The book about earthworms that took Charles Darwin 44 years to write

For most of his adult life, Charles Darwin was mulling over the earthworm question. In the years before his famous adventure on the H.M.S. Beagle, he began investigating how these creatures creates soil-enriching mold during their digestive process. Off and on in the decades after that, he continued to ponder… » 1/23/13 4:50pm 1/23/13 4:50pm