This letter has almost everything you might want from a Darwin letter, and merits a correspondingly, magnificently complete set of notes provided by the Correspondence Project.

First, the letter is to that other doyen of natural selection, Alfred Russel Wallace; and the letter records Darwin's views on the first volume of Wallace's 1876 book The geographical distribution of animals Vol. 1: with a study of the relations of living and extinct faunas as elucidating the past changes of the earth's surface. More than half the letter is taken up by the scientific points that Darwin cannot resist raising ('I have written more than I intended; & I must again say how profoundly your book has interested me.') Darwin's capacious intellect and memory is on display as he comments on matters of organisms extinct and extant, moving from the 'Argus-pheasant' (Darwin's hyphen), through the putative continent of Lemuria (Darwin cannot accept it), mastodon teeth (an article Darwin saw 'some 20 to 30 years ago, in a French Journal ...'), a frog frozen in a glacier, migratory fish, to the insects and flowers of New Zealand. Exhausting.

In the second part of the letter ('Now let me turn to a very different subject.') Darwin thanks Wallace for defending him 'against Mr Mivart'. There is an informative and entertaining commentary on this sorry affair on this site dealing with Mivart. Mivart was a rather tragic figure, who, with his Catholic affiliation, introduces an additional Science versus Religion theme, for good measure. Like Richard Owen, Mivart could not seem quite to make his mind up about Darwin's central ideas, and he wrote several critical accounts. It was one particular article in the Quaterly Review (1874) that finally hardened Darwin's attitude to his critic. The argument also embroiled Darwin's son George (who had been accused of 'encouraging profligacy'), so it became a family matter. Mivart had used selective quotation and baseless accusation against Darwin, who finally broke with Mivart in a suitably comprehensive Victorian drama of manners. All the major names seem to have become involved in the dispute (including, naturally, Huxley and Hooker). The aggrieved Darwin, still smarting two years after the event, reports to Wallace 'I wrote of course to him to say that I would never speak to him again. I ought, however, to be contented, as he is the one man who has ever, as far as I know, treated me basely.'

There is a bonus P.S. to the letter, where Darwin says he is 'very sorry that you have given up Sexual Selection' (Darwin himself had not), and we are back to the 'Argus pheasant' (this time without the hyphen).

Adrian Friday