V. UP THE RIVER OF TAPIRS

Here we were to begin our trip overland, on pack-mules and pack-oxen, scores of which had been gathered to meet us. Several days were needed to apportion the loads and arrange for the several divisions in which it was necessary that so large a party should attempt the long wilderness march, through a country where there was not much food for man or beast, and where it was always possible to run into a district in which fatal cattle or horse diseases were prevalent. Fiala, with his usual efficiency, took charge of handling the outfit of the American portion of the expedition, with Sigg as an active and useful assistant. Harper, who like the others worked with whole-hearted zeal and cheerfulness, also helped him, except when he was engaged in helping the naturalists. The two latter, Cherrie and Miller, had so far done the hardest and the best work of the expedition. They had collected about a thousand birds and two hundred and fifty mammals. It was not probable that they would do as well during the remainder of our trip, for we intended thenceforth to halt as little, and march as steadily, as the country, the weather, and the condition of our means of transportation permitted. I kept continually wishing that they had more time in which to study the absorbingly interesting life-histories of the beautiful and wonderful beasts and birds we were all the time seeing. Every first-rate museum must still employ competent collectors; but I think that a museum could now confer most lasting benefit, and could do work of most permanent good, by sending out into the immense wildernesses, where wild nature is at her best, trained observers with the gift of recording what they have observed. Such men should be collectors, for collecting is still necessary; but they should also, and indeed primarily, be able themselves to see, and to set vividly before the eyes of others, the full life-histories of the creatures that dwell in the waste spaces of the world.

At this point both Cherrie and Miller collected a number of mammals and birds which they had not previously obtained; whether any were new to science could only be determined after the specimens reached the American Museum. While making the round of his small mammal traps one morning, Miller encountered an army of the formidable foraging ants. The species was a large black one, moving with a well-extended front. These ants, sometimes called army-ants, like the driver-ants of Africa, move in big bodies and destroy or make prey of every living thing that is unable or unwilling to get out of their path in time. They run fast, and everything runs away from their advance. Insects form their chief prey; and the most dangerous and aggressive lower- life creatures make astonishingly little resistance to them. Miller's attention was first attracted to this army of ants by noticing a big centipede, nine or ten inches long, trying to flee before them. A number of ants were biting it, and it writhed at each bite, but did not try to use its long curved jaws against its assailants. On other occasions he saw big scorpions and big hairy spiders trying to escape in the same way, and showing the same helpless inability to injure their ravenous foes, or to defend themselves. The ants climb trees to a great height, much higher than most birds' nests, and at once kill and tear to pieces any fledglings in the nests they reach. But they are not as common as some writers seem to imagine; days may elapse before their armies are encountered, and doubtless most nests are never visited or threatened by them. In some instances it seems likely that the birds save themselves and their young in other ways. Some nests are inaccessible. From others it is probable that the parents remove the young. Miller once, in Guiana, had been watching for some days a nest of ant-wrens which contained young. Going thither one morning, he found the tree, and the nest itself, swarming with foraging ants. He at first thought that the fledglings had been devoured, but he soon saw the parents, only about thirty yards off, with food in their beaks. They were engaged in entering a dense part of the jungle, coming out again without food in their beaks, and soon reappearing once more with food. Miller never found their new nests, but their actions left him certain that they were feeding their young, which they must have themselves removed from the old nest. These ant- wrens hover in front of and over the columns of foraging ants, feeding not only on the other insects aroused by the ants, but on the ants themselves. This fact has been doubted; but Miller has shot them with the ants in their bills and in their stomachs. Dragon-flies, in numbers, often hover over the columns, darting down at them; Miller could not be certain he had seen them actually seizing the ants, but this was his belief. I have myself seen these ants plunder a nest of the dangerous and highly aggressive wasps, while the wasps buzzed about in great excitement, but seemed unable effectively to retaliate. I have also seen them clear a sapling tenanted by their kinsmen, the poisonous red ants, or fire-ants; the fire-ants fought and I have no doubt injured or killed some of their swarming and active black foes; but the latter quickly did away with them. I have only come across black foraging ants; but there are red species. They attack human beings precisely as they attack all animals, and precipitate flight is the only resort.