=Removal Slips.=--For various reasons it is frequently necessary to remove cards from the catalogue. When this is done a colored removal slip is placed in the catalogue bearing the author’s name, title, and call number, and the initials of the assistant who has the card. This does not indicate that the book is off the shelf. It may as readily be obtained by copying the call number, author and title from the removal slip, as from the original card. In the process of reclassification, it is necessary to remove the books from the shelves and the cards from the catalogue. When this is done, a card stamped RECLASSIFICATION, bearing the author’s name and the title of the book, is filed in the place of the author card removed. If the book is desired by a reader, it must be requested at the Loan Desk with the statement that the card is marked RECLASSIFICATION. When difficulty is found in using the catalogues or in locating references to material supposedly in the library, inquiry should always be made at the Reference Department. =Other Library Catalogues.=--The catalogues of other large libraries form important bibliographic aids. The following are available in this library: The Union Depository Catalogue, filed in cases in the south corridor, main floor; this includes author cards for the books in the Library of Congress, various government departmental libraries in Washington, D.C., and such cards as have been printed by the John Crerar Library, Harvard University, University of Chicago, University of Illinois, University of Michigan, and Newberry libraries. In the Catalogue Room will also be found certain printed catalogues in book form, chief among which are those of the British Museum, Bibliothèque Nationale, Boston Athenaeum, London Library, Peabody Institute Library, and Surgeon General’s Library. These may be consulted in the Catalogue Room between 9 A.M. and 5 P.M. At other hours apply to the Reference Department. THE BOOK STACK Members of the faculty have free access to the stack. Permits are required of all others. Card for stack permit may be obtained at the Loan Desk by a graduate student and should be filled out and signed by his instructor before being presented to the Associate Librarian for approval. Though undergraduates presenting a reasonable request at the Reference Desk will be given an opportunity to look over the literature of any particular subject, permits for any length of time will only be issued in exceptional cases for, in general, undergraduate needs are met by the Reading Room and Reserved Book collections. As far as possible books are arranged on the nine floors of the stack in proper classification sequence, but as convenience of access has caused some exceptions, a guide is posted on the central case as one enters the stack on the main floor. More detailed charts will be found on each floor. CIRCULATION DEPARTMENT