This correct physiological conception, however, was by no means the most remarkable of the ideas to which Empedoeles was led by his anatomical studies. His greatest accomplishment was to have conceived and clearly expressed an idea which the modern evolutionist connotes when he speaks of homologous parts--an idea which found a famous modern expositor in Goethe, as we shall see when we come to deal with eighteenth-century science. Empedocles expresses the idea in these words: "Hair, and leaves, and thick feathers of birds, are the same thing in origin, and reptile scales too on strong limbs. But on hedgehogs sharp-pointed hair bristles on their backs."(14) That the idea of transmutation of parts, as well as of mere homology, was in mind is evidenced by a very remarkable sentence in which Aristotle asserts, "Empedocles says that fingernails rise from sinew from hardening." Nor is this quite all, for surely we find the germ of the Lamarckian conception of evolution through the transmission of acquired characters in the assertion that "many characteristics appear in animals because it happened to be thus in their birth, as that they have such a spine because they happen to be descended from one that bent itself backward."(15) Aristotle, in quoting this remark, asserts, with the dogmatism which characterizes the philosophical commentators of every age, that "Empedocles is wrong," in making this assertion; but Lamarck, who lived twenty-three hundred years after Empedocles, is famous in the history of the doctrine of evolution for elaborating this very idea.