This is the story of Ab, a man of the Age of Stone, who lived so long ago that we cannot closely fix the date, and who loved and fought well. Once only does the writer depart from accepted theories of scientific research. After an at least long-continued study of existing evidence and information relating to the Stone Ages, the conviction grew upon him that the mysterious gap supposed by scientific teachers to divide Paleolithic from Neolithic man never really existed. No convulsion of nature, no new race of human beings is needed to explain the difference between the relics of Paleolithic and Neolithic strugglers. Growth, experiment, adaptation, discovery, inevitable in man, sufficiently account for all the relatively swift changes from one form of primitive life to another more advanced, from the time of chipped to that of polished implements. Man has been, from the beginning, under the never resting, never hastening, forces of evolution. The earth from which he sprang holds the record of his transformations in her peat-beds, her buried caverns and her rocky fastnesses. The eternal laws change man, but they themselves do not change. Ab and Lightfoot and others of the cave people whose story is told in the tale which follows the author cannot disown. He has shown them as they were. Hungry and cold, they slew the fierce beasts which were scarcely more savage than they, and were fed and clothed by their flesh and fur. In the caves of the earth the cave men and their families were safely sheltered. Theirs were the elemental wants and passions. They were swayed by love, in some form at least, by jealousy, fear, revenge, and by the memory of benefits and wrongs. They cherished their young; they fought desperately with the beasts of their time, and with each other, and, when their brief, turbulent lives were ended, they passed into silence, but not into oblivion. The old Earth carefully preserved their story, so that we, their children, may read it now.