...I am delighted to hear that Brongniart thought Sigillaria aquatic, and that Binney considers coal a sort of submarine peat. I would bet 5 to 1 that in twenty years this will be generally admitted (An unfulfilled prophecy.); and I do not care for whatever the botanical difficulties or impossibilities may be. If I could but persuade myself that Sigillaria and Co. had a good range of depth, i.e., could live from 5 to 100 fathoms under water, all difficulties of nearly all kinds would be removed (for the simple fact of muddy ordinary shallow sea implies proximity of land). [N.B.--I am chuckling to think how you are sneering all this time.] It is not much of a difficulty, there not being shells with the coal, considering how unfavourable deep mud is for most Mollusca, and that shells would probably decay from the humic acid, as seems to take place in peat and in the BLACK moulds (as Lyell tells me) of the Mississippi. So coal question settled--Q.E.D. Sneer away! Many thanks for your welcome note from Cambridge, and I am glad you like my alma mater, which I despise heartily as a place of education, but love from many most pleasant recollections... Thanks for your offer of the 'Phytologist;' I shall be very much obliged for it, for I do not suppose I should be able to borrow it from any other quarter. I will not be set up too much by your praise, but I do not believe I ever lost a book or forgot to return it during a long lapse of time. Your 'Webb' is well wrapped up, and with your name in large letters OUTSIDE. My new microscope is come home (a "splendid plaything," as old R. Brown called it), and I am delighted with it; it really is a splendid plaything. I have been in London for three days, and saw many of our friends. I was extremely sorry to hear a not very good account of Sir William. Farewell, my dear Hooker, and be a good boy, and make Sigillaria a submarine sea-weed. Ever yours, C. DARWIN. CHARLES DARWIN TO J.D. HOOKER. Down [May 6th, 1847]. My dear Hooker,