160 The Botanical Gazette. 
it is easy to find numerous rapidly growing and fresh tubercles — 
The temperature of the soil is sufficiently low, however, to 
retard the growth of many soil organisms, so that the outer 
surfaces of the tubercles do not contain such numbers of bat 
teria as are met with in the warm days of late spring. The 
early season then is the more favorable for the separation a 
the organism. a 
As soon as the plants had attained sufficient size to gather 
a small quantity of the vines an infusion was made and addel 
to agar-agar peptone broth to afford a suitable mediumit” 
which to transplant the organism. 4 
Method of obtaining pure cultures. 
To separate the organism without contamination young but 
fair sized tubercles were selected. These were washed cate 
fully and finally rinsed in distilled water and allowed to dra 
until the surface was not wet. A razor was then heated, 1 
to redness, but to such a degree as would probably killa 
adherent germs. A small segment was then removed 108 
sharp-pointed platinum needle was thrust into the ae 
twisted part way around, withdrawn, and with this a pe | 
was made in the vetch agar in culture tubes. The first tf 
coccus and Bacterium. Others showed no evidence i? ; 
in a few 
. 
spl & 
» an examination was made of the organism. 
