CLASSIFICATION OF THE BACTERIA. Te 
They are divided into two categories, accord- 
Ing as the pigment is soluble or not in water. 
1. Coloring matter insoluble. 
M. Prodigiosus, Cohn (Monas prodigiosa, Ehrb. ; 
— Palmella prodigiosa, Mont. ;— Bacteridium 
prodigiosum, Schroeter). 
A red gelatinous mass, pink carmine, develop- 
ing upon cooked alimentary substances placed 
in damp air, never before cooking. 
It has also been observed in red milk, at- 
tributed incorrectly to lesions of the teats, 
etc. (Cohn), 
M. luteus, Cohn (Bacteridium luteum, Schreeter). 
A yellow gelatinous mass studied by Schrceter 
and Cohn upon potatoes. 
2. Coloring matter, soluble. 
M. aurantiacus, Cohn (Bacteridium auriantiacum, 
Schroeter). 
Little drops, or stains, more or less extended, 
golden yellow, cultivated by Schroeter, upon 
slices of cooked potato; by Cohn, upon hard 
white of egg. 
M. chlorinus, Cohn. 
A glairy yellowish-green pigment found upon 
hard white of egg, not reddened by acids, but 
loses its color. 
M. cyaneus, Cohn (Bacteridium cyaneum, Schree- 
ter). 
Pigment deep blue, observed by Schroeter 
