London: Arnold, 1920.

London: Rivingtons, 1887.

London: E. Arnold, [1891?]

Chicago: The Open Court Publishing Company, 1892-97.

Chicago, The Open court publishing company, 1892-97.

New York [etc.]The Macmillan company,1902. | Princeton Theological

New York :Macmillan,1902. | University of Toronto - Pontif

New York [etc.]The Macmillan Company,1902. | MBLWHOI Libra

London ;E. Arnold, 1896.

article by C. Lloyd Morgan published in Creation by Evolution, 1928

entry in Dictionary of National Biography