The manufacture of stone tools was a development of the greatest importance, considerably facilitating the consumption of meat. The tools could also be used for pounding and for sharpening stakes for digging, thus increasing the sources of vegetable foods. Sometimes bone was also used. Natural stones were intensively collected at the habitation sites and must have been used as aids to hunting and protection. Indeed, since fire-making was unknown, such stones must have been one of man’s chief means of keeping other scavengers away from his larder.