MICROBES, OR BACTERIA. 93 



which we must say a few words, since these microbes 

 play an important part in nature, connected with 

 hygiene and domestic economy ; the second section 

 includes Micrococcus pathogenis, or the producers of 

 disease, which must detain us longer. 



The genus Bacterium, of which the name indicates 

 that it is rod-shaped, also includes some coloured 

 species and more which are colourless, such as the 

 bacteria of putrefaction, of stagnant waters, of vegetable 

 infusions, etc. (Fig. 49). 



The genus Ascococcus is less common. The cells, 

 united in groups or families, form mucilaginous, 

 wrinkled membranes on the surface of putrefying 

 liquids, on the juice of meat, on the infusion of 

 hay, etc. 



Bacillus (or Bacteridice, Davaine) forms an ex- 

 tremely important genus, characterized by its long, 

 flexible, and articulated filaments ; this genus includes 

 the butyric ferment, and the microbe which produces 

 the disease called anthrax, or splenic fever. 



Leptothrix buccalis is found in the human saliva 

 and between the teeth (Fig. 51, k). 



Cladothrix dichotoma forms a kind of fine grass, 

 which appears like a whitish mucilage on the surface 

 of putrefying liquids (Fig. 51, p). 



Vihrio rugula and V. serpens are found in 

 infusions in the form of tolerably thick filaments, 

 which have only one inflection, while their successors 

 are spirally curved (Fig. 51, I). 



