132 NATURAL INHERITANCE. (CHAP.
R.F.F. series without revising all, as they hang together and support one another.
General View of Kinship.-We are now able to deal with the distribution of statures among the Kinsmen in every near degree, of persons whose statures we know, but whose ancestral statures we either do not know, or do not care to take into account. We are able to calculate Tables for every near degree of Kinship on the form of Table 11, and to reconstruct that same Table in a shape free from irregularities. We must first find the Regression, which we may call w, appropriate to the degree of Kinship in question. Then we calculate a value f for each line of a Table corresponding in form to that of Table 11, in which f was found to be equal to 1.50 inch. We deduce the value off from that of w by
means of the general equation p2w2+f 2= p2) p being
equal to 1.7 inch. The values to be inserted in the several lines are then calculated from the ordinary table (Table 5) of the "probability integral."
As an example of the first part of the process, let us suppose we are about to construct a table of Uncles and their Nephews, we find w and f as follows: A Nephew is the son of a Brother, therefore in this case we have w='I x I=1; whence f=1.66.
The Regression, which we call w, is a convenient and correct measure of family likeness. If the resemblance of the Kinsman to the Man, was on the average as perfect as that of the Man to his own Self, there would be no Regression at all, and the value of w would be 1.