We have reason to believe that the Big Game Hunters wandered over Illinois and the adjoining states during the last advance of the glaciers. Around 12,000 B.C. the climate in the Midwest became milder, the glaciers “retreated,” and the mighty torrents—the Mississippi, the Ohio and the Illinois that had torn irresistibly down their valleys—shrank into smaller, less turbulent rivers that occupied but a fraction of their former beds. The great shaggy mammoths, musk oxen, the ground sloths and the giant beavers moved westward toward the mountains or to the north. Some of the Big Game Hunters with their families may have followed the retreating glacier and the herds; others stayed behind in country to which they had grown attached. With the great herds gone, the human families remaining in Illinois had to hunt the game animals that now frequented the area—deer, elk (wapiti), bear and smaller mammals. The large hunting party was no longer practicable. The game roamed over the country singly or by twos or threes and had to be stalked by one or two hunters. Families were compelled to live widely separated one from another in order to secure ample food throughout the year. Thus developed a new way of life which we call the Archaic phase or culture. The hunter, as time passed, learned the secret habits of the deer, bear and raccoon and the more sluggish fishes. His wife and daughters learned the haunts and ways of the smaller animals, the rodents, turtles and lizards, discovered where edible greens, wild tubers, nuts and fruits grew and where mussels and snails abounded in creeks and rivers. With increasing knowledge Archaic man made better and fuller use of his changed and changing surroundings, food became more plentifully available, life easier and less hazardous though still very difficult from our standpoint. [Illustration: Fig. 4. Hafted primitive stone adze and grooved ax, with modern steel-bitted ax in the background. (B.B.)] With new needs and some leisure from the labor of providing food, Archaic man invented specialized devices, new methods of making tools and weapons, the more skillful among them shaping the objects carefully into symmetrical forms pleasing to the eye of others and strangely satisfying to the maker.[7] He pecked a hollow in both sides of his cobblestone hammer so he could grip it securely and use it more skillfully. He pecked and ground diorite and granite into adzes, hatchets (celts), and axes with a groove for hafting. These were a decided improvement over flaked choppers. He ground and polished banded and highly-colored shale (“slate”) into prismatic and cylindrical spearthrower weights and bored them with a tube, sand and water. His own person he decked out with necklaces and oval pendants (made by boring a hole in smooth flat waterworn pebbles) and with bone ornaments cut to shape, ground, engraved and polished. These he and his wife wore as had their forefathers but not the skin robes of glacial times.