476 
Journal of Agricultural Research 
Vol. XXV, No. i* 
The organism is motile by means of from one to four unipolar flagella 
which are about 2 to 3 times the length of the cell (fig. 2). Flagella 
have been demonstrated in agar cultures 1 to 4 days old by the methods of 
Casares-Gil, of Duckwall, and of Loeffler, as modified by Shunk. 
Endospores and marked involution forms have not been noted. With 
the use of Ribbert's dahlia capsule stain, both the Wisconsin and the 
eastern strains tested have shown a thin but definite enveloping sheath. 
The organism is decolorized by Gram's method. 
CULTURAL CHARACTERS 
The cultural characters as here described were first worked out at 
Madison with the Wisconsin red-clover organism. It has therefore 
seemed expedient to designate that as the type strain, and unless other¬ 
wise specified the following descriptive characters are based on these 
Wisconsin studies. In all cases, however, the results obtained in the 
Raleigh and Washington studies are in essential agreement with these. 
In the Wisconsin studies the nutrient broths contained 1 per cent peptone 
and 0.3 per cent Liebig's beef extract; the nutrient agars the same with 
addition of 1.8 per cent of bacto-agar; the peptone broths either 1 or 2 
per cent of Difco peptone. The cultures were kept in dark, well-venti¬ 
lated incubators held at approximately 25 0 C. Color determinations 
follow the Ridgway color standards. 4 
Agar poured plates. —On nutrient agar, colonies appear after 48 
hours, and in 5 days have attained a diameter of 2 to 3 mm. They are 
circular in outline with entire margins, convex or slightly umbonate, 
smooth, glistening, and opaque white. Submerged colonies remain 
small and are lenticular in shape. The agar is unchanged in color and 
no odor is developed. 
On potato agar 5 6 growth is more abundant, and in 5 days the colonies 
are 3 to 4 mm. in diameter. They are circular, having entire margins, a 
surface which is rugose at the center, and a tendency toward contoured 
markings at the periphery (PI. 5). The colonies are white and butyrous in 
consistency. 
Agar stabs. —On nutrient agar the surface growth was at first mod¬ 
erate with a faintly beaded outline along the line of the stab. Later it 
became more abundant at the surface with colony characters like those 
on plates. A decided fluorescence was apparent in cultures 2 weeks old. 
The growth on potato agar was limited to the upper one-half inch of 
the line of stab as a faintly beaded line. The surface growth was mod¬ 
erate, convex, smooth, glistening, and opaque grayish white. The 
colonies become larger than in poured plates but are never larger than 
3 to 4 mm. 
Agar slants. —From 5 to 10 days are required on nutrient agar to 
secure an abundant growth. It is then filiform, spreading, with an entire 
margin toward the base of the stroke, glistening, and translucent. When 
one removes a portion of the growth with a platinum needle, it is found 
to adhere in a butyrous opaque mass. A slight fluorescence appears in 
the medium in 2-week-old cultures. 
On potato agar more abundant growth occurs which is dull and raised. 
The surface is rugose with radial folds extending outward from the line 
4 Ridgway, Robert, color standards and color nomenclature. 43 p. 53 col. pi. Washington, 
D. C. 1912. 
6 Potato agar as used in the Wisconsin laboratory contained 1,000 cc. water, aoo gm. potato, so gm. 
dextrose, and 18 gm. bacto-agar. 
