essentially a product of the twentieth century, has been characterized by the rapid increase in their number, from 50 in 1907 to 3,473 in 1962, and by significant changes in their functions. The growth of services offered by special libraries has been directly related to the expansion of research and development programs, reflecting especially the impetus given to such programs by the two world wars and the major emphasis accorded research since World War 11. “In its first 150 years as a nation, the United States-Government and industry combined-spent some $18 billion for R & D. That total was matched in the five-year period, 1950 to 1955, and almost matched again in the single fiscal year of 1962,”l This mushrooming of research has stimulated the development of new libraries as well as the expansion of existing ones. Research organizations, businesses, governmental agencies, and similar enterprises established libraries in order to centralize materials housed in individual laboratories and offices and to unify informationlike activities. Initially, therefore, the special library’s role was restricted to that of a repository. Due in part to the librarian’s effort to provide additional justification for the existence of the library, the idea of an information or reference function emerged. Leading to the establishment of reference services, the librarian gradually assumed responsibility for assisting the user to obtain the information he needed, first helping those who were unable to manage alone and then providing assistance in order to save the time of the research worker. Special librarians have slowly expanded the service role, and in some libraries service now includes active collaboration of the librarian in the conduct of specific projects or research activity.