GENERAL SYSTEMATIC BACTERIOLOGY 237 



This family name has been commonly used by recent bacteriologists 

 who have discussed Beggiatoa (q.v.), among them Chester (1901, p. 379), 

 Schmidt and Weis (1902, p. 92), Kendall (1902, p. 486), Migula (1904, 

 p. 145), Corsini (1905), Erwin F. Smith (1905, p. 162), Clements (1909,' 

 p. 7), Frost (1911, p. 60), Schneider (1912, p. 23), and Bergey et al. 

 (1923, p. 407). 



Buchanan (1918, p. 463) included three genera, Thiothrix, Beggiatoa 

 and Thioploca. 



Beggiatoeae. A subfamily of the family Leptothrichaceae proposed 

 by Hansgirg (1888, p. 263). The group is defined as follows: "Faden 

 mit lebhaften, oscillarien-artiger Bewegung, im protoplasmatischen 

 Zellinhalte Schwefelkornchen and nicht selten auch einen rosenrothen 

 oder violetton Farbtoff enthaltend." One genus only, Beggiatoa, is 

 included. 



Betabacterium. A generic name proposed by Orla-Jensen (1919, p. 

 175) for certain lactic rods. The genus is described in a somewhat in- 

 formal fashion, but the following quotations will probably serve to 

 identify the group. 



The betabacteria (Table XXXI) are in most respects so closely allied to the 

 betacocci that they may be regarded as the analogous rod forms, and they can, 

 like the betacocci, be divided into those which ferment arabinose (Nos. 1-20) 

 and those which do not (Nos. 21-33). The Bacterium casei [varieties] formerly 

 described by me are typical representatives of these groups, and as they also 

 differ in morphological respects — the arabinose-fermenting rods being generally 

 shorter than the others — we consider ourselves justified in establishing the species 

 Betabacterium breve and Betabacteriutn longum. Besides occurring in vegetable 

 matter, they are also found in cheese, faeces and kefir grains. The rods forming 

 the tissue of the kefir grains (Nos. 1 and 2) are, however, so different from the 

 remaining betabacteria that they must undoubtedly be reckoned as a distinct 

 species which we will call Betabacterium caucasicum, as the kefir rods are now for 

 the most part known under the name of Bac terium caucasicum. This last name is 

 also erroneously used for streptobacteria, which are likewise also found in kefir 

 (though not as a rule in the grains themselves), and which are considerably easier 

 to obtain in pure cultures. 



Most of the betabacteria are not altogether killed by heating until 75°. They 

 form inactive lactic acid, at times with a surplus of dextro-lactic acid. The 

 great majority of strains develop gas (carbonic acid and more or less hydrogen). 

 When the development of gas is strong, succinic acid is also formed. The power to 

 form any considerable quantity of gas, and thus succinic acid, is, however, soon 

 lost in artificial nutritive substrates, and in most of our strains, gas development 

 could only be observed by sowing out closely in sugar agar tubes. From laevu- 

 lose, some few strains can form a small amount of mannite, and as the mannite- 

 forming mash hsicieTmm Lactobacillus fermentatum, which has been closely studied 

 by Jan Smit, has the greatest resemblance to the betabacterium (judging from 



