190 
Journal of Agricultural Research 
Vol. I, No. 3 
The diseased sugar-beet leaves were collected by Dr. Townsend in 
Utah and California on inspection trips to the sugar-beet sections of the 
West and were sent to the laboratory in Washington for examination. 
Leaves similarly diseased were also received from Oregon during the 
summer of 1909, but, so far as known to the writers, the trouble has not 
been noticed up to the present time in any other beet-growing State. 
The first leaves came from Utah and had dark-brown, often black, 
irregular spots and streaks from 3 mm. to 1.5 cm. in diameter. They 
occurred on the petiole, midrib, and larger veins. Occasionally the 
discoloration extended along the veins for some distance, and the tissue 
on either side was brown and dry; sometimes there were corklike pro¬ 
tuberances at the central point of the spots. In badly diseased petioles 
the tissue had softened as though affected with a soft rot, but when only 
a few spots occurred there was no indication of softness. 
Unlike the spot diseases due to Cercospora and Phyllosticta, this 
spotting did not spread through an entire beet field, but was generally 
limited to small areas. 
The tissue embracing the dark spots was examined with the micro¬ 
scope as soon as the material was received and was found to be filled 
with very active bacteria; no fungous hyphae were seen. Some of the 
leaves were placed in a moist chamber and carefully watched for several 
days, but there was no fungous mycelium in or around the spots. 
ISOLATION OF THE ORGANISM FROM THE TWO HOSTS 
The method of isolating the bacterial organism from the diseased 
sugar-beet and nasturtium leaves was by means of poured agar plates. 
Spots from the soundest leaves were used, the tissue being immersed in 
mercuric chlorid (1:1,000), washed in sterile water, and mashed in 
bouillon. The plate colonies were up in 24 hours. They were round, 
thin, smooth, glistening, whitish in reflected light, bluish in trans¬ 
mitted light, and 1 to 5 mm. in diameter. In three days the agar in the 
immediate neighborhood of the colonies had changed to a yellowish- 
green color. No other colonies appeared on the plates. 
With young subcultures from these plate colonies needle-prick inocu¬ 
lations were made into sugar-beet and nasturtium plants, in order to 
prove that the right organism had been isolated in either case. The 
inoculations with the separate organisms from the two hosts are as fol¬ 
lows : 
INOCULATIONS WITH ORGANISM ISOLATED FROM SUGAR-BEET LEAF 
Inoculations with the organism isolated from sugar-beet leaves into 
healthy sugar-beet leaves of plants growing in the greenhouse proved 
that the right organism had been isolated, for in three days there were 
black spots at all points of inoculation. The checks were free from 
