=Native Ability, Independence and Energy Eugenically Desirable.--=Although we can not sift out with certainty the superior from the inferior in our normal population by the property test or the educational standard alone, it is undoubtedly true that, on the whole, native ability, independence and energy are present to a higher degree in our well-to-do and prosperous families than in the stocks which merely hold their own or which gradually decline, and there is no gainsaying the fact that in so far as the lower classes are where they are through actual deficiency--and there are enormous numbers in this category--they threaten our very existence as a race. It is imperative that the great middle class in particular establish in some way a selective birth-rate, by increased fertility on their own part, and diminished fecundity on the part of inferior stocks, which will offset or more than offset the disproportionate increase of the socially unfit. =Four Children to Each Marriage Required to Maintain a Stock.--=It is estimated that under present conditions an average of at least four children should be born to each marriage if a stock is to maintain its numbers undiminished. Some of our most valuable strains are falling far short of this average. In a statistical table on the relative fertility of different stocks, prepared by Pearson, we find the mentally defective, criminal, deaf-mute and degenerate stocks heading the list with averages ranging from five to seven children per family, while the American graduate (based on Harvard statistics) and the English intellectual types average less than two children per marriage. While the death-rate is higher in the undesirable classes mentioned, it is by no means enough higher to compensate for the difference in birth-rates. Thus while certain very desirable types are not maintaining themselves genetically, other extremely undesirable ones are rapidly more than replacing themselves. Investigations made by Heron in London show that this condition as regards English desirables did not exist sixty years ago; then the richer a community was in professional men and well-to-do families, the higher was the birth-rate.