On Certain Bacteria from the Air of New York City. 323 



For this i-eason, I have felt some hesitation about describing new 

 species, but I see no other so satisfactor}- way of treating the 

 undetermined cultures. The method of simpl}' describing them 

 without the application of a scientific name is eminenth' confus- 

 ing, as I have experienced in going over the literature. I do not 

 think it should be commended even though it ma^- avoid the pos- 

 sible creation of synonj-mic names. 



Species among the Bacteria. 



The appearance of the new work on water bacteria * b}' the 

 Franklands, with its appendix repeating the old descriptions of 

 bacteria, brings up again the practical difficult}' in the determina- 

 tion of species. There is nothing to be said of these descrip- 

 tions which would not apply equally to those of any of the recent 

 diagnostic treatises such as those of Eisenberg or Sternberg ; all 

 are in an equally unsatisfactory condition. 



This condition is due not to a lack of discrimination on the 

 part of the authors of these works, but to a fault}' method of de- 

 scribing species which has come to be prevalent. The result is 

 illustrated in Frankland's synoptic table, which, for example, 

 contains ninety species under a single heading (bacilli which 

 liquefy gelatin, p 396), these species only to be distinguished by 

 laboriousl}' reading through the several descriptions, many of 

 which present no tangible points of difference. Dr. Stei'nberg, 

 too, has made a valiant and praiseworthy effort to prepare a 

 "bacterial diagnosis" (See Manual of Bacteriology, pp. 753-768), 

 but the positive differential characters given in the several de- 

 scriptions became exhausted long before he reached the separa- 

 tion of individual species. 



Let us look into the matter a little further. La Semaine 

 Medicale of June 16, 1894, contains an article b}^ Drs. F. Helme 

 and Paul Range, in which the authors review the characters 

 which are in use to separate the genera and species of the bacteria. 

 As they point out the ultimate characters used to separate species 

 are physiological. The generic characters are morphological, but 

 of such a nature as would scarcely be considered reliable among 

 the higher forms. This results from the simple organization of 

 the bacteria. As we proceed from the higher to the lower forms 



* " ilicro-organisms in "Water," by Percy Frankland, Pli. D., and Mrs. 

 Percy Frankland (1894). 



