64 GENERAL SYSTEMATIC BACTERIOLOGY 



2. Undulating membrane absent. Cells round in cross section. 



Treponema Schaud. 

 B. Form changeable, not greatly elongate. 



Trypanosoma and Trypanoplasma 



New genera named during this year were Rhodocapsa and Rhodothece, 

 red sulphur bacteria, by Molisch (1906), Actinohacterium by Haass 

 (1906) and Lipobacter by de Kruyff (1906) for certain lipolytic and fat 

 oxidizing bacteria. 



Lotsy (1907) apparently alone among writers on classification or 

 bacteria has followed Fischer in his classification of bacteria. 



Molisch (1907) in his " Purpurbakterien " created the order Rhodobac- 

 teria to include all of the forms which contain bacteriopurpurin. Many 

 new genera of these forms which do not contain sulphur granules are 

 included. A key to the families and to the subfamilies of the Thior- 

 rhodaceae and to the genera of the Athiorhodaceae which he gives may be 

 translated as follows : 



Molisch's Key to the Sulphur Bacteria (1907) 



Order Rhodobacteria 

 Bacteria whose cell contents are colored rose, red, violet or carmine by the 

 presence of bacteriopurpurin, and as far as studied, by bacteriochlorin. 



A. Cells have the ability to deposit granules of free sulphur in the cell contents. 



Family I. Thiorhodaceae 

 I. Cells united in families. 



a. Division of cells in three directions of space. 



Subfamily 1. T hiocapsaceae 

 h. Division of cells first in three, then in two directions of space. 

 Subfamily 2. Lamprocystaceae 



c. Division of cells in two directions of space. 



Subfamily 3. T hiopediaceae 



d. Division of cells in one direction of space. 



Subfamily 4. Amoebobacteriaceae 

 II. Cells always swarming. 



a. Not capsulated. Subfamily 5. Chromatiaceae 



b. Capsulated Subfamily 6. Rhodocapsaceae 



B. Cells are unable to deposit free granules of sulphur in the cell contents. 



Family II. Athiorhodaceae 

 I. Cells united into families. 



a. Cells rodshaped, embedded many together in a common capsule. 



Genus Rhodocystis 



b. Cells spherical or short rods, in chains, each chain enclosed in a 



capsule Genus Rhodonostoc 



II. Cells free. 



a. Cells spherical, non-motile. 



Genus Rhodococcus 



