Marx Brothers "The Cocoanuts" (1925–1926) and "Animal Crackers" (1928–1929). Playwright George S. Kaufman worked on the last two and helped sharpen the brothers' characterizations. Out of their distinctive costumes, the brothers looked alike, even down to their receding hairlines. Zeppo could pass for a younger Groucho, and played the role of his son in "Horse Feathers". A scene in "Duck Soup" finds Groucho, Harpo, and Chico all appearing in the famous greasepaint eyebrows, mustache, and round glasses while wearing nightcaps. The three are indistinguishable, enabling them to carry off the "mirror scene" perfectly. The stage names of the brothers (except Zeppo) were
Influences on Karl Marx "when Darwin drew the conclusions from his research work and brought them to the knowledge of the public, we spoke of nothing else for months but Darwin and the enormous significance of his scientific discoveries". Historian Richard Weikart points out that Marx had started to attend "a series of lectures by Thomas Henry Huxley on evolution". In August 1866, Marx referred to Pierre Trémaux's "Origine et transformations de l'homme et des autres êtres" (1865) in another letter to Engels as "a very important advance over Darwin". He went further to claim that "in its historical and political application" the book