DEAR PROFESSOR HUXLEY--A short time before Mr. Darwin's death, I had a conversation with him concerning the observations which had been made by Mr. Murray upon coral-reefs, and the speculations which had been founded upon those observations. I found that Mr. Darwin had very carefully considered the whole subject, and that while, on the one hand, he did not regard the actual facts recorded by Mr. Murray as absolutely inconsistent with his own theory of subsidence, on the other hand, he did not believe that they necessitated or supported the hypothesis advanced by Mr. Murray. Mr. Darwin's attitude, as I understood it, towards Mr. Murray's objections to the theory of subsidence was exactly similar to that maintained by him with respect to Professor Semper's criticism, which was of a very similar character; and his position with regard to the whole question was almost identical with that subsequently so clearly defined by Professor Dana in his well-known articles published in the _American Journal of Science_ for 1885. It is difficult to imagine how any one, acquainted with the scientific literature of the last seven years, could possibly suggest that Mr. Murray's memoir published in 1880 had failed to secure a due amount of attention. Mr. Murray, by his position in the _Challenger_ office, occupied an exceptionally favourable position for making his views widely known; and he had, moreover, the singular good fortune to secure from the first the advocacy of so able and brilliant a writer as Professor Archibald Geikie, who {328} in a special discourse and in several treatises on geology and physical geology very strongly supported the new theory. It would be an endless task to attempt to give references to the various scientific journals which have discussed the subject, but I may add that every treatise on geology which has been published, since Mr. Murray's views were made known, has dealt with his observations at considerable length. This is true of Professor A. H. Green's _Physical Geology_, published in 1882; of Professor Prestwich's _Geology, Chemical and Physical_; and of Professor James Geikie's _Outlines of Geology_, published in 1886. Similar prominence is given to the subject in De Lapparent's _Traité de Géologie_, published in 1885, and in Credner's _Elemente der Geologie_, which has appeared during the present year. If this be a "conspiracy of silence," where, alas! can the geological speculator seek for fame?--Yours very truly, JOHN W. JUDD. _October 10, 1887._ * * * * * {329} IX AGNOSTICISM