This book of standard equipment for every bacteriological worker has in the first edition in five years received major revision, has been entirely rewritten and enlarged to more than 1000 pages, double the size of the first edition. The index has been greatly improved and is now excellent.
There has been extensive rearrangement of genera and nine generic terms added. The difficulty of satisfactorily classifying material supported by incomplete data has been partially met by placement of the indeterminate species in an appendix to each genus of the classified species. We wonder if Leptospira icteroides, here given the dignity of a classified species, should not have been dropped to the indeterminate group.
Consideration has been given to the decisions on nomenclature by the International Congresses of Microbiology and of the type species concept of the International Rules of Botanical Nomenclature of the Fifth International Botanical Congress.