The purpose of this brief foreword is unchanged from the first edition; it is simply to make you, the reader, hungry for the scientific
feast that follows. These 11 volumes (planned) on the prokaryotes offer an expanded scientific menu that displays the biochemical
depth and remarkable physiological and morphological diversity of prokaryote life. The size of the volumes might initially discourage
the unprepared mind from being attracted to the study of prokaryote life, for this landmark assemblage thoroughly documents the
wealth of present knowledge. But in confronting the reader with the state of the art, the Handbook also defines where more work
needs to be done on well-studied bacteria as well as on unusual or poorly studied organisms.