56 GENERAL SYSTEMATIC BACTERIOLOGY 



1. Filaments unbranched. 



a. No distinction between base and apex. 



Chlamydothrix Migula 



b. Filaments enlarged toward tips: 



(1) Sheath relatively thick. . .Crenothrix Cohn 



(2) Sheath relatively thin .... Phragmidiothrix Engler 



2. Filaments branched dichotomously . »Sp/!aero/27us Kiitzing 



II. Order Thiobacteria; Cells without a "Centralkorpor" but with sulfur inclu- 

 sions. Colorless, or rose, red or violet, with bacteriopurpurin. 



A. Filamentous, destitute of bacteriopurpurin. 



Family Beggiatoaceae 



1. Threads attached, non-motile Thiothrix Winogr. 



2. Threads free, motile Beggiatoa Trev. 



B. Containing bacteriopurpurin. 



Family Rhodohacteriaceae 



1. Cells united in families. Division of cells in three directions of 



space Subfamily Thiocapsaceae 



a. Families small compact, enclosed singly or several together 



in a cyst. Capable of swarming. 



Thiocystis Winogr. 



b. Non-swarming, globose cells spread out upon the substratum 



in flat families, loosely enveloped in a common gelatin. 



Thiocapsa Winogr. 



c. Non-swarming cells arranged in packets like Sarcina. 



Thiosarcina Winogr. 



2. Cells united into families. Division of cells first in three, then in 



two, directions of space. 



Subfamily Lamprocystaceae 

 Families first solid, then globose hollow, perforated net. 



Lamprocystis Schroeter 



C. Cells united into families. Divisions in two directions of space. 



Subfamily Thiopediaceae 

 Families tubular formed of cells arranged in fours. 



Thiopedia Winogr. 



D. Cells united in families. Division in one direction of space. 



Subfamily Amoebobacteriaceae 



1. Cells connected by plasma threads. Families amoeboid motile, 



Amoebobacter Winogr. 



2. Not as "1": 



a. Cells arranged in network, united by their ends. 



Thiodictyon Winogr. 



b. Cells not arranged in network: 



(1) Capable of swarming. Cells loosely aggregated in 



gelatin Thiothece Winogradsky 



(2) Non-motile, cells closely appressed in colony. 



Thiopolycoccus Winogr. 



E. Cells free, capable of swarming at any time. 



Subfamily Chromatiaceae 



