into detail, supported by a host of painstaking observations, the making of which had taken him half a lifetime. Darwin, without going further than cursorily into the causes of variation, argued as follows: We know that variations do occur in every kind of living creatures. Some of these variations lead to something, while others do not. An enormously greater number of animals and plants are born than reach maturity and can in their turn continue the race. What is the regulating factor? His answer is, The struggle for existence—in other words, the weeding out of the less fit, or rather of the owners of those variations which are not so well adapted to their surroundings.
For 'adapted' we had better read 'adaptable,' because a variation which does not answer, which cannot be made use of, or, still more notably, is a hindrance or disadvantage, does not become an adapted feature. There is often a confusion between adaptation as an accomplished fact, a feature,
