PREFAC E. 



AT the present time there is no work that deserves the name of 

 a text- book on bacteriology published in the English language on 

 this side of the Atlantic. 



The want of such a book has long been felt. 



While a student in Professor Koch's laboratory at the Hygienic 

 Institute in Berlin the past summer, the third edition of " Fraenkel's 

 Grundriss der Bakterienkunde " was recommended to me as a text- 

 book. 



It is now published in six different languages. 



In addition to this testimony to the merit of the work, I heard 

 many favorable comments on it by teachers in several different 

 laboratories on the Continent which I visited during the summer of 

 1890. 



A few changes have been made in the book and the presenta- 

 tion of the matter changed from the lecture style. 



I append some extracts taken from the preface to the first 

 German edition. 



The book " does not claim complete or exhaustive discussion of 

 the subject and presents no statements from literature. . . . Only 

 such facts and observations have been given as were examined by 

 myself. ... I have at all times been assisted by Dr. Koch's 

 weighty advice, and am thus fortunate enough to know that my 

 views are in complete harmony with those of the master of recent 

 bacteriology. Being convinced that this circumstance will enhance 

 the value of the work, I avail n^self of this opportunity to express 

 my heartfelt gratitude to my revered instructor and chief/' 



Jo, H. LINSLEY, M.D., 



39 Gramercy Park. 

 April, 1891. 



