Chapter XIX): Wallace, Darwinism, 1889; Romanes, Darwin and After

Darwin, vol. I, 1892; Metcalf, An Outline of the Theory of Organic Evolution, 1904, good for illustrations. Color: Poulton, The Colors of Animals; Chapters in Weismann's The Evolution Theory, 1904. Mimicry: Weismann, _loc. cit._ Sexual Selection: Darwin, The Descent of Man, new ed., 1892. Inadequacy of Nat. Selection: Spencer, The Inadequacy of Natural Selection, 1893; Morgan, Evolution and Adaptation, 1903. Kellogg, Darwinism To-day, 1907, contains a good account of criticisms against Darwinism.