Book excerpt: The author's aim in these essays, which complement his pioneering books on natural history, has been to find out more about the different categories of people who engaged in this field in the past, and to piece together how the subject has been shaped by changes in society as a whole. For long the historical study of natural history was neglected, being questionably science as historians of science chose to define that word; David Allen's work has done much to remedy this. One group of the essays included here seeks to reinterpret and document more fully topics covered in The Naturalist in Britain; others look at crazes that swept society, notably the Victorian mania for fern collecting, and at the biographies of some of the leading naturalists in 18th- and 19th-century Britain.