Page:Popular Science Monthly Volume 76.djvu/139

Rh enormous production of eggs that the species does not die out. If, for instance, only one half of the descendents of one pair of cod-fish should survive, then in the third generation the whole Atlantic Ocean would be packed full of cod-fish! So overpopulation brings its own dangers when members of the same species must fight for space and food and kill one another, or migrate to new regions, before the marvelous balance in nature is readjusted.

Standing in the west wind, on the ocean-ward cliffs of Skaftö, one feels the deep-stirring obsession of the sea. It is no wonder that the Vikings could not resist the siren call of wind and wave. To-day their descendants Lovén, Nordenskiöld and Nansen, sailing forth into the great unknown, have made conquests in the realm of nature that will endure forever.