My dear Sir

I thank you for your “Christmas Card”, and heartily return your good wishes.¹ What you say about the coats of mules is new to me, as is the statement about hermaphroditism in hybrid moths.² This latter fact seems to me particularly curious; and to make a very wild hypothesis I should be inclined to account for it by reversion to the primordial condition of the two sexes being united; for I think it certain that hybridism does lead to reversion.³

I keep fairly well, but have not much strength, and feel very old.

My dear Sir | Yours sincerely | Charles Darwin.