My dear Hooker

How good you have been to send me so splendid a lot of leaves.— I have worked many hours at them, & made rough notes on all.² I have resolved it w^d. be waste of time to work longer at them, as some were slightly withered & this may affect the bloom, & it is better to work deliberately on a few living plants.³ But my notes will be of the greatest service when I get plants from Rollisson & Co;⁴ & if results prove interesting, I may ask you for 2 or 3 living species. You will not conceive such ignorance as mine, yet I cannot distinguish all the Eucalypti from the Acacias. Therefore I have returned by this post the spec^s. in a tin box, each with a number attached; & if you will take them out in any order write the number down & put opposite E for Eucalyptus & A for Acacia, (I suppose these are sub-genera, but I can say genera in large sense.)⁵ & the specimens will be ten-fold more valuable to me.— But if you chance to know specific name, please add them. About the specimens numbered 2. 4. 7. 10. 14. 22. 24. 25. 27. & 31. I have made fuller notes, (i.e the temp. at which bloom removed &c &c) & the specific names in their case would probably be more useful to me; but do not go & hunt them up. Perhaps you would roll the whole lot up in brown paper & return them; & then if I find the subject promises well, I could send any one or two about which I felt particular interest for name, or for living specimen.— My notion is that perhaps vertical position serves as protection against rain soaking the leaf, owing to the bloom, when present, being easily removed; it may turn out all a hallucination: it is not, however, I think so with Mimosa pudica & some others.⁶

The branches of Acacia farnesiana⁷ arrived withered & leaflets closed, still I could see enough to make me wish much to examine the plant, if you think it can be sent safely. If sent please have marked conspicuously on Label “To be sent off immediately in a Fly.” Remember address is “Orpington St. S.E. Railway.”

I will write again soon.—

I have thought of several rather troublesome experiments for Drosophyllum, so can you lend me a plant, I will return it in a fortnight.—⁸

The secreting & absorbing glands are the same in Drosera & Dionæa, but apparently not so in Drosophyllum.⁹

We go to Henrietta’s House on Friday week & stay there a week—¹⁰ I am knocked up with my work.—

Yours affect | C. Darwin

I shall be so glad for seeds of Lathyrus nissolia¹¹

P.S. I have just rec^d the enclosed from Lyell, to be forwarded to you, & to be returned to him. Mr Wood’s remarks are interesting, though I hardly agree with one of them.¹²

It w^d be a g^t anomaly (tho’ such do occur) if a new & strongly marked variety transmitted its characters, without selection during at least 2 or 3 generations. It is likely enough in the case of those vars of apples such as Hawthorndeans which do transmit their characters, that they have gone through this process.

With respect to extinction, Mr Wood has overlooked or disregarded what I have said on rarity preceding extinction.¹³ It w^d be easy to specify certain cetaceans which are very rare; & I suppose Mr Wood w^d not be much astonished at this fact; of rarity or if he w^d, there is cause in every Family for his astonishment.

The competition of better adapted forms seems to me a sufficient explanation; & I sh^d be unwilling to admit sterility without at least some direct evidence. I was at first much surprized at Mr Wood’s statement about the sterility of seedling apples; but I now think without sufficient cause. Apples, like so many other plants, have been rendered somewhat sterile (& the fruit consequently enlarged) thro’ changed conditions, & they apparently have transmitted this sterility.—

I have lately had a good instance of such transmission: in a lot of common Convolvulus (Ipomœa purpurea) one plant appeared which was very sterile (& this is a rare circumstance) & a second, slightly sterile. I self-fertilized them & raised seedlings this year; & the sterility has been transmitted to both lots in nearly the same relative degrees, but not equal to that of their parents.¹⁴ If you think this P.S. worth sending to Lyell, pray do so, but not otherwise.

C. Darwin