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 his earnest thanks.

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