"A Theory of Heredity" ("Journal of the Anthropological Institute," 1875).

In this paper Mr.Galton admits that the hypothesis of organic units "must lie at the foundation of the science of heredity," and proceeds to show in what respect his conception differs from the hypothesis of pangenesis.

The copy of Mr.Galton's paper, which Darwin numbered in correspondence with the criticisms in his letter, is not available, and we are therefore only able to guess at some of the points referred to.) I cannot fully grasp, only here and there conjecture, what are the points on which we differ.

I daresay this is chiefly due to muddy-headedness on my part, but I do not think wholly so.

Your many terms, not defined, "developed germs," "fertile," and "sterile germs" (the word "germ" itself from association misleading to me) "stirp," "sept," "residue," etc., etc., quite confounded me.