At the end of the third volume of the _Anatomy_ are some ‘General Conclusions,’ which contain, so far as human intelligence can penetrate the meaning of Owen’s ‘dark speech,’ his final views on the origin of species. We have already shown that his mind was first turned to this momentous question during his visit to Paris in 1831, and that subsequently, during his work on the Physiological and Osteological Catalogues of the Museum of the College of Surgeons, it was continually in his thoughts. During this period he read, and was profoundly influenced by, Oken’s _Lehrbuch der Naturphilosophie_, a translation of which was published by the Ray Society, in 1847, at his instance. In his _Archetype and Homologies of the Vertebrate Skeleton_ (1848) he says: ‘The subject of the following essay has occupied a portion of my attention from the period when, after having made a certain progress in comparative anatomy, the evidence of a greater conformity to type, especially in the bones of the head of the vertebrate animals, than the immortal Cuvier had been willing to admit, began to enforce a reconsideration of his conclusions, to which I had previously yielded implicit assent.’ Out of the study here indicated there grew a revision of the vertebrate skeleton, in which the homologues (_i.e._ the same organs in different animals, under every variety of form and function) were recognized, and a new system of osteological nomenclature was proposed. In this Owen did excellent work, which has been generally accepted. But in his anxiety to recognize and account for ‘the one in the many,’ he adopted Oken’s idea of the skeleton being resolvable into a succession of vertebræ, and evolved the idea of an archetype. It is almost inconceivable that the clear-headed and sagacious interpreter, whose sober conclusions we have indicated through a long series of zoological and paleontological memoirs, should have ever adopted these transcendental speculations. But there was evidently a metaphysical side to his mind, and he took a keen, almost a puerile, delight in this child of his fancy. He even had a seal engraved with a symbolical representation of it. To show that we are not exaggerating we will quote his own account of his views when sending the seal to his sister: ‘It represents the archetype, or primal pattern—what Plato would have called the “Divine Idea”—on which the osseous frame of all vertebrate animals has been constructed. The motto is “The One in the Manifold,” expressive of the unity of plan which may be traced through all the modifications of the pattern, by which it is adapted to the varied habits and modes of life of fishes, reptiles, birds, beasts, and human kind. Many have been the attempts to discover the vertebrate archetype, and it seems now generally felt that it has been found’ (i. 388).