chapter 13

. E. Darwin: Krause's Life of E. Darwin translated into English, 1879; Packard, _loc. cit._ Goethe: Die Idee der Pflanzenmetamorphose bei Wolff und bei Goethe, Kirchoff, 1867; Goethe's Die Metamorphose der Pflanzen, 1790. Oken: His Elements of Physiophilosophy, Ray Soc., 1847. Cuvier and St. Hilaire: Perrier, La Philosophie Zoologique avant Darwin, 1884; Osborn, _loc. cit._ Darwin and Wallace: The original communications of Darwin and Wallace, with a letter of transmissal signed by Hooker and Lyell, published in the _Trans. Linnæan Soc._ for 1858, were reprinted in the _Pop. Sci. Mo._, vol. 60, 1901. Darwin: Personality and biography (For references to his theory see under