December 14, 1900.] 



SCIENCE. 



913 



It is now universally recognized that the 

 first requisite toward successful work in 

 this field is the use of culture media of uni- 

 form standard composition. With the view 

 to the accomplishment of this end, the 

 methods of preparation of media recom- 

 mended by the Bacteriological Committee 

 in their Report of 1897 are in general use. 

 Taken as a whole, they seem to have given, 

 and to still give, general satisfaction. It is 

 true, however, that in several laboratories 

 these recommendations are departed from 

 with regard to the manipulations which ap- 

 parently affect but little the question of 

 uniformity. Practice, furthermore, varies 

 somewhat in a number of laboratories, with 

 reference to the use of meat infusion as com- 

 pared with meat extract ; in the preparation 

 of milk for a culture medium ; and in the 

 reaction of various media for species work. 

 Each of these points requires attention. 



Concerning those tests and procedures to 

 be employed in order to secure diagnostic 

 data in species work, it is plain that the 

 recommendations of 1 897 have caused ma- 

 terial advances over previous methods. It 

 is certain, however, that the 1897 Report in 

 this respect has thus far met less support 

 and approval than in the case of the prepa- 

 ration of culture media. The report has 

 evidently set at work a leavening process 

 in several places, and an improved state 

 of affairs will presumably result in time. 

 Why it is that with test after test there is 

 a disagreement as to value among experi- 

 enced workers is a matter which is not now 

 understood, and which suggests unappreci- 

 ated differences in procedures. 



Relative to the results of those tests 

 which are considered to be of differential 

 value, and to the method of recording them, 

 opinion is widely at variance. 8ome be- 

 lieve that they should be confined to those 

 of a positive and definite nature. Other 

 workers consider that they cannot be made 

 too detailed and exhaustive. 



In brief terms it may be said that, with 

 regard to the general subject of species dif- 

 ferentiation, a material step in advance has 

 been taken in conseqaence of the Report of 

 the Bacteriological Committee of 1897. As 

 a result of the added knowledge coming to 

 various workers through the general use of 

 the 1897 Report as a guide, the time has ar- 

 rived when that Report can and should be 

 revised. Concerning the new evidence 

 which has been obtained since that Report 

 was prepared, it has not yet reached your 

 Committee in a form adequate to allow 

 changes to be recommended at this time. 

 In fact, there are many indications which 

 go to show that the amount of directly 

 comparable evidence from the various lab- 

 oratories is much less than is generally re- 

 alized, owing to the wide variety in the na- 

 ture of the species work now going on in 

 this country. 



In the opinion of your Committee the 

 real issue for discussioQ to-day on this 

 topic is not the question of detailed points 

 of improvement, but rather the best gen- 

 eral procedure by which species work can 

 be elevated to a higher plane of excellence. 

 This matter has received considerable 

 thought from the Committee, and it would 

 appear that as a first requisite it will be 

 necessary to secure the cooperation of the 

 workers in other branches of bacteriology. 

 It would also appear to be necessary to se- 

 cure comparable data upon corresponding 

 cultures of the same species from a consid- 

 erable number of experienced workers. 

 Further, it would be very desirable if data 

 from the same species could be obtained at 

 the same laboratory with culture media pre- 

 pared by a number of other investigators. 



Fermentation Tests and the Detection of B. eoli 

 eomrnunis and other Specific Forms. — While 

 these methods come within the scope of 

 general species methods for bacteria, it is 

 considered that they are entitled to separate 

 consideration. This is due to the fact that 



