Sequels

I

TROPICAL midges of sorts live less than a day — sequoias have felt their sap quicken with the warmth of three thousand springs. Somewhere between these extremes, we open our eyes, look about us for a time, and close them again. Modern political geography and shift of government give us Methusalistic feelings; but a glance at rocks or stars sends us shuddering among the other motes, which glisten for a moment in the sunlight and then vanish.

We who strive for a little insight into evolution, and the meaning of things as they are, forever long for a glimpse of things as they were. Here at my British Guiana laboratory I wonder what the land was like before the dense mat of vegetation covered every rock and grain of sand; or how the rivers looked when first their waters trickled to the sea.

All our stories are of the middles of things — without beginning or end; we scientists are plunged suddenly upon a cosmos in the full uproar of æons of precedent, unable to look ahead, while to look backward we must look down.

Exactly a year ago I spent two hours in a clearing in the jungle back of Kartabo laboratory, and let my eyes and ears have full swing.¹ Now, in August of the succeeding year, I came again to this clearing, and found it no more a clearing. Indeed, so changed was it, that for weeks I had passed close by without a thought of the jungle meadow of the previous year; and now what finally turned me aside from my usual trail was a sound. Twelve months ago I wrote: ‘From the monotone of underworld sounds a strange little rasping detached itself, a reiterated, subdued scraping or picking. It carried my mind instantly to the throbbing theme of the Nibelungs, onomatopoetic of the little hammers forever busy at their underground work. I circled a small bush at my side, and found that the sound came from one of the branches near the top; so with my glasses I began a systematic search.’ This was as far as I ever got; for a flock of parrakeets exploded close at hand and blew the lesser sound out of mind. If I had stopped to guess, I should probably have considered the author a longicorn beetle or some fiddling orthopter.

Now, a year later, I suddenly stopped twenty yards away; for at the end of the silvery cadence of a wood-hewer, I heard the low, measured, toneless rhythm which instantly revived in my mind every detail of the clearing. I was headed toward a distant palm-frond, beneath whose tip was a nest of Rufous Hermits; for I wished to see the two atoms of hummingbirds at the moment when they rolled from their petit-pois egg-shells. I gave this up for the day, and turned up the hill, where, fifty feet away, were the stump and bush near which I had sat and watched. Three times I went past the place before I could be certain; and even at the last I identified it only by the relative position of the giant tauroneero tree, in which I had shot many cotingas. The stump was there, a bit lower and more worn at the crevices, leaking sawdust like an over-loved doll; but the low shrub had become a tall sapling, the weeds — vervain, boneset, velvet-leaf — all had been topped and killed off by dense-foliaged bushes and shrubs, which a year before had not raised a leaf above the meadow-level. The old vistas were gone, the landscape had closed in, the wilderness was shutting down. Nature herself was ‘letting in the jungle.’ I felt like Rip Van Winkle, or even more alien, as if the passing of time had been accelerated and my longed-for leap had been accomplished, beyond the usual ken of mankind’s earthly lease of senses.

All these astounding changes had come to pass through the unceasing heat and moisture of a tropical year; and under deliberate scientific calculation there was nothing unusual in the alteration. I remembered the remarkable growth of one of the laboratory bamboo shoots during the rainy season — twelve and a half feet in sixteen days; but that was a single stem, like a blade of grass, whereas here the whole landscape was altered — new birds, new insects, branches, foliage, flowers, where, twelve short months past, was open sky above low weeds.

In the hollow root on the beach, my band of crane-flies had danced for a thousand hours; but here was a sound which had apparently never ceased for more than a year — perhaps five thousand hours of daylight. It was a low, penetrating, abruptly reiterated beat, occurring about once every second and a half, and distinctly audible a hundred feet away. The ’low bush,’ from which it proceeded last year, was now a respectable sapling, and the source far out of reach overhead. I discovered a roundish mass among the leaves; and the first stroke of the axe sent the rhythm up to once a second, but did not alter the timbre. A few blows, and the small trunk gave way, and I fled for my life. But there was no angry buzzing, and I came close. After a cessation of ten or fifteen seconds the sound began again, weaker but steady. The foliage was alive with small Axteca ants; but these were tenants of several small nests near by and at the catastrophe overran everything.

The largest structure was the smooth carton nest of a wasp — a beautiful species, pale yellowish-red with winecolored wings. Only once did an individual make an attempt to sting, and, even when my head was within six inches, the wasps rested quietly on the broken combs. By careful watching, I observed that many of the insects jerked the abdomen sharply downward, hitting the comb, or shell, of smooth paper a forceful blow, and producing a very distinct noise. I could not at first see the mass of wasps that were giving forth the major rhythm, as they were hidden deep in the nest, but the fiftyodd wasps in sight kept perfect time; or occasionally an individual skipped one or two beats, coming in regularly on every alternate or every third beat. Where they were two or three deep, the uppermost wasps struck the insects below them with their abdomens in perfect rhythm with the next beat. For half an hour the sound continued, then died down, and was not heard again. The wasps dispersed during the night, and the nest was deserted.

It reminded me of the telegraphing ants, which I have often heard in Borneo — a remarkable sweeping roll, caused by the host of insects striking the leaves with their heads, and produced only when they are disturbed. It appeared to be of the nature of a warning signal, giving me opportunity to back away from the stinging legions that filled the thicket against which I pushed.

The rhythm of these wasps was very different. They were peaceable, not even resenting the devastation of their home; but always and always must the inexplicable beat, beat, beat be kept up, serving some purpose quite hidden from me. During succeeding months I found two more nests, with similar habits of sound-vibrations that led to their discovery. From one small nest, which fairly shook with the strength of their beats, I extracted a single wasp and placed him in a glass-topped metal box. For three minutes he kept up the rhythmic beat. Then I began a more rapid tattoo on the bottom of the box, and the changed tempo confused him, so that he stopped at once, and would not tap again.

A few little Mazaruni daisies lived on hero and there, blossoming bravely, trying to believe that the shade was lessening and not daily becoming more dense. But their leaves were losing heart and paling in the scant light. Another six months, and dead leaves and moss would obliterate them, and the zone of brilliant flowers and gorgeous butterflies and birds would shift many feet into the air, with the tops of the trees as a new level.

As long as I remained by my stump, my visitors were of the jungle. A yellow-bellied trogon came quite close, and sat, as trogons do, very straight and stiff, like a poorly mounted bird, watching passing flycatchers and me and the glimpses of sky. At first he rolled his little cuckoo-like notes, and his brown mate swooped up, saw me, shifted a few feet farther off, and perched, full of curiosity, craning her neck and looking first with one eye, then the other. Now the male began a content song. With all possible variations of his few and simple tones, on a low and very sweet timbre, he belied his unoscine perch in the tree of bird-life and sang to himself. Now and then he was drowned out by the shrilling of cicadas; but it was a delightful serenade, and he seemed to enjoy it as much as I did. A few days before, I had made a careful study of the syrinx of this bird, whom we may call, rather euphoniously, Trogonurus curucui, and had been struck by the simplicity of both muscles and bones. Now, he having summoned his mate in regular accents, there followed this unexpected whisper song. It recalled similar melodies sung by pheasants and Himalayan partridges, usually after they had gone to roost.

Once the female swooped after an insect; and in the midst of one of the sweetest passages of the male trogon, a green grasshopper shifted his position. He was only two inches away from the singer, and all this time had been hidden by his chlorophyll-hued veil. And now the trogon fairly fell off the branch, seizing the insect almost before the tone died away. Swallowing it with considerable difficulty, the harmony was taken up again, a bit throaty for a few notes. Then the pair talked together in usual trogon fashion, and the sudden shadow of a passing vulture drew forth discordant cat-calls, as both birds dashed from sight, to avoid the fancied hawk.

A few minutes later the vocal seal of the jungle was uttered by a quadrille bird. When the notes of this wren are heard, I can never imagine open blazing sunshine, or unobstructed blue sky. Like the call of the wood pewee, the wren’s radiates coolness and shadowy quiet. No matter how tropic or breathless the jungle, when the flute-like notes arise, they bring a feeling of freshness, they start up a mental breeze, which cools one’s thoughts; and although there may be no water for miles, yet we can fairly hear the drip of cool drops falling from thick moss to pools below. First an octave of two notes of purest silver; then a varying strain of eight or ten notes, so sweet and powerful, so individual and meaningful, that it might stand for some wonderful motif in a great opera. I shut my eyes, and I was deaf to all other sounds while the wren sang. And as it dwelt on the last note of its phrase, a cicada took it up on the exact tone, and blended the two final notes into a slow vibration, beginning gently, and rising with the crescendo of which only an insect, and especially a cicada, is master.

Here was the eternal, hypnotic tomtom rhythm of the East, grafted upon supreme Western opera. For a time my changed clearing became merely a sounding-box for the most thrilling of jungle songs. I called the wren as well as I could, and he came nearer and nearer. The music rang out only a few yards away. Then he became suspicious, and after that each phrase was prefaced by typical wren-scolding. He could not help but voice his emotions, and the harsh notes told plainly what he thought of my poor imitation. Then another feeling would dominate, and out of the maelstrom of harshness, of tumbled, volcanic vocalization, would rise the pure silver stream of single notes.

III

The wren slipped away through the masses of fragrant Davilla blossoms, but his songs remained and are with me to this moment. And now I leaned back, lost my balance, and grasping the old stump for support, loosened a big piece of soft, mealy wood. In the hollow beneath, I saw a rainbow in the heart of the dead tree.

This rainbow was caused by a bug; and when we stop to think of it, we realize how little there is in a name. For when we say bug, — or, for that matter, bogy or bug-bear, — we are garbling the sound which our very, very forefathers uttered when they saw a spectre or hobgoblin. They called it bugge, or even bwg; but then, they were more afraid of spectres in those days than we are, who imprison will-o’-thewisps in Very lights, and rub fox-fire on our watch-faces. At any rate, here was a bug who seemed to ill-deserve his name; although, if the Nibelungs could fashion the Rheingold, why could not a bug conceive a rainbow?

Whenever a human, and especially a house-human, thinks of bugs, she thinks unpleasantly and in superlatives. And it chances that evolution, or natural selection, or life’s mechanism, or fate, or a creator, has wrought them into form and function also in superlatives. Cicadas are supreme in longevity and noise: one of our northern species sucks in silent darkness for seventeen years, and then, for a single summer, breaks all American long-distance records for insect’s voices. To another group, known as Fulgorids, gigantic heads and streamers of wax have been allotted. Those possessing the former rejoice in the name of lantern flies, but they are at present unfaithful-vestal bugs; indeed, it is extremely doubtful if their wicks were ever trimmed or lighted. To see a big wax-bug flying with trailing ribbons slowly from tree to tree in the jungle is to recall the streaming trains of a flock of peacocks on the wing.

The Membracids most of all deserve the name of bugges, for no elf or hobgoblin was ever more bizarre. Their legs and heads and bodies are small and aphid-like; but aloft there spring minarets and handles and towers and thorns and groups of hairy balls, out of all reason and sense. Only Stegosaurus and Triceratops bear comparison. Another group of five-sided bugs are the skunks and civet-cats among insects, guarding themselves from danger by an aura of obnoxious distillation.

Not the least, strange of all this assemblage is the author of our rainbow in the stump. My awkwardness had broken into a hollow, which opened to the light on the other side of the rotten bole. A vine had tendriled its way into the crevice, where the little weaver of rainbows had found board and lodging. We may call him toad-hopper or spittlebug — or, as Fabre says, ‘Contentonsnous de Cicadelle, qui respecte le tympan.’ Like all its kindred, the bubble-bug finds Nirvana in a sappy green stem. It has neither strong flight nor sticky wax, thorny armature nor gas-barrage, so it proceeds to weave an armor of bubbles, a cuirass of liquid film. This, in brief, was the rainbow which caught my eye when I broke open the stump. Up to that moment no rainbow had existed — only a little light sifting through from the vine-clad side. But now a ray of sun shattered itself on the pile of bubbles, and sprayed out into a curved glory.

Bubble-bugs blow their froth only when immature, and their bodies are a distillery, or home-brew, of sorts. No matter what the color, or viscosity, or chemical properties of sap, regardless of whether it flows in liana, shrub, or vine, the bug’s artesian product is clear, tasteless, and wholly without the possibility of being blown into bubbles. When a large drop has collected, the tip of the abdomen encloses a retort of air, inserts this in the drop, and forces it out. In some way an imponderable amount of oil or dissolved wax is extruded and mixed with the drop — an invisible shellac, which toughens the bubble and gives it an astounding glutinous endurance. As long as the abdominal air-pump can be extended into the atmosphere, so long does the pile of bubbles grow until the insect is deep buried, and to penetrate this is as unpleasant an achievement for small marauders as to force a cobweb entanglement. I have draped a big pile of bubbles around the beak of an insect-eating bird, and watched it shake its head and wipe its beak in evident disgust at the clinging oily films. In the north we have the bits of fine white foam which we characteristically call frog-spittle; but these tropic relatives have bigger bellows, and their covering is like the interfering mass of film that emerges from the soap-bubble bowl when a pipe is thrust beneath the surface and that delicious gurgling sound is produced.

The most marvelous part of the whole thing is that the undistilled well that the bubble-bug taps would often overwhelm it in an instant, either by the burning acidity of its composition, or by the rubber coating of death into which it hardens in the air. Yet from this current of lava or vitriol our bug does three wonderful things: it distills sweet water for its present protective cell of bubbles; it draws purest nourishment for continual energy to run its bellows and pump; and simultaneously it fills its blood and tissues with a pungent flavor, which in the future will be a safeguard against the attacks of birds and lizards. Little by little its wings swell to full spread and strength; muscles are fashioned in its hind-legs, which, in time, will shoot it through great distances of space; and pigment of the most brilliant yellow and black forms on its wing-covers. When, at last, it shuts down its little still and creeps forth through the filmy veil, it is immature no longer, but a brilliant frog-hopper, sitting on the most conspicuous leaves, trusting, by pigmental warning, to advertise its inedibility, and watchful for a mate, so that the future may hold no dearth of bubble-bugs.

IV

On my first tramp each season in the tropical jungle, I see the legionary army ants hastening on their way to battle, and the leaf-cutters plodding along, with chlorophyll hods over their shoulders, exactly as they did last year, and the year preceding, and probably a hundred thousand years before that. The Colony Egos of army and leaf-cutters may quite reasonably be classified, at least according to kingdom. The former, with carnivorous, voracious, nervous, vitally active members, seems an intangible, animal-like organism; while the stolid, unemotional, weatherswung Attas resemble the flowing sap of the food on which they subsist — vegetable.

Yet, whatever the simile, in the case of both of these colonies of ants, the net of unconscious precedent is too closely drawn, the mesh of instinct is too fine, to hope for any initiative. This was manifested by the most significant and spectacular occurrence I have ever observed in the world of insects. Some two years or more ago I studied, and reported upon, a nest of Ecitons, or Army Ants.² Eighteen months later, apparently the same army appeared and made a similar nest of their own bodies, in the identical spot above the door of the outhouse, where I had found them before. Again we had to break up the temporary resting-place of these nomads, and killed about three quarters of the colony with various deadly chemicals.

In spite of the tremendous slaughter, the Ecitons, in late afternoon, raided a small colony of Wasps-of-the-Painted-Nest. These little chaps construct a round, sub-leaf carton-home, as large as a golf-ball, which carries out all the requirements of counter-shading and ruptive markings. The flattened, shadowed under-surface was white, and most of the sloping walls dark brown, down which extended eight white lines, following the veins of the leaf overhead. The side close to the stem of the leaf, and consequently always in deep shadow, was pure white. The eaves, catching high lights, were black.

All this marvelous merging with leaf-tones went for naught when once an advance Eciton scout located the nest. As the deadly mob approached, the wasplets themselves seemed to realize the futility of offering battle, and the entire colony of forty-four gathered in a forlorn group on a neighboring leaf, while their little castle was rifled — larvæ and pupæ torn from their cells, and rushed down the stems to the chaos that was raging in the Ecitons’ own home. The wasps could guard against optical discovery, but the blind Army Ants had senses which transcended vision, if not even scent.

Late that night, our lanterns showed the remnants of the Eciton army wandering aimlessly about, making near approach impossible, but apparently lacking any definite concerted action.

At six o’clock the next morning I was starting for a swim, when, at the foot of the laboratory steps, I saw a swiftly moving, broad line of Army Ants on safari, passing through the compound to the beach. I traced them back under the servants’ quarters, through two clumps of bamboos, to the out-house. Later, I followed along the column down to the river sand, through a dense mass of underbrush, through a hollow log, up the bank, back through light jungle — to the out-house again; and on a large fallen log, a few feet beyond the spot where their nest had been, the ends of the circle actually came together. It was the most astonishing thing, and I had to verify it again and again before I could believe the evidence of my eyes. It was a strong column, six lines wide in many places, and the ants fully believed that they were on their way to a new home; for most were carrying eggs or larvæ, although many had food, including the larvæ of the Painted-Nest wasplets. For an hour at noon, during heavy rain, the column weakened and almost disappeared; but when the sun returned, the lines rejoined, and the revolution of the vicious circle continued.

There were several places which made excellent points of observation, and here we watched and marveled. Careful measurement of the great circle showed a circumference of twelve hundred feet. We timed the laden Ecitons, and found that they averaged two to two and three quarters inches a second. So a given individual would complete the round in about two hours and a half. Many guests were plodding along with the ants — mostly staphylinids, of which we secured five species: a brown Histerid beetle, a tiny Chalcid, and several Phorid flies, one of which was winged.

The fat Histerid beetle was most amusing, getting out of breath every few feet, and abruptly stopping to rest, turning around in its tracks, standing almost on its head, and allowing the swarm of ants to run up over it and jump off. Then on it would go again, keeping up the terrific speed of two and a half inches a second, for another yard. Its color was identical with the Ecitons’ armor, and when it folded up, nothing could harm it. Once a worker stopped and antennæd it suspiciously; but aside from this, it was accepted as one of the line of marchers.

All the afternoon the insane circle revolved; at midnight, the hosts were still moving; the second morning many had weakened and dropped their burdens and the general pace had very appreciably slackened. But still the blind grip of instinct held them. On, on, on they must go! Always before in their nomadic life there had been a goal — a sanctuary of hollow tree, snug heart of bamboos; surely this terrible grind must end somehow. In this crisis, even the Spirit of the Army was helpless. Along the normal paths of Eciton life he could inspire endless enthusiasm, illimitable energy; but here his material units were bound upon the wheel of their perfection of instinct. Through sun and cloud, day and night, hour after hour, there was found no Eciton with individual initiative enough to turn aside an ant’s breadth from the circle that he had traversed perhaps fifteen times.

Fewer and fewer now came along the well-worn path; burdens littered the line of march, like the arms and accoutrements thrown down by a retreating army. At last, a scanty single line struggled past — tired, hopeless, bewildered, idiotic, and thoughtless to the last. Then some half-dead Eciton straggled from the circle along the beach, and threw the line behind him into confusion. The desperation of total exhaustion had accomplished what necessity and opportunity and normal life could not. Several others followed his scent instead of that leading back toward the out-house; and as an amœba gradually flows into one of its own pseudopodia, so the forlorn hope of the great Eciton army passed slowly down the beach and on into the jungle. Would they die singly and in bewildered groups, or would the remnant draw together, and, again guided by the supermind of its Mentor, lay the foundation of another army, and again come to nest in my out-house?

Thus was the ending still unfinished, the finale buried in the future — and in this we find the fascination of Nature and of Science. Who can be bored for a moment in the short existence vouchsafed us here, with dramatic beginnings barely hidden in the dust, with the excitement of every moment of the present, and with all of cosmic possibility lying just concealed in the future, whether of Betelgeuse, of Amœba, or — of ourselves? Vogue la galère!