Francis Galton's rabbit experiments disproved Darwin's theory of gemmules

Besides their part in the many rites of Easter and in the Christian legendarium, rabbits also played a role in the scientific establishment of the mechanisms of heredity. And in a rather unexpected fashion. Darwin supposed that certain capsules containing hereditary information were lodged in the germ cells. In his view, these particles, the so-called gemmules, were conveyed through the blood from the tissues of the organism, carrying the requisite information, into the cells of the reproductive organs. That Darwin was mistaken in this was demonstrated plainly by his contemporary Francis Galton with an experiment on rabbits: he took albinos and black rabbits and transfused the blood of individuals of one colouring into animals of the other. If Darwin's theory were correct, then together with the blood of the black rabbit the information about black fur ought to have passed into the germ cells of the albino, and the offspring of such a rabbit, after mating with another white rabbit, would nevertheless have turned out black. Which did not happen in a single combination. Galton, however, came to the conclusion that the germ cells already contain hereditary information, and of two kinds: one influencing the new organism, and one passed on in a dormant state to its descendants, which was, on the whole, the foundation for understanding the dual nature of heredity, to be confirmed by discoveries in the future.