Thanks for abstract of Etna paper [Philos. Trans. R. Soc. Lond. 148 (1858): 703–86]. Never expected to see Élie de Beaumont’s theory ["craters of elevation"] so completely upset. "He must have picked out favourable cases for measurement."

More than satisfied by what was done at Linnean Society [joint reading of CD’s and Wallace’s papers: "Tendency of species to form varieties", Collected papers 2: 3–19]. Intends to prepare longer abstract.