CHAPTER XVIII

Weismann's The Evolution Theory, translated by J.A. and Margaret Thomson, 2 vols., 1904, contains the best statement of Weismann's views. It is remarkably clear in its exposition of a complicated theory. The Germ-Plasm, 1893; Romanes's An Examination of Weismannism, 1893. Inheritance of Acquired Characters: Weismann's discussion, _loc. cit._, vol. II, very good. Romanes's Darwin and After Darwin, vol. II. Personality of Weismann: Sketch and brief autobiography, in _The Lamp_, vol. 26, 1903, portrait; Solomonsen, Bericht über die Feier des 70 Geburtstages von August Weismann, 1905, 2 portraits.

Mutation-Theory of De Vries: Die Mutations-Theorie, 1901; Species and Varieties, their Origin by Mutation, 1905; Morgan, Evolution and Adaptation, 1903, gives a good statement of the Mutation Theory, which is favored by the author; Whitman, The Problem of the Origin of Species, _Congress of Arts and Science, Universal Exposition, St. Louis_, 1904; Davenport, Evolution without Mutation, _Journ. Exp. Zool._, April, 1905.