“I saw, also, that the preservation”: Peckham 1959, p. 178.

of which two survive to reproduce: Peckham 1959, p. 178.

“Approaching the subject [of evolution]”: The precise date of this letter is not known, but because it was sent from Moor Park, it had to be before November 12, 1857. In Darwin and Seward 1903, vol. 1, p. 102.

he wrote in his book The Variation: Darwin 1868, vol. 2, p. 374.

First, in a letter written on January 22: Marchant 1916, vol. 1, p. 166.