“If in any country or district”: Darwin 1909 [1842], p. 3.

In reality, Darwin even relied: Hodge 1987.

“When a character which has been lost”: Darwin 2009 [1859], p. 160.

This notion of some latent “tendency”: Darwin returned to this notion of a latent tendency in a letter he wrote to Wallace on September 23, 1868 (Darwin and Seward 1903, vol. 2, p. 84). Darwin wrote: “I think impossible to see how, for instance, a few red feathers appearing on the head of a male bird, and which are at first transmitted to both sexes, would come to be transmitted to males alone. It is not enough that females should be produced from the males with red feathers, which should be destitute of red feathers; but these females must have a latent tendency to produce such feathers, otherwise they would cause deterioration in the red head-feathers of their male offspring.”

In a letter to Wallace on January 22: Darwin was working on the fifth edition of The Origin; in F. Darwin 1887, vol. 3, p. 107. See also Bulmer 2004, Morris 1994.