[90] Kräfte zweiter Hand. The primary forces are the chemical and mechanical forces, the secondary are those which control and guide these for certain ends.
[91] Pp. 9, 10. The italics are Prof. Henslow’s.
[92] This statement taken literally is, of course, quite too sweeping. Professor Henslow clearly means here by “variations” those alone which are important enough to have selection-value, favourable or otherwise. Insignificant variations are always occurring.
[93] Henslow, Origin, etc., p. 102.
[94] Ibid., p. 80.
[95] Ibid., p. 40.
[96] A. R. Wallace, Darwinism (1890), p. 427.
[97] Marie v. Chauvin, ‘Ueber die Verwandlungsfähigkeit des mexikanischen Axolotl.’ Zeitschrift für wissenschaftliche Zoologie, XLI, p. 385. See also The Cambridge Natural History, sub voce.
[98] Haeckel, History of Creation (English trans.), I, p. 150.