GENERAL SYSTEMATIC BACTERIOLOGY 221 



Cells cylindrical or elliptical, free or united in pairs during their division^ 

 rarely in fours, never in chains (Leptothrix or Torula), sometimes in zoogloea 

 (differing from the zoogloea of spherical bacteria by a more abundant and firmer 

 intercellular substance), having spontaneous movements, oscillatory and very 

 active, especially in media rich in alimentary material and in presence of oxygen. 



He includes descriptions only of species which have already been 

 noted. The}' are separated into three groups, the bacteria of putre- 

 faction, those causing lactic and acetic fermentation, and the chromo- 

 genic forms. 



Thin (1880) described a Bacterium foetidum from malodorous per- 

 spiration. The culture methods used did not insure pure cultures. 



Winter (1880, p. 51) characterizes Bacterium (which he ascribes to 

 Cohn) as follows : 



Zellen kurz cylindrisch, lang elliptisch oder spindelformig, durch Quertheil- 

 ung sich vermehrend, spontan beweglich. Die Tochterzellen trennen sich 

 entweder bald nach der Theilung von einander oder bleiben zu 2 bis mehr ketten- 

 artig vereinigt. Auch Zoogloea-Bildung ist haufig. Sporenbildung ahnlich wie 

 bei Bacillus. 



He lists and describes eight species, none new. It will be noted that 

 he includes for the first time the possibility of spore formation as a 

 character of the genus. 



Van Tieghem (1881) described a green organism from rain water 

 which had collected in the pileus of a Polyporus, giving it the name 

 Bacterium viride. 



Thin (1881) also described a Bacterium decalvans from alopecia 

 areata. 



Zopf (1883, p. 48) materially modified the definition of the genus fol- 

 lowing the conception of pleomorphism, to include those organisms show- 

 ing four growth forms, cocci, short rods, long rods and filaments, the 

 latter never with differentiation of base and tip. The following year 

 (1884, p. 45) he used the same definition. He included in the genus 

 some seventeen species, most of which are still recognized. Organisms 

 previously described by other authors as in the genus Bacillus are 

 included, such as Bacterium tuberculosis, Bad. typhosum, Bact. subtile 

 and Bact. anihracis. His Bact. ianthinum was the Bacteridium viola- 

 ceum of Schroeter and the Chromobacterium violaceum of Bergonzini. 

 The only organism apparently newly named and placed in this genus 

 was Bacterium acidi-lactici. The description is scarcely adequate to 

 identify this organism as the one now generally recognized under this 

 name. The specific name acidi-lactici has been used in so many senses 



