No thesis or subject was vouchsafed to me by the Council, but, having gratefully accepted the honour, I was bound to find one for myself.  It soon dawned upon me that the object sought by my selection might have been that, considering the intimate terms upon which Mr. Darwin extended to me his friendship, I could from my memory contribute to the knowledge of some important events in his career.  It having been intimated to me that this was in a measure true, I have selected as such an event one germane to this Celebration and also engraven on my memory, namely, the considerations which determined Mr. Darwin to assent to the course which Sir Charles Lyell and myself had suggested to him, that of presenting to the Society, in one communication, his own and Mr. Wallace’s theories on the effect of variation and the struggle for existence on the evolution of species.

You have all read Francis Darwin’s fascinating work as editor of his father’s “Life and Letters,” where you will find (Vol.  II., p. 116) a letter addressed, on the 18th of June, 1858, to Sir Charles Lyell by Mr. Darwin, who states that he had on that day received a communication from Mr. Wallace written from the Celebes Islands requesting that it might be sent to him (Sir Charles).

In a covering letter Mr. Darwin pointed out that the enclosure contained a sketch of a theory of Natural Selection as depending on the struggle for existence so identical with one he himself entertained and fully described in MS. in 1842 that he never saw a more striking coincidence:  had Mr. Wallace seen his sketch he could not have made a better short abstract, even his terms standing “as heads of chapters.”  He goes on to say that he would at once write to Mr. Wallace offering to send his MS. to any journal; and concludes:  “So my originality is smashed, though my book [the forthcoming ’Origin of Species’], if it will have any value will not be deteriorated, as all know the labour consists in the application of the theory.”

After writing to Sir Charles Lyell, Mr. Darwin informed me of Mr. Wallace’s letter and its enclosure, in a similar strain, only more explicitly announcing his resolve to abandon all claim to priority for his own sketch.  I could not but protest against such a course, no doubt reminding him that I had read it and that Sir Charles knew its contents some years before the arrival of Mr. Wallace’s letter; and that our withholding our knowledge of its priority would be unjustifiable.  I further suggested the simultaneous publication of the two, and offered—­should he agree to such a compromise—­to write to Mr. Wallace fully informing him of the motives of the course adopted.

In answer Mr. Darwin thanked me warmly for my offer to explain all to Mr. Wallace, and in a later letter he informed me that he was disposed to look favourably on my suggested compromise, but that before making up his mind he desired a second