Congratulates CD on the Copley Medal.

Directs CD to his short memoir on crossing ["De l’hybridité", C. R. Hebd. Acad. Sci. 59 (1864): 837–45].

Thanks CVN for reference to the Comptes Rendus [Académie Française].

Mentions CVN’s work on Cucurbitaceae and notes that he (CD) has quoted extensively from it in Variation.

Hopes to send paper on Lythrum [Collected papers 2: 106–31] soon.

Mentions exchange of photographs.