From Asa Gray   14 January [1868]

Letter and/or further information available at https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-5786.xml.

Also published in The Correspondence of Charles Darwin, vol. 16.

Please cite as “DCP-LETT-5786,” in Ɛpsilon: The Charles Darwin Collection accessed on 7 May 2024, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5786