Journal of Agricultural Research 
Vol. XXV, No. 3 
150 
Desiccation 
The organism as it occurs in the host tissues seems to be very resistant 
to drying. Successful isolations were made from diseased leaves which 
had been kept in the herbarium 2 X years. On potato agar cultures 
kept in the ice box, where growth is abundant, the organism was viable 
after 3 months. When beef-peptone bouillon was inoculated with 
transfers from these cultures, good growth developed. The organism is 
very readily killed when dried on sterilized cover glasses. Smears were 
made from 2-day-old broth cultures on sterilized cover glasses and were 
placed in sterilized Petri dishes. All cells were dead at the end of 24 
hours. 
TECHNICAL, DESCRIPTION 
On the basis of the foregoing studies, the organism is characterized 
briefly as follows: 
Bacterium viridifaciens n. sp . 5 
Cylindrical rods rounded at ends, solitary or occasionally in pairs, in short chains in 
old cultures; individual rods 0.3 to 0.7 by 0.7 to 2.2/*; motile by one to several flagella; 
aerobic; no spores; no capsules in agar or beef broth cultures. 
Superficial colonies on nutrient agar, circular, smooth, glistening, flat, butyrous- 
opalescent, with faint gyrose to marmorated markings; margin undulate; medium 
stained a pale lumiere green. 
Gelatin moderately liquefied; no acid produced in milk; casein digested without co¬ 
agulation; litmus reduced in milk; hydrogen-sulphid gas not produced; nitrates re¬ 
duced; acid produced in media containing dextrose and saccharose; no growth in Cohn’s 
solution; thermal death point between 49 0 and 50° C; not acid fast; gram-negative. 
Group number 211.2322133. 
Pathogenic on varieties of Phaseolus lunatus Linn, forming lesions on leaves, stems, 
and pods. 
Type locality: Racine, Wis. 
Distribution: Eastern and southern Wisconsin. 
INOCULATION EXPERIMENTS 
The bacterial spot has been reproduced many times with characteristic 
symptoms under greenhouse and field conditions by spraying water sus¬ 
pensions of, the organism on healthy plants. From lesions produced in 
this way the original type organism has been repeatedly recovered. The 
disease could always be produced with a newly isolated strain of the 
organism by spraying a water suspension of the organism upon uninjured 
leaves, both old and young ones, and placing the plants in a moist cham¬ 
ber from 12 to 24 hours. Wounds are unnecessary for infection. When 
carried in culture for several months, the organism became less patho¬ 
genic. 
Several varieties of lima beans were used in the inoculation experi¬ 
ments including Fordhook, King of the Garden, Dreer’s Bush, Burpee’s 
Bush, and Henderson’s Bush. All varieties were susceptible, but the 
spots developed to larger size on the Fordhook than on the other varie¬ 
ties. ~ 
Besides these varieties of lima beans, Alaska peas and wax beans were 
inoculated under both greenhouse and field conditions. No infection 
developed on any of the plants. 
In making the inoculations in the greenhouse the following method 
was usually employed: Lima beans were planted in previously sterilized 
5 According to Migula’s classification and Buchanan’s revision ( 2), 
nas viridifaciens n. sp. 
the combination would be Pseudomo - 
