62 Report OF THE BACTERIOLOGIST OF THE 
tests of packages Nos. 2, 3 and 4. One stock culture had been 
isolated from an alfalfa nodule in our laboratory, while the other 
was that received from the Department at Washington. This 
came to us April 20: accompanied by the following letter: 
WASHINGTON, .D. C., April 20, 1905. 
Pror. H. A. HARDING, 
Geneva, N. Y. 
Dear Sir :—Since writing you that it would be impossible to 
send you a culture for alfalfa, owing to the material being 
exhausted, I find that it has been necessary to make up a fresh 
lot of cultures. Consequently I am sending you a pure culture 
for alfalfa and hope it may reach you in time for your experi- 
ments. Yours very truly, 
A. F. WOODS 
Chief Pathologist and Physiologist. 
The appropriate amount of sterile ammonium phosphate solu- 
tion was added at the end of twenty-four hours and there was a 
good turbidity in both flasks on the following day. Plates made 
on the third day gave an abundant growth in both cases of prac- 
tically pure Ps. radicicola. Three foreign colonies were the 
maximum number found on any plate. The three samples of 
cotton, Nos. 2, 3, and 4, examined at the same time and handled 
in as nearly the same way as was possible did not produce a sin- 
gle colony which was thought to be Ps. radicicola. 
In carrying out these tests of the cotton, there is always a 
short exposure to laboratory air, both in introducing the cotton 
and in making the plates. In order to check this factor, flasks of 
sterile media to which no cotton was added, received their pro- 
portion of ammonium phosphate solution and were otherwise 
manipulated as were the test flasks of June 6,13 and 14. Plates 
from these check flasks developed only a single colony of bacteria 
and no yeasts. A few mold colonies also appeared. 
On June 7 a similar task received its ammonium phosphate in 
the form of crystals from a National Nitro-Culture Co. package. 
While this flask did not become turbid, a plate inoculated with a 
single platinum loop produced about 200 colonies of bacteria not 
resembling Ps. radicicola. On June 8 a sterile flask received 100 
