Charles Darwin's health improved substantially in 1866 under a dietary and exercise regime prescribed by his physician Henry Bence Jones. With renewed vigour, he worked steadily on his manuscript of Variation of Plants and Animals under Domestication, submitting all but the final chapter to his publisher in December. He also worked on the fourth, and much revised, edition of Origin which was delivered to printers in July, and preparations were begun for a third German edition of Origin. His improved health allowed him a more active social life. At Down, Darwin entertained a number of scientific colleagues whom he had known previously only through correspondence. He also made his first appearance in London scientific society in many years, touring the Zoological Gardens at Regent's Park, and appearing at a soiree at the Royal Society.

Volume 13 contains letters for 1865, the year Charles Darwin published his long paper on climbing plants and continued work on his book, The Variation of Plants and Animals under Domestication. 1865 was also the year when Robert FitzRoy committed suicide; Joseph Dalton Hooker became director of the Royal Botanic Gardens, Kew; and Charles Lyell and John Lubbock quarrelled over an alleged incident of plagiarism. The volume includes a supplement of over 100 letters discovered or redated since the series began publication, including a fascinating collection written when Darwin was 12.

As the sheer volume of his correspondence indicates, 1862 was a very productive year for Darwin. This was not only the case in his published output (two botanical papers and a book on the pollination mechanisms of orchids), but more particularly in the extent and breadth of the botanical experiments he carried out. The promotion of his theory of natural selection also continued: Darwin's own work expanded on it, Thomas Henry Huxley gave lectures about it and Henry Walter Bates invoked it to explain mimicry in butterflies. This volume concentrates on the progress of his scientific work, but also records the effects of Darwin's continuing ill health and the serious illness of two of his children.

The correspondence in this volume continues to reveal the variety of responses to Darwin's species theory in the second year following the publication of The Origin of Species. Darwin also begins to turn to new "evolutionary" projects that illustrate how the theory could be applied to solving important problems in natural history. The letters also yield important new information about contemporary research.

Volume 8 opens with Darwin eagerly scrutinizing each new review, as one by one all the major media of the day carried notices of the book. To those who express their views privately in letters, Darwin responds patiently and thoughtfully, answering their objections and attempting to guide their fuller understanding of the operation of natural selection. His more personal thoughts emerge in letters to his friends Joseph Dalton Hooker, Charles Lyell, and Thomas Henry Huxley. This volume presents a wealth of detailed information, giving the full range of response to the Origin and revealing how Victorians coped with a theory that many recognized would revolutionize thinking about the organic world and human ancestry.

Volume 12 of The Correspondence of Charles Darwin provides the full authoritative texts of all known and available letters to and from Charles Darwin. The letters are accompanied by detailed explanatory footnotes and relevant supplementary materials, offering unparalleled insights into Darwin's experiments, thoughts, friendships, and family life. Volume 12 of this continuing series contains letters from 1864, when Darwin, despite continuing illness, was carrying out botanical experiments and working on his book, The Variation of Plants and Animals Under Domestication.

To mark the bicentenary of the birth of Charles Darwin, and the sesquicentenary of "On the Origin of the Species," the Society for the History of Natural History have issued a special publication, "Darwin in the Archives."

This "Archives of Natural History" special publication will include facsimiles of papers on Darwin published before 2005 in the "Journal of the Society for the Bibliography of Natural History" and "Archives of Natural History"; a reprint of the Sherborn Fund Facsimile no 3 (1968) of Charles Darwin's "Questions About the Breeding of Animals" (1840); an introduction by Sir Gavin de Beer; and a specially commisioned essay about the Society's particular contribution to Darwin scholarship by guest associate editor, Duncan Porter.