To Verlagsbuchhandlung Wilhelm Engelmann   21 April [1868]

Letter and/or further information available at https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-6133F.xml.

Please cite as “DCP-LETT-6133F,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-6133F