Dear Sir.

I am sufficient of a philosopher to regard nothing as small which belongs to Biology.² Now that you mention the contraction of the orbicular muscles of the eyelids, in consonance with scratching for the relief of pruritus, I remember to have seen it often but without taking any particular note of it. The wonder is, that in the state of irritation that, in pruritus, occupies so large an extent of the c⁠⟨⁠u⁠⟩⁠taneous nervous plexuse⁠⟨⁠s⁠⟩⁠, so little reflex excitement should be set up in the motor and in the organic system. And looking to the close relation between the sensory nerves of the skin and the special muscles of the skin, e.g. the occipito-frontalis,³ the platysma myoides⁴ of the neck, and the cutaneous sphincters, such a sympathy as you refer to might almost necessarily be expected. In the c⁠⟨⁠a⁠⟩⁠se of the elimination of tears, y⁠⟨⁠o⁠⟩⁠u no doubt infer that pressure against the lachrymal glands would excite function, just as would a particle of sand in contact with the conjunctiva and without any emotional interference.

I am sorry I cannot give you the precise information you desire;—but I will bear your question in mind, f⁠⟨⁠o⁠⟩⁠r future observation,⁵

I am, Dear Sir; | very faithfully yours | Erasmus Wilson

Charles Darwin Esqr