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.