Men who practiced Abbevillian culture had some flaked tools—which they may have used for scraping—but their best-recognized output was a crude hand ax. It was not too well formed. Undoubtedly they also used wood and bone, but we have no sure evidence of this. Some assign Abbevillian culture to the first interglacial period, about 500,000 years ago. Some move it up 200,000 years, into the second interglacial. Some even place it in the third. Perhaps it lasted through all three. At any rate, the men who made it liked a fairly warm climate. As neither they nor their Acheulean successors made fire or controlled it effectively, the early Europeans probably retreated to Africa during the glaciations. [Illustration: _Ancient implements of bone and wood. Left, part of the thigh bone of a mammoth, found at Piltdown, England, in the same deposit as the now infamous skull; it, too, is a forgery. Right, part of a wooden spear, its point hardened by fire, found at Clacton-on-Sea, England, and probably made by Acheulean or Mousterian man. (Left, after Dawson and Woodward, 1917; right, after Crawford, 1921.)_] The Acheulean hand ax was thinner and better, and it is found with various kinds of scrapers and cleavers. Probably it was this culture that left us part of a very crude wooden spear at Clacton-on-Sea, in England, though some date it a little later. The earliest association of human remains with tools in Europe is that of the Swanscombe skull and Acheulean tools in Pleistocene gravels of the Thames in Kent. We are not too sure about the physical appearance of the men of Abbevillian and Acheulean times. For the Abbevillian there is possibly a fragment of jaw, a most interesting one, to be sure, but not actually found with any kind of artifact. For Acheulean times there are no dependable skeletons to help us, and not even complete skulls. In fact, there are not as many candidates for the position as we thought we had a decade or so ago. Galley Hill man turned out to be a case of mistaken identity. He has a thick skull and a few other primitive traits—a fossil type of modern man, perhaps, but not nearly as old as we once thought. His bones lacked a fluorine mineral content typical of other fossils that belonged in the interglacial deposits where the Galley Hill skull reposed, eight feet below the surface.