Part 16

After the shower all came forth at full speed, but for some minutes there was considerable confusion. The sluice of water had evidently washed away much of the scent which stood for guide-posts, directing signs, and pointing hands along the trail. Only after many false starts were the old pathways discovered and again traversed. In one place the ants climbed a huge log and marched along the top for six or seven yards. I timed them carefully and found that on this straightaway track their average speed was two and a half feet in ten seconds. So they covered a mile in three hours and a half, and in all the army ants I have ever watched this rate of speed never slackens; in fact, it frequently greatly increases. When hot on the scent of prey they double their usual gait.

There are as many ludicrous sights to be seen in the ranks of army ants as there are among the banner-decked processions of the leaf-cutters. Along the tree-trunk track came three big white-heads straddling an inch-worm--in this case an inch-and-a-half-worm. They leaned forward and downward, the heads of those behind overlapping the abdomens in front, and they looked for all the world like the riders of an old-fashioned three-seated bicycle, spurting along the trail. Another simile, even more vivid, evoked the vision of some weirdly constructed, elongated myriopod with eighteen legs. After a hard fight, in the course of which I was stung twice, I unseated the trio and took the measuring worm away from them. As I lifted it from where it had fallen, at least fifty ants hurled themselves at the spot, jaws snapping, trembling with violent rage. I walked ten feet away and dropped the worm in the midst of another column, and within an equal number of seconds three new white-heads had mounted it and were hustling it along--the replicas in appearance and method of the first team.

Many species of stranger ants were killed and carried off as food, but now and then I noted a most significant exception. In three different parts of the glade I saw good-sized, pale, flesh-colored ants which walked unharmed in the very ranks of the terrible host. Unharmed they were, but not wholly above suspicion, and their progress was not an easy one. For every unburdened ant which passed leaped at the pale one, antennaed it fiercely for a moment and reluctantly released it. One could read their indecision as they slowly loosened their hold, turning again and again and waving their antennae as if to make sure that it was not better to act on their suspicion and slay at once. Finally, they always passed on. The pale ones had some strange inaudible password, some sensory parole which protected them. And their total lack of fear showed their knowledge of their immunity. Even with the added sense of sight which they possessed, they chose voluntarily to accept this dubious, reluctantly accorded friendship. But it was probable that, even if they lived in the very community or nest of the army ants, theirs was the hard-earned dependence of neutrals who were liable to be knocked down at a moment's notice, and searched for any strange, inimical scent which would spell instant death.

In one place the army column made a slight detour round a hillock of sandgrains upon which a host of tiny brown ants was laboring. I thought it remarkable that such immunity should be accorded these dwarfs, and I sought the reason. It was forthcoming at once when I gingerly lifted a big soldier with the forceps and dropped him on the ant-hill. What occurred was a replica of the usual army ant scene, but enacted as if viewed through the large end of an opera-glass. Scores of the minute brown chaps rushed forth and for a moment fairly overbore the white-headed giant. Indeed, before he could recover he was dragged partly down a sandy hole. His jaws brandished and champed, but his assailants were so small that they slipped through them unharmed. Many actually seized the jaws themselves and were hurled through the air as they snapped together. Regaining his feet, the great army ant staggered off and, fortunately for him, rolled down a slope into another column of his own kind. Here he freed himself little by little, scraping off the minute fighting browns with the help of two very small workers, whose jaws, being much less in size, were better able to grip the diminutive furies. Their assistance was half-hearted, and the odor of the dead and dying pygmies was distinctly disliked by them. They were apparently well aware of the capabilities of these small cousins, and held them in high respect. This outburst of successful defense on the part of the small ants was unexpected. I glanced back at their hill and saw them unconcernedly piling up grains as if nothing had occurred to disturb them. I wondered if, with senses perfectly attuned, with an enlarging-glass ability of observation, one might not find still lesser communities which would in their turn consider the little brown ants as giants, and on the space of a pin's head attack them and fly at their throats.

A species of silvery-gray ant which was abundant in the glade was an object of special enmity, and even after one of these was killed and being carried along, passing army ants would rush up and give it a vicious, unnecessary nip. One such ant made its escape from the hold of a small worker; but before it had taken ten steps it was actually buried under a rolling mass of army ants. The flying leap with which these athletes make their tackle would delight the heart of any football coach, although their succeeding activities belong rather to savage warfare. Termites, or so-called white ants, are, curiously enough, immune from attack. Yet these slow-moving, fat-bodied creatures would seem first-rate food, and the fight which they could put up would not stand an instant before a concerted rush of battling army ants. The saving character is doubtless odor or taste. I dropped a tunnelful of these insects in the path of the army ants and they were quite ignored, although the black-and-white-headed fellows were terribly angry and excited.

I coveted a small beetle of peculiar pattern which the ants were hurrying along, and in taking it from them I accidentally cut an army ant in two. His abdomen rolled down a small slope and caused considerable panic among his fellows. They formed a ring round it and waved their antennae in mid-air, the scent of the blood of their own kind causing them to forget hurry and burdens and their normal activities. The front part of the ant seemed but little inconvenienced and endeavored to seize and carry the load it had dropped. Little by little it began to realize that all was not right, and after one or two attempts to turn and investigate, it ran rapidly down the trail. I made a dab at it to put it out of what seems better called inconvenience than misery, but succeeded only in bisecting the thorax, so that there remained the head and front pair of legs. These lost nothing in activity, and by means of the single pair of legs the head rowed itself rapidly along, its antennae twiddling vigorously those of every ant it met. This was uncanny, a little too much, and I ground the fraction of ant to powder. No wonder the army ant is such a virile creature, endowed with the most extreme emotions, when, with such a small section of its anatomy remaining it can continue to show such astounding activity.

One could study for hours the interactions among the army ants themselves. More than once I saw a good-sized ant transporting one of its fellows, exactly as it would carry a bit of booty. I tried to examine this ant, and to my surprise, both attacked me ferociously. The one which was carried was neither dead, ill, nor disabled, but very much alive. I cannot even suggest an explanation of this phenomenon, as it did not seem an attempt to aid a comrade in distress.

As dusk began to settle down, I found a column of ants which must have discovered and sacked the city of some stranger ants. They were laden with ant-booty: eggs, larvae, and dead ants by the hundred. It was comprehensible, but what I did not at first understand was a dense line of ants moving solidly in one direction, all laden with large eggs and immature ants, which they were carrying with great care. A large number of the huge soldiers patrolled the outer flanks of the column, more than I had seen with all the other traffic lines together. I realized at last that I was looking at an actual moving of a portion of the army ant household itself. It was guarded and transported with all the care of which these insects were capable. The infant ants rested safely in the great jaws, the same jaws which all day had been busy slashing and biting and tearing, and carrying food for these same infants.

And now the tropical night began to close down and I made my way back to the sandpit. The last of the columns was making its way out, systematically from the bottom up, each ant following in turn. The moment the last bit of prey passed up the column, by some wonderfully delicate and subtile sense, every ant knew of it, and the corduroy rose, the hand-rails unjointed themselves, the ropes unspliced, the embankments dislodged of their own volition, and stepping-stones took to themselves legs. After hours of total inactivity, these sentient paraphernalia of the via formica became, once more, beings surcharged with ceaseless movement, alert and ready to become a useful cog in the next movement of this myriad-minded machine. I jumped down into the pit. The great gold-spotted toad stretched and scratched himself, looked at me, and trembled his throat. I was not an army ant! The millipede cautiously reared its head from the sand and felt timidly about.

I looked out and saw the last of the mighty army disappearing into the undergrowth. I listened and heard no chirp of cricket, nor voice of any insect in the glade. Silence brooded, significant of wholesale death. Only at my feet two ants still moved, a small worker and a great white-headed soldier. Both had been badly disabled in the struggles in the pit, and now vainly sought to surmount even the first step of the lofty cliff. They had been ruthlessly deserted. The rearing of new hosts was too easy a matter for nature to have evolved anything like stretchers or a Red Cross service among these social beings. The impotence of these two, struggling in the dusk, only emphasized the terrible vitality of their distant fellows. As the last twilight of day dimmed, I saw the twain still bravely striving, and now the toad was watching them intently. A poor-me-one called mournfully from a distance, and I walked slowly toward home.

A YARD OF JUNGLE

Within five minutes the daily downpour of tropical rain would drench the jungle. At this moment the air was tense with electricity, absolutely motionless, and saturated with odorous moisture. The voices of all the wild creatures were hushed. The sense of mystery which is always so dominant in a tropical jungle seemed nearer, more vital, but more than ever a mystery. Its insistency made one oblivious of the great heat. The beating of one's heart became a perceptible sound, absurdly loud. All the swamp and jungle seemed listening to it.

Suddenly a voice came out of the heart of this mystery, and fittingly enough, the voice seemed something a little more or less than human, and also fittingly it uttered but a single word, and that word a question. And the listener realized that the answer to the question was the only thing which made life and work worth while. The throb of the blood in his veins was forgotten, and all his senses reached out to the sights and sounds and scents about him. And again the great black frog called from its slimy seat hidden in the still blacker water of the jungle swamp. Its voice was deep, guttural, and a little inhuman, but it asked as plainly as any honest man could ask, Wh--y? And after a minute, Wh--y?

I squatted in the center of a trail. Within walking distance behind me flowed the yellow waters of the Amazon, and the igarape from which the frog had called was even now feeling the tidal heave of the ocean. Ahead, the jungle stretched without a break for three thousand miles or more. And here for a week I had suffered bodily torture, twisting into unhappy positions for hours at a time, watching the birds which crowded the berry-laden foliage of a single jungle tree. In the cool of early morning, throughout the terrible breathless heat of mid-day and the drenching downpour of afternoon, the frog and I put our questions. There was hope in our interrogation. And my five senses all gave aid, and my hand wrote down facts, and my mind pondered them.

In the very suburbs of Para, at the mouth of the great Amazon and within a hundred miles of the equator, I found a Mecca of bird-life. It was a gastronomic Mecca to be sure, a tall, slender, wild cinnamon tree,--canella do matto the natives called it. For a full week I invited torture by attempting to study the bird-life of this single tree. This thing had not been done before; it might not be worth the doing. But testing such possibilities are as important to a naturalist's work as following along the more conventional and consequently more certain lines of investigation. I had no time for exploration of the surrounding country; so I had determined to risk all my precious hours upon intensive observation in one spot.

The century before, a plantling had pushed up through the jungle mold and had won success in the terrible competition of the tropics--the helpless, motionless, silent strife of the vegetable folk. Year by year the lichen-sculptured trunk had pushed its way upward toward light and air, miraculously saved from the deadly embraces of the lianas which crawled forever through the jungle. Today it had gained an accepted place. Although no forest giant, with no great buttresses or masses of parasitic growths, it held up its branches and twigs in full sunlight a hundred feet or more above the ground. And its twiggy fingers were laden with a wonderful harvest of fruit, uncounted berries which attracted the birds from distant roosts and drinking places.

Here, then, a thousand combinations of fate had led me, and here I suffered day by day. Bound to the earth like other normal men, my eyes should have been directed forward. Now I forced them upward for hours at a time, and all the muscles of neck and shoulders revolted. Then eyestrain and headache and a touch of fever followed, and I cast about for means to ameliorate my bodily ills. I dragged a canvas steamer chair to my place of vigil and all my body was grateful.

In memory, there now remain only the highlights of new discoveries, the colorful moments of unalloyed realization of success. Nevertheless this new method of tropical work brought its own new delights and trials. One joy lay in the very difficulties to be overcome. Every sense came into play. Sight, first and foremost, had been put to the most severe of tests in attempting to record the happenings against the glare of the sky high up among the foliage of this bit of jungle. I strained through my high-power glasses, until, when I looked without them, the world seemed withdrawn, dwarfed, as in the horrid imaginings of fever. The glasses gained in weight as I held them pointing vertically until they fairly dropped from my aching arms. My ears strove to catch every song, every note which might prove a character of worth. The jungle scents played upon my emotions and sometimes dominated my work; the faint aroma from some invisible orchid overhead, the telltale musk from a passing mammal, the healthful scent of clean jungle mold. As for taste, I had tested the aromatic berries and fruit of my canella tree, and for science' sake had proved two warningly colored insects. My sense of feeling had operated involuntarily and wholly aside from my scientific desires. Whether stimulated by dozens of mosquitoes, scores of ants, or hundreds of betes rouges or "mucuims," the insistency of discomfort never discouraged a primary desire to delve as deeply as possible into the secrets of this small area of tropical jungle.

As I walked slowly about beneath the tree or lay back resting in the chair, I seemed to be watching creatures of another world. Whether I ogled them with glasses or now and then brought one down with a charge of small shot, I was a thing of no account to the berry-eating flocks high overhead. A vulture soaring lower than usual passed over the tree, and the shadow of his partial eclipse of the sun froze every bird to instant silence and complete immobility. But my terrestrial activities wrought no excitement. The shot whistled through the foliage, one of their number dropped from sight, and life for the rest went on without a tremor. To ancestral generations, danger had come always from above, not below.

The very difficulty of observation rendered this mode of research full of excitement, and at the same time made my method of work very simple. Against the sky, green, blue, or black feathers all appear black, and the first two days my glasses helped but little. For several minutes I would watch some tiny bird which might have been a yellow warbler had I been three thousand miles farther north. After memorizing personal characters, scrutinizing its flight and method of feeding, striving to fix its individuality, I would secure the bird, and find in all probability that it was a calliste, or tanager of brilliant plumage. Tomorrow, if I were lucky, I might be able to tell off the numbers of this species, to watch them and to know that I was watching them. But recognition would not be by way of the cerulean or topaz or amethystine hues of plumage, but by the slight idiosyncrasies of flirting tail or wing or of general carriage.

Day by day, as I came to know better the jungle about me, I began to perceive a phase which did not change. Even when the sun shone most brightly, when the coolness of early morning had not yet passed, the mood of the Amazon jungle remained. It was consistent, this low swampy jungle, in its uniform, somber mystery. In spite of wholesale exaggeration it was the dangers which came to mind. Of all places in the world this was probably fullest of life, both in numbers and diversity. Yet it was death--or the danger of death--which seemed in waiting, always just concealed from view.

Beneath my tree I squatted silently. Just overhead the foliage might have been almost northern. The finely cut leaves were like willow, and at one side an oak, unusual but still an oak, reached out a thousand thousand motionless leaves, breaking the glare into innumerable patches. But ahead, the terrible interlacing of vines and thorny ropes, the strangle-hold of serpentine lianas on every available trunk--all this could be only tropic.

The ground glistened here and there with a film of black water which revealed the swamp. Everywhere the mold and leaves of a hundred years lay scattered, the last fallen still green. Many feet above, great fans dangled, rayed fronds dry and crackling, fallen from high overhead, and suspended, waiting for the interfering twigs and foliage to die in turn and permit them to seek dissolution in the mold.

The jungle was bright with flowers, but it was a sinister brightness--a poisonous, threatening flash of pigment, set off by the blackness of the shadows. Heliconia spikes gleamed like fixed scarlet lightning, zigzagging through the pungent air. Now and then a bunch of pleasing, warm-hued berries reminded one of innocuous currants, but a second glance showed them ripening into swollen, liver-hued globes which offered no temptation to taste. One tree dangled hideous purple cups filled with vermilion fruits, and not far away the color sequence was reversed. A low-growing, pleasant-leaved plant lifted bursting masses of purple-black, all dripping like wounds upon the foliage below. Many flowers were unrecognizable save by their fragrance and naked stamens, advertised neither by color nor form of blossom. I despaired of flowers worthy of the name, until close by my foot I saw a tiny plant with a comely, sweet-scented blossom, grateful to the eye and beautiful as our northern blooms are beautiful. The leaf was like scores lying about, and I realized that this was a sproutling of the giant tree. Nothing but the death of this monster could give the light and air which the little plant needed. It was doomed, but it had performed its destiny. It had hinted that much of the beauty of the jungle lay far above the mold and stagnant water. And then I remembered the orchids high overhead. And the realization came that the low-growing blooms needed their glaring colors to outshine the dim, shadowy under-jungle, and their nauseous fumes to outscent the musky vapors of decay.

The plants of the jungle won success either by elbowing their neighbors and fighting their path up to sunlight, or else by adapting their needs to the starvation meed of air and light allotted to the lowly growths. The big-leaved churacas had found another means of existence. They lived like permanent rockets, bursting in mid-air. A long, curved stem shot up and reached far out into space. It was so slender as to be almost invisible in the dim light. At its tip radiated a great burst of foliage, leaves springing out in all directions, and absorbing nutrition which a sapling growing amid the undergrowth could not possibly do.

From daybreak to dark the canella tree was seldom deserted. Usually a score or more birds fluttered and fed among its branches, and true to tropic laws, there were comparatively few individuals but a multitude of species. In the few hours I was able to devote to its study, I identified seventy-six different kinds, and together with those which I saw but could not name, I judge that more than a hundred species must have come to the berries during that week in early May. The first day I secured sixteen specimens, all different; and the following day yielded fourteen more, only one of which was a duplicate of the first day's results.

The bird visitors to the tree arrived in one of two characteristic ways. Many came direct and swiftly, singly or in pairs, flying straight and with decision. These came from a distance, with full knowledge of the berries. They fed quietly, and when satiated flew off. The second method of arrival was wholly casual,--loose flocks drifting slowly from the neighboring jungle, sifting into the tree, and feeding for a time before passing on. When these left it was rather hastily, and in answer to the chirps and calls of the members of their flock who had not been beguiled by the berries and hence had forged steadily ahead.

These more or less well-defined flocks are very characteristic of all tropical jungles. Little assemblages of flycatchers, callistes, tanagers, antbirds, manakins, woodhewers, and woodpeckers are drawn together by some intangible but very social instinct. Day after day they unite in these fragile fraternities which drift along, gleaning from leaves, flowers, branches, trunks, or ground, each bird according to its structure and way of life. They are so held together by an intangible gregarious instinct that day after day the same heterogeneous flock may be observed, identifiable by peculiarities of one or several of its members. The only recognizable bond is vocal--a constant low calling; half unconscious, absent-minded little signals which keep the members in touch with one another, spurring on the laggards, retarding the overswift.