My dear Sir

I have read your chapt. with great interest.¹ I will give my opinion, whatever that may be worth, without any exaggeration. I would not shorten or omit a sentence; & I hardly remember any Travels of which I would say that. The whole seems to me excellent. If other chapters are as good, I believe your book will be the best of the class of Nat. History Travels.— I do not pretend to be a judge of style; for I have never attended systematically to the subject; but yours seems to me very good, just what is wanted.— I strongly suspect that you are better fitted to criticise my style than I to criticise yours.—

I have hardly anything to remark. That is a capital discussion on the effects of climate on the dress of species; very original & throws new light on subject.—² There is one point, I think, you had better carefully attend to; viz when referring to English insects or other animals always, when possible, to give in addition to scientific name a common English name—as when speaking of Vanessas, to say such as our nettle-Peacock &c— I would I think even add, when speaking of Cicindela, a word of description, such as bright green colour with spots of gold   So with Amara the little oval coppery Beetles which run on hot days across our paths.— It seems to me to add greatly to interest if you can call before the Readers mind some definite object— Remember not one in a hundred knows the scientific names.— So with respect to the gigantic ant, I would give the length of our largest British ant R. rufa.—³ I will scribble a few very trifling miscellaneous remarks.—

p. 8 & p. 40— you use “former & latter”— to my private taste this is a great bore; at p. 40 I had to read back. Macaulay, I observe, always prefers repeating the word, rather than use “latter”, if not close to that which is referred to.⁴

p. 9. Have you goodish evidence that rocks are Cretaceous— if not, I would not use the term.—

You speak of “we”— I suppose you give Preface & there explain “we”. It would add to value of your remarks, if reader from first knew that you were solely engaged in Nat. Hist pursuits.—

p. 21. what does “4$\frac{1}{5}$” of population mean?

p. 49. Would it not be well to say how many species of Lepidoptera found in Para in contrast with number in Grt. Britain

It occurs to me doubtfully, (but you would certainly be better judge) whether the History of Para (which seems to me very well done) had not better be inserted at end of chapter; as being so very distinct a subject.⁵ So with Ants, it occurred to me that the little description of the Sexes & Workers ought, perhaps, to be inserted before Leaf-carrying Ant, as you allude to “worker minors”, which would confound ordinary reader.— Would it not be well just to say that this Leaf-carrier has been alluded to by almost every traveller in Brazil & is so conspicuous & no explanation of habit given— I have heard it suggested gravely that each ant carried leaf as parasol!

You probably know that it is good plan, when your subject greatly changes to leave open space of a line between the two paragraphs— Have No^s of Chapter at head of Page, it is so useful for reference.— Make Index— you know of course easiest plan.—

I should think that Murray would prefer seeing two or three Chapters.—⁶ Whenever you tell me I will write strongly to Murray & send his answer to you.⁷ Remember to dispose of only 1^st. Edit. Murray’s usual plan is to take all risk & give certain share of profits; but all this will have to be arranged after he has considered your M.S. which will probably take him a week or two.— Perhaps he would buy the 1^st. Edit. & give Bill at 6 or 9 months.

I return your M.S. by this Post.— You will see that my remarks are quite useless: but if you like to send another chapter, I will read it with pleasure. I heartily congratulate you on the probability of your producing a popular Book, that it will be an excellent one I am sure.—

My dear Sir | Yours very sincerely | Ch. Darwin