214 



SCIENCE. 



[N. S. Vol. XXIII. No. 580. 



Does not liquefy beef oi* synthetic gelatin ; 

 does not form indol. Aerobic; does not 

 form nitrites or nitrates ; does not form gas. 



Litmus milk: with velvet bean there is 

 apparently no change in seven days at 

 28° C. ; after sixteen days the litmus is 

 almost decolorized and some acid has been 

 produced. Soy bean is similar, except the 

 milk becomes scarcely acid, and subse- 

 quently a very slow precipitation of the 

 casein takes place. Alfalfa, on the other 

 hand, produces alkali very distinctly, and 

 forms a viscous pellicle. 



Potato cylinders: the velvet bean organ- 

 ism produces a colorless to grayish-white, 

 even growth. The soy bean has a very 

 spreading growth, between clay and cream 

 buff. Alfalfa, colorless to grayish- white ; 

 the colorless areas separated from the 

 whitish ones, giving a coagulated appear- 

 ance. 



Variations in Gas Productian iy Bacteria- 

 producing Soft Rot in Vegetables: H. A. 

 Harding and M. J. Prucha, New York 

 Agricultural Experiment Station. 

 During the past five years the group of 

 organisms connected with the soft rot of 

 vegetables has been studied jointly by the 

 Botanical Department of the University of 

 Vermont and the Bacteriological and 

 Botanical Departments of the New York 

 Agricultural Experiment Station. In this 

 study about forty-five cultures, including 

 six which have been described in literature 

 as distinct species, have been studied in de- 

 tail. A comparative study of their points 

 of difference has been repeated ten times in 

 most eases. 



This group lies just on the border line of 

 gas formation from dextrose, lactose and 

 saccharose in Smith tubes. In all eases 

 there is growth in the closed arm and 

 production of acid. A majority of the 

 cultures produce gas, ranging in amount 

 from a small bubble to a e.e. These 



determinations have been made each time 

 in duplicate or in triplicate. 



As optimum conditions are obtained an 

 increasing number of cultures produce gas 

 from all of these different sugars. A 

 culture known as Vermont XL VIII. which 

 has long been considered as a type of the 

 class fermenting only lactose was recently 

 induced to produce gas from dextrose at 

 the Vermont Laboratory. 



Some striking differences still remain. A 

 culture known as 0.2e was studied in the 

 laboratory about a year and then inoculated 

 into a plant in the greenhouse. It there 

 produced the typical soft rot. A culture 

 isolated from this experimental plant was 

 called 0.2f . The second culture agrees with 

 the first in pathogenicity and in all other 

 cultural characteristics except that of gas 

 formation. While 0.2f ferments all three 

 sugars 0.2e forms gas only from lactose and 

 saccharose. This notwithstanding that 

 these two cultures have now been studied 

 together for some years. 



Other similar instances have been ob- 

 sei'ved but this will suffice to indicate that 

 there are cases where a single routine test 

 of fermentation may lead to errors in classi- 

 fication. 



The Employment of Glycerin as a Differ- 

 entiating Medium for Certain Bacteria: 

 Eduardo Andrade, Florida Board of 

 Health. 



It has been determined by previous in- 

 vestigations of the writer that the addition 

 of glycerin to nutrient media increases the 

 acid-producing power of some intestinal 

 bacteria. As an indicator for this change, 

 acid fuchsin Griibler is neutralized to the 

 point of decolorization with caustic potash. 

 Both inorganic and organic acids react on 

 the indicator, changing it to red. Alkalies 

 decolorize it and change it to a light yellow 

 ■'Color. The indicator is extremely sensi- 



