My dear Sir

I beg to send you a copy of a paper lately read before the Anthropological Institute and to hope that you will not find in it any expression which can be construed into anything disrespectful.¹ I owe too much both of my taste for science and of my scanty knowledge to your books to be guilty of anything of the kind, and I should like to have the opportunity of correcting anything of which you disapprove in a future paper. In the reading of facts it is impossible that we should all agree, & it is only by the conflict of opinion that we arrive at the truth. If I differ from my master however I cannot do so in the terms which are congenial to some controversialists. I am afraid I have forgotten myself once or twice with M^r Wallace.² My excuse is that he indulged in some rather contemptuous phrases which are irritating & not very convincing.

Captain Galton has asked me to enlarge 2 or 3 letters which appeared in Nature into a paper on the areas of upheaval & subsidence in the Earths crust.³ I have found the work by no means easy, but have collected a good many observations on the rise of land in various places which promise a curious result. This I will send you if you care to have it. Evidence of depression is less easy to find. Your work on Coral islands is the main collection of facts on the subject.⁴ I have added a good many places to your list, but am not well satisfied with my work. It seems to me that mangrove swamps which surround many coasts ought to be evidence pro or con on this matter. Your experience of tropical countries is so great and your range of facts so great also that I venture to hope you may have considered this question, namely whether mangroves grow in a subsiding area or not. I can only be sure of one place where a mangrove forest is to be found in an area of upheaval & in this all the trees are dead. If I can do anything of any kind for you in Lancashire I hope you will make use of me.

I remain | Yours very respectfully | Henry H. Howorth

C. Darwin E^sq.