—— as a Horticulturist. Gardeners’ Chronicle, with portrait, March 6th, 1875, pp. 308, 309.
—— before the French Academy. Nature, vol. 2, 1870, pp. 261, 298, and 309.
—Das Ausland, 1870, pp. 855-857.
—— Biography of. Biograph, vol. 6, 1881, pp. 525-529.
—Smithsonian Miscellaneous Collections, by William H. Dall, vol. 25, 1883, pp. 56-59.
—— Contributions to Philosophy. Smithsonian Miscellaneous Collections, by John W. Powell, vol. 25, 1883, pp. 60-70.
—— Critics on. Contemporary Review, by T. H. Huxley, vol. 18, 1871, pp. 443-476; reprinted in Critiques and Addresses, by Huxley, 1873.
—— et ses Critiques. Revue des Deux Mondes, by Auguste Laugel, tome 74, sêconde période, 1868, pp. 130-156.
—— und seine Gegner. Aus Ausland, 1871, pp. 88-91.
—— Cross and Self-Fertilisation in the Vegetable Kingdom. American Journal of Science, by Asa Gray, vol. 13, 3rd Series, 1877, pp. 125-141.