At last their first week in this new world of beauty and mystery came to an end. At Belem they boarded a well-appointed steamer and embarked for the thousand-mile voyage to Manaos, which is only six degrees from the equator and one of the hottest cities of the world. There followed another week of a life that was strange and new to the travelers from Cornwall. There were silent, steaming days when the earth seemed to swoon beneath the glare of the lurid sun, and only at night would a breath of air cross the water, which gleamed like a silver burning-glass. For their very lives' sake, white men and Indians alike had learned to keep as quiet and cool as possible during those fiery hours. Only Hen, coming from a race that since the birth of time had lived close to the equator, moved about with a cheerfulness which no amount of heat or humidity could lessen. At night, when the fatal sun had reluctantly disappeared in a mass of pink and violet clouds, the life-bringing breeze would blow in fresh and salt from the far-away sea, and all living creatures would revive. The boys soon learned that, in the mid-heat of a tropical summer, the night was the appointed time for play and work, and they slept during the day as much as possible in shaded, airy hammocks.

One evening, after an unusually trying day, the night wind sprang up even before the sun had set. Here and there, across the surface of the river, flashed snow-white swallows with dark wings. As the fire-gold of the sun touched the horizon, the silver circle of the full moon showed in the east, and for a moment the two great lights faced each other. Then the sun slipped behind the rim of the world, and the moon rose higher and higher, while the Indian crew struck up a wailing chant full of endless verses, with a strange minor cadence like the folk-songs of the Southern negro. Hen Pine translated the words of some of them, and crooned the wailing melody:

Down the echoing channels, through the endless gloomy forests, the cadence of the song rose and fell.

Suddenly, in the still moonlight from the river-bank came a single low note of ethereal beauty and unutterable sorrow. Slowly it rose and swelled, keeping its heartbreaking quality and exquisite beauty. At the sound the men stopped singing, and it seemed as if an angel were sobbing in the stillness. On and on the song went, running through eight lonely, lovely notes which rose and swelled until there seemed to be nothing in the world except that beautiful voice, finally ending in a sob which brought the tears to Will's eyes. Then out into the moonlight flitted the singer, a quiet-colored little brown-and-gray bird, the celebrated solitaire, the sweetest, saddest singer of the Brazilian forest.

After all this music, supper was served. It began with a thick, violet-colored drink in long glasses filled with cracked ice. The boys learned from Professor Ditson that this was made from the fruit of the assai-palm. It was strangely compounded of sweet and sour and had besides a fragrance and a tingle which made it indescribably refreshing. This was followed by an iced preparation made from the root of the manioc, whose juice is poisonous, but whose pulp is wholesome and delicious. Before being served it had been boiled with the fruit of the miriti-palm, which added a tart sweetness to its taste which the Northerners found most delightful. The next course was a golden-yellow compound of a rich, nutty flavor, the fruit of the mucuju-palm, which has a yellow, fibrous pulp so full of fat that vultures, dogs, and cats eat it greedily. For dessert, there was a great basket of sweet lemons, mangos, oranges, custard-apples, and other fruits.

After supper they all grouped themselves in the bow and there, in comfortable steamer-chairs, watched the steamer plow its way through a river of ink and silver. That day, Jud, while in his hammock, had seen, to his horror, what seemed to be a slender vine, dangling from one of the trees, change into a pale-green snake some eight feet long, whose strange head was prolonged into a slender, pointed beak. Even as the old man stared, it flashed across the deck not two feet away from him and disappeared in another tree. So perfectly did its color blend with the leaves that the instant it reached them it seemed to vanish from sight.

"It was the palm-snake," said Professor Ditson, after Jud told them of his experience. "It lives on lizards, and, although venomous, has never been known to bite a human being. If you had only been brave enough," he went on severely, "to catch it with your naked hand, we might even now have an invaluable record of the effects of its venom."

"What is the most venomous snake in the world?" broke in Will, as Jud tried to think of words strong enough to express what he thought of the scientist's suggestion.

"The hamadryad or king cobra," returned the professor. "I once secured one over fourteen feet long."

"How did you catch it?" queried Will.

"Well," said the professor, "I came across it by a fortunate accident. I was collecting butterflies in India at a time of the year when it is especially pugnacious, and this particular snake dashed out of a thicket at me. It came so unexpectedly that I had to run for my life. It seems ridiculous that I should have done so," he went on apologetically, "but the bite of the hamadryad is absolutely fatal. This one gained on me so rapidly that I was at last compelled to plunge into a near-by pond, since this variety of snake never willingly enters water."

"What happened then?" inquired Will, as the scientist came to a full stop.

"When I reached the opposite shore, a quarter of a mile away, and was about to land," returned the professor, "out of the rushes this same snake reared up some six feet. With the rare intelligence which makes the hamadryad such a favorite among collectors, it had circled the lake and was waiting for me."

"Snappy work!" said Jud, shivering. "I can't think of any pleasanter finish to a good swim than to find a nice fourteen-foot snake waitin' for me. What did you do then?"

"I floated around in deep water until my assistant came and secured the snake with a forked stick. It is now in the New York ZoÖlogical Gardens at the Bronx," concluded the professor.

Jud drew a deep breath. "That reminds me," he said at last, "of a time I once had with a pizen snake when I was a young man. I was hoein' corn up on a side hill in Cornwall when I was about sixteen year old," he continued. "All on a sudden I heard a rattlin' an' down the hill in one of the furrows came rollin' a monstrous hoop-snake. You know," he explained, "a hoop-snake has an ivory stinger in its tail an' rolls along the ground like a hoop, an' when it strikes it straightens out an' shoots through the air just like a spear."

"I know nothing of the kind," broke in Professor Ditson.

"Well," said Jud, unmoved by the interruption, "when I saw this snake a-rollin' an' a-rattlin' down the hill towards me, I dived under the fence an' put for home, leavin' my hoe stickin' up straight in the furrow. As I slid under the fence," he went on, "I heard a thud, an' looked back just in time to see the old hoop-snake shoot through the air an' stick its stinger deep into the hoe-handle. It sure was a pizen snake, all right," he went on, wagging his head solemnly. "When I came back, an hour or so later, the snake was gone, but that hoe-handle had swelled up pretty nigh as big as my leg."

There was a roar of laughter from Will and Joe, while Jud gazed mournfully out over the water. Professor Ditson was vastly indignant.

"I feel compelled to state," he said emphatically, "that there is no such thing as a hoop-snake and that no snake-venom would have any effect on a hoe-handle."

"Have it your way," said Jud. "It ain't very polite of you to doubt my snake story after I swallowed yours without a word."

At Manaos they left the steamer, and Professor Ditson bought for the party a montaria, a big native boat without a rudder, made of plank and propelled by narrow, pointed paddles. Although Hen and Pinto and the Professor were used to this kind of craft, it did not appeal at all favorably to the Northerners, who were accustomed to the light bark-canoes and broad-bladed paddles of the Northern Indians. Joe was especially scornful.

"This boat worse than a dug out," he objected. "It heavy and clumsy and paddles no good either."

"You'll find it goes all right on these rivers," Professor Ditson reassured him. "We only have a few hundred miles more, anyway before we strike the Trail."

Under the skilful handling of Hen and Pinto, the montaria, although it seemed unwieldly, turned out to be a much better craft than it looked; and when the Northerners became used to the narrow paddles, the expedition made great headway, the boys finding the wide boat far more comfortable for a long trip than the smaller, swifter canoe.

After a day, a night, and another day of paddling, they circled a wide bend, and there, showing like ink in the moonlight, was the mouth of another river.

"White men call it Rio Negros, Black River," the Indian explained to the boys; "but my people call it the River of Death."

As the professor, who was steering with a paddle, swung the prow of the boat into the dark water, the Indian protested earnestly.

"It very bad luck, Master to enter Death River by night," he said.

"Murucututu, murucututu," muttered the witch-owl, from an overhanging branch.

Hen joined in Pinto's protest.

"That owl be layin' a spell on us, Boss," he said. "Better wait till mornin'."

The professor was inflexible.

"I have no patience with any such superstitions," he said. "We can cover fully twenty-five miles before morning."

The Mundurucu shook his head and said nothing more, but Hen continued his protests, even while paddling.

"Never knew any good luck to come when that ol' owl's around," he remarked mournfully. "It was him that sicked them vampires on to Will here, an' we're all in for a black time on this black ribber."

"Henry," remarked Professor Ditson, acridly, "kindly close your mouth tightly and breathe through your nose for the next two hours. Your conversation is inconsequential."

"Yassah, yassah," responded Hen, meekly, and the montaria sped along through inky shadows and the silver reaches of the new river in silence.

About midnight the forest became so dense that it was impossible to follow the channel safely, and the professor ordered the boat to be anchored for the night. Usually it was possible to make a landing and camp on shore, but to-night in the thick blackness of the shadowed bank, it was impossible to see anything. Accordingly, the party, swathed in mosquito-netting, slept as best they could in the montaria itself.

It was at the gray hour before dawn, when men sleep soundest, that Jud was awakened by hearing a heavy thud against the side of the boat close to his head. It was repeated, and in the half-light the old man sat up. Once again came the heavy thud, and then, seemingly suspended in the air above the side of the boat close to his head, hung a head of horror. Slowly it thrust itself higher and higher, until, towering over the side of the boat, showed the fixed gleaming eyes and the darting forked tongue of a monstrous serpent. Paralyzed for a moment by his horror for all snake-kind, the old man could not move, and held his breath until the blood drummed in his ears. Only when the hideous head curved downward toward Joe did Jud recover control of himself. His prisoned voice came out then with a yell like a steam-siren, and he fumbled under his left armpit for the automatic revolver which he wore in the wilderness, night and day, strapped there in a water-proof case.

"Sucuruju! Sucuruju! Sucuruju!" shouted Pinto, aroused by Jud's yell. "The Spirit of the River is upon us!" And he grasped his machete just as Jud loosened his revolver.

Quick as they were, the huge anaconda, whose family includes the largest water-snakes of the world, was even quicker. With a quick dart of its head, it fixed its long curved teeth in the shoulder of the sleeping boy, and in an instant, some twenty feet of glistening coils glided over the side of the boat. The scales of the monster shone like burnished steel, and it was of enormous girth in the middle, tapering off at either end. Jud dared not shoot at the creature's head for fear of wounding Joe, but sent bullets as fast as he could pull the trigger into the great girth, which tipped the heavy boat over until the water nearly touched the gunwale. Pinto slashed with all his might with his machete at the back of the great snake, but it was like attempting to cut through steel-studded leather. In spite of the attack, the coils of the great serpent moved toward the boy, who, without a sound, struggled to release his shoulder from the terrible grip of the curved teeth. The anaconda, the sucuruju of the natives, rarely ever attacks a man; but when it does, it is with difficulty driven away. This one, in spite of steel and bullets, persisted in its attempt to engulf the body of the struggling boy in its coils, solid masses of muscle powerful enough to break every bone in Joe's body.

It was Hen Pine who finally saved the boy's life. Awakened by the sound of the shots and the shouts of Jud and Pinto, he reached Joe just as one of the fatal coils was half around him. With his bare hands he caught hold of both of the fierce jaws and with one tremendous wrench of his vast arms literally tore them apart. Released from their death grip, Joe rolled to one side, out of danger. The great snake hissed fiercely, and its deadly, lidless eyes glared into those of the man. Slowly, with straining, knotted muscles, Hen wrenched the grim jaws farther and farther apart. Then bracing his vast forearms, he bowed his back in one tremendous effort that, in spite of the steel-wire muscles of the great serpent, bent its deadly jaws backward and tore them down the sides, ripping the tough, shimmering skin like so much paper. Slowly, with a wrench and a shudder, the great water-boa acknowledged defeat, and its vast body pierced, slashed, and torn, reluctantly slid over the side of the boat.

As Hen released his grip of the torn jaws, the form of the giant serpent showed mirrored for an instant against the moonlit water and then disappeared in the inky depths below. Joe's thick flannel shirt had saved his arm from any serious injury, but Professor Ditson washed out the gashes made by the sharp curved teeth with permanganate of potash, for the teeth of the boas and pythons, although not venomous, may bring on blood-poisoning, like the teeth of any wild animal. Jud was far more shaken by the adventure than Joe, who was as impassive as ever.

"Snakes, snakes, snakes!" he complained. "They live in the springs and pop up beside the paths and drop on you out of trees. Now they're beginnin' to creep out of the water to kill us off in our sleep. What a country!"

"It's the abundance of reptile life which makes South America so interesting and attractive," returned Professor Ditson, severely.

It was Pinto who prevented the inevitable and heated discussion between the elders of the party.

"Down where I come from," he said, "lives a big water-snake many times larger than this one, called the Guardian of the River. He at least seventy-five feet long. We feed him goats every week. My grandfather and his grandfather's grandfather knew him. Once," went on Pinto, "I found him coiled up beside the river in such a big heap that I couldn't see over the top of the coils."

"I don't know which is the worse," murmured Jud to Will, "seein' the snakes which are or hearin' about the snakes which ain't. Between the two, I'm gettin' all wore out."

Then Pinto went back again to his predictions about the river they were on.

"This river," he said, "is not called the River of Death for nothing. The old men of my tribe say that always dangers come here by threes. One is passed, but two more are yet to come. Never, Master, should we have entered this river by night."

"Yes," chimed in Hen, "when I heered that ol' witch-owl I says to myself, 'Hen Pine, there'll be somethin' bad a-doin' soon.'"

"You talk like a couple of superstitious old women," returned Professor Ditson, irritably.

"You wait," replied the Indian, stubbornly; "two more evils yet to come."

Pinto's prophecy was partly fulfilled with startling suddenness. The party had finished breakfast, and the montaria was anchored in a smooth, muddy lagoon which led from the river back some distance into the forest. While Will and Hen fished from the bow of the boat the rest of the party curled themselves up under the shade of the overhanging trees to make up their lost sleep. At first, the fish bit well and the two caught a number which looked much like the black bass of northern waters. A minute later, a school of fresh-water flying-fish broke water near them and flashed through the air for a full twenty yards, like a flight of gleaming birds.

As the sun burned up the morning mist, it changed from a sullen red to a dazzling gold and at last to a molten white, and the two fishermen nodded over their poles as little waves of heat ran across the still water and seemed to weigh down their eyelids like swathings of soft wool. The prow of the boat swung lazily back and forth in the slow current which set in from the main river. Suddenly the dark water around the boat was muddied and discolored, as if something had stirred up the bottom ten feet below. Then up through the clouded water drifted a vast, spectral, grayish-white shape. Nearer and nearer to the surface it came, while Hen and Will dozed over their poles. Will sat directly in the bow, and his body, sagging with sleep, leaned slightly over the gunwale.

Suddenly the surface of the water was broken by a tremendous splash, and out from its depth shot half the body of a fish nearly ten feet in length. Its color was the gray-white of the ooze at the bottom of the stream in which it had lain hidden until attracted to the surface by the shadow of the montaria drifting above him. Will awakened at the hoarse shout from Hen just in time to see yawning in front of him a mouth more enormous than he believed any created thing possessed outside of the whale family. It was a full five feet between the yawning jaws, which were circled by a set of small sharp teeth. Even as he sprang back, the monster lunged forward right across the edge of the boat and the jaws snapped shut.

Will rolled to one side in an effort to escape the menancing depths, and although he managed to save his head and body from the maw of the great fish, yet the jaws closed firmly on both his extended arms, engulfing them clear to the shoulder. The little teeth, tiny in comparison with the size of the jaws in which they were set, hardly more than penetrated the sleeves of his flannel shirt and pricked the skin below, but as the monster lurched backward toward the water its great weight drew the boy irresistibly toward the edge of the boat, although he dug his feet into the thwarts and twined them around the seat on which he had been sitting. Once in the river, the fatal jaws would open again, and he felt that he would be swallowed as easily as a pike would take in a minnow.

Even as he was dragged forward to what seemed certain death, Will did not fail to recognize a familiar outline in the vast fish-face against which he was held. The small, deep-set eyes, the skin like oiled leather, long filaments extending from the side of the jaw, and the enormous round head were nothing more than that of the catfish or bullhead which he used to catch at night behind the mill-dam in Cornwall, enlarged a thousand times.

Although the monster, in spite of its unwieldy size, had sprung forth, gripped its intended prey, and started back for the water in a flash, yet Hen Pine was even quicker. In spite of his size, there was no one in the party quicker in an emergency than the giant negro. Even as he sprang to his feet he disengaged the huge steel machete which always dangled from his belt. Hen's blade, which he used as a bush-hook and a weapon, was half again as heavy as the ordinary machete, and he always kept it ground to a razor edge. He reached the bow just as the great, gray, glistening body slipped back over the gunwale, dragging Will irresistibly with it. Swinging the broad heavy blade over his head, with every ounce of effort in his brawny body, Hen, brought the keen edge down slantwise across the gray back of the river-monster, which tapered absurdly small in comparison with the vast spread of the gaping jaws. It was such a blow as Richard the Lion-hearted might have struck; and just as his historic battle-sword would shear through triple steel plate and flesh and bone, so that day the machete of Hen Pine, unsung in song or story, cut through the smooth gray skin, the solid flesh beneath, and whizzed straight on through the cartilaginous joints of the great fish's spine, nor ever stopped until it had sunk deep into the wood of the high gunwale of the boat itself. With a gasping sigh, the monster's head rolled off the edge of the boat and slowly sank through the dark water, leaving the long, severed trunk floating on the surface. Reaching out, the negro caught the latter by one of the back fins and secured it with a quick twist of a near-by rope.

"That's the biggest piraiba I ever see," he announced. "They're fine to eat, an' turn about is fair play. Ol' piraiba try to eat you; now you eat him." And while Will sat back on the seat, sick and faint from his narrow escape, Hen proceeded to haul the black trunk aboard and carve steaks of the white, firm-set flesh from it.

"Every year along the Madeira River this fish tip over canoes and swallow Indians. They's more afraid of it," Hen said, "than they is of alligators or anacondas."

When Hen woke up the rest of the party and told them of the near-tragedy Pinto croaked like a raven.

"Sucuruju one, piraiba two; but three is yet to come," he finished despondingly. The next two days, however, seemed to indicate that the River had exhausted its malice against the travelers. The party paddled through a panorama of sights and sounds new to the Northerners, and at night camped safely on high, dry places on the banks. On the morning of the third day the whole party started down the river before daylight and watched the dawn of a tropical day, a miracle even more beautiful than the sunrises of the North. One moment there was perfect blackness; then a faint light showed in the east; and suddenly, without the slow changes of Northern skies, the whole east turned a lovely azure blue, against which showed a film and fretwork of white clouds, like wisps of snowy lace.

Just as the sun came up they passed a tall and towering conical rock which shot up three hundred feet among the trees and terminated in what looked like a hollowed summit. Pinto told them that this was Treasure Rock, and that nearly half a thousand years ago the Spaniards, in the days when they were the cruel conquerors of the New World, had explored this river. From the ancestors of Pinto's nation and from many another lesser Indian tribe they had carried off a great treasure of gold and emeralds and diamonds. Not satisfied with these, they had tried to enslave the Indians and make them hunt for more. Finally, in desperation the tribes united, stormed their persecutors' camp, killed some, and forced the rest to flee down the river in canoes. When the Spaniards reached the rock, they landed, and, driving iron spikes at intervals up its steep side, managed to clamber up to the very crest and haul their treasure and stores of water and provisions after them by ropes made of lianas. There, safe from the arrows of their pursuers in the hollow top, they stood siege until the winter rains began. Then, despairing of taking the fortress, the Indians returned to their villages; whereupon the Spaniards clambered down, the last man breaking off the iron spikes as he came, and escaped to the Spanish settlements. Behind them, in the inaccessible bowl on the tip-top of the rock, they left their treasure-chest, expecting to return with the reinforcements and rescue it. The years went by and the Spaniards came not again to Black River, but generation after generation of Indians handed down the legend of Treasure Rock, with the iron-bound chest on its top, awaiting him who can scale its height.

Jud, a treasure-hunter by nature, was much impressed by Pinto's story.

"What do you think of takin' a week off and lookin' into this treasure business?" he suggested. "I'll undertake to get a rope over the top of this rock by a kite, or somethin' of that sort, an' then I know a young chap by the name of Adams who would climb up there an' bring down a trunk full of gold an' gems. What do you say?"

"Pooh!" is what Professor Amandus Ditson said, and the expedition proceeded in spite of Jud's protests.