134   NATURAL INHERITANCE.   [CHAP.

heritages that blend and those that are mutually exclusive, must be here borne in mind. It would be a poor prerogative to inherit say the fifth part of the peculiarity of some gifted ancestor, but the chance of 1 to 5, of inheriting the whole of it, would be deservedly prized.

Separate Contribution of each Ancestor.-In making the statement that Mid-Parents whose Stature is P±D have children whose average stature is P±ID, it is supposed that no separate account has been taken of the previous ancestry. Yet though nothing may be known of them, something is tacitly implied and has been tacitly allowed for, and this requires to be eliminated before we can learn the amount of the Parental bequest, pure and simple. What that something is, we must now try to discover. When speaking of converse Regression, it was shown that a peculiarity in a Man implied a peculiarity of ~ of that amount in his MidParent. Call the peculiarity of the Mid-Parent D, then the implied peculiarity of the Mid-Parent of the MidParent, that is of the Mid-Grand-Parent of the Man, would on the above supposition be ID, that of the MidGreat-Grand-Parent would be ID, and so on. Hence the total bequeathable property would amount to D(1 +4+.+&c.)=D .

Do the bequests from each of the successive generations reach the child without any, or what, diminution by the way ? I have not sufficient data to yield a direct reply, and must therefore try limiting suppositions.

First, suppose the bequests by the various generations