PART I. INTRODUCTION 



CHAPTER I 



HISTORY OF BACTERIOLOGY 



Introduction. Bacteriology is that branch of biological 

 science which treats of bacteria. Bacteria are a definite and 

 circumscribed group of microorganisms lying near the base 

 of the ladder of life. They will be accurately described in 

 the following chapters. It is frequently found desirable to 

 discuss other microorganisms with the bacteria, both on 

 account of the fact that they are closely related, and also be- 

 cause they produce similar changes, or are studied by similar 

 methods. The more inclusive term " microbiology," which 

 is used by the French, would be much better than the term 

 "bacteriology" to describe the subject-matter discussed in this 

 book. Custom, however, has fixed the word "bacteriology" 

 in this country, and it will be used here, but not infrequently 

 in the broader sense. While bacteria are associated with 

 disease production, the majority of them are not disease-pro- 

 ducing, and if there were no disease-producing bacteria in the 

 world, bacteriology would still be a great science. In this 

 book bacteria will be considered from a biological stand- 

 point, and their structure and functions studied without 

 any particular application in view. It is therefore a general 



