Publication of "Geological Observations on South America"; being Part III. of the "Geology of the Voyage of the 'Beagle'". 1851: Publication of a "Monograph of the Fossil Lepadidae" and of a "Monograph of the sub-class Cirripedia". "I fear the study of the Cirripedia will ever remain 'wholly unapplied,' and yet I feel that such study is better than castle-building." 1854: Publication of Monographs of the Balanidae and Verrucidae. "I worked steadily on this subject for...eight years, and ultimately published two thick volumes, describing all the known living species, and two thin quartos on the extinct species... My work was of considerable use to me, when I had to discuss in the "Origin of Species" the principles of a natural classification. Nevertheless, I doubt whether the work was worth the consumption of so much time." "From September 1854 I devoted my whole time to arranging my huge pile of notes, to observing, and to experimenting in relation to the transmutation of species." 1856: "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'." 1858: Joint paper by Charles Darwin and Alfred Russel Wallace "On the Tendency of Species to form Varieties; and on the perpetuation of Varieties and Species by Natural Means of Selection," communicated to the Linnean Society by Sir Charles Lyell and Sir Joseph Hooker. "I was at first very unwilling to consent (to the communication of his MS. to the Society) as I thought Mr Wallace might consider my doing so unjustifiable, for I did not then know how generous and noble was his disposition." "July 20 to Aug. 12 at Sandown (Isle of Wight) began abstract of Species book." 1859: Nov. 24. Publication of "The Origin of Species" (1250 copies). "Oh, good heavens, the relief to my head and body to banish the whole subject from my mind!... But, alas, how frequent, how almost universal it is in an author to persuade himself of the truth of his own dogmas. My only hope is that I certainly see many difficulties of gigantic stature." 1860: Publication of the second edition of the "Origin" (3000 copies). Publication of a "Naturalist's Voyage". 1861: Publication of the third edition of the "Origin" (2000 copies). "I am going to write a little book... on Orchids, and to-day I hate them worse than everything." 1862: Publication of the book "On the various contrivances by which Orchids are fertilised by Insects". 1865: Read paper before the Linnean Society "On the Movements and Habits of Climbing plants". (Published as a book in 1875.) 1866: Publication of the fourth edition of the "Origin" (1250 copies). 1868: "I have sent the MS. of my big book, and horridly, disgustingly big it will be, to the printers." Publication of the "Variation of Animals and Plants under Domestication".