BACTERIA. 6l 



I. Subfamily. 



The cells are united into colonies. Cell division takes place in three directions of 

 space. 



Genus : Thiocystis WINOGRADSKY. 



The colonies are small, compact, and enveloped either singly or in groups by a 

 gelatinous cyst. The colonies are also capable of breaking up and the cells moving 

 about. 



Genus : Thiocapsa WINOGRADSKY. 



The cells are globular in shape and spread out on a substratum in flat colonies. 

 These colonies are surrounded by a common gelatinous secretion similar to a capsule. 

 The cells are non-motile. 



Genus : Thiosarcina WINOGRADSKY. 



The colonies form packets similar to the genus Sarcina of the Eubacteria. The 

 cells are non-motile. 



II. Subfamily Lamprocystaceae. 



The cells are formed into families. Cell division takes place first in three then in 

 two directions of space. 



Genus : Lamprocystis SCHRO'TER. 



The cells in the beginning are solid, then hollow, becoming perforated like a net. 

 They separate into small groups and become motile. 



III. Subfamily Thiopediaceae. 



The cells are united into colonies. Cell division takes place in two directions of 

 space. 



Genus : Thiopedia WINOGRADSKY. 



The families are formed similar to tubes and are composed of cells arranged in 

 fours and capable of motility. 



IV. Subfamily Amcebobacteriacese. 



The cells are united into colonies. Cell division takes place in one direction of 

 space. 



Genus : Amcebobacter WINOGRADSKY. 



The cells are united into colonies, and after division in one direction of space 

 remain attached together by threads of protoplasm. The colonies possess amoeboid 

 motility. The cells change form by contraction and the spreading out of the proto- 

 plasm. 



Genus : Thiothece WINOGRADSKY. 



The colonies are inclosed by a thick, gelatinous cyst. The cells are capable of 

 moving and are very loosely surrounded by a common gelatin. 



Genus : Thiodictyon WINOGRADSKY. 



The colonies are solid, non-motile, and consist of small cells which are pressed 

 together. 



V. Subfamily Chromatiacese. 



The cells are free and capable at all times of motility. 



Genus : Chromatium PERTY. 



The cells are moderately thick, elliptical or cylindric-elliptical in shape 



Genus: Rhabdochromatium WINOGRADSKY. 



