VILI DISCUSSION OF THE DATA OF STATURE. lot

tical one, the sum of the entries in the four adjacent squares. I then noticed (see Fig. 11) that lines drawn through entries of the same value formed a series of concentric and similar ellipses. Their common centre lay at the intersection of those vertical and horizontal lines which correspond to the value of 684 inches, as read on both the top and on the side scales. Their axes were similarly inclined. The points where each successive ellipse was touched by a horizontal tangent,

lay in a straight line that was inclined to the vertical in

FIG .11.

PRPS-0-NOWN _1q%

the ratio of Is, and those where the ellipses were touched by a vertical tangent, lay in a straight line inclined to the horizontal in the ratio of 1. It will be obvious on studying Fig. 11 that the point where each successive horizontal line touches an ellipse is the point at which the greatest value in the line will be found. The same is true in respect to the successive vertical lines. Therefore these ratios confirm the values of the Ratios of Regression, already obtained by a different method, namely those of I from Mid-Parent to Son, and of