viii PREFACE 



two nations which by their individual characteristics supplement each 

 other. France claims such great teachers as Lamarck, Claude Bernard, 

 and Pasteur, true pioneers in the field of biology. By her spirit per- 

 haps, too traditionalistic and suppressed by old administrative ma- 

 chinery, she has not always understood fully the real utility of her 

 universities and given to her scientists the necessary means for carry- 

 ing on their work. On the other hand, America, with no such rich 

 heritage from the past, has built up modern laboratories with a new 

 spirit and equipped them with the necessary resources. She probably 

 possesses the greatest universities in the world. She lays claim to able 

 investigators and, thanks to her marvelous scientific organization and 

 to her numerous investigators, is sure to gain very rapidly a foremost 

 place in the scientific world. If the American savants have the desire 

 to profit by the discoveries of the French, their elders, France has 

 much to gain by imitating America in her practical ideas, her spirit of 

 organization, her methods of work, and her tremendous activity. 



The book which Professor Tanner has undertaken to present to the 

 public cannot be regarded as a simple translation of my work; it is a 

 new edition resulting from intimate collaboration of translator and 

 author. Microbiology is progressing so rapidly that the French edi- 

 tion, now six years old, is no longer abreast with recent acquisitions of 

 the science. It was found necessary to make numerous editions and 

 to modify certain chapters in which Professor Tanner and myself have 

 shared the labor. Professor Tanner, known by his work on the bio- 

 chemistry of bacteria, has undertaken the revision of the Chapter on 

 Physiology of the Yeasts which was no small task, for since the dis- 

 covery of zymase by Buchner, the biochemical investigations on yeasts 

 have followed each other without interruption and have become in- 

 creasingly valuable. As for myself, I have borne the task of revising 

 the Chapters on Morphology, Phylogeny and Description of Species, 

 subjects with which I am more familiar. Professor Tanner had, then, 

 a preponderant part in the translation of this new edition and the 

 book has certainly gained much by the collaboration of a physiologist 

 so well qualified. 



ALEXANDRE GUILLIERMOND 



LYON, September 8, 1919 



