When the Metropolitan Museum came into being in 1870, the founders stressed its role in giving popular instruction. Ever since then its public has expressed interest in obtaining a general guidebook to all the multiple facets of its encyclopedic collections. But a museum is a living, constantly changing institution, and the preparation of such a guide presents many problems. The scope and depth of the Museum's holdings are described with flexibility in mind, so that alterations to the building and changes in the collections can be readily accommodated in future editions of this "Guide". …