[505] _Biolog. Centrlbl._, xiv., 1894, xv., 1895. _Formative Reize in der thierischen Ontogenese_, Leipzig, 1901. [506] "La Morphologie dynamique," No. i. of the _Collection de Morphologie dynamique_, Paris, 1911. [507] "Forme, Puissance et Stabilite des Poissons," No. iv. of the _Collection_, Paris, 1912. CHAPTER XIX SAMUEL BUTLER AND THE MEMORY THEORIES OF HEREDITY We have laid stress upon the distinction established by Roux between the two stages of development--the automatic and the functional--because of the light which it seems to throw upon the phylogenetic relation of form to function. We have pointed out, too, the paramount role that function plays in Roux's theories of development and heredity, and we have brought out the close kinship existing between his theory and that of Lamarck. For Roux, as for Lamarck, the function creates the organ, and it is only after long generations that the organ appears before the function. It so happened that just about the time when Roux's papers were beginning to appear a brilliant attempt was made by Samuel Butler to revive and complete the Lamarckian doctrine. A man of singular freshness and openness of mind, combining in an extraordinary degree extreme intellectual subtlety with a childlike simplicity of outlook, Butler was one of the most fascinating figures of the 19th century. He was not a professional biologist, and much of his biological work is, for that reason, imperfect. But he brought to bear upon the central problems of biology an unbiassed and powerful intelligence, and his attitude to these problems, just because it is that of a cultivated layman, is singularly illuminating.