IOWA ACADEMY OF SCIENCES. 
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blue liquid on top. The curd was dissolved slowly. In twenty- 
five days the process was completed, excepting a small portion 
in the bottom of the flisk. 
Dunham' s peptone solution . — No color produced; the medium 
became cloudy, which was in no way characteristic. It failed 
to grow in Dunham’s rosalic acid solution. 
Several blue organisms have been described. 
Bacillus cyanogenus is a well known inhabitant of milk. This 
is a non-liquefying, actively motile bacillus. Has not been 
found here at Ames. Gessard has shown that in presence of 
an acid it produces an intense blue color, and in milk not 
sterilized containing lactic acid germs, a sky blue color is 
produced. 
Jordan has also described a Bacillus cyanogenus, which is less 
motile forming a deep brown color on potato, but he says 
undoubtedly Bacillus cyangenus. Beyerinck^ has also described 
a blue organism obtained from cheese, the Bacillus cyaneo-fuscus. 
The original paper has not been seen but according to the 
description given by Sternberg this is a small bacillus 0.2-0. 6 
u. long and one half as thick. It is an aerobic liquefying 
motile bacillus, and when cultivated in a solution containing 
one-half per cent of peptone the culture media acquires at first a 
green color, which later changes to blue, brown and black. 
Subsequently the color is entirely lost. More recently Wm. 
Zangemeister'^ has described a biciilus cyaneo-fluorescens. 
This species is in many respects similar to Bacillus cyanogenus. 
It is however somewhat shorter and very actively motile. 
Gelatin is not liquefied and the bright greenish fluorescent 
pigment dfliuses through it. 
Our species also came from cheese and the blue color disap- 
pears, but the organism in question never produces a black 
color. The species so far as we have been able to determine 
is new, and we have therefore given it the name of Micrococcus 
cyanogenus. 
Staphylococcus pyogenes, Ogstonvar. Rosenbach.— This, 
the most common of the pyogenic micrococci has been found 
quite frequently here at Ames. It has at different times been 
isolated from ordinary carbuncle, fistula, dirt under the finger 
nails, etc. It has been found more commonly in suppurative 
abscesses than any other organism. It is pathogenic to mice 
^Sternberg: Manual of Bacteriology p. 727. 
3Kurze Mitteilungen uber Bakterien der-blauen Milch. Oentralblatt f. Bakt. u 
Parsitenkunde. Erste Abt., XVIII, p. 321. 
