136 
IOWA ACADEMY OP SCIENCES. 
Very few attempts have been made to study our local bac- 
teriological floras. It is indeed a very difficult matter. 
The following works describe Chromogenes: 
Saccardo: Sylloge Fungorum VIII. 
Sternberg: Manual of Bacteriology. 1892. 
Trelease: Observations on several Zoogloea (Studies Biol. 
Lab. of the Johns Hopkins University). 1885. 
P. & G. C. Prankland: Micro-organisms in Water. 1894. 
Adametz: Die Bakterien der Trink-und Nutzwasser. Mitth. 
der Oester Versuchstation fur Brauerei-und Malzerei in Wien, 
1888. Heft 1. 
Jordan: A report on certain species of bacteria observed in 
sewage. Rep. Mass. State Board of Health, 1888-1890, plate II. 
Eisenberg: Bakteriologische Diagnostik. 1888. 
Welz: Bakteriologische Untersuchnyer der Freiburger Luft, 
Zeiritschrift fur Hygiene XI, p. 121. 
No attempt will be made to give description of common 
species found here at Ames, simply a record of tlieir occurrence 
including some laboratory observations. 
Micrococcus cyanogenus. N. SP. 
Source , — During the latter part of May, 1894, a foreign blue 
color was observed on an old milk culture of an organism 
obtained from cheese; later the same was found in an old milk 
culture of Bacillus aromaticus. A transfer from the first milk 
tube was made to another tube of sterilized milk, the typical 
color appearing in three or four days. The organism was sep- 
arated by pouring plates of agar. 
Morphology.— K small micrococcus occurring singly or in 
groups; motility not determined. An aerobic liquefying 
micrococcus. 
Agar . — Nearly colorless, with a slight tinge of blue, produc- 
ing an irregular film on surface, growing at temperature of 
room. 
Gelatin . — A creamy white layer not spreading on surface, 
soon liquefying, forming a funnel-shaped area, later the 
medium was liquefied with a creamy white sediment in the 
bottom of the tube. 
Milk . — Sterilized milk inoculated produces in three days a 
slight blue layer on surface, which increases in intensity, 
becoming quite blue for one- third of an inch on the seventh day. 
On the eighth day it appeared rather muddy; on the ninth day 
only a faint blue color remained; it coagulated milk with a 
