SUBGROUPS AND GENERA OF THE BACTERIACEAE 29 



belonging to Thiohacteria; Spirilleae, Pacineae, and Mycono- 

 stoceae are based upon genera now placed with the Spirillaceae. 

 Fischer (1895, p. 139) subdivided his family Bacillacei as 

 follows : 



Key to subfamilies of Bacillacei. Fischer 



A. Non motile. Non flagellate I, Bacillei 



B. Motile. With flagella 



I. Polar flagella only. 



a. A single polar flagellum II. Bactriniei 



b. A tuft of polar flagella III. Bactrillei 



II. With diffuse flagella IV. Bactridiei 



Chester (1897, p. 63) grouped certain genera to constitute the 

 farnily Mycobacteriaceae. The most important differential 

 characters are the formation of cJavate-cuneate cells, lack of 

 endospores, and true dichotomous branching. 



Later Fischer (1903, p. 60) separated his family Bacillaceae 

 into three subfamilies as follows: 



Key to subfamilies of Bacillaceae. Fischer 



A. Spore-bearing rods unchanged in shape, cylindrical. Includes all non- 



sporulating forms Subfamily I. Bacilleae 



B. Spore-bearing rods modified in shape. 



I. Spore-bearing rods spindle shaped Subfamily II. Clostridieae 



II. Spore-bearing rods drumstick shaped.. Subfamily III. Plectridieae 



The families proposed by Jensen (1909a, p. 344) which would be 

 included under our definition of Bacteriaceae may be separated 

 by the following key: 



Key to the families of Bacteriaceae. Fischer 



A. Without spores, motile or non-motile; when the former, with polar flagella, 



typically water forms, securing energy almost exclusively by oxidative 

 processes. 



I. Obligate aerobes, oxidizing carbon, hydrogen or nitrogen com- 

 pounds without production of noteworthy amounts of unoxi- 



dized split products I. Oxydobacteriaceae 



II. Luminous and fluorescent bacteria II. Luminobacteriaceae 



B. With or without spores, either peritrichous or non-motile, not typically 



water forms, do not secure energy exclusively as "A." 



I. Typically not obligate anaerobic or micro-aerophilic. 



a. Usually producing acids from carbohydrates. 



I. Acidobacteriaceae 



b. Usually bringing about an alkaline reaction by the develop- 



ment of ammonia II. Alkalibacteriaceae 



