an MORPHOLOGY OF THE BACTERIA. 
by Warming and Giard. They are found in va- 
rious media — in sea-water, in hot sulphur springs, 
in fresh water containing animal or vegetable mat- 
ter in a state of putrefaction. They appear some- 
times upon bread, meats, and in general upon 
cooked food placed in a humid atmosphere. The 
different colors which they present are red, yel- 
low, orange, and blue. It is probably to anal- 
ogous organisms that we must attribute the blue 
color presented by pus under certain circum- 
stances, the green and blue color studied by 
M. Chalvet, and the orange-yellow, bright red, 
and blue colors observed by C. Eberth in perspi- 
ration. 
In Norway, red bacteria appear in summer in 
such masses that the borders of the sea are some- 
times colored of an intense red (Warming). 
Movement. — The bacteria are met in two dif- 
ferent states. They are active or motionless; but 
it is now well settled for the greater number that 
the same species may present itself sometimes in 
a state of repose, sometimes in a state of move- 
ment. 
The movements of the bacteria are of two kinds, 
—a movement of the corpuscle upon itself and a 
movement of translation. The first is sometimes 
nothing more than a molecular or brownien move- 
ment, which occurs in the smallest forms. But at 
other times it is more extended, and consists in a 
movement of rotation round the axis, or a bend- 
ing of the body. This flexibility is, above all, 
