GENERAL SYSTEMATIC BACTERIOLOGY 49 



b. Cells with flagellar 



1. Cells with 1, rarely 2 or 3 polar flagella. 



Microspira Schroeter 



2. Cells with tuft of polar flagella Spirillum Ehr. 



II. Cells flexuous Spirochaeta Ehr. 



Key to the Genera of Chlamydobacteriaceae 



I. Cells contents without sulfur granules: 



a. Cell filaments unbranched: 



1. Cell division continually in one direction of space. 



Streptothrix Cohn emend. 



2. Cell division before conidia formation in 3 directions of space. 



X. Cells surrounded by a very delicate, scarcely visible sheath 



(marine) Phragmidiothrix Engler 



XX. Sheaths definitely recognizable (fresh water). 



Crenothrix Cohn 



b. Cell filaments branched Cladothrix Cohn 



II. Cell contents with sulfur granules Thiothrix Winogr. 



Key to the Genera of the Beggiatoaceae 

 One genus only Beggiatoa Trev. 



It will be noted that in Migula's classification emphasis is put largely 

 upon the shape of the cell, motility and the distribution of flagella on 

 the bacterial cells. Spores are not regarded as useful in the differentia- 

 tion of genera. Neither the sulfur bacteria nor the Myxobacteria are 

 recognized as distinct groups. 



In 1895 appeared the first classification of Alfred Fischer. The 

 principal differential characteristic wUl be noted in the family Bact- 

 eriaceae which is divided into sixteen genera based upon cell form, spore 

 production, and location of tjie flagella. No species were known for 

 several of the genera which he included. The classification of this 

 family follows: 



Fischer's Classification of Bacteria (1895) 

 Key to Genera of Bacteriaceae 



I. Family Bacillel. Non-flagellate. 



a. Producing endospores. 



1. Spore bearing rod cylindric Bacillus 



2. Spore bearing rod spindle shaped. . .Paracloster 



3. Spore bearing rod clavate Paraplectrum 



b. Producing arthrospores Arthrobacter 



II. Family Bactriniel. One polar flagellum. 



a. Producing endospores. 



1. Spore bearing rod cylindric Bactrinium 



