Columbia subject headings:
Biology--History.
Darwin, Charles, 1809-1882.
Natural history.
Natural selection--History.
Naturalists--England--Biography.
Harvard subject headings:
Biology--History
Darwin, Charles, 1809-1882
Natural history--History
Natural selection--History.
Naturalists--England--Biography
Princeton subject headings:
Biology--History.
Darwin, Charles, 1809-1882.
Natural history--History.
Natural selection--History.
Naturalists--England--Biography.