John Bartram (1699-1777), the first native-born American to devote his entire life to the study of nature, was an eminently practical man, a scientist devoted to the rigorous description of living things. Among his subjects was the Venus flytrap, along with hundreds of species of plants and animals, fully one quarter of all the plants identified and sent to Europe during the colonial period. His son William (1739-1823) was a pioneering naturalist...