Principles of western civilisation

I PROJECTED EFFICIENCY 59

continued progress towards increasing differentiation of function and complexity of structure in the adult individual. On the other hand, we have the fixed and immutable necessity imposed upon nature, by the fundamental conditions of the problem, of return ing for every new individual life to exactly the same starting-point as at the beginning—the single cell. The effort to bridge effectively the ever-increasing interval of helplessness in the individual, which intervenes between this startingpoint and the adult stage of continuously increasing complexity, gives rise to a new and imposing class of phenomena in the functions which begin to attach to parenthood. We see the burden of the future continuing to press with ever-increasing weight upon the present as these functions develop under the stress of Natural Selection. We realise how great a struggle has, in reality, centred round this institution of parenthood throughout the evolution of life, and see how one type after another has failed and fallen behind, in the struggle to meet in the most efficient manner the growing demands of the future upon the present. The lower forms of life, in which the young leave the egg in an immature state and are cast upon the world without parental care, are gradually left behind. In the birds the burden of the future is more efficiently met. Development is carried far forward in the egg, and the young have the advantage of parental care afterwards. In the mammals, another shoot on the tree of life has carried the possibilities of parenthood much higher. The young are no longer subjected to the risks of a separate existence in the

1 Cf. Essays, by A. Weismann, vol. i. pp. 152, 153.