264   Life and Letters of Francis Galton

Gal ton next sketches out what procedure an active society promoting Eugenics migh4 adopt. It might, he considers

(1) Disseminate knowledge of the laws of heredity as far as known and encourage their further investigation.

Incidently he emphasises the importance for Eugenics of the actuarial side of heredity, and remarks on its advance in recent years, and how the average degree of resemblance-the measure of kinship in each grade-is now obtainable, so that in the mass the effects of blood relationship can be dealt with even as actuaries deal with the birth- and death-rates. This actuarial side of heredity was ever present in Galton's mind, and was the topic of his Herbert Spencer lecture on Eugenics.

(2) Inquire into the present and the past rates of fertility of various social groups-classified according to their civic efficiency. Galton says that there is strong reason for believing from the history of ancient and modern nations that their rise and fall depends upon changes in this relative fertility. He considers that while there are causes at work which tend to check fertility in the classes of higher civic worth, nevertheless types of our race may be found which can be highly civilised without losing fertility, even as some animals become more fertile the more they are domesticated.

(3) Collect data as to large and thriving families. Galton considers that a "large" family may be taken as one in which there are at least three male children. His definition of a "thriving" family is important, and it seemed to me overlooked in the discussion ; it is one in which the children have gained distinctly superior positions to those achieved by the average of their classmates in early life. It is clear that such a list of " thriving" families-a " Golden Book," of really noble stirps-must precede any attempt to encourage fertility in the classes of higher civic worth. But the formation of such a "Golden Book," even for a single social group such as the clerical, legal or academic professions, is a matter of extraordinary difficulty. Galton soon dropped the idea of making it depend on the children reaching "superior positions." He saw that it must depend upon the achievements of the stirp or stock as a whole. It was from the standpoint of this idea that Galton set Schuster to work on Noteworthy Families in modern science; that was to form the first section of the "Golden Book." Further portions of it were in part prepared and the "Register of Able Families" was an offshoot from the same idea. Judged from the aim of the " Golden Book," Noteworthy Families (Modern Science) gains more meaning, if we cannot overlook its defects.

What Eugenics needs is a book of "Noble Families" in a modern sense; it could at first only apply to the upper classes, and there would certainly be numerous omissions and erroneous inclusions in the early issues.- It would contain, just as a peerage does, a list of all families within which, inside a given range of ancestry and collaterals, a certain percentage of members had reached posts falling into a carefully selected list, or achieved results in politics, art, literature or science of a- certain degree of worth. New families would

* See our present volume, p. 121.