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956 
One strain from Kyoto of the acid type which was isolated by Dr. Yoshida (30), 
who regarded it as a variety of the dysentery bacillus (Shiga). The organism 
was identified by me. 
A comparison of all these cultures revealed the fact that they could 
not be distinguished one from another, either culturally or morphologic- 
ally, although minor differences were shown to exist, particular in their 
characteristics in artificial culture media. 
In addition to the agglutination test, the action of bacteriolytic immune 
serum upon all the strains was studied, since this is perhaps the most 
important test for the differentiation and identification of bacteria. This 
was performed in vitro, as the virulence of the different strains varied 
greatly. ' 
{TYPES AS DETERMINED BY FERMENTATION. 
All the strains of dysentery bacilli mentioned above have been cul- 
tivated for many generations on artificial media (common agar). In 
many instances in which the organisms were isolated by myself, the first 
fermentation tests were made immediately upon isolation; in others this 
was impossible, as the organisms were sent to me subsequent to their 
isolation. Multiple tests as proposed by Hiss have been made, and the 
final tests of all the strains were performed more than a year after their 
isolation, because my investigations on this subject continued for about 
one year. Whenever unexpected reactions or appearances were mani- 
fested, fresh plate cultures were made to determine the purity of the 
original culture and the experiments were repeated with the various colo- 
nies. The same results were invariably obtained. Dextrose, maltose, 
saccharose, dextrin, lactose, and alcohol-mannite were the fermentable 
substances used. The tests with galactose, levulose, and inulin were 
omitted since, according to Hiss, no differences of value as distinguished 
from those obtained with dextrose, were shown to exist on cultivation 
in this medium, and none of the bacilli fermented inulin with acid 
production. 
* The common peptone-water solution was used as a nutrient medium, to which the 
carbohydrates were added in sufficient quantity to form a 1.3 per cent solution, 
as suggested by Lentz. Merck’s preparation of litmus, highly purified, was used 
in all the experiments and was added in sufficient amount to form a 0.6 per cent 
solution. The peptone medium was composed of 0.5 per cent sodium chloride and 
1 per cent peptone [sic.] in 100 cubic centimeters hydrant water; it was sterilized 
in the usual manner and its reaction tested and, if necessary, it was neutralized. 
Sugar was then added and the medium placed in tubes and sterilized for from 
ten to fifteen minutes on three consecutive days. The color of the medium is 
of a light blue. A sufficient acid production changes the medium to a red color ; 
when acid is formed to a less extent, the color is altered to purple. The variations 
in composition of the nutrient media to which the sugars were added, and the 
variations in the salts present, which Hiss undertook were not performed by me 
