Marx Brothers stage during the middle of a Groucho monologue to see if Groucho would be thrown off. However, to the audience's delight, Groucho merely reacted by commenting, "First time I ever saw a taxi hail a passenger". When Harpo chased the girl back in the other direction, Groucho calmly checked his watch and ad-libbed, "The 9:20's right on time. You can set your watch by the Lehigh Valley." The brothers' vaudeville act had made them stars on Broadway under Chico's management and with Groucho's creative direction—first with the musical revue "I'll Say She Is" (1924–1925) and then with two musical comedies:
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