Very many thanks about the Elodea, which case interests me much. I wrote to Mr. Marshall (100/1. W. Marshall was the author of "Anacharis alsinastrum, a new water-weed": four letters to the "Cambridge Independent Press," reprinted as a pamphlet, 1852.) at Ely, and in due time he says he will send me whatever information he can procure. Owen is indeed very spiteful. (100/2. Owen was believed to be the author of the article in the "Edinburgh Review," April, 1860. See Letter 98.) He misrepresents and alters what I say very unfairly. But I think his conduct towards Hooker most ungenerous: viz., to allude to his essay (Australian Flora), and not to notice the magnificent results on geographical distribution. The Londoners say he is mad with envy because my book has been talked about; what a strange man to be envious of a naturalist like myself, immeasurably his inferior! From one conversation with him I really suspect he goes at the bottom of his hidden soul as far as I do. I wonder whether Sedgwick noticed in the "Edinburgh Review" about the "Sacerdotal revilers,"--so the revilers are tearing each other to pieces. I suppose Sedgwick will be very fierce against me at the Philosophical Society. (100/3. The meeting of the "Cambridge Phil. Soc." was held on May 7th, 1860, and fully reported in the "Cambridge Chronicle," May 19th. Sedgwick is reported to have said that "Darwin's theory is not inductive--is not based on a series of acknowledged facts, leading to a general conclusion evolved, logically out of the facts...The only facts he pretends to adduce, as true elements of proof, are the varieties produced by domestication and the artifices of crossbreeding." Sedgwick went on to speak of the vexatious multiplication of supposed species, and adds, "In this respect Darwin's theory may help to simplify our classifications, and thereby do good service to modern science. But he has not undermined any grand truth in the constancy of natural laws, and the continuity of true species.") Judging from his notice in the "Spectator," (100/4. March 24th, 1860; see "Life and Letters," II., page 297.) he will misrepresent me, but it will certainly be unintentionally done. In a letter to me, and in the above notice, he talks much about my departing from the spirit of inductive philosophy. I wish, if you ever talk on the subject to him, you would ask him whether it was not allowable (and a great step) to invent the undulatory theory of light, i.e. hypothetical undulations, in a hypothetical substance, the ether. And if this be so, why may I not invent the hypothesis of Natural Selection (which from the analogy of domestic productions, and from what we know of the struggle for existence and of the variability of organic beings, is, in some very slight degree, in itself probable) and try whether this hypothesis of Natural Selection does not explain (as I think it does) a large number of facts in geographical distribution--geological succession,