[93] To Huxley, May 27, 1865, Life, vol. II, p. 228.
[94] Aristotle, Historia Animalium, Book I, chapter VI.
[95] Life, vol. I, p. 126.
[96] To Hooker, April 14, 1855, Life, vol. I, p. 415.
[97] To Hooker, March 26, 1863, More Letters, vol. I, p. 474.
[98] Genetics and Eugenics, p. 181.
[99] De Vries, Species and Varieties, p. 769.
[100] Different Forms of Flowers, p. 156.
[101] To Gray, April 3, 1860, Life, vol. II, p. 90.
[102] Zur Naturwissenschaft, Einzelne Betrachtungen und Aphorismen, section III.