Edge of the Jungle

by William Beebe

I thought of the first handful of sand thrown out for the base of Cheops, of the first brick placed in position for the Great Wall, of a fresh-cut trunk, rough-hewn and squared for a log-cabin on Manhattan; of the first shovelful of earth flung out of the line of the Panama Canal. Yet none seemed worthy of comparison with even what little I knew of the significance of this ant's labor, for this was earnest of what would make trivial the engineering skill of Egyptians, of Chinese patience, of municipal pride and continental schism.

Imagine sawing off a barn-door at the top of a giant sequoia, growing at the bottom of the Grand Cañon, and then, with five or six children clinging to it, descending the tree, and carrying it up the cañon walls against a subway rush of rude people, who elbowed and pushed blindly against you. This is what hundreds of leaf-cutting ants accomplish daily, when cutting leaves from a tall bush, at the foot of the bank near the laboratory.

There are three dominant labor-unions in the jungle, all social insects, two of them ants, never interfering with each other's field of action, and all supremely illustrative of conditions resulting from absolute equality, free-and-equalness, communalism, socialism carried to the (forgive me!) anth power. The Army Ants are carnivorous, predatory, militant nomads; the Termites are vegetarian scavengers, sedentary, negative and provincial; the Attas, or leaf-cutting ants, are vegetarians, active and dominant, and in many ways the most interesting of all.

The casual observer becomes aware of them through their raids upon gardens; and indeed the Attas are a very serious menace to agriculture in many parts of the tropics, where their nests, although underground, may be as large as a house and contain millions of individuals. While their choice among wild plants is exceedingly varied, it seems that there are certain things they will not touch; but when any human-reared flower, vegetable, shrub, vine, or tree is planted, the Attas rejoice, and straightway desert the native vegetation to fall upon the newcomers. Their whims and irregular feeding habits make it difficult to guard against them. They will work all round a garden for weeks, perhaps pass through it en route to some tree that they are defoliating, and then suddenly, one night, every Atta in the world seems possessed with a desire to work havoc, and at daylight the next morning, the garden looks like winter stubble—a vast expanse of stems and twigs, without a single remaining leaf. Volumes have been written, and a whole chemist's shop of deadly concoctions devised, for combating these ants, and still they go steadily on, gathering leaves which, as we shall see, they do not even use for food.

Although essentially a tropical family, Attas have pushed as far north as New Jersey, where they make a tiny nest, a few inches across, and bring to it bits of pine needles.

In a jungle Baedeker, we should double-star these insects, and paragraph them as "Atta, named by Fabricius in 1804; the Kartabo species, cephalotes; Leaf-cutting or Cushie or Parasol Ants; very abundant. Atta, a subgenus of Atta, which is a genus of Attii, which is a tribe of Myrmicinæ, which is a subfamily of Formicidæ," etc.

With a feeling of slightly greater intimacy, of mental possession, we set out, armed with a name of one hundred and seventeen years' standing, and find a big Atta worker carving away at a bit of leaf, exactly as his ancestors had done for probably one hundred and seventeen thousand years.

We gently lift him from his labor, and a drop of chloroform banishes from his ganglia all memory of the hundred thousand years of pruning. Under the lens his strange personality becomes manifest, and we wonder whether the old Danish zoölogist had in mind the slender toe-tips which support him, or in a chuckling mood made him a namesake of C. Quintius Atta. A close-up shows a very comic little being, encased in a prickly, chestnut-colored armor, which should make him fearless in a den of a hundred anteaters. The front view of his head is a bit mephistophelian, for it is drawn upward into two horny spines; but the side view recalls a little girl with her hair brushed very tightly up and back from her face.

The connection between Atta and the world about him is furnished by this same head: two huge, flail-shaped antennæ arching up like aerial, detached eyebrows—vehicles, through their golden pile, of senses which foil our most delicate tests. Outside of these are two little shoe-button eyes; and we are not certain whether they reflect to the head ganglion two or three hundred bits of leaf, or one large mosaic leaf. Below all is swung the pair of great scythes, so edged and hung that they can function as jaws, rip-saws, scissors, forceps, and clamps. The thorax, like the head of a titanothere, bears three pairs of horns—a great irregular expanse of tumbled, rock-like skin and thorn, a foundation for three pairs of long legs, and sheltering somewhere in its heart a thread of ant-life; finally, two little pedicels lead to a rounded abdomen, smaller than the head. This Third-of-an-inch is a worker Atta to the physical eye; and if we catch another, or ten, or ten million, we find that some are small, others much larger, but that all are cast in the same mold, all indistinguishable except, perhaps, to the shoe-button eyes.

When a worker has traveled along the Atta trails, and has followed the temporary mob-instinct and climbed bush or tree, the same irresistible force drives him out upon a leaf. Here, apparently, instinct slightly loosens its hold, and he seems to become individual for a moment, to look about, and to decide upon a suitable edge or corner of green leaf. But even in this he probably has no choice. At any rate, he secures a good hold and sinks his jaws into the tissue. Standing firmly on the leaf, he measures his distance by cutting across a segment of a circle, with one of his hind feet as a center. This gives a very true curve, and provides a leaf-load of suitable size. He does not scissor his way across, but bit by bit sinks the tip of one jaw, hook-like, into the surface, and brings the other up to it, slicing through the tissue with surprising ease. He stands upon the leaf, and I always expect to see him cut himself and his load free, Irishman-wise. But one or two of his feet have invariably secured a grip on the plant, sufficient to hold him safely. Even if one or two of his fellows are at work farther down the leaf, he has power enough in his slight grip to suspend all until they have finished and clambered up over him with their loads.