FOREWORD 



The contributions relating to the various substrates and media used for the 

 cultivation of bacteria, yeasts, and molds, are widely scattered in the hterature. 

 Very frequently they are not adequately indexed. For some years it has been 

 felt that a key to the various media and substrates proposed for the growth of 

 microorganisms would prove helpful. The fact that these formulae were not 

 readily available has led to a great amount of dupHcation m the hterature. A 

 search of the hterature has therefore been undertaken and the formulae tor 

 about 7000 various media that have been proposed brought together. The 

 task of securing this material was performed most acceptably by Mr. H. W. 

 Schoenlein, who was also associated in the development of the keys The task 

 of organizing the compilation, of planning the presentation, and of final editmg 

 was undertaken by Dr. Max Levine. It was found possible greatly to curtail 

 the number of separate formulae by use of the subheading Variants m many 



The compilation presented in the following pages was made possible by a 

 grant to the Society of American Bacteriologists by the Digestive Ferments 

 Company of Detroit, Michigan. At the request of the Society of American 

 Bacteriologists, the Department of Bacteriology at the Iowa State College 

 accepted the task of compilation. The interest, helpfulness, and support of the 

 Digestive Ferments Company throughout the progress of the work cannot be 

 too greatly appreciated. 



The system of classification of the media, together with the arrangement of 

 keys, indices, etc., should make possible a ready review of the media which 

 have been proposed for growing different types of organisms and containing 

 different ingredients. The primary subdivisions into Groops on the basis of 

 physical characteristics and nature of the sohdifying agent is the logical one 

 both from the standpoint of history and the standpoint of usefulness. The 

 secondary subdivisions based upon the chemical characteristics of the constitu- 

 ents of the media are in fine with modern trend toward emphasis upon physiol- 

 ogy and metabolism of microorganisms. 



It is hoped that this compendium of information will prove very generally 

 useful to all bacteriologists and in all bacteriological laboratories. 



R. E. Buchanan. 



