8 
PREFACE 
giving complete and detailed directions, taking nothing 
for granted and leaving nothing to one’s imagination. 
For this reason I have laid much stress on cultural 
diagnosis giving much prominence to the several culture 
media used for the differentiation of the various mem¬ 
bers of the typhoid-colon-dysentery group. In each chap¬ 
ter a section is provided on Bacteriologic Diagnosis, 
under which all tests called for in connection with the 
particular disease are enumerated and complete technic 
is given, usually describing but one method—the one 
which has proved most serviceable in my hands. 
Sections on Immunotherapy of individual diseases are 
provided in each chapter wherever called for, and at 
the end of each chapter a summary of the most important 
characteristics is given. 
Since the bacteriology is usually taught to the first 
year pupils, the lecturer on bacteriology usually has to 
refer to other allied subjects, especially physiology and 
histology; I have endeavored to make such references as 
clear as I knew how by giving the full description and 
derivation of the terms used. 
A complete questionnaire is provided at the end of the 
book to facilitate the review of the subject. 
Numerous textbooks, monographs and magazine articles 
have been consulted—too numerous to be mentioned in 
their entirety, but whenever special references were made, 
I have, at all times, endeavored to give full credit where 
it is due. 
In the section on history, I have briefly reviewed the 
most prominent achievements of the American bacteriolo¬ 
gists. 
I have tried to incorporate as much of the newer con¬ 
tributions to the theory and practice of bacteriology and 
