Dear Darwin

I am writing or rather intending to write on a very curious subject   Why do salmon rise or why do not they always rise at the fly   the first short paper or rather letter to Buckland will be published in one of the next no^s of Land and Water²   Negretti & Zambra³ are preparing some instruments for me viz

and compass to be fitted in a box of a portable form to go with me fishing by means of which I shall always be able to ascertain the state of the atmosphere at any time and tabulating the observations I hope to come to some results.

Have in your travels made any observations of the sort or observed anything that will help conclusions   if you have or can give me any hints I shall be much obliged to you. Hoping that you are in better health than when you wrote last and that all your party are well also

I remain yours truly | Tho C Eyton

I shall a supplement out shortly to Osteologia⁴   Have you seen Alphonse Milne Edwards book on the fossil birds of France.⁵ I was yesterday trying to make from the old book of what country the rabbit was originally a native but was not very successful.⁶