The paths or trails of the Attas represent very remarkable feats of engineering, and wind about through jungle and glade for surprising distances. I once traced a very old and wide trail for well over two hundred yards. Taking little Third-of-an-inch for a type (although he would rank as a rather large Atta), and comparing him with a six-foot man, we reckon this trail, ant-ratio, as a full twenty-five miles. Belt records a leaf-cutter's trail half a mile long, which would mean that every ant that went out, cut his tiny bit of leaf, and returned, would traverse a distance of a hundred and sixteen miles. This was an extreme; but our Atta may take it for granted, speaking antly, that once on the home trail, he has, at the least, four or five miles ahead of him. The Atta roads are clean swept, as straight as possible, and very conspicuous in the jungle. The chief high-roads leading from very large nests are a good foot across, and the white sand of their beds is visible a long distance away. I once knew a family of opossums living in a stump in the center of a dense thicket. When they left at evening, they always climbed along as far as an Atta trail, dropped down to it, and followed it for twenty or thirty yards. During the rains I have occasionally found tracks of agoutis and deer in these roads. So it would be very possible for the Attas to lay the foundation for an animal trail, and this, _à la_ calf-path, for the street of a future city. The part that scent plays in the trails is evidenced if we scatter an inch or two of fresh sand across the road. A mass of ants banks against the strange obstruction on both sides, on the one hand a solid phalanx of waving green banners, and on the other a mob of empty-jawed workers with wildly waving antennæ. Scouts from both sides slowly wander forward, and finally reach one another and pass across. But not for ten minutes does anything like regular traffic begin again. When carrying a large piece of leaf, and traveling at a fair rate of speed, the ants average about a foot in ten seconds, although many go the same distance in five. I tested the speed of an Atta, and then I saw that its leaf seemed to have a peculiar-shaped bug upon it, and picked it up with its bearer. Finding the blemish to be only a bit of fungus, I replaced it. Half an hour later I was seated by a trail far away, when suddenly my ant with the blemished spot appeared. It was unmistakable, for I had noticed that the spot was exactly that of the Egyptian symbol of life. I paced the trail, and found that seventy yards away it joined the spot where I had first seen my friend. So, with occasional spurts, he had done two hundred and ten feet in thirty minutes, and this in spite of the fact that he had picked up a supercargo.