To A. A. Gould 6 April 1
Down Bromley Kent
My dear Sir
I write one line to return you my very sincere thanks for the kind manner in which you have so effectually & completely procured me an answer from the highest authority on the habit of your Cuckoo.2 If you have any communication with Dr Brewer, I hope that you will present him my best thanks. How Mr Yarrell could have erred so much I cannot conceive; & I am heartily glad I did not trust to his authority.3
I, also, regretted very sincerely that I had not the pleasure of seeing you when in England; but I was at that time quite incapable of any exertion, & this is indeed almost my chronic state.
I cannot help much regretting to hear that your time is so much taken up that you have but little leisure for natural History. An account of the Japan shells, would, I shd think, be very interesting under a geographical point of view, to which you have so much attended.4
With my sincere thanks for your constant kindness to me, pray believe me | My dear Sir | Yours very sincerely | C. Darwin
Thanks AAG for procuring an authoritative answer from T. M. Brewer on the habits of the [American] cuckoo. Surprised William Yarrell erred so much.
Wishes AAG had time to give an account of Japanese shells, which would be interesting from the geographical point of view.