From the age of six I had a mania for drawing the forms of things. By the time I was fifty I had published an infinity of designs, but all I produced before the age of seventy is not worth taking into account. At seventy-five I have learned a little about the real structure of nature—of animals, plants and trees, birds, fishes, and insects. In consequence when I am eighty I shall have made still more progress. At ninety I shall penetrate the mystery of things; at a hundred I shall certainly have reached a marvellous stage; and when I am a hundred and ten, everything I do—be it but a line or dot—will be alive.on this, also see the true names of things, wheatcakes, and a certain atlas.