8 FROM TEE PREFACE TO THE FIRST EDITION. 



room, but have only employed citations to facilitate detailed 

 studies, especially pointing out recent reviews with numer- 

 ous references. Every bacteriologic investigator will be un- 

 able to dispense with the aids which we have employed : 

 Centralblatt fiir Bakteriologie und Parasitenkunde (Redak- 

 teur Uhlworm, Kassel, seit 1887), Baumgarten's Jahres- 

 bericht iiber die pathogenen, und Koch' s Jahresbericht iiber 

 die zymogenen, etc. , Organismen. By their comprehensive 

 index they quickly furnish a complete abstract of literature. 

 If we have been able to somewhat further the diagnosis 

 of bacteria, to lighten the task of the beginner, to indicate 

 the numerous difficulties of this work, which are partly un- 

 determined and too little appreciated, then we are rewarded 

 for the great labor which we have expended. We hope 

 especially to furnish the student in bacteriology a sub- 

 stantial aid, and to make it possible for him to better 

 appreciate what is seen and heard. We beg our critics 

 not to censure too strongly defects and mistakes, which 

 necessarily entered because of the enormous material. 



Prof. De. K. B. Lehmann. 



