To W. D. Fox   6 February [1868]¹

My dear Fox

I thank you very sincerely for your most cordial congratulations. George’s success has been a very great pleasure to us.² Whenever you come to London it will give me & Emma very great pleasure to see you here, but I hope that you will stay the night with us. You give but a poor account of your own health.³ I hope that what you fear is not the case. I have known quite a large number of men who the D^rs declared (falsely as it afterwards appeared) to have had their hearts affected; & how many men there are who live to good old age although their hearts are certainly affected.

There is so much detail in my book that you will never be able to read it through; but some of the chapters, such as that on Reversion are I think curious. You will find several facts given on your authority.⁴

Believe me my dear old friend | yours very sincerely | Charles Darwin