Leop. Carol. Akad. (Nova Acta), tom. xxxv, 1869.
      Müller, Fritz. — Ueber einige Befruchtungserscheinungen. — Botanische Zeitung, No 14, 1869, p. 224.
      — Umwandlung von Staubgefässen in Stempel bei Begonia. Uebergang von Zwitterblüthigkeit in Getrenntblüthigkeit bei Chamissoa. Triandrische Varietät eines monandrischen Epidendrum. — Botanische Zeitung, No 10, 1870, p. 149.
      Weale, J.P. Mansel. — Note on a Species of Disperis found on the Kageberg, South Africa — Journal of Linnean Society, Botany, vol. xiii, 1871, p. 42.
      — Some Observations on the Fertilisation of Disa macrantha. — Journal of Linnean Society, vol. xiii, 1871, p. 45.
      —Notes on some Species of Habenaria found in South Africa. — Journal of Linnean Society, vol. xiii, p. 47.
      Cheeseman, T.F. — On the Fertilisation of the New-Zealand Species of Pterostylis. — Transact. of the New-Zealand Institute, vol. v, 1873, p. 352.
      Müller, Hermann. — Die Befruchtung der Blumen durch Insekten, ecc. Leipzig, 1873 pag. 74-86.
      Cheeseman, T.F. — On the Fertilisation of Acianthus cyrtostylis. — Transact. of the New-Zealand Institute, vol. vii, 1874 (issued 1875), p. 349.
      Müller, Hermann. — Alpine Orchids adapted to Cross-fertilisation by Butterflies. — Nature, Dec. 31, 1874.
      Delfino. —Ulteriori osservazioni sulla Dicogamia nel Regno vegetale. Parte seconda, fasc. ii, Milano, 1875, p. 149, 150.
      Lubbock, Sir J. — British Wild Flowers. London, 1875, p. 162-175.
      Fitzgerald, R.D. — Australian Orchids. Part i, 1875, Part ii, 1876, Sydney, New South, Wales.