From early in 1856, when he was persuaded that the time had come to publish an account of his heterodox theories, through to 1857, Darwin's letters in this volu... » 

From early in 1856, when he was persuaded that the time had come to publish an account of his heterodox theories, through to 1857, Darwin's letters in this volume document the labour involved in composing his big species book, his zest for research, and his unflagging determination to succeed. «