482 
Journal of Agricultural Research 
Vo!. XXV, No. iz 
Certain other investigations as instanced by those with soybean 
blights (6) and tobacco wildfire and angular leafspot (u) have shown 
the value of rare sugars in differentiating closely related plant patho¬ 
genic bacteria. No doubt recognition of this value will be further appre¬ 
ciated as a larger number of bacterial diseases of plants come to be known. 
TOLERATION OE ACID AND ALKALI 9 
Peptonized beef broth was adjusted with normal solutions of sodium 
hydroxid and hydrochloric acid as shown in Table V. Titration was 
made of each grade of bouillon with phenolphthalein for Fuller’s scale 
value, and the P H value of each was determined by both the colorimetric 
and the electrometric methods. 
Two stock bouillons were used, one a 0.3 per cent solution of Liebig’s 
beef extract, the other a fresh beef infusion. To each of these was added 
1 per cent Difco peptone. All the beef-extract media were from the same 
stock ( + 8 Fuller’s scale value, P H value 6.7) and all the beef infusion was 
from one stock ( + 22 Fuller’s scale value, P H value 6.4). The initial 
tests of the media and the inoculations were made on the same day. 
Inoculations were made from 24-hour-old beef-bouillon cultures, all in 
vigorous condition, having been grown under favorable conditions for a 
number of days before transfers were made to the bouillon used for inocu¬ 
lations. The cultures were from the following sources: 
Virginia clover. —Strain 3, from white clover, natural infection, 
September, 1921; strain 4, from red clover, natural infection, August, 
1921; strain M, from red clover inoculated with strain 3. Reisolated 
December, 1921. 
Wisconsin clover. —Cultures from the Wisconsin laboratory, No. 
276, isolated 1920, and No. 210, isolated 1916. 
Bacterium sojae. —Strain L, a culture received in November, 1921, 
from the North Carolina laboratory; strain 8, a reisolation made in De¬ 
cember, 1921, at Washington from soybeans inoculated with strain L. 
Bacterium glycineum. —No. 270, isolated from soybean in 1919, 
culture received November, 1921, from the Wisconsin laboratory. 
These several cultures of the various organisms had previously been 
compared with others from the same host plant and had been found en¬ 
tirely representative, and all, except the Wisconsin clover cultures, 
were actively pathogenic. The Wisconsin cultures were perhaps from 
earlier isolations and produced in the Washington experiments in 1921 
and 1922 only weak infections. 
Bouillons for this test were inoculated in February, 1922. The inocu¬ 
lated tubes were kept in a dark, well-ventilated room at 26 to 27" C. 
The results of this test as shown in Table V indicate that the Virginia 
clover strains are less tolerant of alkali than any of the other organisms. 
The Wisconsin clover strains show only slightly less tolerance of alkali 
than the soybean organisms. A difference in the age of the Wisconsin 
and Virginia clover strains may account for their different reaction in 
alkaline media. 
9 The following statements and table on toleration of add and alkali are based on studies made by Lucia 
McCulloch at Washington, D. C. 
