ABSTRACT
ALL through our studies there runs a big idea—the idea of evolution. This means that everything is the outcome of a long natural process of Becoming. Wherever we look we find that the present is the child of the past and the parent of the future. The rock-records tell us plainly that the present-day one-toed horse began to evolve from extinct ancestors, which had four toes in front and three behind, and were only about a foot high. It is certain that birds evolved from a stock of extinct reptiles, and reptiles from amphibian ancestry, and amphibians from fishes. So it is all along the line, the animals of to-day have behind them a half-known pedigree which leads back and back to simpler and, as we say, more “generalised” ancestors. The only exception is in the case of those living creatures that have degenerated or retrograded in connection with a parasitic or a sedentary way of living. For their ancestors would be higher not lower on the scale. Evolution has been on the whole progressive, but in certain cases it has been retrogressive. In other words, while evolution has usually been onwards and upwards in its sublimely slow changes, it has sometimes slipped backwards and downwards.
