AGRICULTURAL AND 

 INDUSTRIAL BACTERIOLOGY 



CHAPTER I 



THE DEVELOPMENT OF AGRICULTURAL AND INDUSTRIAL 

 BACTERIOLOGY 



BACTERIOLOGY is frequently defined as that branch of 

 science which has to do with bacteria, but in a broader 

 sense it may include consideration likewise of those yeasts, 

 molds, and protozoa which may be studied most conven- 

 iently and satisfactorily by the methods used in the study 

 of the true bacteria. Those who use the term bacteriology 

 in the narrower sense have adopted microbiology to desig- 

 nate that science which includes consideration of all forms 

 of microscopic life. In this volume the term bacteriology 

 will be used in the broader sense. The terms microbe, 

 microorganism, and germ are used popularly to designate 

 any one of these minute forms of life to be considered. 

 Of these terms, microorganism is probably most commonly 

 used, and is to be preferred. Agricultural and industrial 

 bacteriology may be defined, therefore, as that branch of 

 science which deals with microorganisms, that is, bacteria, 

 yeasts, molds and the protozoa, as they may affect agricul- 

 ture or the industries directly or indirectly. 



Agricultural bacteriology draws its material from many 

 sources. It is necessary briefly to consider the size, shape, 

 and structure of microorganisms, that is to study mor- 

 phological bacteriology. The relationship of bacteria and 



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