of correlation is about the same here as among the English Quakers of the Beeton-Pearson investigation, whose mortality was shown in the two preceding tables. In the healthiest group from the royal families—the cases in which the father lived to old age—the amount of child mortality is about the same as that of the Hyde family in America, which Alexander Graham Bell has studied—namely, somewhere around 250 per 1,000. One may infer that the royal families are rather below par in soundness of constitution.76
All these studies agree perfectly in showing that the amount of child mortality is determined primarily by the physical constitution of the parents, as measured by their longevity. In the light of these facts, the nature of the extraordinarily low child mortality shown in the 340 families from the Genealogical Record Office, with which we began the study of this point, can hardly be misunderstood. These families have the best inherited constitution possible and the other studies cited would make us certain of finding a low child mortality among them, even if we had not directly investigated the facts.
If the interpretation which we have given is correct, the conclusion is inevitable that child mortality is primarily a problem of eugenics, and that all other factors are secondary. There is found to be no warrant for the statement so often repeated in one form or another, that "the fundamental cause of the excessive rate of infant mortality in industrial communities is poverty, inadequate incomes, and low standards of living."77 Royalty and its princely relatives are not characterized by a low standard of living, and yet the child mortality among them is very high—somewhere around 400 per 1,000, in cases where a parent died young. If poverty is responsible in the one case, it must be in the other—which is