Acknowledges receipt of CD’s Primula paper [J. Linn. Soc. Lond. (Bot.) 10 (1869): 437–54].

Nectar-sucking birds fertilise tropical flowers.

Writing a "Dualistic apologia for Pangenesis" [see translation in Sci. Opin. 2 (1869): 365–7, 391–3, 407–8].

Homology of the orchid rostellum.

Cautions FD about fluid in labellum of Coryanthes.

T. H. Farrer is enthusiastic about FD’s papers.

Believes humming-birds fertilise many American flowers.

Mentions his reply to FD’s criticisms ["Pangenesis: Mr Darwin’s reply to Professor Delpino", Sci. Opin. 2 (1869): 426; Collected papers 2: 158–60].

Suggests that FD study fertilisation of Gramineae.