PREFACE TO THE FIRST EDITION 



IN the following pages I have endeavoured to ar- 

 range briefly and concisely the various methods at 

 present in use for the study of bacteria, and the 

 elucidation of such points in their life-histories as are 

 debatable or still undetermined. 



Of these methods, some are new, others are not; 

 but all are reliable, only such having been included 

 as are capable of giving satisfactory results even in 

 the hands of beginners. In fact, the bulk of the 

 matter is simply an elaboration of the typewritten 

 notes distributed to some of my laboratory classes in 

 practical and applied bacteriology; consequently an 

 attempt has been made to present the elements of 

 bacteriological technique in their logical sequence. 



I make no apology for the space devoted to illus- 

 trations, nearly all of which have been prepared 

 especially for this volume; for a picture, if good, 

 possesses a higher educational value and conveys a 

 more accurate impression than a page of print; and 

 even sketches of apparatus serve a distinct purpose 

 in suggesting to the student those alterations and 

 modifications which may be rendered necessary or 

 advisable by the character of his laboratory equip- 

 ment. 



The excellent and appropriate terminology intro- 

 duced by Chester in his recent work on "Determina- 

 tive Bacteriology" I have adopted in its entirety, 

 for I consider it only needs to be used to convince 

 one of its extreme utility, whilst its inclusion in an 

 elementary manual is calculated to induce in the 

 student habits of accurate observation and concise 

 description. 



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