CHAPTER XV
Ant wonders—Leaves cut for mushroom-growing—How ants plant mushrooms—A nest in a mushroom-bed—“Psychic plasticity”—Two opinions—Ant stupidity—Unfair comparisons—The ant and the servant-maid—Mushroom-growing beetles—Choked by ambrosia—Intelligent uselessness—Automatic phraseology—A curious insect.
ANTS, as everybody knows, have a special faculty for doing extraordinary things. Only a few of these have been mentioned in the last and preceding chapters, and only a few more can be touched upon in this. To do the subject anything like justice, a whole large book would be required, not a few chapters merely of a quite small one. What ants do, indeed, reminds me of the refrain, constantly repeated, of a certain old ballad lately brought to my notice, viz.—
“Wonders, notable wonders! never the like was heard.”
For instance, they grow mushrooms (rice, or some cereals, they used to grow and reap, but lately they have not been allowed to); they use their own larvæ as an implement to sew or stick things together with, thus making little shuttles of them; they make bridges of their own bodies, by which they pass over rivers—even wide ones, it would seem, at least for them—which otherwise would be impassable; they allow themselves to be made into honey-pots and kept full for the good of the general community, who take a little of them when they want it; they have cemeteries, and would appear even to feel something like awe or respect in the presence of their own dead; they cause certain plants to grow and come to maturity, which would otherwise die, in order to make a house in them, and so on and so on, many other wonders equally notable, to say nothing of those which have already been recounted.
To take the first on the list—I hardly believe in a classification of wonders—Belt, who was an engineer, but ought to have given up his whole life to observations of this sort, was the first, I believe, to find out that ants were mushroom-growers. Like others, when he came to Nicaragua he saw the leaf-cutting ants passing in long, double columns backwards and forwards between their nests and the trees, the homeward-bound column laden with their little crescent-shaped bits of green leaf, the outgoing one empty-handed. “The first acquaintance a stranger generally makes with them,” says Belt, “is on encountering their paths on the outskirts of the forest crowded with the ants; one lot carrying off the pieces of leaves, each piece about the size of a sixpence, and held up vertically between the jaws of the ant; another lot hurrying along in an opposite direction empty-handed, but eager to get loaded with their leafy burdens. If he follows this last division, it will lead him to some young trees or shrubs, up which the ants mount; and where each one, stationing itself on the edge of a leaf, commences to make a circular cut, with its scissor-like jaws, from the edge, its hinder feet being the centre on which it turns. When the piece is nearly cut off it is still stationed upon it, and it looks as though it would fall to the ground with it, but on being finally detached the ant is generally found to have hold of the leaf with one foot, and soon righting itself, and arranging its burden to its satisfaction, it sets off at once on its return. Following it again, it is seen to join a throng of others, each laden like itself, and, without a moment’s delay, it hurries along the well-worn path. As it proceeds, other paths, each thronged with busy workers, come in from the sides, until the main road often gets to be seven or eight inches broad, and more thronged than the streets of the city of London. Standing near the mounds, one sees from every point of the compass ant-paths leading to them, all thronged with the busy workers carrying their leafy burdens. As far as the eye can distinguish their tiny forms, troops upon troops of leaves are moving up towards the central point and disappearing down the numerous tunnelled passages. The outgoing empty-handed hosts are partly concealed amongst the bulky burdens of the incomers, and can only be distinguished by looking closely amongst them.”[[60]]
It used to be supposed that these leaves themselves, in a decaying state, were the food of the ants, whilst another theory was that they were used to make a sort of underground roof to the nest with. Belt’s discovery took everybody—including himself—completely by surprise. “I believe,” he says, “the real use they make of them is as a manure, on which grows a minute species of fungus, on which they feed: that they are in reality mushroom growers and eaters”;[[60]] and he thus narrates the circumstances which led him to this conclusion:—
“When I first began my warfare against the ants that attacked my garden, I dug down deeply into some of their nests. In our mining operations we also, on two occasions, carried our excavations from below up through very large formicariums, so that all their underground workings were exposed to observation. I found their nests below to consist of numerous rounded chambers, about as large as a man’s head, connected together by tunnelled passages leading from one chamber to another. Notwithstanding that many columns of the ants were continually carrying in the cut leaves, I could never find any quantity of these in the burrows, and it was evident that they were used up in some way immediately they were brought in. The chambers were always about three-parts filled with a speckled brown flocculent, spongy-looking mass of a light and loosely connected substance. This mass, which I have called the ant-food, proved on examination to be composed of minutely subdivided pieces of leaves, withered to a brown colour and overgrown and lightly connected together by a minute white fungus that ramified in every direction throughout it.”[[60]] Belt assured himself in many ways, but not through actually seeing them do so, that this fungus was what the ants fed on, and he adds, “that they do not eat the leaves themselves I convinced myself; for I found near the tenanted chambers deserted ones filled with the refuse particles of leaves that had been exhausted as manure for the fungus, and were now left, and served as food for larvæ of Staphylinidæ and other beetles.”[[60]]