Chapter XVII

); Life and letters by his son, 3 vols., 1887, new ed., 1896; More Letters of Charles Darwin, 2 vols., 1903; Chapter in Marshall's Lectures on the Darwinian Theory; Darwin, Naturalist's Voyage around the World, 1880; Gould, Biographical Clinics, for Darwin's illness due to eye-strain; Poulton, Chas. Darwin and the Theory of Natural Selection, 1896. Wallace: My Life, 2 vols., 1905; The Critic, Oct., 1905. Huxley: Life and Letters by his son, 1901; Numerous sketches at the time of his death, 1895, in _Nature_, _Nineteenth Century_, _Pop. Sci. Mo._, etc., etc. Haeckel: His Life and Work by Bölsche, 1906.

##