PREFACE TO SEVENTH EDITION 



The general format of the seventh edition of Bergey's Manual of Deter- 

 minative Bacteriology differs but Uttle from that of the sixth edition. How- 

 ever, examination will reveal many changes in the content as the result of a 

 thoroughgoing revision. Among these the following seem to be worthy of special 

 comment. 



The most obvious change is that of the separation into two volumes of the 

 material comparable to that which appeared in the sixth edition. The present 

 volume is entitled the seventh edition of Bergey's Manual of Determinative 

 Bacteriology. This Manual contains an outlined classification of the bac- 

 teria and the descriptions of the taxa from Class to Species and Subspecies, to- 

 gether with the appropriate keys. Nearly all species regarded as having been 

 inadequately described or that could not be definitely placed have been excluded, 

 together with many of the less important synonyms of the accepted species. 

 These, together with the index to all the literature of both accepted and poorly 

 described organisms have been transferred to a volume to be known as the 

 Index Bergeyana. The latter volume will include all descriptions and citations 

 to species formerly found as appendices or indefinitely placed as species incertae 

 sedis. The host and habitat index will also be found in the Index Bergeyana. 

 The net result is that the Manual itself contains descriptions of many more 

 species with more adequate descriptions than have former editions; the transfer 

 of much material to the Index Bergeyana has meant a reduction in the number 

 of pages and a book of more convenient size and greater usefulness. The Index 

 Bergeyana should prove to be an invaluable tool for the research microbiologist, 

 containing, as it will, references to the whole field of systematic bacteriology and 

 an index to the names of described species, both valid and invalid. 



Much material of historical value and interest in the sixth and earlier editions 

 of the Manual has been excluded, not because it is lacking in real value to the 

 student, but because repetition of its publication is now unnecessary. 



This edition of the Manual represents the coordinated results of the work of 

 one hundred contributors, about thirty-five more than assisted in preparing the 

 sixth edition. The contributors to the Manual are to be regarded in all nomen- 

 clatural matters as strictly the authors of their sections. All new names of taxa 

 and the names of all new combinations are to be ascribed to these authors, and 

 not to the editors of the Manual. Contributors from countries other than the 

 United States are more numerous than in the earlier editions. In other words, 

 the Manual is rapidly assuming the character of an international publication. 

 To all of these contributors the sincere thanks of the Board of Editors, and par- 

 ticularly of the Editor-in-Chief, are due. The seventh edition is a tribute to the 

 patience, care and scientific acumen of these individuals. Special note should be 

 taken of the assistance rendered in the office of the Editor-in-Chief by Mr. 

 Erwin Lessel, Miss Maude Hogan, Mrs. Eleanore Heist CUse and Mrs. Margaret 

 Edson Breed. 



