Natural science specimens are ideal for evaluating the past and present condition of the earth. The maintenance of such collections is expensive, for the objects are often fragile and rare. Furthermore, these collections, by their very nature, grow with time and thus require increasing space to house them. Criteria for accessioning and deaccessioning specimens, rate of collections growth, and storage methods are discussed. The Smithsonian's new Museum Support Center (MSC) is presented as a current solution to the problem of efficient storage and maintenance of collections. Directors of major natural history museums are responsible for maintaining and judiciously expanding their collections, which serve as a data bank to monitor the state of the globe.