My dear Sir

I am much obliged by your kind letter of Saturday, & greatly pleased that you approve of the specimen of Index sent to you through M^r Murray.—¹ I notice your objection to the long list of references under the head of “Dogs”, & will endeavour to pick out such as may be considered useful catch-lines,²—or rather I will try to strike out some other principle in the subsequent parts of the book.— The portion relating to the introduction might, I think, remain as it is, unless you positively object to it,—the excess is at all events a fault on the right side.—

You would probably notice that I did not Index all the author’s names cited in the notes, but only those whose statements are actually quoted,—will you be kind enough to let me know whether this will be satisfactory, or whether you would wish all author’s names to appear in the Index, with references to all the places in which they occur.—

I will write at once to M^r Murray to send me the remaining Sheets,—& I think, if nothing unforeseen happens to prevent me, that I ought to be able to finish everything in a fortnight.— I should have made more progress already, but my work on the Zoological Record was interrupted for several weeks by illness in the early part of the summer, & with all my efforts I have been unable to make up the lost time.—³

It will be desirable that I should read the first proofs of the Index, & equally so that you should also look over them.—

Believe me, | My dear Sir | Your’s very truly | W. S. Dallas.

C. Darwin Esq^r. F.R.S.