Charles Darwin an Ernst Haeckel, Down, 6. Februar 
Down. | Bromley. | Kent. S. E.
My dear Haeckel
I was delighted to receive your cordial & very interesting letter. The photograph is so good that it is like having you in the room. I am delighted to hear of the splendid success of your lectures; but this must depend far more on the lecturer than on the subject – I fear you take much too sanguine a view of the progress of our || belief in the descent-theory. I have just read a little book by Ernest Faivre who is very courteous & evidently sincere, but he cannot see a shadow of a reason in favour of the common descent of allied species. I am in a little confusion whether you have received the English or German Edition of my book; I first ordered the German edition to be sent to you, forgetting that you read English easily, but I subsequently directed the || English to be sent to you. If you have both perhaps you will pass on the German edition with my compliments to Prof. Gegenbaur. If ever you have time to read my book I think you will find it of use in giving you a large body of facts on certain subjects.
Pray give my compliments to yr Russian friend Mikluska: I do not quite understand what you tell me about his discovery in regard to the swim-bladder; for I thought every one admitted that it was the homologue of the lungs. I am sorry to read what you say about Dohrn; || but I was fearful, from a little paper that he sent me, that he was rather wild in his views. I have not yet recd the paper from yr relation Dr Bleek; I wish he had ever attended to the Australian languages, for I am very curious to know whether they shew any affinity with the languages of Africa. Pray keep the book on the Canary I’s as long as you like. As for myself I keep in much the same state as during the last year & am able to do a fair share of work. I have just finished 2 papers on the fertilization of plants, & have now begun a small book on the Descent of Man & on sexual selection, which || will appear to you an incongruous union.
I am delighted to hear that you are so well in health & so happy. How fortunate it was that yr career was not cut short by falling down from that lofty Alpine pinnacle.
Believe me my dear Häckel
yours very sincerely