Darwin Francis, ред., Life and letters of Charles Darwin. Lond., 1897.
Darwin Francis and Seward A. C., More letters of Charles Darwin. New. York, 1903.
Huxley Leonard, Life and letters of Thomas Huxley. Lond., 1900.
Huxley Julian, A new judgment. Lond., 1945.
Jrwine William, Thomas Henry Huxley. Lond., 1960.