This will cause occasional irregularities in the progression of numbers of the “Accession Number” column, but it is of much greater importance not to allow extensive blanks to occur in this series of numbers, as it will play havoc with the charging system later on. This method of re-entering cannot be done with stock books having the accession numbers ready printed, and librarians who use this form must make up their minds to run a very irregular series of numbers. The whole process can be simplified by the use of a loose-leaf accession book, such as the “Kalamazoo” ledgers. As entries become congested by the substitution of other books for those originally stocked, the congested pages can be re-written as a whole. A register of discarded books or withdrawals can be kept in a separate book--the superseded loose leaves can be filed for the purpose--if it is thought desirable to retain a record of books which have been and are no longer in the library; but experience has not shown such a record to have any precise or practical value. As in many other branches of library work, the tendency in accession work is to elaborate every process instead of simplifying it. The simplest form of stock book is that in which a specially ruled counterfoil is attached to the order forms and which only provides columns for accession and class numbers, author, title and number of volumes, publisher and price. After all a stock book need only be a kind of record of origin, and not necessarily an epitome, of the catalogue and classification. What a stock book is wanted for is to answer the questions: When did a given book come; where did it come from; what did it cost; how many books does the library possess; what are they about? There are so many records which give other particulars, that it seems a great waste of time to repeat a large number of the particulars given in some stock books. =227.= The withdrawals book is the necessary complement of the stock book, and in it is entered every book permanently withdrawn from the library for any reason. The ruling given below will show better than description its scope and style: