My dear Lubbock

Your remarks seem to me admirably good, & I am sure I sh^d. have thought so, if I had never heard your name & whether or no they concurred with my notions.—² I thank you heartily & am pleased at the high compliment you pay the Origin.—³ Such remarks as yours, (I do not mean the compliment!) I feel sure are the true way of advancing our general belief on Species; viz by showing that several subordinate questions are illustrated by our view. Such remarks as yours just make the difference whether a memoir does or does not advance Biology. And how few naturalists deal in them!

Now for a few details. Your remarks on links in classification seem to me excellent.⁴ I am especially glad to see your observations on variability of secondary sexual characters:⁵ this is important likewise in the practical classificatory work of naturalists.

There is misprint & omission of word in one paragraph. p. 168.—⁶

I have omitted one remark on p. 167 (7 l. from top): would it not be well to change “although” into “and”? for when one first reads sentence it seems as if you thought that it was a rule that aberrant forms sh^d. be rich in genera & species,—which would be almost a contradiction in terms.⁷ Your following good remarks show that this is not meant.—

With respect to domestication & variability;⁸ I do not think your sentences clear; in fact I can hardly understand the last.— They want clearing, altering & amplifying.—   Possibly it may aid you just to say to what conclusion I arrived on this subject.— Changes in the conditions of life (at least abrupt changes) certainly tend to induce some degree of sterility: they likewise certainly tend to cause variability in successive generations; but I could never satisfy myself, whether at same time they caused both; whether they caused either sterility or variability; or whether variability ensued after the sterility ceased. Many of our domestic productions are more fertile than the aboriginal forms in the wild state & are more variable; so that there is no necessary relation between variability & lessened fertility. I am rather inclined to view sterility & variability, as alternatives produced by changes of conditions.** But this again relates only to when a being is first subjected to a considerably change from its natural to domestic conditions.— It is an obscure question, & you had better be cautious.— Thanks for Annals & Owen⁹

I cannot find after search Millepora conplanata; but you have I think the other Millepora; & they differ only in growing in great masses.—

Ever yours | C. Darwin

P.S.** | As far as I remember all that I have said in Origin is that changed conditions of life in some inexplicable way strongly affect the generative system, as shown by the induced tendency to sterility; & therefore one need not be surprised at other & lesser changes of conditions so far affecting the reproductive system, that the offspring are produced not quite like their parents.—

In your last sentence I cannot see why species which are partially variable are most likely to lose their fertility.—

Heaven knows whether you will be able to decipher or understand my scribble—