Great natural history museums are among world's premier institutions of scientific research, training, and education. The research produced by these museums, based on their collections of biological, geological, and anthropological specimens, has been of incalculable importance in formulating and testing most fundamental theories and principles of these and related disciplines. In biological sciences, for instance, contributions from past curators of these collections form pillars of modern evolutionary biology [e.g., ([ 1 ][1]–[ 3 ][2])]. We therefore read with deep concern of plans to drastically reduce role of scientific research at one of world's greatest museums of natural history, Chicago's Field Museum (Budget crunch to shrink science programs at Chicago's Field V. Morell, News & Analysis, 4 January, p. [19][3]). The collections of Field Museum are an irreplaceable scientific resource, and scientists who care for, augment, and make them available for study by others are also renowned contributors to science in their own right. Their loss would be a blow not just to Museum, but to scientific enterprise as a whole. In making bequest that endowed Smithsonian, Smithson epitomized what has become mission of modern natural history museums: They are institutions for the increase and diffusion of knowledge ([ 4 ][4]). Many science museums can mount exhibits for diffusion of knowledge, but only museums such as Field, with its collections and scientists, can contribute so much to its increase. For Field Museum to abandon this duty would be unconscionable. We urge Museum's authorities and supporters to find a way to prevent such a calamity. 1. [↵][5]1. E. Mayr , Systematics and Origin of Species (Columbia Univ. Press, New York, 1942). 2. 1. G. G. Simpson , Tempo and Mode in Evolution (Columbia Univ. Press, New York, 1944). 3. [↵][6]1. B. Rensch , Neuere Probleme der Abstammungslehre (Enke, Stuttgart, 1947). 4. [↵][7]1. J. Smithson , James Smithson makes his will (1826); [http://siarchives.si.edu/collections/siris\_sic\_638][8]. [1]: #ref-1 [2]: #ref-3 [3]: http://www.sciencemag.org/content/339/6115/19.full [4]: #ref-4 [5]: #xref-ref-1-1 View reference 1 in text [6]: #xref-ref-3-1 View reference 3 in text [7]: #xref-ref-4-1 View reference 4 in text [8]: http://siarchives.si.edu/collections/siris_sic_638