2 MANUAL OF MICROBIOLOGICAL METHODS 



subject very close to the field of bacterial taxonomy, i.e., the naming and 

 classifying of bacteria. Inasmuch as bacteria cannot be classified with- 

 out studying their characteristics in pure culture, it is an obvious conclu- 

 sion that pure culture study is a necessary prelude to bacterial taxonomy. 

 It must be recognized, nevertheless, that one can consider pure culture 

 study without regard to taxonomy and that one can study the taxonomy 

 of bacteria without paying special attention to the methods of pure cul- 

 ture study. Since this distinction can be made and the committee edit- 

 ing this series of publications is a committee on technic, care has always 

 been taken to maintain the distinction so as not to interfere with the 

 functions of other committees that have been appointed and to deal with 

 matters of nomenclature and classification. 



PUBLICATIONS OF THE COMMITTEE ON TECHNIC 



Descriptive charts. The first descriptive chart actually adopted by 

 the Society of American Bacteriologists was in 1907. The chart has been 

 revised from time to time and at present there are two forms : one known 

 as the Standard Descriptive Chart and the other as the Descriptive 

 Chart for Instruction. The latter is very much simpler than the former. 

 The formxer is printed on both sides of an 83^- by 11-in. sheet of light 

 cardboard; the latter on a sheet of heavy paper of the same size. 



The object of the descriptive chart is to provide a space for recording 

 the most important characteristics of a single culture. The Standard 

 Chart is the most complete and is intended especially for advanced work 

 in bacteriology. Unfortunately, however, it does not meet modern 

 research needs at all perfectly because each group of bacteria requires its 

 own set of tests and no form can be drawn up sufficiently detailed to cover 

 all of them. The Chart for Instruction, on the other hand, is so much 

 simpler and contains so much blank space that it sometimes is found to 

 be more satisfactory in research work than the Standard Chart. It is, 

 however, intended primarily for students to use in characterizing cultures 

 furnished them in connection with their classwork. 



Manual of Microbiological Methods. The origin of the present manual 

 traces back to a committee report which was printed in the Journal of 

 Bacteriology and was distributed in reprint form by the committee (1918). 

 It was only 14 pages long and covered only the methods used in carrying 

 out the determinations called for on the descriptive chart of those days. 

 After one or two minor revisions it was converted in 1923 into the ''Man- 

 ual of Methods for Pure Culture Study of Bacteria," which as remarked 

 above was published in loose-leaf form until 1956. The first edition was 

 only 48 pages in length and, like its predecessor, was confined wholly to 

 the methods needed in using the chart. Gradually, hoAvever, it was 



