My dear Häckel

I thank you for yr very interesting letter, which it has given me much pleasure to receive. I never heard of any thing so odd as a Prior in the holy Catholic Church believing in our ape-like progenitors.¹ I much hope that the Jesuits will not dislodge him.

What a wonderfully active man you are! & I rejoice that you have been so successful in yr work on sponges.

Your book with 60 plates will be magnificent.² I shall be glad to learn what you think of Clarke’s view about sponges being flagellate infusorians: some observers in this country believe in him.³ I am glad you are going fully to consider inheritance, which is an all-important subject for us. I do not know whether you have ever read my Chapter on Pangenesis:⁴ my ideas have been almost universally despised; & I suppose that I was foolish to publish them; yet I must still think that there is some truth in them; any how they have aided me much in making me clearly understand the facts of inheritance.

I have had bad health this last summer, & during 2 months was able to do nothing.⁵ But I have now almost finished a new edit. of the Origin, which Victor Carus is translating. There is not much new in it, except one chapter in which I have answered, I hope satisfactorily, M^r Mivart’s supposed difficulty on the incipient development of useful structures. I have also given my reasons for quite disbelieving in great & sudden modifications.⁶ I am preparing an essay on expression in man & the lower animals; it has little importance, but has interested me.⁷ I doubt whether my strength will last for much more serious work. I hope however to publish next summer the results of my long continued experiments on the wonderful advantages derived from crossing.⁸ I shall continue to work as long as I can; but it does not much signify when I stop, as there are so many good men fully as capable, perhaps more capable than myself, of carrying on our work; & of these you rank as the first.

With cordial good wishes for your success in all your work, & for your happiness, believe me | my dear Häckel | yours very sincerely | Charles Darwin