58 Report’ OF THE BACTERIOLOGIST OF THE 
abundant. April 22, the plates of both kinds of agar contained 
abundant but miscellaneous growth. No colonies resembled Ps. 
radicicola. 
Third attempt.—On April 17, a portion of the Department cot- 
ton, the size of a walnut, was placed in a sterile flask containing 
40 ce. of sterile distilled water and: 5cc. of melted (3.31) agar. On 
the following day plates were made with (38.31) agar and quanti- 
ties of fluid from the flask ranging from-a drop to 1 cc. On 
April 27, no colonies had appeared on the plates which had 
received 1 cc. and % cc. respectively, and in the entire series 
only an occasional colony appeared on a few of the plates. These 
colonies did not resemble Ps. radicicola. 
Fourth attempt.—The authentic culture of Ps. radicicola which 
we desired before attacking the main problem had now been 
received from Washington (see p. 62), but our repeated 
failures seemed to justify another examination of the Department 
cotton. This time the cotton culture was allowed to develop in 
the nutrient solution which was said to be favorable to the desired 
germ. but unfavorable to the growth of other forms.® ~ 
On April 24, a piece of the Department cotton the size of a test 
tube plug was placed in a sterile flask containing 250 cc. (1.31) 
bouillon. By April 27 the mixture was decidedly turbid and an 
examination in hanging drop showed an abundant growth of 
yeasts. On April 29 plates were made with (3.20 and 3.31) agar, 
inoculating with one loop from the flask and making a transfer 
from this tube to two other tubes. May 5 there was an abundant 
growth on all of the plates. <A few of the colonies were yellow. 
The remainder were chalky though somewhat transparent and 
might be mistaken for Ps. radicicola. Microscopic examination 
showed these colonies to be veasts. | 
CONTROL. OF THE MEDIA. 
Such repeated failures would have cast suspicion upon the 
quality of our media but for some accompanying observations. 
On April 12 and 19 cultures were made in considerable numbers 
from nodules on alfalfa plants. On each of these days we used 
for this purpose portions of the same media which were used on 
*Moore, G. T., and Robinson, T. R. U.S. Dept..of Agr., Farmer’s Bul. 
No. 214, p. 16, 1905. 
