200 BACTERIOLOGY 



they have been described as motile, or slightly so, are in reality non-motile, or at least 

 ■devoid of flagella, and are therefore members of the genus Bacterium. 



Without definite knowledge on all questionable points of this kind the author has not 

 presumed to any private interpretations, and has strictly adhered to the facts as set forth 

 by the authors of the species in question. 



SYNOPSIS OF THE GENUS 



I. Without endospores, or at least their presence not reported. 



A. Aerobic and facultative anaerobic. 



1 . Without pigment on gelatin or agar. 



a. Colonies on gelatin plates roundish, not ameboid or proteus-like. 



* Gelatin not liquefied. 



t Decolorized by Gram's method. Class I, p. 201. 

 tt Stained by Gram's method. Class II, p. 227. 

 ** Gelatin liquefied. Class III, p. 230. 



b. Colonies on gelatin plates becoming streaming, forked, ameboid, 



twisted, irregular, cochleate. 



* Gelatin liquefied. 



Stained by Gram's method. Class IV, p. 244. 

 Not stained by Gram's method. Class V, p. 246. 

 ♦* Gelatin not liquefied. Class VI, p. 248. 



2. Produce pigment on gelatin or agar, chromogenic bacilli. 



a. Pigment yellowish on gelatin. 



* Gelatin liquefied. Class VII, p. 250. 



** Gelatin not liquefied. Class VIII, p. 254. 



b. Pigment reddish on gelatin or agar. 



* Gelatin liquefied. Class IX, p. 256. 

 ** Gelatin not liquefied. Class X, p. 259. 



c. Pigment brownish, black-gray on gelatin. Class XI, p. 260. 



d. Pigment blue-violet on gelatin or agar. Class XII, p. 261. 



3. Colonies colorless, or colored slightly yellowish or greenish, but with 



a yellow-green or blue-green fluorescence. Class XIII, p. 262. 



B. Obligate anaerobic. Class XIV, p. 265. 



II. Bacilli produce endospores. 



A. Non-chromogenic ; without pigment on gelatin or agar. 

 I. Aerobic and facultative anaerobic. 



a. Rods not swollen at sporulation — B. subtilis type. 



