My dear Sir

I was very sorry to hear of your illness. From what I have been told poisoning of the blood is most dangerous and often causes extreme suffering. Now that you have begun to recover (and indeed must have a good deal of strength to have so kindly written me so long a letter) I trust and suppose that there is no risk in your complete and early recovery. Your letter is most rich in facts even for you; and I can say nothing stronger than this.² What you tell me about the erection of the feathers is exactly what I wanted to learn. It seems in all cases, and more especially with Birds, to be more closely connected with anger than fear.³ I have seen the Ratel turning head over heels; and if it was really established that they thus free themselves from Bees, the case would be capital for me: I am writing this in London and shall go to Z. G. tomorrow morning and will ask Bartlett whether he has ever heard any authentic accounts from Travellers.⁴ The Cytisus case ought to be well watched: At present, without some intermediate form, I know that Botanists would simply declare that there was some blunder. I am watching a tree in which the bud of C. purpureum died and the stock pushed forth shoots close beneath.⁵

You do not say so, but I supose the fatter of the litter of 4 long-haired rabbits had the blood of the first long-haired rabbit in his veins. I think there can be no doubt now that variegation is contagious; but yours is rather a new case.

I shall go to press very soon with my Man Book and Sexual Selection and keep Expression for a separate Essay.⁶

With cordial thanks | Yours very sincerely | Ch. Darwin.