MICROBES, OR BACTERIA. 119 
the corpuscles of the blood, and the cells of. which all 
our tissues consist, as true anaérobic microbes; so 
likewise are the microbes which, when introduced into 
the blood, are the cause of certain diseases. The 
important consequences of this fact, which it is neces- 
sary to note, will appear presently. 
X.—TueE Microses or SULPHUROUS WATERS. 
The formation of the sulphurous springs which 
are so numerous in the Pyrenees and in other parts 
of France, appears to be due to the presence of small 
alge of the family Oscil- 
latoria,'and of the genera 
Oscillaria and Beggiatoa 
(Fig. 64). These microbes 
are of the same structure 
as those of which we have 
spoken above, but they contain chlorophyl, and also 
a blue colouring matter. They are placed in the 
group Cyanophycece, which, as Zopf believes, contains 
species that are sometimes green, and sometimes 
colourless, like Bacillus and Leptothrix, which they 
resemble in their mode of reproduction. 
According to Louis Ollivier, these algee reduce the 
sulphates of waters charged with sulphate of lime, 
transforming them into sulphur. They even accumu- 
late sulphur in their cells. When sulphur is thus 
Fig. 64.—Beggiatoa alba, microbe of 
sulphurous springs. 
