PREFACE 



BACTERIOLOGY, in the few years of its existence, has be- 

 come one of the great subjects of the day. A knowledge 

 of it is important to students of many different branches of 

 science. At the present time it is usually taught, in English- 

 speaking countries at least, with special reference to some 

 particular application, such as medicine or agriculture. There 

 is a growing demand for treatises on the subject of general 

 bacteriology. The authors have attempted to meet this need 

 in the present volume. 



The material presented here has been used in college 

 classes for a number of years with interest and profit. 



The authors wish to express their sincere acknowledgment 

 for the particular help received from the works of Fischer, 

 Lafar, E. F. Smith, Wells, and others mentioned in the body 

 of the text, and for the ideas and inspiration imparted by 

 their former teacher, Dean H. L. Russell, of the University 

 of Wisconsin. For suggestions and assistance in the revision 

 of the manuscript, we are indebted to Professor M. P. Rave- 



nel, of the University of Wisconsin. 



W. D. F. 

 E. F. McC. 

 JULY, 1910. 



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