THE CLASSIFICATION OF BACTERIA. 259 



GENERA. 



1. Coccacece. 

 Cells without organs of motion. 



a. Division in one plane . . . 1. Streptococcus. 



b. Division in two planes . . .2. Micrococcus. 



c. Division in three planes . . .3. Sarcina. 

 Cells with organs of motion. 



a. Division in two planes . . .4. Planococcus. 

 6. Division in three planes . . . 5. Planosarcina. 



2. Hacleriacece. 



Cells without organs of motion . . 1. Bacterium. 

 Cells with organs of motion (flagella). 



a. Flagella distributed over the whole 



body 2. Bacillus. 



6. Flagella polar . . . . .3. Pseudomonas. 



3. Spirillacece. 

 Cells rigid, not snake-like or flexuous. 



a. Cells without organs of motion . 1. Spirosoma. 

 6. Cells with organs of motion (flagella). 



1. Cells with 1, very rarely 2 to 3 



polar flagella . . . .2. Microspira. 



2. Cells with polar flagella-tufts . 3. Spirillum. 

 Cells flexuous 4. Spirochseta. 



4. Chlamydobacteriacece. 

 Cell contents without granules of sulphur. 



a. Cell threads unbranched. 



I. Cell division always only in one plane 1. Streptothrix. 

 II. Cell division in three planes previous 

 to the formation of conidia. 



1. Cells surrounded by a very delicate, 



scarcely visible sheath (marine) . 2. Phragmidiothrix. 



2. Sheath clearly visible (in fresh water) 3. Crenothrix. 



6. Cell threads branched . . 4. Cladothrix. 

 Cell contents containing sulphur granules 5. Thiothrix. 



5. Seggiatoacea. 



Only one species known (Beggiatoa, Trev.), which is scarcely 

 separable from Oscillana. 



