Page:George Archdall Reid 1896 The present evolution of man.djvu/42

30 (presently to be noticed) which has the support of many eminent men of science. The mere fact, however, that organisms vary more frequently in the direction of their ancestry than in any other direction, appears to me to raise a strong presumption in its favour. But whether it be true or not, this at least is known to be true; if any characteristic become of little or no importance in the struggle for existence it is certain to undergo retrogression, i.e. cessation of natural selection is invariably followed by retrogression.