creating a feeling of family solidarity—this is perhaps its chief office in the United States. It has, or can have, biological significance, and this in two ways: either in relation to pure science or applied science. In connection with pure science, its function is to furnish means for getting knowledge of the laws of heredity. In application, its function is to furnish a knowledge of the inherited characters of any given individual, in order to make it possible for the individual to find his place in the world and, in particular, to marry wisely. It is obvious that the use of genealogy in the applied science of eugenics is dependent on previous research by geneticists; for marriage matings which take account of heredity can not be made unless the mode of inheritance of human traits has previously been discovered.
The historical, social, legal and other aspects of genealogy do not concern the present discussion. We shall discuss only the biological aspect; not only because it alone is germane to the present book, but because we consider it to have by far the greatest true value, accepting the criterion of value as that which increases the welfare of mankind. By this criterion, the historical, legal and social aspects of genealogy will be seen, with a little reflection, to be of secondary importance to its biological aspect.
(2) Genealogy now is too often looked upon as an end in itself. It would be recognized as a science of much greater value to the world if it were considered not an end but a means to a far greater end than it alone can supply. It has, indeed, been contended, even by such an authority as Ottokar Lorenz, who is often called the father of modern scientific genealogy, that a knowledge of his own ancestry will