do not believe that chance, or accidental circumstance has brought about, these results. The wasps, for instance, have built hexagonal cells, but they have not displayed such ingenuity as the bees have done. Their combs have only one course of cells, and they have not the foundation which serves the bees for their double rows. Hence there is less strength, more irregularity, and a loss of time, of material, and of room, which really means that a quarter of the labor employed and a third of the space occupied is lost. We also find certain other domesticated bees, not so far progressed in civilization, which only build one row of cells for rearing their young, and which support horizontal combs one above another on costly columns of wax. Their food store-cells, are like a row of round pots, and the bees make but a clumsy use of the spaces between them. Indeed, when we compare their City with the Wonderful City of the bees of which we are speaking, it is like comparing a row of huts with a modern laid out city. If the result is not charming, it is severely logical, and demonstrates the genius of the race which is forever fighting to get the most out of matter, space, and time.

Buffon had a theory which has been revived once more, that the bees did not intend to make hexagonal cells, but rather round ones, and that owing to the crowding of the workers all around, the round ones became hexagonal. It is said also that crystals, fish-scales of certain kinds, soap-bubbles, etc., follow the same law, and Buffon advances this experiment to prove it. "Take a vessel and fill it full with peas or any other round grains, pour as much water upon them as will fill the spaces between them, close the vessel tightly, and boil the water. It will be found that the round peas have become six-sided. One sees clearly that this must be so from purely mechanical causes; each one of the round grains tends in the course of swelling as it boils to fill up the utmost space that it can, and by the extension and pressure of all alike they become hexagonal. Each bee wishes to occupy as much room as possible in its allotted space, therefore as the bodies of the bees are round or cylindrical, their cells become hexagonal because of the extension and pressure of all alike."

Here then we see reciprocal obstacles working a wonder, somewhat in the same way perhaps as the vices of men bring about a general virtue, so that the race odious, often so far as individuals are concerned, is tolerable in the mass. Broughman, Kirby, and Spence and others claim that the observations of soap-bubbles and peas prove nothing in this connection, for the effect of compression is only to produce irregular hexagonal forms, and does not explain the earlier form of the base of the cells.

To this one might rejoin that there are more ways than one of dealing with the blind law of necessity, for the wasp and the bumble-bee and many other species in similar circumstances and with the same end in view, arrive at very different, and manifestly inferior, results. Indeed it might be said further that even if the bee-cells did conform to the laws of crystallization as in the case of snow, or Buffon's soap-bubbles, or boiled peas, they show also in their general symmetry, in their well-determined angle of inclination, etc., that there are many other laws not followed by inert matter to which they also conform.

In order to assure myself that the hexagonal form of the cell was the outcome of the bee-brain, I cut out from the centre of a honey-comb a round piece not quite so large as a silver dollar, containing both brood-cells and honey-cells. I cut into this disc, at the point where the pyramidal bases of the cells were joined, and I fixed on the base of the section thus exposed a piece of tin of the same size, and so stout that the bees could not bend or twist it. Then I replaced the disc of comb, with the piece of tin as described. One side of the comb showed, of course, nothing extraordinary, but on the other side was to be seen a hole at the bottom of which was a round piece of tin occupying the place of about thirty cells. At first the bees were disconcerted, and came in crowds to examine and study this wonderful abyss; for some days they wandered about it in agitation without coming to any decision. But as I fed them well every evening, the time soon came when they needed more cells in which to store their provisions. Then most likely the famous engineers, the sculptors, and the waxmakers, were summoned to show the way to fill up this useless chasm.

A heavy curtain, or garland, of the wax-making bees covered the spot so as to develop the necessary heat; others went down into the hole and began the work of solidly fixing the metal in place by means of little claws of wax around its entire circumference, attaching them to the walls of the cells which surrounded it. Then they set to work to make three or four cells in the upper part of the disc, attaching them to these waxen claws. Each of these new cells was more or less unfinished at the top, so as to leave material wherewith to fasten it to the next cell, but below on the piece of tin was always three very clear, and precise angles from which would grow the three upright lines which regularly marked the outline of the first half of the next cell. After about forty-eight hours, although three or four bees at most could work at the same time in the opening, the whole surface of the piece of tin was covered with the outlines of the new cells. They were certainly somewhat less regular than those in an ordinary comb.... But they were all perfectly hexagonal; not a line was bent, not an angle out of shape; nevertheless all the ordinary conditions of bee-life were changed. The cells were not dug out of a block of wax as Huber described, nor were they made according to Darwin, circular at first, and then made into hexagons by the pressure of their neighbors. Here was no question of reciprocal obstacles, seeing that the cells were made one by one, and these first outlines were sketched on a kind of table. It would appear therefore that the hexagonal form is not the result of any mechanical necessity, but that it forms the plan resulting from the experience, the intelligence, and the will of the bee. Another curious thing which I accidentally noticed was that the cells built upon the tin were not provided with any other floor than the tin itself. The engineers of the working party evidently reasoned that the tin was sufficient to retain the liquid honey, and that it was not necessary, therefore, to line it with wax. But a little while after, when some honey was placed in the cell, they probably found that the metal effected some change in it, for upon taking counsel together they covered the surface of the tin with a kind of diaphanous varnish.

If we wish to throw light on all the secrets of this geometrical architecture, we shall find many more interesting questions to examine--for example, that of the form of the first cells, which are attached to the roof of the hive--a form which is modified so that the cells can fit its curve and touch the roof at the greatest possible number of points.

It would be necessary to notice also, not only the direction in which the main streets of the hive run, but the alley-ways and passages which run in and out and around the comb, as much for the circulation of the air as for the traffic; and it should be remarked that these are planned so as to avoid long detours or confusion in the traffic....

Before we leave this subject let us, only for a minute, stop to consider the wonderful and mysterious way in which the bees make their plans and work together when they are occupied in carving out their cells, on both sides of the comb, where neither can see the other. Look through one of these transparent combs, and you will see clearly and sharply cut out in this diaphanous wax a network of prisms arranged in so perfectly fitting a manner that one might think they were stamped out of steel.

Those who have never seen the inside of a hive can have little idea of the appearance of these honeycombs. Let us take a countryman's hive in which the bee has been left free to work as he pleases. This bell-like shape is divided from top to bottom by five, six, eight, and sometimes ten, slices of wax, so to speak, perfectly parallel with each other, which take the exact shape of the curve of the walls of the hive. Between each one of these slices is a space of about half an inch in which the bees move about. When they begin to build one of these slices at the top of the hive, the wall of wax is quite thick, and hides entirely the fifty or sixty bees who are working on one side from the fifty or sixty at work on the other. Unless they have a sight which can pierce the most opaque bodies, neither can see what is doing on the other side. Nevertheless, a bee on one side does not dig a hole or add a fragment of wax which does not correspond exactly with a protuberance or a cavity on the other side. How do they contrive to do this? How does it happen that one does not dig too far, and the other not far enough?

How is it that every angle coincides in such magnificent perfection? Who tells the bee to begin here and to end there? Once again we must be satisfied with the reply that does not answer: "It is one of the mysteries of the hive." Huber has tried to explain it by saying that at certain intervals, by the pressure of their feet or their teeth, they produce a slight projection of the wax on the other side of the comb, or that they can determine the thickness of the block of wax by its flexibility, its elasticity, or some other physical property which it may possess; or, again, that their antennae are able to serve as compasses in enabling them to examine what is going on in the darkness of the other side; or, last of all, he suggests that all the cells mathematically derive their shape and dimensions from those of the first row, which is built without the need of further concert on the part of the workers. But one can easily see that these explanations are not sufficient; the first are guesses which cannot be verified; the others simply change but do not remove the mystery. But if it is good to change a mystery as often as possible, it is never good to flatter one's self that to change it means to remove it!

WASPS

(FROM THE NATURALIST IN NICARAGUA.)

BY THOMAS G. BELT, F.G.S.

[Illustration]

I one day saw a small black and yellow banded wasp hunting for spiders; it approached a web where a spider was stationed in the centre, made a dart towards it--apparently a feint to frighten the spider clear of its web; at any rate it had that effect, for it fell to the ground, and was immediately seized by the wasp, who stung it, then ran quickly backwards, dragging the spider after it, up a branch reaching to the ground until it got high enough, when it flew heavily off with it. It was so small, and the spider so heavy, that it probably could not have raised it from the ground by flight. All over the world there are wasps that store their nests with the bodies of spiders for their young to feed on. In Australia, I often witnessed a wasp combating with a large flat spider that is found on the bark of trees. It would fall to the ground, and lie on its back, so as to be able to grapple with its opponent; but the wasp was always the victor in the encounters I saw, although it was not always allowed to carry off its prey in peace. One day, sitting on the sandbanks on the coast of Hobson's Bay, I saw one dragging along a large spider. Three or four inches above it hovered two minute flies, keeping a little behind, and advancing with it. The wasp seemed much disturbed by the presence of the tiny flies, and twice left its prey to fly up towards them, but they darted away with it. As soon as the wasp returned to the spider, there they were hovering over and following it again. At last, unable to drive away its small tormentors, the wasp reached its burrow and took down the spider, and the two flies stationed themselves one on each side the entrance, and would, doubtless, when the wasp went away to seek another victim, descend and lay their own eggs in the nest.

[Illustration: WASPS' NEST.]

[Illustration: THE SAND-WASP.]

The variety of wasps, as of all other insects, was very great around Santo Domingo. Many made papery nests, hanging from the undersides of large leaves. Others hung their open cells underneath verandahs and eaves of houses. One large black one was particularly abundant about houses, and many people got stung by them. They also built their pendent nests in the orange and lime trees, and it is not always safe to gather the fruit. Fortunately they are heavy flyers, and can often be struck down or evaded in their attacks. They do good where there are gardens, as they feed their young on caterpillars, and are continually hunting for them. Another species, banded brown and yellow (_Polistes carnifex_), has similar habits but is not so common. Bates, in his account of the habits of the sand-wasps at Santarem, on the Amazon, gives an interesting account of the way in which they took a few turns in the air around the hole they had made in the sand before leaving to seek for flies in the forest, apparently to mark well the position of the burrow, so that on their return they might find it without difficulty. He remarks that this precaution would be said to be instinctive, but that the instinct is no mysterious and unintelligible agent, but a mental process in each individual differing from the same in man only by its unerring certainty. I had an opportunity of confirming his account of the proceedings of wasps when quitting a locality to which they wished to return, in all but their unerring certainty. I could not help noting how similar they were to the way in which a man would act who wished to return to some spot not easily found out, and with which he was not previously acquainted. A specimen of the _Polistes carnifex_ was hunting about for caterpillars in my garden. I found one about an inch long, and held it out towards it on the point of a stick. It seized it immediately, and commenced biting it from head to tail, soon reducing the soft body to a mass of pulp. It rolled up about one-half of it into a ball, and prepared to carry it off. Being at the time amidst a thick mass of a fine-leaved climbing plant, before flying away, he took note of the place where it was leaving the other half. To do this, it hovered in front of it for a few seconds, then took small circles in front of it, then larger ones round the whole plant. I thought it had gone, but it returned again, and had another look at the opening in the dense foliage down which the other half of the caterpillar lay. It then flew away, but must have left its burden for distribution with its comrades at the nest, for it returned in less than two minutes, and making one circle around the bush, descended to the opening, alighted on a leaf, and ran inside. The green remnant of the caterpillar was lying on another leaf inside, but not connected with the one on which the wasp alighted, so that in running in it missed it, and soon got hopelessly lost in the thick foliage. Coming out again, it took another circle, and pounced down on the same spot again, as soon as it came opposite to it. Three small seed-pods, which here grew close together, formed the marks that I had myself taken to note the place, and these the wasp seemed also to have taken as its guide, for it flew directly down to them, and ran inside; but the small leaf on which the fragment of caterpillar lay, not being directly connected with any on the outside, it again missed it, and again got far away from the object of its search. It then flew out again, and the same process was repeated again and again. Always when in circling round it came in sight of the seed-pods down it pounced, alighted near them, and recommenced its quest on foot. I was surprised at its perseverance, and thought it would have given up the search; but not so, it returned at least half a dozen times, and seemed to get angry, hurrying about with buzzing wings. At last it stumbled across its prey, seized it eagerly, and as there was nothing more to come back for, flew straight off to its nest, without taking any further note of the locality. Such an action is not the result of blind instinct, but of a thinking mind: and it is wonderful to see an insect so differently constructed using a mental process similar to that of man. It is suggestive of the probability of many of the actions of insects that we ascribe to instinct being the result of the possession of reasoning powers.

[Illustration: WASP AND HOLE IN THE SAND.]

A WASP AND ITS PREY

(FROM THE INSTINCTS AND HABITS OF THE SOLITARY WASPS.)[6]

BY G. W. AND E. G. PECKHAM.

[6] Reprinted by permission from Bulletin No. 2, Series I, of The Wisconsin Geological and Natural History Survey, 1898.

[Illustration]