Students of UFOs pondered the unusual phenomenon: “If the observers really did see what they described, and if all these objects were machines guided by a single intelligence, then what mysterious experiment were they performing? What purpose was served by the strange ballet of paired saucers? What was the meaning of the whitish streak appearing between two saucers on separation? What, finally, was the ‘angel’s hair’ that sublimed so readily in the air?”[XI-5, p. 150] UFO enthusiasts have suggested various theories of the nature and origin of the mysterious substance. According to one hypothesis[XI-5, p. 149], angel hair might be produced in the wake of a spacecraft moving in a force field; ionization of the atmosphere would produce ultraheavy particles which would react with ordinary air to form a kind of precipitate-angel hair--which would disintegrate as ionization decreased (see _Chapter_ IX). Another theory suggests that angel hair might be a chain polymer of cellulose containing radioactive carbon 14 (the carbon 14 being produced by the action of cosmic rays on atoms of nitrogen in the atmosphere), hydrogen, and oxygen from moisture in the air, the three elements combining under the action of ultraheavy particles produced by ionization[XI-6]. This theory overlooks the fact that cellulose is not formed from a combination of carbon dioxide, oxygen, and hydrogen in air. Rather, it is made by living organisms in a series of complicated enzymic reactions. Even if cellulose could be made by the hypothetical reaction suggested, it would contain no more carbon 14 than does the ordinary carbon dioxide in the air. To French entomologists, the angel hair seen in October 1952, was no mystery at all. The objects dancing the strange ballet were not spaceships, but spiders. Far from performing a mysterious experiment, they were merely carrying out the well-established routine of migration. Each year the young spiders of most species leave the nests of their infancy and prepare to establish their own homes. Crawling by the hundreds or the thousands to the tops of fence posts, walls, or trees, they spin long silken webs which, inflated by the air, carry the tiny emigrants up from the ground. These gossamer parachutes drift up and along on rising air currents, sometimes to great heights; they may soar for a few yards or for many miles over hills and valleys. These migrating balloonists have been observed as high as 14,000 feet, and at sea 200 miles from any land. Eventually drifting back to earth, the spiders detach the now useless parachutes and move off to build new nests for the coming year, while the abandoned gossamer may pile up in great masses on trees, fences, telephone wires, and ground, to decay and vanish in a matter of hours. These gossamer showers sometimes include so many outworn webs that the filmy blankets of fine silk may be several inches deep and may cover an entire landscape like snow.