THE selection, examination, and classification of the valuable matter contained in periodical literature is performed by two agencies, viz. certain abstracting and indexing societies and journals. “Science Abstracts” and the abstracts published by the chemical societies of England, France, Germany, and the United States are examples of the former class, while the “International Catalogue of Scientific Literature,” the “Engineering Index,” the “Index Medicus,” the “Index to Legal Periodicals,” and the various indexes published by the Anglo-American library associations represent the latter. Almost without exception, where the same field is covered by both types of publication, the two agencies work independently of each other. Further, in this country the publication of abstracts generally precedes the corresponding index publication, especially where the latter makes any pretence to completeness. This obviously is an indefensible arrangement; for the index material, which is the result of the wider survey, should be accessible to the abstractor prior to the preparation of the abstracts. We propose to indicate how this change could be accomplished with a minimum of disturbance to existing interests. It should be observed that the phrase “periodical literature” is used in its widest sense to include society publications and institutional reports, as well as annual, quarterly, monthly, and weekly publications.