The stone is still there in the garden. That’s what gets me. It’s not the house itself – houses decay slowly and can be preserved pretty easily, especially in Britain where even an eighteenth-century country house is not “old.” It’s not even the tree behind the house, alive when Charles Darwin still lived in his Down House, now propped up by guywires against inevitable collapse as a kind of totem of the great naturalist’s existence. If you leave the rear exit, the one that takes you to Darwin’s preserved greenhouse and the stunning flora on a pretty path lined in that particular English way of making the perfectly manicured seem somehow “natural,” you might glance to the left and see behind a small iron fence a one-foot-wide stone. A round mill stone or pottery wheel, it was, or appears to have been.