A few words in regard to the printing of the lists known as "Additions and corrections" will, I think, be needed for a full understanding of the subject headings. I have already spoken of the lists of additions issued in connection with the old A. L. A. list, before the Library of Congress list of headings began to be printed. When letter A of our new list was ready for press, there had been four of these lists issued, the additions being cumulated in each successive number. The corrections in the lists appeared but once, and were carried over by the catalogers to copies of the A. L. A. list. The headings in these early supplementary lists have, of course, been incorporated in the Library of Congress list, as far as the letters have been printed. Even after the new list was begun, it was found impossible to dispense with the "Additions and corrections" lists, as the library catalog grew and expanded. We have continued to issue them from time to time, as occasion has demanded, and have included in them new headings in the section of the alphabet not yet printed, as well as additions to the letters which have already appeared in print. Each "Additions and corrections" list is cumulative, as far as the additions are concerned, so that a library possessing the main list and the latest supplementary list has a complete record of all the Library of Congress headings which have been printed. As was the case in the lists supplementary to the A. L. A. headings, the corrections noted appear but once, and should be carried over by catalogers to the main list of subject headings. The classification numbers, and cross references to related subjects, known as the "See also" references, are not included in the supplementary lists. Direct "See" references from one subject to another, or from one form of name to another, are, however, usually included, that the cataloger may avoid the pitfalls lurking for the unwary. Including the early supplementary lists, there have been, up to the present time, eight lists of "Additions and corrections" issued, and number 9 is ready for the press. Having now touched upon some general features in regard to the issuing of the list of subject headings, with its supplementary lists, I will conclude with a word as to a later and fuller edition. The list now being issued is a preliminary list, printed as manuscript, and, to some extent, experimental in its nature. While it is being made as complete and inclusive as present conditions seem to warrant, the intention has been to reissue it later in book form, wider in its scope and more inclusive in its references. Concerning the date of issue of the fuller edition, should this desired consummation be brought about, it is impossible at this time to make a statement. Probably it will be best to wait until the remaining classes of books in the library are reclassified and re-cataloged, before any definite decision as to date is reached.