PREFACE TO THE FIFTH EDITION ix 



Dr. J. Howard Mueller, Assistant Professor of Bacteriology, has 

 critically revised the sections dealing with the chemical metabolism of 

 bacteria, and Miss Ann KuttniT, Instructor in the department, has 

 elaborated, and revised the chapter dealing with the anaerobic- in- 

 fections which have gained such an important place in the study of 

 traumatic injuries. We are indebted to Dr. Oscar Tcague for valuable 

 suggestions in connection with the chapters on cholera and plague. 



HANS ZINSSER 

 FREDERICK F. RUSSELL 



