For some time, the growing stature of political science as an independent social science has been a notable feature in American universities. Yet, up to the present time, the categories of this new field of scientific endeavor have not found their way into the indexing departments of libraries, nor have they been recognized by indexers of other collections. Even the editors of encyclopedias, people of great learning and ability, have omitted some of the most significant topics of political science, because of the lack of any accepted index indicating the range of the field and focusing attention upon its primary categories. The American Political Science Review itself is confronted with the problem of a suitable subject-index. The growing complexity of all kinds of materials bearing upon the work of political scientists, and more particularly the increasing mass of public documents, has become more and more baffling. Even the skillful indexers of the Congressional Record, for example, seem unaware of the major topics of interest for political science, and thus no sign-posts of the usual kind have been made available to workers in our field.