Thanks AdeC for his memoir ["Étude sur l’espèce", Ann. Sci. Nat. (Bot.) 4th ser. 18 (1862): 59–110].

CD astonished at the amount of variability in the oaks.

CD differs from most contemporaries in thinking that the vast continental extensions of Forbes, Heer, and others are not only advanced without sufficient evidence but are opposed to much weighty evidence.

AdeC’s comment on CD’s work [Origin] is generous.

CD is satisfied at the length AdeC goes with him and is not surprised at his prudent reservations. He remembers how many years it took him to change his old beliefs. The great point is to give up immutability. So long as species are thought immutable there can be no progress in "epiontology" [see ML 1: 234 n.]. CD is sure to be proved wrong in many points but the subject will have "a grand future".

CD thinks that he believes in as much migration as AdeC, only he does not believe nearly so much in continental extensions. CD also believes more in modification in form though he suspects the difference is not so great.

Thanks AdeC for information on melons, oranges,

and Swiss lake-habitation discoveries.

CD is almost tired of his book on variation under domestication, for his knowledge is insufficient to treat the plant part well, but he has done so much that he will finish it.