228 BIOLOGY AND TECHNIQUE 



and in the publications of Herter, Kendall, Rettger, Torrey 23 and 

 others. 



BACTERIA IMPORTANT BECAUSE OF THEIR FREQUENT PRESENCE 

 IN THE INTESTINAL CHANNEL 



Bacillus Acidophilus. 2 * A Gram-positive bacillus which easily 

 undergoes granular degeneration and grows under conditions of 

 acidity, not supported by most other bacteria. It is closely related 

 to the Bacillus bulgaricus, does not form spores, and is closely 

 related to a group of similar organisms which have not been suffi- 

 ciently studied to be conclusively classified. (See Kendall, Jour. 

 Med. Res., 1910, 22, and Rahe, Jour. Infec. Dis., 15, 1914, 41.) Its 

 isolation can, according to Kendall, best be accomplished by in- 

 oculating the original material into dextrose broth containing 0.25 

 per cent acetic acid. Two or three transfers on a medium like this 

 after intervals of several days will give pure cultures. Does not 

 liquefy gelatin, has been associated by Escherich with acute diarrhea 

 in children. Does not produce gas. 



Bacillus AcidopMlus Aerogenes. Described by Torrey and Rahe 25 

 which closely resembles the Bacillus acidophilus, except that it 

 produces gas in mono-, di- and some polysaccharids. 



Bacillus Bifidus of Tissier. This is a strictly anaerobic bacillus. 

 It was described by Tissier in 1900. (See also, Noguchi, Jour. 

 Exper. Med., 12, 1910, 182.) It is spoken of as Bifidus because it 

 will often show a bifid branching at the ends, a condition in which 

 it is not shown in smears from the intestinal contents. It is found 

 early in the stools of nursing children. It produces considerable 

 amounts of acid, but no gas from carbohydrates. Morphologically 

 this organism is often described as Gram-positive, but, as a matter 

 of fact, many members are Gram-negative, and often the bacilli 

 themselves may be Gram-negative with Gram-positive granules scat- 

 tered through them. 



Bacillus Mesentericus. This is a Gram-positive, aerobic, spore 

 bearing bacillus which is active proteolytic and concerned with 

 putrefaction in the intestinal channel. The organism is more closely 



83 Torrey, Jour, of Infec. Dis., 16, 1915, 72. 



84 Moro, Wien. klin. Woch., 5, 1900 ; Finkelstein, Deut. med.. Woch., 22, 1900. 

 25 Torrey and Rahe, Jour, of Infec. Dis., 17, 1915, 437, 



