MICROBES, OR BACTERIA. 119 



the corpuscles of the blood, and the cells of which all 

 our tissues consist, as true anaerobic 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. THE MICROBES OF 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 



algse of the family Oscil- 



latoria, and of the genera 

 Oscillaria and Beggiatoa 

 (Fig. 64). These microbes 



are of the same structure Fig M ._ Keffgiataa aZta> microba of 

 as those of which we have suipuu.ous springs. 



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 Leptuthrix, which they 

 resemble in their mode of reproduction. 



According to Louis Ollivier, these algae 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 



