Mary Terrall's new book is a beautifully-written, carefully-researched, and compellingly-argued account of the practices of natural history in the eighteenth-century francophone world. Catching Nature in the Act: Reaumur and the Practice of Natural History in the Eighteenth Century (University of Chicago Press, 2014) explores this world via the work of Antoine Ferchault de Reaumur and his vast and varied networks of correspondents, assistants, colleagues, and co-naturalists. As we read, we follow this loose network across the bakeries, gardens, tidepools, hedges, studies, academies, kitchens, poultry yards, specimen collections, and other spaces of quotidian life and their associated practices of natural history. As these men and women observed, chased, collected, dissected, preserved, painted, described, and tested, they practiced the production of knowledge about the natural world as a part of their intimate, daily lives. The chapters of Terrall's book observe them as they in turn observe aphids, mayflies, sea anemones, chickens, and other creatures as a means to understand larger questions about the nature of generation, metamorphosis, reproduction, and other lived behaviors and processes. They feed material from inside the quills of young pigeon feathers to spiders in order to study spider silk and its commercial potential. They glue glass to cocoons to create windows into the metamorphoses of the butterflies inside. They use hog bristles to turn tiny polyps inside-out and observe how they responded. They draw, they incubate, and they incorporate practices and materials from the physical sciences to do so. Catching Nature in the Act contributes thoughtfully to several interrelated historiographical threads in the history of science - the histories of practice and place, the importance of the household as a space of observation and experiment, the role of networks of correspondence and collaboration, the relationship between natural science and theology - and offers helpful revisions of dominant approaches to each of those historiographies of science and its histories. It is a must-read for historians of science, and a fascinating narrative for any interested reader.