``We are now in the Amazon system of rivers,'' he announced with satisfaction one day. ``You see, the water is running South.'' But almost immediately they crossed a stream flowing in the opposite direction. ``Very curious,'' said Dr. Messinger. ``A discovery of genuine scientific value.''

Next day they waded through four streams at intervals of two miles, running alternately North and South. The chart began to have a mythical appearance.

``Is there a name for any of these streams,'' he asked Rosa.

``Macushi people called him Waurupang.''

``No, not river where we first camped: These rivers.''

``Yes, Waurupang.''

``This river here.''

``Macushi people call him all Waurupang.''

``It's hopeless,'' said Dr. Messinger.

``Don't you think that possibly we have struck the upper waters of the Waurupang?'' suggested Tony, ``and have crossed and recrossed the stream as it winds down the valley.''

``It is a hypothesis,'' said Dr. Messinger.

When they were near water they forced their way through blind bush; the trail there was grown over and barred by timber; only Indian eyes and Indian memory could trace its course; sometimes they crossed little patches of dry savannah, dun grass growing in tufts from the baked earth; thousands of lizards scampered and darted before their feet and the grass rustled like newspaper; it was burning hot in these enclosed spaces. Sometimes they climbed up into the wind, over loose red pebbles that bruised their feet; after these painful ascents they would lie in the wind till their wet clothes grew cold against their bodies; from these low eminences they could see other hill tops and the belts of bush through which they had travelled, and the file of porters trailing behind them. As each man and woman arrived he sank on to the dry grass and rested against his load; when the last of them came up with the party Dr. Messinger would give the word and they would start off again, descending into the green heart of the forest before them.

Tony and Dr. Messinger seldom spoke to one another, either when they were marching or at the halts for they were constantly strained and exhausted. In the evenings after they had washed and changed into clean shirts and flannel trousers, they talked a little, mostly about the number of miles they had done that day, their probable position and the state of their feet. They drank rum and water after their bath; for supper there was usually bully beef stewed with rice and flour dumplings. The Indians ate farine, smoked hog and occasional delicacies picked up by the way--armadillo, iguana, fat white grubs from the palm trees. The women had some dried fish with them that lasted for eight days; the smell grew stronger every day until the stuff was eaten, then it still hung about them and the stores but grew fainter until it merged into the general indefinable smell of the camp.

There were no Indians living in this country. In the last five days of the march they suffered from lack of water. They had left the Waurupang behind and the streams they came to were mostly dry; they had to reconnoitre up and down their beds in search of tepid, stagnant puddles. But after two weeks they came to a river once more, flowing deep and swift to the Southeast. This was the border of the Pie-wie country and Dr. Messinger marked the place where they stopped, Second Base Camp. The cabouri fly infested this stream in clouds.

``John, I think it's time you had a holiday.''

``A holiday what from, mumsey?''

``A change ... I'm going to California in July. To the Fischbaums--Mrs. Arnold Fischbaum, not the one who lives in Paris. I think it would do you good to come with me.''

``Yes, mumsey.''

``You would like it, wouldn't you?''

``Me? Yes, I'd like it.''

``You've picked up that way of talking from Brenda. It sounds ridiculous in a man.''

``Sorry, mumsey.''

``All right then, that's settled.''

At sunset the cabouri fly disappeared. Until then, through the day, it was necessary to keep covered; they settled on any exposed flesh like house-flies upon jam; it was only when they were gorged that their bite was perceptible; they left behind a crimson, smarting circle with a black dot at its centre. Tony and Dr. Messinger wore cotton gloves which they had brought for the purpose, and muslin veils, hanging down under their hats. Later they employed two women to squat beside their hammocks and fan them with leafy boughs; the slightest breeze was enough to disperse the flies, but soon as Tony and Dr. Messinger dozed the women would lay aside their work, and they woke instantly, stung in a hundred places. The Indians bore the insects as cows bear horse-flies; passively with occasional fretful outbursts when they would slap their shoulders and thighs.

After dark there was some relief for there were few mosquitoes at this camp but they could hear the vampire bats all night long nuzzling and flapping against their netting.

The Indians would not go hunting in this forest. They said there was no game, but Dr. Messenger said it was because they were afraid of the evil spirits of the Pie-wie people. Provisions were not lasting as well as Dr. Messinger had calculated. During the march it had been difficult to keep a proper guard over the stores. There was a bag of farine, half a bag of sugar and a bag of rice short. Dr. Messinger instituted careful rationing; he served them himself, measuring everything strictly in an enamel cup; even so the women managed to get to the sugar behind his back. He and Tony had finished the rum except for one bottle which was kept in case of emergency.

``We can't go on breaking into tinned stores,'' said Dr. Messinger peevishly. ``The men must go out and shoot something.''

But they received the orders with expressionless, downcast faces and remained in camp.

``No birds, no animals here,'' explained Rosa. ``All gone. May be they get some fish.''

But the Indians could not be persuaded to exert themselves. They could see the sacks and bales of food heaped on the bank; it would be plenty of time to start hunting and fishing when that had been exhausted.

Meanwhile there were canoes to be built.

``This is clearly Amazon water,'' said Dr. Messinger. ``It probably flows into the Rio Branco or the Rio Negro. The Pie-wies live along the bank and the City must from all accounts be down-stream of us, up one of the tributaries. When we reach the first Pie-wie village we will be able to get guides.''

The canoes were made of woodskin. Three days were spent in finding trees of suitable age and straightness and in felling them. They cut four trees and worked on them where they lay, clearing the brush for a few feet round them. They stripped the bark with their broad-bladed knives; that took another week. They worked patiently but clumsily; one woodskin was split in getting it off the trunk. There was nothing Tony and Dr. Messinger could do to help. They spent that week guarding the sugar from the women. As the men moved about the camp and the surrounding bush, their steps were soundless; their bare feet seemed never to disturb the fallen leaves, their bare shoulders made no rustle in the tangled undergrowth their speech was brief and scarcely audible, they never joined in the chatter and laughing of their women; sometimes they gave little grunts as they worked; only once they were merry, when one of them let his knife slip as he was working on the tree-trunk and cut deeply into the ball of his thumb. Dr. Messinger dressed the wound with iodine, lint and bandages. After that the women constantly solicited him, showing him little scratches on their arms and legs and asking for iodine.

Two of the trees were finished on one day, then another next day (that was the one which split) and the fourth two days after that; it was a larger tree than the others. When the last fibre was severed four men got round the trunk and lifted the skin clear. It curled up again at once making a hollow cylinder, which the men carried down to the water-side and set afloat, fastening it to a tree with a loop of vine-rope.