Your letters are always much kind. I shall be proud to receive your monograph on the Radiolariæ which I saw & much admired in London; but I know so little of the group that ina truth I am not worthy of your present. I sent off a few days since to Jena a copy of a paper by me, which if you have time I think is || worth your reading.
My health continues very weak & I have no strength to spare, so I am sure you will excuse the brevity of this note.
With very sincere respect believe me my dear Sir
Yours truly obliged
Charles Darwin ||
P S. Jan 3.
By a mistake this letter was put in a wrong envelope & you will have have recieved another note adressed to a friend which I fear will have surprized you.
Please to tear it up. As there has been so much delay owing to my unfortunate mistake, I have directed this to Jena instead of to Berlin.