(Moritz Wagner, Darwin’s Theory and the Law of the Migration of Organisms. Leipzig, 1868.)
[41. ] Rudolf Virchow, Vier Reden über Leben und Kranksein. Berlin, 1862.
(Rudolf Virchow, Four Discourses on Life and Disease. Berlin, 1862.)
[42. ] Friedrich Müller, Ethnographie (Reise der österreichischen Fregatte Novara. Anthropologischer Theil. 3 Abtheilung). Wien, 1868.
(Friedrich Müller, Ethnography (Voyage of the Austrian Frigate Novara. Anthropological Part. 3rd Part). Vienna, 1868.)
[43. ] Ludwig Büchner, Die Stellung des Menschen in der Natur, in Vergangenheit, Gegenwart und Zukunft. Leipzig, 1870.
(Ludwig Büchner, Man’s Place in Nature in the Past, the Present, and the Future. Leipzig, 1870.)
[44. ]John Lubbock, Prehistoric Times. London, 1867.
[45. ]Herbert Spencer, A System of Philosophy. (1. First Principles. 2. Principles of Biology. 3. Principles of Psychology, etc.) London, 1867. 2nd Edition.
[46. ] Wilhelm Wundt, Vorlesungen über die Menschen- und Thierseele. Leipzig, 1863.