INTRODUCTORY I44-5 



As just stated, the original object of this Manual was to supply the 

 methods to be used in the study of organisms according to the 

 Descriptive Chart. As the subject developed, however, it was felt 

 that there are other fields of pure culture study equally important and 

 these have been added from time to time. The present Manual 

 deals with so many lines of tcchnic that it is essentially a laboratory 

 handbook covering those procedures referred to above as comprising 

 the field of pure culture study. It is coming to be used more and 

 more for this purpose, and in a number of institutions is now put in 

 the hands of all students in certain classes of bacteriology. Thus 

 used, it has the advantage over conventional texts in that the Com- 

 mittee behind it is consistently endeavoring to keep it up to date. 



The present edition of this Manual contains ten leaflets bearing 

 the following titles: I. Introductory; II. Preparation of Media; III. 

 The Study of Obligately Anaerobic Bacteria; IV. Staining Pro- 

 cedures; V. Routine Tests for the Descriptive Chart; VI. Further 

 Biochemical Methods; VII. The Study of Pathogenic Aerobes; VIII. 

 Serological Methods; IX. The Determination of pH and Titrable 

 Acidity; X. Inoculations with Bacteria Causing Plant Disease. 



The system adopted for keeping the Manual up to date is by means 

 of subscriptions to this quarterly publication, Pure Culture Study 

 OF Bacteria. Nearly every issue of this quarterly contains a revi- 

 sion of some one of the ten leaflets. Anyone owning a copy of the 

 Manual can subscribe to Pure Culture Study of Bacteria by 

 filling out the card attached to the front of the Manual and sending it 

 in to the publishing agency with a year's subscription. Thus, any 

 student who first purchases a copy merely in connection with his class 

 work, can easily arrange to have it kept up to date if he finds that he 

 is going into bacteriological work permanently. It is in this way 

 that the owner is able to profit from the loose-leaf type of publication 

 which has been adopted. 



HISTORICAL 



The first efforts toward producing a descriptive chart for character- 

 izing bacteria were made by two different individual investigators, 

 H. W. Conn, and S. de M. Gage. The work of these two investi- 

 gators called the matter to the attention of bacteriologists in general 

 and it was finally brought before the Society of American Bacteriolo- 

 gists by F. D. Chester at the Philadelphia meeting in December 1903, 

 and then again at the 1904 meeting when he explained his idea of a 

 "group number" which would be descriptive of the salient charac- 

 ters of an organism. On his recommendation the Society appointed 



