six shelves each, each section being designated by a numeral. Each shelf is designated by a letter of the alphabet, beginning at the bottom with A. The alcoves have no distinguishing mark, the books being arranged therein by subjects which the distributing librarian is expected to carry in his mind. The first catalogue, in four volumes, was compiled by Dr. Cogswell and printed in 1861. This was followed in 1866 by an index of subjects from the same hand. Recently a catalogue in continuation of Dr. Cogswell's, bringing the work down to the end of 1880, has been prepared, and is being printed at the Riverside Press, Boston. The current card catalogue is arranged on the dictionary plan, giving author and subject under one alphabet. Opposite each title is written the number of the alcove and the letter designating the shelf. By the regulations the reader is required to find the title of the book desired in the catalogue, write it with the number and letter on a slip of paper provided for the purpose, and give it to the distributing librarian, who despatches one of his boy Mercuries to the shelf designated for the work. More often than not, however, the reader asks directly for the book desired, without consulting the catalogue, and it is rarely that the librarian cannot from memory direct his messenger to the section and shelf containing it. In the matter of theft and mutilation of books the library depends largely on the honor of readers, although some safeguards are provided. All readers are required to enter their names and addresses in a book, and the volume on being given out is charged to them, to be checked off on its return: it would be difficult, too, for a thief to purloin books without being detected by the employees or the porter in the vestibule. Yet books are stolen occasionally. In June, 1881, a four-volume work by Bentley on "Medicinal Plants," valued at sixty dollars, was taken from the library. It was soon missed, and search made for it without avail. A few weeks later, however, it was discovered by the principal librarian in a Broadway book-stall and recovered.