Dear Sir,

In sending you my little pamphlet on Muscular conditions expressive of states of the brain I have marked certain passages which appear to me to have a direct bearing on some subjects which you have done so much to elucidate and direct our attention to.¹ It has long appeared to me a most useful method to look upon our daily patients in the light thrown upon all cases by the view of the unity of the organized world—

Yours very truly | Francis Warner

Charles Darwin Esq