 …cares not for mere external appearance; she may be said to scrutinise with a severe eye, every nerve, vessel &amp; muscle; every habit, instinct, shade of constitution,—the whole machinery of the organisation. There will be here no caprice, no favouring: the good will be preserved &amp; the bad rigidly destroyed.… Can we wonder then, that nature’s productions bear the stamp of a far higher perfection than man’s product by artificial selection. With nature the most gradual, steady, unerring, deep-sighted selection,—perfect adaption [sic] to the conditions of existence.… (Natural Selection 1856 [1974: 224–225])