BiblioVault may have an electronic file which would meet your requirements for this title:
Faith in a Seed: The Dispersion Of Seeds And Other Late Natural History Writings
Henry D. Thoreau, Bradley P. Dean, Abigail Rorer, Robert Richardson and Gary Paul Nabhan
Paper: 978-1-55963-182-2
Cloth: 978-1-55963-181-5
Electronic: 978-1-59726-287-3