Feb. i8, 1918 Tobacco Wildfire 455 



kept at a temperature of 20° to 25° C. By the fourth day the surface 

 colonies have attained a diameter of 2 to 3 mm. They are grayish white 

 in color, circular in outline, are appreciably raised, and have a smooth 

 margin and a smooth, wet -shining surface. Buried colonies are biconvex. 



In stroke cultures a filiform growth which widens at the base of the 

 slant is formed. Growth is moderate and does not give rise to the 

 production of odor. In stab cultures growth is best at the surface of 

 the agar, and the line of puncture is filiform. In stab cultures on nutri- 

 ent gelatin a filiform growth also appears along the line of puncture, 

 with the greatest growth at the surface of the medium. No evidence of 

 liquefaction occurs until the tenth day, when it becomes crateriform, 

 and is complete within 30 days. 



Growth on potato cylinders is nontypical in appearance, and there is 

 no evidence of diastatic activity. 



With a 2 per cent solution of Difco peptone as a basal solution, five 

 solutions were prepared by adding i per cent of one of the following 

 carbon compounds : Dextrose, saccharose, lactose, glycerin, and dextrin. 

 No gas formed in fermentation tubes containing any of these media. 

 A vigorous growth with strong clouding and a surface pellicle occurred 

 in all in the open arm. In the presence of dextrose and saccharose a 

 distinctly visible clouding gradually extended upward into the closed 

 arm, while in the case of the other carbon compounds the closed arms 

 remained clear. The organism is therefore regarded as aerobic in general. 



Acid formation in stab cultures on litmus-glycerin, litmus-dextrose, 

 litmus-lactose, and litmus-saccharose agar begins within four to six 

 days, but no gas formation occurs on any of these media. 



Growth on litmus milk presents a very characteristic appearance. 

 During the first three days following inoculation there is a deepening 

 of the blue color. Two days later coloration begins to become strati- 

 form, and by the seventh or eighth day four distinct layers are evident. 

 The upper one is between plumbeus and violaceous in color (5), the 

 next is lilacinus, the third, violaceous, and the lowermost approximates 

 caesius. These colors lose their intensity after a few days and become 

 more or less blended, and by the tenth day there is evident reduction 

 of the litmus and precipitation of the casein. Reduction proceeds 

 rather slowly and is complete by the twenty-fourth day. 



There is no reduction of nitrates in nitrate-peptone broth, although 

 a conspicuous clouding occurs. Furthermore, no gas is formed; and 

 the tests for ammonia, indol, and skatol were negative. 



The thermal death point of this organism, as determined by exposing 

 newly inoculated tubes of bouillon in the customary manner, was found 

 to be about 65° C. It is manifestly quite sensitive to desiccation, 

 since no growth appeared after six days when bouillon cultures were 

 placed on sterile slides in sterile petri dishes. 



The group number of Baclerhim iabactim according to the numerical 

 system of the Society of American Bacteriologists is 2>2i-2222032. 



