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Starting with the postu- late of the organism as the subject of congenital variations which it is the business of the theory somehow to get con- served and securely placed outside of the individual history, in the phylogenic register of the race, its effect is to remove the stress of the movement from the individual variation and put it on a general tendency or adaptability of the organism, an adaptability that is likely to remain the same substantially over long stretches of time and that renders it possible, when any variation does occur, as for example the appearance of antlers on the elks head, for the individual organism in which it appears to adjust its whole constitution to this change. This adjustment will involve, for example, a redistribution of the life- forces and a larger development of the bones and muscles of the elks neck and shoulders at the expense of the more remote parts of his body. We have here an ex- planation of what the rival theories left to accident, the survival of a variation that in itself would in its first stages be detrimental or at least not definitely useful. This survival is secured by a species of blanket-mortgage which shields the young variation by hiding it in a group until its majority has been reached. No theory is obliged to show how variations may survive outside of definite and determinate limits, for evolution has its negative side and its unwritten history of variations which failed to survive either because they did not fall in with the general trend of the organism in which they ap- peared, or because they were able to find no point of accom- modation to the environment. prev next |