From human remains, weapons, tools and other vestiges of human activity,
found in the more recent deposits on the earth’s surface, the presence
of man in these far off ages is made increasingly certain. The
Pleistocene or Quaternary epoch, as represented by these objects of
primitive culture, ranged over a vast period of time which has been
conveniently divided into two great epochs, the Paleolithic or Old
Stone, and the Neolithic or New Stone Age, these being so named from the
material chiefly used by primitive peoples in the manufacture of their
weapons and other implements. The distinction between the two periods,
which are not to be taken as chronological, since they overlap in many
places, is based essentially on the different treatment of the material,
which during the immeasurably longer Old Stone Age was at first merely
chipped, flaked, or otherwise rudely fashioned, but in the New more
carefully worked and polished.