Lyell and Poulett Scrope, in this country, resumed the work of the Italians and of Hutton; and the former, aided by a marvellous power of clear exposition, placed upon an irrefragable basis the truth that natural causes are competent to account for all events, which can be proved to have occurred, in the course of the secular changes which have taken place during the deposition of the stratified rocks.  The publication of ‘The Principles of Geology,’ in 1830, constituted an epoch in geological science.  But it also constituted an epoch in the modern history of the doctrines of evolution, by raising in the mind of every intelligent reader this question:  If natural causation is competent to account for the not-living part of our globe, why should it not account for the living part?

By keeping this question before the public for some thirty years, Lyell, though the keenest and most formidable of the opponents of the transmutation theory, as it was formulated by Lamarck, was of the greatest possible service in facilitating the reception of the sounder doctrines of a later day.  And, in like fashion, another vehement opponent of the transmutation of species, the elder Agassiz, was doomed to help the cause he hated.  Agassiz not only maintained the fact of the progressive advance in organisation of the inhabitants of the earth at each successive geological epoch, but he insisted upon the analogy of the steps of this progression with those by which the embryo advances to the adult condition, among the highest forms of each group.  In fact, in endeavoring to support these views he went a good way beyond the limits of any cautious interpretation of the facts then known.

[Sidenote:  Darwin]

Although little acquainted with biological science, Whewell seems to have taken particular pains with that part of his work which deals with the history of geological and biological speculation; and several chapters of his seventeenth and eighteenth books, which comprise the history of physiology, of comparative anatomy and of the palaetiological sciences, vividly reproduce the controversies of the early days of the Victorian epoch.  But here, as in the case of the doctrine of the conservation of energy, the historian of the inductive sciences has no prophetic insight; not even a suspicion of that which the near future was to bring forth.  And those who still repeat the once favorite objection that Darwin’s ‘Origin of Species’ is nothing but a new version of the ‘Philosophie zoologique’ will find that, so late as 1844, Whewell had not the slightest suspicion of Darwin’s main theorem, even as a logical possibility.  In fact, the publication of that theorem by Darwin and Wallace, in 1859, took all the biological world by surprise.  Neither those who were inclined towards the ‘progressive transmutation’ or ‘development’ doctrine, as it was then called, nor those who were opposed to it, had the slightest suspicion that the tendency to variation in living beings, which all admitted as