3/8 BACTERIOLOGY 



10. Cladothrix non-liquefaciens Ravenel 



I.e., 16. 



Morphology. Long chains and filaments with false branching. No spiral 

 or coccoid forms. Filaments segmented into rods of various lengths 

 which have square ends. 



Gelatin colonies. Deep : in 2 days arborescent radiate ; in 7 days colonies 

 show reddish yellow centres and radiately arborescent borders. Surface : 

 in 2 days minute, whitish yellowish ; centres grayish, dense, opaque, 

 yellow, borders of interlacing coarse filaments and spear points. 



Agar slant. Growth thin, whitish, with smooth edges marked by yellowish 

 points ; later an elevated yellowish salmon-colored band, with a whitish 

 bloom on the surface. Many offshoots from the lower side of the 

 growth into the agar. 



Gelatin stab. In depth, an arborescent growth ; on the surface, after 7 days, 

 a white dry button. A slight brownish discoloration of the medium at 

 the surface. 



Potato. Growth yellowish, rough, dry, rugose, later with a pinkish tinge ; not 

 abundant. 



Bouillon. On the surface a thin pulverent film; medium clear; a whitish, 

 flocculent sediment. 



Habitat. Soil. 



THIOTHRIX Winogradsky 



Bot. Zeitung, 1887. 



Filaments fixed, of unequal diameter, surrounded by a delicate difficultly dis- 

 cernible sheath, non-motile. Sulphur granules enclosed in the plasma. 

 The filaments produce at their ends rod-shaped gonidia, which become 

 detached, and, fixing themselves to some substratum, develop into new 

 filaments. 



I. Filaments very slender. 



i. Thiothrix tenuissima Winogradsky 



I.e. 



Filaments not exceeding 0.5 /x broad. 

 Habitat. Found in sulphur water. 



II. Filaments thicker. 



