30 R. E. BUCHANAN 



II. Typically anaerobic or micro-aerophilic. 



a. Characteristically producing butyric acid from carbohy- 

 drates I. Butyribacteriaceae 



h. Characteristically bringing about putrefactive changes in 

 proteins II. Putribacteriaceae 



An examination of the genera which have been proposed by- 

 various authors would seem to indicate that an important differ- 

 ential character is that of endospore production. Separation 

 upon this basis throws all the spore-bearing rods together, a 

 grouping which appears to be wholly natural and to represent 

 true relationships. Of the rod-shaped organisms which do not 

 produce spores it seems that the acid-fast bacteria related to 

 the tubercle bacillus likewise represent a very distinct group. 



For the three tribes of the Bacteriaceae the names Bacilleae 

 Bacterieae, and Mycobacterieae may be used. The principal 

 differential characters may be summarized in the following key: 



Key to the Tribes of the Bacteriaceae 



A. Cells not acid-fast. 



I. Typically producing endospores under favorable conditions. 



Tribe I. Bacilleae 

 II. Not producing endospores Tribe II. Bacterieae 



B. Cells acid-fast, frequently showing some tendency to branching 



Tribe III. Mycobacterieae 



Tribe I. Bacilleae Trevisan 1889, p. 12 in part 



Synonyms : 



Eubacilleae Trevisan, 1889, p. 939 in part 

 Bactrillei Fischer, 1895, p. 139 in part 

 Bacillei Fischer, 1895, p. 139 in part 

 Bactrinei Fischer, 1895, p. 139 in part 

 Bacilleae Fischer, 1903, p. 60 in part 

 CloUrideae Fischer, 1903, p. 60 in part 

 Plectrideae Fischer, 1903, p. 61 in part 

 Alkalibacteriaceae Jensen, 1909a, p. 343 in part 

 Butyribacteriaceae Jensen, 1909a, p. 343 in part 

 Putribacteriaceae Jensen, 1909a, p. 343 in part 



Cells rodshaped, never spiral or strictly filamentous, single or in 



