PREFACE 



This book originated from a regular course on the 

 physiology of bacteria given to advanced students at the 

 University of Illinois in the years 1913 and 1914, and 

 again at Cornell University since 1927. It would have 

 been published long ago had not the consequences of the 

 war interfered. This required a complete rewriting of 

 the manuscript; new facts had been discovered; new 

 theories had been substituted for old ones. But the 

 principal conception and the general outline have 

 remained the same. 



In the seventy years since bacteriology became a 

 science, only a few books on the physiology of bacteria 

 have been published. Duclaux' ''Traite de Micro- 

 biologie" (1900) was followed ten years later by Kruse's 

 ''Mikrobiologie." Then came Euler-Lindner's '^Chemie 

 der Hefe " in 1915. Recently, we have the three volumes 

 of Buchanan and Fulmer's '^Physiology and Biochemis- 

 try of Bacteria," and Marjory Stephenson's '' Bacterial 

 Metabolism," the first one being meant essentially as 

 a reference book, and the second emphasizing only one 

 phase of bacterial physiology, namely, the metabolism, 

 though all other functions are also discussed. It is 

 safe to say that all but the last two books are antiquated. 



My own intention in writing this book differed some- 

 what from that of the last named authors, and that 

 might give it a right for existence. It is an attempt to 

 co-ordinate the various simplest functions of life, to 



