In the same year began his correspondence with Asa Gray, who soon became one of his warmest friends. He had numerous questions to ask about the geographical range of plants, and in 1857 he wrote explaining in some detail the views at which he had arrived as to the causes of evolution. My friend Rowland H. Wedgwood, a nephew of Darwin, has given me the following interesting letter to his father, which was written, he believes, probably before 1855. By kind permission, it is here published for the first time. The letter is of great interest, as throwing light upon his work, and also because of this early reference to Huxley:-- “Down, _Sept. 5_. “MY DEAR HARRY,--I am very much obliged for the Columbine seed and for your note which made us laugh heartily. “I had no idea what trouble the counting must have been, I had not the least conception that there would have been so many pods. I am very much interested on this point, and therefore to make assurance sure, I repeat your figures viz. 560 and 742 pods on two plants and 7200 on another. Does the latter number really mean pods and not seeds? Upon my life I am sorry to give so much trouble, but I should be VERY MUCH obliged for a few _average_ size pods, put up separately that I may count the seeds in each pod: for though I counted the seeds in the pods sent before, I hardly dare trust them without counting more. Moreover I sadly want more seed itself for one of my experiments. “The young cabbages are coming up already. Thank you much about the asparagus seeds; as it is so rare a plant, you are my only chance. “We have been grieved to hear about poor Anne and Tom.--Your affect^{te} screw “C. DARWIN. “Have you been acquainted with Mr. Huxley; I think you would find him a pleasant acquaintance. He is a very clever man.” Mr. Francis Darwin believes that the asparagus and cabbage seeds were for the experiments to determine the time during which immersion in salt water could be endured. The object of such experiments was to throw light on the means by which plants are distributed over the earth’s surface. He also informs me that the use of the word “screw” is unique and incomprehensible. Darwin tells us in the “Autobiography” that “early in 1856 Lyell advised me to write out my views pretty fully, and I began at once to do so on a scale three or four times as extensive as that which was afterwards followed in my ‘Origin of Species.’” This work he began on May 14th, and, after working steadily until June, 1858, had written about half the book, in ten chapters, when he received the celebrated letter from Wallace, which altered everything. [Sidenote: ON THE “ATLANTIS” THEORY.]