Charles Darwin First Goes Public on Views of Evolution
Darwin’s book was half way when, on 18 June 1858, he received a paper from Wallace describing natural selection.
Shocked that he had been “forestalled”, Darwin sent it on to Lyell, as requested, and, though Wallace had not asked for publication, he suggested he would send it to any journal that Wallace chose. His family was in crisis with children in the village dying of scarlet fever, and he put matters in the hands of Lyell and Hooker. They decided on a joint presentation at the Linnean Society on 1 July of On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection; however, Darwin’s baby son died of the scarlet fever and he was too distraught to attend.
There was little immediate attention to this announcement of the theory; the president of the Linnean remarked in May 1859 that the year had not been marked by any revolutionary discoveries. Only one review rankled enough for Darwin to recall it later; Professor Samuel Haughton of Dublin claimed that “all that was new in them was false, and what was true was old.” Darwin struggled for thirteen months to produce an abstract of his “big book”, suffering from ill health but getting constant encouragement from his scientific friends. Lyell arranged to have it published by John Murray.
On this date Charles Darwin first went public about his views on the evolution of species. The papers of Darwin and Wallace were read at a meeting of the Linnean Society in London. The following were read at the Society meeting:
(1) Extracts from two sections of Darwin's 1839 manuscript on species variation, titled "The Variation of Organic Beings under Domestication and in their Natural State," and "On the Variation of Organic Beings in the State of Nature; on the Natural Means of Selection; on the Comparison of Domestic Races and true Species."
(2) An abstract from a letter Darwin wrote to Professor Asa Gray of Harvard in September 1857 that again stated his views on species variation.
(3) The essay that Wallace wrote at Ternate Island in the Malay Archipelago in February 1858, titled - "On the Tendency of Varieties to Depart indefinitely from the Original Type."
The reaction to this meeting was a mixture of shock, excitement, and stunned silence.
On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection is the title of a joint presentation of two scientific papers to the Linnean Society of London on 1 July 1858; On The Tendency of Varieties to Depart Indefinitely from the Original Type by Alfred Russel Wallace and an Extract from an unpublished Work on Species from Charles Darwin's Essay of 1844, together with an Abstract of a Letter from Darwin to Asa Gray. This was the first announcement of the Darwin – Wallace theory of evolution by natural selection; the papers appeared in print on 20 August 1858. The presentation of the papers spurred Darwin to write a condensed "abstract" of his "big book" on Natural Selection. The abstract was published in November 1859 as On the Origin of Species.
The papers were read to the Linnean Society of London on 1 July 1858, by the Secretary John Joseph Bennett. Neither author was present. Darwin was attending the funeral of his son, and Wallace was still in Borneo. The meeting was chaired by the President of the society, Thomas Bell, who had written up the description of Darwin's reptile specimens from the Beagle expedition.
About thirty were present, including two unnamed guests from overseas, with many there to hear an obituary notice for the former president and botanist Robert Brown given by Lyell. Wallace's natural history agent Samuel Stevens happened to be present, while Darwin's friends there included William Benjamin Carpenter and the geologist William Henry Fitton. Amongst the others, Daniel Oliver and Arthur Henfry would later support evolution, while Cuthbert Collingwood became an opponent. George Bentham was persuaded by Hooker to step down so that the Darwin and Wallace papers were first on the agenda, followed by six other papers on botanical and zoological topics. Bell had introduced discussions at the end of meetings, but there was no discussion of natural selection, perhaps because of the amount of business that had been dealt with, or possibly due to polite reluctance to speak out against a theory which the eminent Lyell and Hooker were supporting. Bentham noted that the audience appeared fatigued. Hooker later said there was "no semblance of a discussion", though "it was talked over with bated breath" at tea afterwards, and in his reminiscences many years later thought "the subject [was] too ominous for the old school to enter the lists before armouring."  Although Bell apparently disapproved, the Vice-President promptly removed all references to immutability from his own paper which was awaiting publication. 
Darwin wrote to Wallace to explain what had occurred, enclosing a letter which Hooker wrote at Darwin's request. His next action was to get his family away from the danger of infection, both himself and Emma exhausted by sickening fear about the safety of their children. The day after the funeral they moved to his sister-in-law's in Sussex, then on to Portsmouth and the Isle of Wight. At first they stayed in the King's Hotel, Shanklin, and on 30 July Darwin began writing an "abstract" of his book on Natural Selection, planning a short paper in response to Hooker's urging to publish a scientific paper in the Linnean journal. They next rented a villa in Sandown and Darwin pressed on, with the facts he felt necessary to support his "abstract" expanding far beyond the thirty pages Hooker had originally suggested.