My dear Sir
I thank you sincerely for your present of your interesting pamphlet & more especially for the extremely kind & liberal manner in which you allude to my work.—2 I can wish & hope for nothing better.— Permit me to add that I am convinced from my own mental experience, that he who goes as far as you, if he keeps the subject in mind, will ultimately go much further.3
I quite agree with your view of the importance of sexual generation, as far more freely admitting variation, than gemmation;4 but I cannot avoid the suspicion that some more important or at least some other final cause lies hidden.— When an animal is propagated by any process analogous to gemmation, (ie not by sexual generation) I doubt whether it even passes through embryological metamorphoses. On other hand we have reason to suspect that there is always metamorphosis (often concealed) in case of sexual generation.5
But this is a mere loose & crude speculation, which I have sometimes thought of following up.— I daresay it wd. break down.—
With respect to varieties never being infertile together pray look to my abstract of Verbascum & Tobacco cases.—6
At p. 30 you give some grand facts, some of which are unknown to me & will aid me capitally.— 7
With many thanks personally for myself, & for subject-sake, as it is a grand thing for a man in your position deliberately to consider it. I remain | My dear Sir | Yours truly obliged | Charles Darwin
Please cite as “DCP-LETT-2887A,” in Ɛpsilon: The Charles Darwin Collection accessed on