Viewed from an economic standpoint and stated somewhat bluntly, the value of the individual depends in considerable measure on the length of his life. National welfare, so far as it is an expression of possibilities of human performance, is inevitably concerned with the problems of mortality. The health and vigor of a race or group is a decided asset; ill health and its consequences are burdens imposed on the population. Students of civilization have inquired whether or to what extent it is actually necessary for the world to carry this "colossal load" of human misfortune. One can readily understand why every report of a better turn in the mortality trend is so heartily welcomed.
Indications from modern biologic investigations might lead to the conclusion that death is neither inevitable nor fundamentally necessary. The "immortality of protoplasm" is at once suggested by the modern study of tissue cultures. Cell masses kept