An entangled bank clothed with plants of many kinds, birds singing, insects flitting about: Charles Darwin ended his great work with this image, and it is there, in the teeming interrelation of living things, that his argument lives. Published in 1859 after decades of hesitation, the book advances its thesis with the patience of a naturalist who knows that evidence, accumulated in quantity, becomes irresistible. Darwin writes of pigeons and barnacles, orchids and finches, building a case for natural selection with a gentleness that belies its shattering implications. Victorian in courtesy and radical in content, the prose dismantles the fixity of species with the confidence of a man who looked at the world long enough to see it moving.