INFECTIONS OF THE DIGESTIVE TRACT 11 



the growth of the anaerobic microbe which he describes 

 as B. perfringens and which appears to be no other than 

 the organism known in the United States as B. aerogenes 

 capsulatus (Welch) and in Germany as the gas-phlegmon 

 bacillus (Fraenkel). 



The B. bifidus of Tissier is closely related to the 

 organism described by Moro as B. acidophilus and shares 

 with the latter the ability to grow in a more strongly 

 acid medium than can be withstood by meat bacteria. 

 Recent studies of these bacteria by Bjeloussow 1 have 

 led him to identify these acidophile microorganisms 

 with certain acidophile bacteria studied by him, and to 

 which he, as well as Mereschkowsky, 2 attaches con- 

 siderable importance as protective inhabitants of the 

 digestive tract. The capacity to grow in a medium 

 containing one-half or even one per cent, of acetic acid 

 is an indication that the acidophile bacteria might as- 

 sume a dominant position in the digestive tract if pro- 

 vided with suitable food materials for the production 

 of acid. It is stated that if large numbers of these bac- 

 teria be administered to a dog by mouth, other flora may 

 to a large extent be temporarily suppressed. But as 

 in the case of feeding other kinds of microorganisms the 

 leading part can only be maintained by continuously 

 feeding large numbers of the acidophiles. Whether 



*"Zur Biologie und Methodik der Ausscheidung der soge- 

 nannten acidophilen Bakterien," Diss. No. 76, St. Petersburg (Rus- 

 sian) . 



2 "Zur Frage iiber die Rolle der Mikroorganismen im Darm- 

 kanal," Centralbl. /. Bakt. Orig., xxxix, pp. 380, 581, 696, 1905, 

 andxl, p. 118, 1906. 



