670 



A PLEOMORPHIC SLIME BACTERIUM. 



[Bacillus alatus, n.sp.) 



By R. Grbig-Smith, D.Sc, Macleay Bacteriologist to the 



Society. 



(Plate XXXV.) 



In isolating Rhizohium legumiiiosarum from the nodules of 

 Lujnnus luteus, a peculiar bacterium was found forming slimy 

 colonies upon maltose-ammonium-sulphate-agar. Upon this 

 medium, the bacterium grew, as a rod of greater breadth than 

 length, and attached to the broad ends were rounded wing-like 

 structures. The medium was particularly suited for the produc- 

 tion of these forms. The method of division is also peculiar, 

 for as the length is less than the breadth, the cell appears to 

 divide longitudinally. When the microbe has divided, there is 

 but one wing attached, although another soon grows upon the 

 naked end. 



The micro-organism is very pleomorphic. In bouillon, upon 

 nutrient meat-agar and upon potato, it occurs as ordinary short 

 or long rods with rounded ends, and stains uniformly. Upon 

 saccharose-potato-agar, they are of the same shape, but stain 

 bipolarly, and they may or may not be surrounded by a rod-shaped 

 capsule. In saccharose-asparagin-fluid, the approximately oval 

 cells occur in chains. Upon ordinary glucose-gelatin, the wings 

 are pronounced, but both the staining portion and the lateral 

 appendages are long, and in some cases the newly divided cells 

 are spatulate or club-shaped. 



The effect of various carbonaceous nutrients in conjunction 

 with ammonium sulphate and citrate was tested. Glycerin pro- 

 duces a rod-shaped capsule with a short transverse staining por- 

 tion or bar, or with a coccoid, or an almost square staining centre. 



