Collections are the hallmark of museums and those at The Academy of Natural Sciences are among the more important of their kind. The size and scope of its collections have grown substantially since the early years. Currently, there are over 17 million biological specimens, and hundreds of thousands of volumes, journals, illustrations, photographs, and archival items in its library. These collections grew through a combination of means, including the donation or purchase of existing collections or individual items, the collection activities of Academy-sponsored expeditions, or those of individual scientists, whether or not they work at the Academy. Sometimes the Academy is also enlisted to house and care for collections originally gathered by other institutions. For example, a number of the natural history collections at the American Philosophical Society were relocated to the Academy by the end of the 19th century.
But these collections are not maintained just to collect dust. They provide a library of biodiversity. Traditionally, researchers at natural science (or natural history) institutions such as the Academy engaged in biological taxonomy, the science of discovering, describing, naming, and classifying species: in essence, the cataloging of Nature. In recent decades, research has shifted in emphasis to the science of systematics, the study of the evolutionary relationships among these species.
Either way, the collections are invaluable. They provide the type specimens, the reference material that helps establish a species identity. They also provide raw materials with which scientists can investigate the nature of these species, their relationships with other species, their evolutionary history, or even their conservation status. New questions and new technology illustrate the importance of these collections. Titian Peale (1799