After withdrawal, the catheter is handed to the embryologist, who inspects it for retained embryos. The embryo recipient may elect to have her own embryologist conduct further testing. His Cambridge students included neurochemistry pioneer Judah Hirsch Quastel and pioneer embryologist Joseph Needham. The second Master was Leigh Hoadley, an embryologist and professor of zoology. George Linius Streeter was a noted embryologist and Director of the Carnegie Institution of Washington. James Ebert, an embryologist at the Carnegie Institution of Washington, recommended her to the position. He was succeeded by Dr. Philippe Piloquet, an embryologist at the University of Nantes. Charles Otis Whitman, an embryologist, was retained as the first director of the MBL. Dan's son was embryologist Dan Katsuma, and his grandson was operatic composer Dan Ikuma. In the 1960s, "biochemical Lamarckism" was advocated by the embryologist Paul Wintrebert. It is currently working in the embryologist area. The "New York Times" called Twitty "a distinguished embryologist".