|
|
Gallegacia Online Directory 06
Page 01
It is yet a much disputed point to what particular portion of the Glacial Age we can trace the appearance of man. We can profitably note the tendency of scientific thought in this direction. But a short time has elapsed since a few scholars here and there began to urge an antiquity for man extending back beyond the commonly accepted period of six thousand years. Though it is now well known and admitted that there are no good grounds for this estimate, yet such was its hold, such its sway over scientific as well as popular thought, that an appeal to this chronology was deemed sufficient answer to the discoveries of DePerthes, Schmerling, and others. It was but yesterday that this popular belief was overthrown and due weight given the discoveries of careful explorers in many branches, and the antiquity of man referred, on indisputable grounds, to a point of time at least as far back as the close of the preceding geological age.
Each of the winter forms of insects above mentioned can withstand long and severe cold weather--in fact, may be frozen solid for weeks and retain life and vigor, both of which are shown when warm weather and food appear again. Indeed, it is not an unusually cold winter, but one of successive thawings and freezings, which is most destructive to insect life. A mild winter encourages the growth of mould which attacks the hibernating larvae and pupae as soon as, from excess of rain or humidity, they become sickly; and it also permits the continued activity of insectivorous mammals and birds. Thus, moles, shrews, and field mice, instead of burying themselves deeply in the ground, run about freely during an open winter and destroy enormous numbers of pupae; while such birds as the woodpeckers, titmice, and chickadees are constantly on the alert, and searching in every crevice and cranny of fence and bark of tree for the hibernating larvae.
It is in France that we find the greatest wealth of relics of Cave-men. Sir John Lubbock has left us a description of the valley of the Vezere, where these caverns occur. The Vezere is a small tributary of the Dordogne. "The rivers of the Dordogne run in deep valleys cut through calcareous strata: and while the sides of the valley in chalk districts are generally sloping, in this case, owing probably to the hardness of the rock, they are frequently vertical. Small caves and grottoes frequently occur: besides which, as the different strata possess unequal power of resistance against atmospheric influence, the face of the rock is, as it were, scooped out in many places, and thus 'rockshelters' are produced. In very ancient times these caves and rock-shelters were inhabited by men, who have left behind them abundant evidence of their presence.
|
