140 NATURAL INHERITANCE. [CHAP.
Stature, and shown that they were fairly trustworthy. I think they are somewhat more accurate in respect to Eye-colour, upon which family portraits have often furnished. direct information, while indirect information has been in other cases obtained from locks of hair that were preserved in the family as mementos.
Persistence of Eye-colour in the Population.-The first subject of our inquiry must be into the existence of any slow change in the statistics of Eye-colour in the English population, or rather in that particular part of it to which my returns apply, that ought to be taken into account before drawing hereditary conclusions. For this purpose I. sorted the data, not according to the year of birth, but according to generations, as that method best accorded with the particular form in which all my R.F.F. data are compiled. Those personss who ranked in the Family Records as the " children " of the pedigree, were counted as generation I. ; their parents, uncles and aunts, as generation II. ; their grandparents, great uncles, and great aunts, as generation III. ; their great grandparents, and so forth, as generation IV. No account was taken of the year of birth of the "children," except to learn their age ; consequently there is much overlapping of dates in successive generations. We may however safely say, that the persons in generation I. belong to quite a different period to those in generation III., and the persons in II. tothose in IV. I had intended to exclude all children under the age of eight years, but in this particular branch of the inquiry, I