Darwin's Variation of Animals and Plants under Domestication

Darwin's long work, "The Variation of Animals and Plants under Domestication" was published on January 30, 1868. Published a little over eight years after "Origin of Species," the book provides Darwin's data about mechanisms of variation among domestic species and the role of environment in species development. He offered his "provisional hypothesis" on what he called "pangenesis," a kind of particle mechanism for how species features are passed among generations. Darwin didn't have the benefit of Mendel's researches on genetics, which only became widely known over thirty years later. So his provisional hypothesis wasn't as well received as his accumulation of data about variations.