Sir

I beg you will accept my thanks for your letter & for the enclosure.¹ I am very glad that the subject has engaged your attention, & I trust that the result may be the adoption of a course of proceeding which, in your words, will protect animals from the needless suffering to which they are now sometimes subjected,—& may not prevent the future progress of physiology.

I propose to consult confidentially with one or two of those who take a great interest in the subject: & have the honour to remain, Sir, Yours faithfully | Cardwell

Charles Darwin Esq^r.