234 A GUM BACTERIUM FROM A EUCALYPT. 



with this bacterium and with Bac. fevaniforvians, but instead of 

 the calculated 55 grms. of reducing sugars which should have 

 been present there are only 18 grms.; the difference (37 grms.) 

 has disappeared, i.e., it has been converted into acids. 



Although levan can be formed from saccharose, it must not be 

 forgotten that the gum found naturally in the exudate had in all 

 probability been formed from raffinose, the sugar of Eucalyptus 

 manna. This is indicated by the presence of manna in one of 

 the samples. That levan could be produced by the organism 

 from raffinose is to be expected from the fact found in the study 

 of Bac. levaniformans, viz., that the gum was formed chiefly from 

 nascent levulose, and from the fact that raffinose under the 

 influence of invertase splits up into levulose and melibiose. 



Bacterium eucalypti, n.sp. 



Shape, etc. — An actively motile, short coJi-\ike bacterium, 

 measuring generally in the stained and imbedded condition 

 0*5 : 1 /x. It stains well with violet and fuchsin, but feebly with 

 blue; it is decolourised by the Gram method. The flagella are 

 long, and vary in number from one to nine, and are studded over 

 the surface of the cell. No spores are formed. 



Relation to temperature, etc. — The bacterium is aerobic, and 

 appears to grow equally well at 28° and at 37°. 



Nutrient gelatine plate. — Small punctiform colonies are visible 

 in seven days, and by the eleventh day they have become rounded, 

 translucent white, and 3 mm. in diameter. When magnified they 

 appear round or rounded, and finely granular, sometimes with 

 central granules. The edge is smooth and slightly waved. The 

 deep colonies are irregular and finely granular. 



Glucose-gelatine plate. — The colonies are glistening, translucent 

 white and rounded. When magnified they appear rounc^ed and 

 erose with co/^-like striations. The deep colonies are rounded to 

 elliptical, and have a striated margin. 



