THE ILLUSTRATION OF NATURE RECAST: JACOB GREEN'S MODELS OF AMERICAN TRILOBITES

The first major work on trilobites found in North America was also the beginning of a notable experiment in the illustration of species descriptions. Jacob Green (1790-1841), a naturalist and Professor of Chemistry at Jefferson Medical College furnished his papers with plaster-of-Paris casts of trilobites, in lieu of figures; casts, “coloured according to nature,” would provide fellow naturalists with “fac similes” of rare specimens hidden away in the cabinets of institutions and private collectors. The use of exact replicas resonates with Green’s criticism of trilobite classifications based on drawings and other specimen proxies that were exchanged among naturalists and European savants. Green accepted the provisional nature of his own classification, which was largely based on incomplete specimens; the trilobite casts would therefore provide a shared basis for future revisions to be made by naturalists. Green attempted to accurately illustrate his species with “the art of modeling”—then prominent in Europe. An examination of the casts at the Academy of Natural Sciences of Drexel University, which included comparisons with original descriptions, available figures, and ostensible duplicates, showed that the trilobite replicas fell short of Green’s aspirations. Instead, they are simulacra, sometimes even transmogrified renderings, of the originals. Although casts were endorsed by other naturalists in Philadelphia as a way of augmenting collections, the failure of morphological details to register in the plaster medium must have limited their usefulness in taxonomy. The trilobites were just one part of the inventory of casts for sale by Green’s collaborator, the artist Joseph Brano. If the monograph was viewed as simply a detailed catalog of fossils, then its appeal could extend beyond naturalists to educators and casual collectors. In this way, Green and Brano’s plaster museum was an important precursor of Henry Augustus Ward’s more ambitious catalogs of fossil replicas, which were advertised explicitly for the purposes of education and exhibition. The trilobite casts are a silent reminder of the transience of early American natural history collections, preserving the likenesses of specimens lost or destroyed long ago.