The completion of the 40th volume of the Geological Magazine, and the commencement of its Fifth Decade under the Editorship of one who has been responsibly associated with the undertaking since 1864, and has been Editor-in-chief since July, 1865, furnishes a fit opportunity for a retrospect.

In the opening pages of this Magazine Professor Rupert Jones dealt with “ The Past and Present Aspects of Geology.” He remarked on the tendency to encroach upon the theory of Uniformity, upon the right “to call in the agency of forces which, though not seen in operation in nature, may be evoked in the laboratory.” He further referred to “recent discussions respecting the origin of granite, the mode of formation of river-valleys, the excavation of lake-basins, the doctrine of ‘homotaxis,’ and the origin of species.” At that time, owing to the teachings of Huxley, there was more scepticism than there is now as to the exact truth of “the contemporaneity of strata which contain the same or similar fossils, and which are geographically far apart.”