原文 (英语)

INTRODUCTION. 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. In his work the author has been cordially assisted by some of the ablest searchers of two continents into the life history of prehistoric times. With characteristic helpfulness and interest, these already burdened students have aided and encouraged him, and to them he desires to express his sense of profound obligation and hi