The authors of this text have devoted prolonged study to the detailed bacteriology of “Salmonellae and Shigellae.” This volume reflects their interest. About one half is devoted to a detailed definition of the genera and to the serological differentiation of groups and types. One cannot approve the nomenclature used for Shigella. A Commission of the International Congress of Microbiology has made recommendations concerning this. Regrettably, throughout this text, the designations and classification recommended earlier by Weil are still employed. This perpetuates a confusion which can be overcome only by accepting and following the recommendation of a responsible International Committee as virtually all other bacteriologists have done. Despite this weakness, these chapters are the superior ones in the text. There is much useful information, particularly for the mature rather than the beginning worker. There are, by contrast, only two brief and inadequate chapters on the isolation and identification of these organisms, a highly important subject for most clinical and public health laboratories.