514 Marine Microbiology 



sp. primarily on motility and morphology; are usually less active 

 biochemically. In addition, most strains are sensitive to penicillin, 

 whereas the majority of Pseudomomis strains are not. It might 

 just be mentioned in concluding this section on the Achromo- 

 hacter that the only organism which the author has encountered 

 so far which accords with the description of Achromobacter 

 liquefaciens is the Agarbacterium alginicum of Payne and his 

 co-workers ( 1 ) . This organism has the morphological and bio- 

 chemical properties of our Achromobacter group, yet is motile by 

 peritrichous flagella. 



Very occasionally, organisms are encountered which are 

 Gram negative, peritrichous and not obviously Enterobacteria. 

 Moi-phologically they are quite different from the Achromobac- 

 ter, being rather long rods with square ends, e.g., the Achromo- 

 bacter sp. of Beppu and Arima (5). The taxonomic position of 

 these organisms is at present not known. 



The Flavobacteria and Cytophagas:— It is only quite recent- 

 ly that we have begun to pay some detailed attention to the 

 Flavobacteria and Cytophaga groups and our work on these is 

 still in progress. So far as the Flavobacteria are concerned the 

 position has been made somewhat more difficult by the recent 

 proposal of Ferrari and Zannini (16) that there is no justification 

 for the exclusion of Gram positive strains from the genus Flavo- 

 bacterium as has been done in the recent Bergey (6). These 

 authors postulate three groups — each including Gram negative 

 and Gram positive microorganisms — on the basis of their mor- 

 phologies and life cycles. Whatever the merits of these pro- 

 posals we shall deal here only with the Gram negative strains. 

 Even so, the differentiation of the yellow or orange pigmented Cy- 

 tophaga sp. from the Flavobacterium sp. has proven to be one 

 of some difficulty. The Flavobacteria are described in Bergey (6) 

 as non-motile or motile ( peritrichous ) short rods while the Cyto- 

 phagas are described as consisting of long thin rods, often with 

 pointed ends, which show flexing and hence gliding motility on 

 solid surfaces. Consequently, on agar plates, the colonies have a 

 characteristic diffuse margin spreading outwards into the agar. 



Hayes, working recently at Torry Research Station, chose 

 about 60 strains of yellowish pigmented asporogenous rods from 



