96 CLASSIFICATION AND DESCRIPTION OF BACTERIA 
a. Cells straight, rod-shaped, without sheath, 
non-motile, or motile by means of 
flagella... .. 0.00.0. .. ..... .. . 2 Bacteriacex. 
b. Cells crooked, without sheath. .......... 3. Spirillacee. . 
c. Cells inclosed in a sheath................ 4, Chlamydobacteriaces. 
1. Coccacex 
Cells without organs of motion: 
a. Division in one plane . ow... cece eee ees 1. Streptococcus. 
b. Division in two planes. . ......... eee eee 2. Micrococcus. 
c. Division in three planes ................... 3. Sareina, 
Cells with organs of motion: 
a. Division in two planes. ..........2-.00006 4, Planococcus. 
6. Division in three planes . .............00-. 5. Planosarcina. 
2. Bacteriacex 
Cells without organs of motion................0.. 1. Bacterium. 
Cells with organs of motion (flagella): 
a. Flagella distributed over the whole body...... 2. Bacillus. 
b. Flagella polar.......... 0... 0c eee eee eee 3. Pseudomonas. 
3. Spirillaces 
Cells rigid, not snake-like or flexuous: 
a. Cells without organs of motion.............. 1. Spirosoma. 
b. Cells with organs of motion (flagella): 
1. Cells with one, very rarely two to three 
polar flagella... 02... cece eee ee eee 2. Microspira. 
2. Cells with polar flagella-tufts............ 3. Spirillum. 
Cells flexuous... 0.0.0... ccc cece ce eee eens 4. Spirocheta. 
4. Chlamydobacteriacee (Higher Bacteria) 
Cell contents without granules of sulphur: 
a. Cell threads unbranched. 
I. Cell division always only in one plane... 1. Streptothrix. 
IT. Cell division in three planes previous to 
the formation of gonidia: 
1. Cells surrounded by a very delicate, 
scarcely visible sheath (marine)... 2. Phragmidiothrix. 
2. Sheath clearly visible (in fresh 
water)... . ccc eee ee ee eee 3. Crenothrix. 
‘b. Cell threads branched...................00. 4, Cladothrix. 
Cell contents containing sulphur granules......... 5. Thiothrix. 
