vi PREFACE 



The chapter on terminology was necessary in order to make 

 more intelligible the description of species. 



The work does not claim to be a text-book on bacteriology, 

 but aims only to supplement the latter. 



It is evident that bacterial forms cannot be too carefully 

 studied ; the student is therefore urged to make use of the 

 scheme for the study of species as given in Chapter III. 



FREDERICK D. CHESTER. 



Delaware College, 

 Agricultural Experiment Station, 

 Newark, Delaware, 

 December, 1900. 



