. . . Two accounts of Mr. Mitten's life and work have appeared, one in the Journal of Botany for October, 1906, by W. Botting Hemsley and the other in the Bryologist for January, 1907, by William Edward Nicholson, both of which are interesting personal sketches, the latter giving a bibliographical list, but neither of them containing any account of his collections. In a letter dated September 5, 1906, Dr. Wallace states that "Nobody ever touched, or hardly ever saw these collections but Mr. Mitten himself and a few specialist visitors. Although I have never examined them myself, as a friend (and a son-in-law) of Mr. Mitten for forty years, I know something of them and I am inclined to think that they constitute the richest (or nearly the richest) private collection of those groups in existence, while it is doubtful if any public collections are much richer. Mr. Mitten, as you know, has studied and described mosses for nearly sixty years, and for a long time was the greatest British authority on them, and received collections to sort, name, and describe from collectors, museums, and travelers, in every part of the world. Of all these he reserved sets for himself, and has thus accumulated an enormous collection, the nomenclature and arrangement of which he was at work at up to the end of his life." . . .