Sir William Gull has just brought me the enclosed quotations from Chaucer, as illustrations of the closure of the eyes in effort.2 He begs me to send them to you. I have lately seen a terrier who very distinctly frowns during mental excitement—not always with anger, but often, I think, with anxiety, as in expecting food.
Please cite as “DCP-LETT-8713,” in Ɛpsilon: The Charles Darwin Collection accessed on